No. 13 — The Genus Micrathena (Araneae, Argiopidae) in Central America By Arthur M. Chickering The genus Micrathena Sundevall, 1833 with its numerous species, more or less conspicuous webbing, and often gaudy color- ation constitutes an important segment of the arthropod fauna of Central America. For more than thirty years, during repeated visits to Panama and nearby regions, I have been collecting mem- bers of this genus with the intention of publishing the results of my study of all species appearing in my collections. Upon the advice of other araneologists I have recently extended my study to include the whole of Central America. In order to aid me in this work all specimens of the genus in the Museum of Com- parative Zoology at Harvard College have been turned over to me for study. During the summer of 1958, while on a fellowship from the John Simon Guggenheim Memorial Foundation, I was able to work on the extensive collections in the British Museum (Natural History) where I had access to most of the material which furnished the basis for the work of the two Pickard-Cam- bridges published in the Biologia Centrali-Americana. A few days were also spent in the Oxford University Museum where a portion of the Pickard-Cambridge collection is kept. Acknowledgements are due and gratefully rendered to the fol- lowing named individuals and organizations for their numerous courtesies, support, and encouragement of my work for many years: The John Simon Guggenheim Memorial Foundation for its financial aid during two successive years ; Dr. G. Owen Evans, Department of Zoology, British Museum (Natural History), and his staff of co-workers all of whom gave me very friendly encouragement and the loan of important specimens for the pursuit of my work; Professor G. C. Varley and his staff of co-workers at the Oxford University Museum who gave me access to valuable specimens for a brief period and then extended ma- terial on loan as a further aid ; Dr. A. S. Romer, Director, Dr. P. J. Darlington, Jr., Curator of Insects, Dr. Herbert W. Levi, Associate Curator of Arachnology, and Miss Nelda E. Wright, Editor of Publications, all of the staff of the Museum of Com- parative Zoology at Harvard College. The problem of evolution and interspecific relationships in the genus Micrathena are exceedingly interesting, often complex, baffling, and difficult to trace. Females tend to exhibit a high 392 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY degree of abdominal spination involving many different patterns, and often show strongly contrasting and variable color patterns. The males, on the other hand, as adults usually lack definite spines, exhibit much less gaudy coloration, are greatly reduced in size, and possess a set of complex variations in the minute structure of their secondary sexual organs and related parts. The high degree of sexual dimorphism has made it extremely difficult to match adult males with the proper females. More- over, adult males are relatively infrequent in collections. When young the sexes often resemble each other rather closely and this fact can sometimes be used as an aid in matching the sexes accurately. F. Pickard-Cambridge (1904) included a total of thirty-one species in his treatment of the genus Micrathena. One of these (A. fericulum 0. P. -Cambridge) has been transferred to the genus lldebaha Keyserling. Of the remaining thirty species, five had both sexes fully recognized, seven were known only from males, and the remaining nineteen were known only from females. So far as I have been able to determine up to the present time, a total of forty species of the genus Micrathena have been more or less definitely reported from Central America. Eight of these were males unassociated with females; six species included both sexes ; twenty-six species were known only from females. As will be shown in the appropriate places in this paper, all four species described as new by Chamberlin and I vie (1986) have been synonymized with already known species. It now seems quite certain that M. secies (Getaz) is really M. sexspinosa (Halm). It is now generally known that M. comigera (0. P-Cam- bridge) is the male of M. sexspinosa (Halm) and that M. longi- cauda (0. P. -Cambridge) is the male of M. horrida (Tac- zanowski). It has now been possible to complete the identifica- tion of the male of M. schreibersi (Perty). M. clypeata (Walck.), until recently considered to be distinctly a South American species, is now known to be well established in Panama. In addi- tion to the changes noted above, I have been obliged to recognize and describe nine new species, thus bringing the revised list to forty-three as now reported from Central America. Anions these are twenty different kinds of males, nine of which are still unassociated with the proper females. The complete list as the CHICKERING : MICRATHENA IN CENTRAL AMERICA 393 species are understood at the present time may be given as follows : M. bimucronata (0. P.-Cambridge), 1899 M. brevipes (O. P.-Cambridge), 1890 M. catenulata F. P.-Cambridge, 1904 M. clypeata (Walck.), 1805 M. crassa (Keyserling), 1863 M. disjuncta sp. nov. M. donaldi sp. nov. M. duodecimspinosa (O. P.-Cambridge), 1890 M. fidelis (Banks), 1909 M. flaveola (C. L. Koch), 1839 M. funebris (Banks), 1898 M. furcula (O. P.-Cambridge), 1890 M. gladiola (Walck.), 1841 M. gracilis (Walck.), 1805 M. granulata F. P.-Cambridge, 1904 M. horrida (Taczanowski), 1873 M. inaequalis F. P.-Cambridge, 1904 M. insolita sp. nov. M. macfarlanei sp. nov. M. macilenta sp. nov. M. militaris (Fabricius), 1775 M. mitrata (Hentz), 1850 M. mirifica sp. nov. M. modica sp. nov. M. molesta sp. nov. M. parallela (O. P.-Cambridge), 1890 M. patruelis (C. L. Koch), 1839 M. petersi (Taczanowski), 1872 M. quadriserrata F. P.-Cambridge, 1904 M. saccata (C. L. Koch), 1836 M. sagittata (Walck.), 1841 M. schreibersi (Perty), 1833 M. serrata F. P.-Cambridge, 1904 M. sexspinosa (Hahn), 1822 M. spinulata F. P.-Cambridge, 1904 M. striata F. P.-Cambridge, 1904 M. subflava sp. nov. M. subspinosa F. P.-Cambridge, 1904 M. trapa (Getaz), 1891 M. triserrata F. P.-Cambridge, 1904 M. uncata F. P.-Cambridge, 1904 M. vitiosa (O. P.-Cambridge), 1890 M. zilehi Kraus, 1955 394 BULLETIN: MUSE! M OF COMPARATIVE ZOOLOGY Holotypes of all new species described in this paper will be deposited in the Museum of Comparative Zoology at Harvard College. 31. donaldi sp. nov. is named for my son who accom- panied me on two very pleasant and productive collecting trips to Panama. M. macfarlanei sp. nov. is named for Mr. D. Mac- farlane, Commonwealth Institute of Entomology, with whom I was very pleasantly associated during my period of work in the British Museum (Natural History) in the summer of li!58. Genus MlCRATHElS A Sundevall, 1833 A comprehensive definition of the genus Micrathena Sunde- vall is very difficult to draw up because of the great differences which exist between males and females and even among the two sexes themselves. For the present I am simply adopting what 1 consider to be the general understanding among araneologists at the present time. I cannot do better than to accept the definition essentially as given by Xteimoser (1917) in his treatment of the whole genus as he understood it at the time of the publication of his paper. No attempt is made to include all citations which have ap- peared in the literature on this genus. Only those which are considered as particularly pertinent are given here. Those who desire more extensive bibliographies are referred to Fioewer (1912) and Bonnet (1957). Because of unusual difficulties, no satisfactory key to the females in this genus has been worked out. This is in part due to the fact that puzzling variations in spination and some other features occur quite frequently. The accompanying key to the males should be an aid in identification of the different mem- bers of this sex. Key to the Species of Micrathena in Central America Males 1. With a ventral hook on first coxa and a corresponding ridge and groove on second femur {clypeata, disjuncta, duodetimspinosa, furcida, macilenta, mitrata, parallela, patruelis) 12 la. Without any ventral hook on first coxa and without a corresponding ridge and groove on second femur (brevipes, donaldi, gracilis, granidata, horrida, miriflca, modioa, sagittata, sclireibersi, sexspmosa, u neat a, vitiosa) 9 CHICKERING : MICRATHENA IN CENTRAL AMERICA 395 2. Carapace with three pairs of clearly defined dorsolateral foveae .... clypeata, p. 400 2a. Carapace without three pairs of clearly defined dorsolateral foveae (disjuncta, duodecimspinosa, furcula, macilenta, mitrata, parallela, patruelis) 3 3. Abdomen at least twice as long as wide (duodecimspinosa, furcula, ma- cilenta, mitrata, parallela) 4 3a. Abdomen less than twice as long as wide (disjuncta, patruelis) 7 4. With palpal tibia considerably wider than long (macilenta, mitrata, parallela ) 5 4a. With palpal tibia not notably wider than long (duodecimspinosa, fur- cula) 8 5. Abdomen with clearly evident spinules at posterior end (macilenta, parallela) 6 5a. Abdomen with no clearly defined spinules at posterior end mitrata, p. 435 6. Basal palpal tarsal hook nearly as broad at tip as long (Fig. 137) . . parallela, p. 443 6a. Basal palpal tarsal hook not nearly as broad at tip as long (Fig. 104) macilenta, p. 432 7. Abdomen nearly rectangular in outline (Fig. 143) . . . patmelis, p. 445 7a. Abdomen more rounded laterally ; not so nearly rectangular in outline (Fig. 26) disjuncta, p. 403 8. Abdomen with definite tubercles at posterior end, indicating suppressed spines duodecimspinosa, p. 408 8a. Abdomen without definite tubercles at posterior end, indicating sup- pressed spines furcula, p. 416 9. Abdomen slender, at least twice as long as broad (brevipes, gracilis, granulata, horrida, modica, sagittata, schreibersi, sexspinosa, uncata) 10 9a. Abdomen not so slender, about twice as long as broad or less than twice as long as broad (donaldi, mirifica, vitiosa) 18 10. Abdomen with a caudal-like extension (Figs. 75, 86; gracilis, horrida) 11 10a. Abdomen without any caudal-like extension (brevipes, granulata, mo- dica, sagittata, schreibersi, sexspinosa, uncata) 12 11. Base of bulb of palpal tarsus with a rounded knob fitting into a cor- responding concavity in the tarsal hook (Fig. 76) . gracilis, p. 421 11a. Base of bulb of palpal tarsus without such a knob and corresponding concavity as in gracilis horrida, p. 424 12. Palpal tarsal hook extended into a long, distally curved, sickle-like structure (Fig. 180) sexspinosa, p. 456 12a. Palpal tarsal hook not extended into a distinctly sickle-like structure (brevipes, granulata, modica, sagittata, schreibersi, uncata) 13 13. Abdomen constricted in the middle and rounded posteriorly (Fig. 161) schreibersi, p. 452 396 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 13a. Abdomen not constricted in the middle nor smoothly rounded posteriorly (brevipes, granulata, modica, sagittata, uncata) 14 14. Palpal tibia extended distally into a pair of sharp spines (Fig. 156) sagittata, p. 449 14a. Palpal tibia not extended distally into a pair of sharp spines {brevipes, granulata, modica, uncata) 15 15. Palpal tibia extended into a series of three bluntly rounded outgrowths (Pig. 7) brevipes, p. 398 15a. Palpal tibia not extended into a series of three bluntly rounded out- growths (granulata, modica, uncata) 16 16. Palpal tarsal hook a strongly chitinized and granulated plate (Pigs. 81,82) granulata, p. 423 16a. Palpal tarsal hook without a strongly chitinized and granulated plate; tarsal hook tending toward the type more frequently found in the genus (modica, uncata) 17 17. First femur with a group of modified ventral spines near middle of the segment (Fig. 203) uncata, p. 466 17a. First femur without the group of modified spines near middle of seg- ment modica, p. 439 18. Abdomen with four pairs of definite but small spines (Fig. 31) donaldi, p. 405 18a. Abdomen without any definite spines (mirifica, vitiosa) 19 19. Palpal tarsal hook extended into a quadrate, concave, finely granulose plate; with remains of three pairs of spines in the form of tubercles on abdomen vitiosa, p. 466 19a. Palpal tarsal hook not extended into a quadrate, concave, finely granu- lose plate; abdomen without visible remains of tubercles on abdomen mirifica, p. 437 Micrathena bimucronata (0. P. -Cambridge) , 1899 (Figures 1-5) Acrosoma bimucronatum 0. P. -Cambridge, 1899 M. bimucronata F. P.-Cambridge, 1904 M. bimucronata Petrunkevitch, 1911 M. bimucronata Reimoser, 1917 .1/. bimucronata Chickering, 1931 M. bimucronata Mello-Leitao, 1932 M. bimucronata Roewer, 1942 M. bimucronata Bonnet, 1957 Several specimens of this species in the British Museum (Natu- ral History) from Guatemala have been examined and found to agree well with specimens from Costa Rica and Honduras now in the collections of the Museum of Comparative Zoology at Har- vard College. The male is still unknown. One of the specimens CHICKERING: MICRAT1IENA IN CENTRAL AMERICA 397 in the collection of the Museum of Comparative Zoology has been selected as the hypotype from which the following facts have been derived: Total length 5.85 mm.; the abdomen has a short conical tubercle at each anterolateral corner (one specimen was found to have these tubercles drawn out into short spines thus illustrating the variability of the species) and a long stout spine at each posterolateral angle (Figs. 1, 2) ; the carapace has a External Anatomy of Micrathena Figures 1-5, M. bimucronata Figures 6-8, M. brevipes Fig. 1. Abdomen of female, dorsal view. Fig. 2. Posterior surface of abdomen to show appearance of spines. Figs. 3-5. Epigynum; from below, posterior surface, and right lateral view, respectively. Fig. 6. Body of M. brevi'pes, dorsal view. Fig. 7. Right palpal tarsus and tibia. Fig. 8. Palpal tarsal hook, more enlarged. well defined central fovea and two pairs of moderately clear dorsolateral foveae ; the characteristics of the epigynum are shown in Figures 3-5. The species is now known from Guatemala, Costa Rica and Honduras. 398 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Micrathena brevipes (0. P. -Cambridge) , 1890 (Figures 6-8) Acrosomal brevipes O. P.-Cambridge, 1890 A. brevipes Keyserling, 1892 M. brevipes F. P.-Cambridge, 1904 M. brevipes Petrunkevitch, 1911 M. brevipes Reimoser, 1917 M. brevipes Petrunkevitch, 1925 M. brevipes Chickering, 1931 if. brevipes Roewer, 1942 M. brevipes Bonnet, 1957 This species was reported from Honduras in 1931 (Chicker- ing) but the specimens seen at that time are not now in the collection and cannot, therefore, be re-examined for accuracy of determination. My only opportunity to study the species care- fully came during my period of work in the British Museum (Natural History) in the summer of 1958. Two specimens are now in the vial marked "type" but both abdomens are detached and one may not belong to M. brevipes (O.P. -Cambridge). Both cephalothoraces and attached parts are in good condition. The abdomen (Fig. 6) is injured but appears to be similar to that of the male of M . sexspinosa. The chief features of the pal- pal tarsus and tibia are shown in Figures 7 and 8. Keyserling 's description (1892) appears to be accurate and detailed. Total length about 4.5 mm. The legs appear to be devoid of significant spines. The first coxae lack the ventral hook and the second femora lack the corresponding ridges and grooves. The female remains unknown. The species appears to be widely distributed in Central America and has been reported from Mexico, Guate- mala, Honduras, and Panama. Micrathena catenulata F. P.-Cambridge, 1904 (Figures 9-13) M. catenulata Petrunkevitch, 1911 Al. catenulata Reimoser, 1917 M. catenulata Roewer, 1942 M. catenulata Bonnet, 1957 In the Nathan Banks collection in the Museum of Comparative Zoology T have found several females from Mexico which agree well with specimens in the Pickard-Cambridge collection in the CIIICKERING : MICRATIIENA IN CENTRAL AMERICA 399 British Museum (Natural History). I also have two specimens collected by myself in Honduras. Two males were found with the females from Mexico but they are still considered to repre- sent a separate species for reasons which will be given in some detail later in this paper. Female hypotype. Total length 6.695 mm. One difference be- tween the hypotype and the holotype is in respect to abdominal spines. F. P. -Cambridge stated that the "anterior marginal angles" of the abdomen were prominent but did not bear spines. Apparently this is a variable feature because spines occur in these regions in some specimens but not in all. Short anterior marginal spines are extended from the corners of the abdomen in the hypotype. There are also two pairs of relatively large robust spines in dorsal anterior and posterior positions as indi- cated in Figure 9. It was also stated in the original descriptions External Anatomy of Micrathena Figures 9-13, M. eatenulata Fig. 9. Dorsal view of body. Fig. 10. Posterior spine and cusp ; lateral view from right side. Figs. 11-13. Epigynum from below, in posterior view, and in profile from right side, respectively. that immature specimens have a short cusp below each posterior dorsal spine. I have found that this also sometimes occurs in mature females (Fig. 10). The head portion of the carapace is only moderately raised. The sternum is not notably produced 400 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY posteriorly. The features of the epigynum are shown in Figures 11-13. Color in alcohol : the Mexican and Honduran specimens are much lighter in color than the Guatemalan specimens avail- able to F. P. -Cambridge. Apparently the black spots have been reduced and the white parts greatly extended as indicated in Figure 9. Collection records. The specimens studied by F. P. -Cam- bridge were from Guatemala. Other specimens available to me in this study are from Escuintla, Chiapas, Mexico, with no date of collection given, and Lancetilla, Honduras, July, 1929. Micrathena clypeata ( Walckenaer ) , 1805 (Figures 14-20) Epeira clypeata Walckenaer, 1805 M. clypeata Sundevall, 1833 M. clypeata, C. L. Koch, 1838 Plectana clypeata Walckenaer, 1841 M. clypeata Taczanowski, 1879 M. clypeata Simon, 1895 M. clypeata Petrunkevitch, 1911 11. clypeata Reimoser, 1917 M. planata Chambeiiin and Ivie, 1936. New synonymy 31. clypeata Chiekering, 1936 M. clypeata Roewer, 1942 M. planata Roewer, 1942. New synonymy. M. clypeata Bonnet, 1957 M. planata Bonnet, 1957. New synonymy. Until comparatively recently this species has been considered strictly South American, but is now known to be well established in Panama. Chamberlin and Ivie (1936) have given a detailed description of the species under the name M. planata. Female hypotypc. The extremely flattened form of the abdo- men, the numerous smoothly chitinized dorsal abdominal spots, together with the ten abdominal spines (Fig. 14) should make identification certain. Figures 15-17 show the chief features of the epigynum. Male hypotype. Total length 3.9 mm. With body extremely flattened (Fig. 18) ; with a complete but thin dorsal abdominal shield. The first coxa has a distal, ventral, retrolateral hook and the second femur has a corresponding groove and ridge near its proximal end nearly dorsal in position but on the prolateral surface. Palp : the tarsal hook has a characteristic form ; this CHICKERING : MICRATIIENA IN CENTRAL AMERICA 401 and other features of the organ are shown in Figures 1!) and 20. Collection records. All of my records of this species in Panama have come from Barro Colorado Island, C. Z. The female hypotype was taken in August, 1954 ; the male hypotype in August, 1950. Two other males are in the collection : July, External Anatomy of Microthena Figures 14-20, M. clypeata Fig. 14. Dorsal view of body of female. Figs. 15-17. Epigynum from below, in posterior view, and in profile (more enlarged), respectively. Fig. 18. Dorsal view of body of male. Fig. 19. Palpal tarsus of male. Fig. 20. Palpal tarsal hook, retrolateral view (more enlarged). 402 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 1924 (Banks) and July, 1936. Females have been taken from June to August, 1934," 1936, 1950, and 1954. Chamberlin and Ivie (1936) reported both sexes from my collection of 1928. Micrathena cbassa (Keyserling) , 1863 (Figures 21-25) Aerosoma crassum Keyserling, 1863 A. crassum Keyserling, 1892 M . crassa Simon, 1895 M. crassa Petrunkevitch, 1911 M. crassa Reimoser, 1917 M. crassa Petrunkevitch, 1925 M. crassa Roewer, 1942 If. crassa Bonnet, 1957 If. crassa Chickering, 1960 Petrunkevitch (1925) reported this species from Panama but it has not appeared in my collections nor have I found it recorded External Anatomy of Micrathena Figures 21-25, If. crassa Pig. 21. Abdomen, lateral view. Fig. 22. Cephalothorax, lateral view. Figs. 23-2.". Epigynum; from below, posterior view, and in profile, re- spectively. CHICKERING : MICRATHENA TN CENTRAL AMERICA 403 by any other worker. During the summer of 1958 I had an opportunity to study the species in the Keyserling collection in the British Museum (Natural History) and I have commented on it elsewhere (1960). The most significant features of the species may be given as follows: There is considerable variation in the size of the females with the length varying from about 7.6 to 8.5 mm. ; head and thorax well separated by a deep trans- verse groove ; the median thoracic fovea is clearly denned ; behind the median fovea the thorax rises very sharply into a pronounced gibbosity (Fig. 22) ; there are no clearly defined dorsolateral foveae ; sternum only moderately convex ; abdomen with four pairs of spines as shown in Figure 21 ; features of the epigynum as shown in Figures 23-25. Collection records are restricted to Colombia and Panama. The male is still unknown. MiCRATHENA DISJUNCTA Sp. UOV. (Figures 26-30) Male holotype. Total length 3.705 mm. Carapace 1.755 mm. long, 1.24 mm. wide opposite interval between second and third coxae where it is widest ; .66 mm. tall shortly behind well defined central fovea ; rises gently from just behind PME to this region and then descends to posterior border. Eyes. Eight in two rows as usual. Seen from above, posterior row moderately recurved, anterior row strongly recurved. Seen from in front, anterior row very slightly recurved, posterior row gently procurved, all measured by centers. Ocular tubercles moderately well developed. Central ocular quadrangle only slightly wider behind than in front, slightly wider behind than long. Ratio of eyes AME : ALE : PME* : PLE = 5:5: 6.5 : 5 (long diameters used when there are differences). AME separated from one another by nearly two diameters, from ALE by about three diameters. PME separated from one another by nearly five-fourths of their diameter, from PLE by nearly three times their diameter. Laterals only separated by a broad line. Height of clypeus equal to a little more than twice the diameter of AME. Chelicerae, Maxillae, and Lip. All apparently normal to males of the genus. Fragility of the specimen prevents close examina- tion of such structures as teeth along the fang groove but details appear to be unnoteworthy for the proper description of the holotype. 404 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Sternum. Simple scutiform ; moderately convex ; terminates bluntly between fourth coxae which are separated by about one- half of their width. Legs. 1423. Width of first patella at "knee" .16245 mm., tibial index of first leg 10. Width of fourth patella at "knee" .11913 mm., tibial index of fourth leg 10. 26 External Anatomy of Micrathena Figures 26-30, M. disjuncta Fig. 2C. Dorsal view of body of male. Fig. 27. Right first femur, prolateral view. Fig. 28. Right second femur, prolateral view. Fig. 29. Male palpal tarsus. Fig. 30. Palpal tarsal hook, more enlarged. CHICKERING : MICRATHENA IN CENTRAL AMERICA 405 Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters) .990 .924 .462 4.422 .72(i .748 .400 3.634 .440 .418 .330 2.288 4. 1.540 .396 .814 .770 .435 3.955 Palp .198 .0975 .1300 — .440 .866 With numerous robust spines on legs 1, 2, and 4 ; those on femora appear to be most significant (Figs. 27-28). First coxa with a ventral hook and second femur with the corresponding proximal, prolateral ridge and groove. Palp. Most essential features shown in Figures 29 and 30. Both tibia and patella are very short and without special modifications. Tarsal hook similar to that found in several other species. Abdomen General shape shown in Figure 26. Poorly devel- oped tubercles at posterior end may represent suppressed spines which show in immature males and in adult females. Color in alcohol. Carapace yellowish white in a broad central stripe with a broad dusky stripe on each side (Fig. 26). Legs yellowish with variations. Mouth parts and sternum nearly white. Abdomen: dorsum with a broad, central, broken, white stripe and a semi-transparent cross in the middle ; nearly black across posterior end and on each side a nearly black stripe (Fig. 26) ; just lateral to the black stripe are narrow, irregular, brownish stripes. Type locality. The holotype male is from Barro Colorado Is- land, C. Z.. January, 1958. No paratypes have appeared in my collection. The female is unknown. MlCRATHENA DONALDI sp. UOV. (Figures 31-34) Male holotype. Total length 4.68 mm. Carapace 1.917 mm. long; 1.125 mm. wide opposite second coxae where it is widest; median eyes on a prominent tubercle and lateral eyes on two confluent tubercles; only slightly raised behind median thoracic fovea. Eyes. Eight in two rows as usual; viewed from above, both rows strongly recurved ; viewed from in front, both rows pro- curved. Central ocular quadrangle wider behind than in front in ratio of 25 : 17, wider behind than long in ratio of 25 : 22. 406 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Ratio of eyes AME : ALE : PME : PLE = 8 : 7 : 10 : 8. AME separated from one another by five-eighths of their diameter, from ALE by seven-fourths of their diameter. PME separated from one another by nearly their diameter, from PLE by three- halves of their diameter. LE separated from one another by about the diameter of AME. Height of clypeus equal to nearly twice the diameter of AME. Clypeus sharply slanted backward because of strong development of median ocular tubercle. Chelicerae. Moderately well developed ; parallel. Teeth along fang groove not observed because of danger of injury to holo- type. Maxillae and Lip. As usual in males of the genus, without noteworthy features. Sternum. Moderately convex ; strongly and irregularly corru- gated throughout ; sternal suture procurved ; with well developed lateral sternal tubercles and low tubercles opposite coxae 1-3 and with a blunt, low tubercle at posterior end which is not extended between fourth coxae which are only slightly separated. Legs. 4123. Width of first patella at "knee" .12996 mm., tibial index of first leg 10. Width of fourth patella at "knee" .11913 mm., tibial index of fourth leg 7. Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters) 1. 1.170 .450 .845 .747 .520 3.732 2. 1.170 .410 .780 .650 .520 3.530 3. .780 .270 .520 .440 .396 2.406 4. 1.625 .390 1.200 1.105 .625 4.945 Palp .528 .176 .396 ■ .726 1.826 Leg spines very sparsely and poorly developed. Coxal ventral hook and corresponding second femoral groove and ridge lack- ing. Palp. General characters like those of male of M. sagittata but with tibia resembling that of M. brevipes (Figs. 32-34). The tibia appears to be quite distinctive and the same can be said for the tarsal hook. Abdomen. General form shown in Figure 31. Abdominal spines much more prominent than usual in mature males ; two posterior pairs are relatively large and conspicuous; there is a pair of short marginal spines somewhat behind the middle and another pair of very small dorsal spines somewhat in front of the middle : these suggest that the female should be found among CIIK'KERING : MICRATIIENA IN CENTRAL A MKKK 'A 401 those with four pairs of more or less conspicuous abdominal spines such as M. fidelis (Banks). Fig. Fig. Fig. ferent Fig. Fig. Fig. Fig. Fig. Fig. Fig. External Anatomy of Micratliena Figures 31-34, If. donaldi Figures 35-40, M . duodecimspinosa 31. Dorsal view of body of male. 32. Left palpal patella, tibia, and tarsus, nearly prolateral view. 33. Distal end of palpal conductor and associated structures; dif- view from that in Fig. 32. 34. Palpal basal tarsal hook. 35. Dorsal view of male allotype. 36. Eight second patella and tibia, prolateral view. 37. Left palpal tibia and tarsus. 38. Posterior surface of cymbium and tarsal hook from a paratype. 39. Palpal tibia and tarsal hook. 40. Another view of tarsal hook more enlarged ; from a paratype. 408 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Color in alcohol. Legs dark brown, almost black, above, but yellowish below. Carapace and sternum a dark mahogany brown. Abdomen : dorsum with three whitish spots as shown in Figure 31 ; with remaining surface a mosaic of black, whitish, brown, much streaked and dotted. Type locality. Holotype male from Barro Colorado Island, C. Z., August, 1936. Two paratype males from the same locality, July, 1936. Mr. Banks collected one male in the same localitv, July, 1924. Micrathena duodecimspinosa (0. P. -Cambridge) , 1890 (Figures 35-45) Acrosoma 12-spinosum O. P. -Cambridge, 1890 Acrosoma 12-spinosa Keyserling, 1892 M. 12-spinosa F. P.-Cambridge, 1904 A. 12-spinosa Banks, 1909 M. duodecimspinosa Petrunkevitch, 1911 M. duodecimspinosa Reimoser, 1917 M. duodecimspinosa Chiekering, 1936 M. duodecimspinosa Roewer, 1942 M. duodecimspinosa Kraus, 1955 M. duodecimspinosa Bonnet, 1957 Females of this species have been well described by Keyser- ling (1892), F. P.-Cambridge (1904), and Reimoser (1917). Abdominal spines are probably the best single clues to identifica- tion. Female hypotype. Total length 7.475 mm. The salient features of body form are shown in Figures 41 and 42. In all of my Panamanian specimens the posterior spines are bright red. Fea- tures of the epigynum are shown in Figures 43-45. Kraus (1955) has recently reported finding immature males but, so far as I have been able to determine, the mature male has never been described. For this reason, one of several males from Boquete, Chiriqui, Panama, has been selected as the allo- type and described as follows : Male allotype. Total length 4.973 mm. Carapace 1.885 mm. long, 1.43 mm. wide opposite interval between second and third coxae where it is widest ; median fovea well developed ; nearly level throughout from PME to posterior declivity (Fig. 35). Eyes. Eight in two rows as usual ; viewed from above, both rows strongly recurved ; viewed from in front, anterior row slightly procurved and posterior row strongly procurved, all CHICKERING : MICRATHENA IN CENTRAL AMERICA 409 measured by centers. Central ocular quadrangle wider behind than in front in ratio of 10 : 9 ; wider behind than long in about the same ratio. Ratio of eyes AME : ALE : PME : PLE = 6 : 4.5 : 8 : 5. AME separated from one another by about their diameter, from ALE by about 3.3 times their diameter. PME separated from one another by about their diameter, from PLE by 2.5 times their diameter. Laterals only slightly separ- ated. Laterals on a rather marked tubercle. Height of clypeus equal to about 1.5 times the diameter of AME. External Anatomy of Micrathena Figures 41-45, M. duodeeims'pinosa Fig. 41. Dorsal view of body of female. Fig. 42. Spines at posterolateral corner of abdomen; viewed from pos- terior surface. Figs. 43-45. Epigynum from below, posterior surface, and in profile (right side), respectively. Chelicerae. Moderately well developed ; essentially parallel ; only slightly concave along outer border ; basal boss small but clearly present ; apparently four teeth on promargin and three on retromargin of well developed fang groove (observed on paratype to avoid injury to allotype). Maxillae and Lip. As usual in the genus; details unnote- worthy. Sternum. Only slightly convex; extended between all coxae and with posterior coxae only slightly separated. 410 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Legs. 1423. Width of first patella at "knee" .18411 mm., tibial index of first leg 12. Width of fourth patella at "knee" .16245 mm., tibial index of fourth leg 12. Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters) 1. 1.430 .435 1.105 1.072 .585 4.627 2. 1.300 .422 .845 .910 .520 3.997 3. .950 .325 .520 .550 .390 2.735 4. 1.820 .390 .910 .975 .500 4.595 Palp .352 .132 .120 .572 1.176 There is a rather poorly developed ventral distal hook on the first coxa and a corresponding short prolateral proximal groove and ridge on the second femur. The first two pairs of legs are notably spiny, particularly the tibiae ; the ventral spines on the second tibiae (Fig. 36) are short and robust. Trichobothria are prominent on the tibiae. Palp. Both patella and tibia are very short. The features of the tarsus and tarsal hook are shown in Figures 37-40. Abdomen. 3.120 mm. long; continued posterior to spinnerets about four-ninths of total length ; remains of posterolateral spines, prominent in females, appear as short tubercles at pos- terior end. Other features as usual in the genus. Color in alcohol. Legs brownish with variations; first two darkest. Chelicerae and palps yellowish with palpal tarsus light brown. Lip very dark brown like sternum. Maxillae dark gray- ish. Carapace brownish with variations. Abdomen with a dark irregular central series of spots and an irregular series of dorso- lateral white spots making a pattern difficult to describe (Fig. 35) ; venter brownish dappled with yellowish white spots. Collection records. The hypotype female is from Barro Color- ado Island, C. Z., July, 1954. The allotype male is from Boquete, Chiriqui, Panama, July, 1939 at which time several paratype males were also taken. Females and immature males are in the collection from Barro Colorado Island, C. Z., June, 1934; June- July, 1936; June, 1939; July, 1954; January, 1958; France Field, C. Z., August, 1939. Several females are in the collection of the Museum of Comparative Zoology from Rio Jesus Maria, Costa Rica, January (Biolley and Tristan), and also from San Jose, Costa Rica (Valerio). The Cambridges had females from Mexico, Guatemala, and Panama. CHICKERING : MICRATHENA IN CENTRAL AMERICA 411 MlCRATHENA FIDELIS (Banks), 1909 (Figures 46-49) Acrosoma fidelis Banks, 1909 M. fidelis Petrunkevitch, 1911 Al. fidelis Eeimoser, 1917 il. fidelis Boewer, 1942 M. fidelis Bonnet, 1957 This species is, apparently, known only from the holotype fe- male which was very briefly described by its author without illustrations. These facts would seem to warrant a full descrip- tion in accord with my usual formula. The description is taken directly from the original specimen. Female holotype. Total length 7.02 mm. Carapace 2.34 mm. long; 2.015 mm. wide opposite second coxae where it is widest; with the median fovea as usual in the genus ; cephalic portion somewhat convex behind PME, then transversely depressed just anterior to median fovea ; conspicuously swollen just posterior to median fovea. Eyes. Eight in two rows as usual ; lateral eyes on a slightly raised tubercle ; viewed from above, both rows moderately re- curved; viewed from in front, anterior row slightly recurved, posterior row gently procurved ; central ocular quadrangle wider behind than in front in ratio of 17 : 14, slightly wider behind than long. Katio of eyes AME : ALE : PME : PLE = 4.5 : 5:7: 3.5. AME separated from one another by their diameter, from ALE by four times their diameter. PME separated from one another by about five-sevenths of their diameter, from PLE by a little less than three times their diameter. Laterals almost in contact. Height of clypeus equal to a little less than the diam- eter of AME. Chelicerae. Robust, vertical, nearly parallel, very convex in front, especially in proximal half ; fang fairly robust and evenly curved ; promargin of fang groove with four teeth, retromargin with three. Maxillae and Lip. As usual in the genus ; without noteworthy features. Sternum. Elongate scutiforni; quite convex throughout; not continued between coxae ; with procurved sternal suture and moderately well developed sternal tubercles at each anterolateral corner. Posterior coxae separated by a little more than one- seventh of their width. 412 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Legs. 1423. Width of first patella at "knee" .352 mm., tibial index of first leg 13. Width of fourth patella at "knee" .264 mm., tibial index of fourth leg 12. External Anatomy of Hierathena Figures 46-49, M. fidelis Figures 50-54, M. flaveola Fig. 46. Dorsal view of body of female. Fig. 47-49. Epigynum from below, in posterior view, and in profile from right side, respectively. Fig. 50. Dorsal view of body of female. Fig. 51. Lateral view of spines at posterolateral corner of abdomen. Figs. 52-54. Epigynum from below, in posterior view, and in profile from right side, respectively. CHICKERING : MICRATHENA IN CENTRAL AMERICA 413 Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters) Legs with numerous spines and low tubercles from which hairs extend. Numerous trichobothria observed on tibiae and meta- tarsi. Abdomen. General form and eight spines shown in Figure 46. Otherwise as usual in the genus. Epigynum. In general quite similar to others in the genus but a profile view seems to show distinctive features (Figs. 47-49). Type locality. The only specimen known to me is the holotype described by Banks (1909) and collected at Tablazo, Costa Rica (Tristan), September. The male remains unknown. MlCRATHENA FLAVEOLA (C. L. Koch), 1839 (Figures 50-54) Acrosoma flaveolum C. L. Koch, 1839 Plectana flaveola Walckenaer, 1841 M. flaveola Petrunkeviteli, 1911 11. flaveola Reimoser, 1917 M. flaveola Roewer, 1942 M. flaveola Bonnet, 1957 This species has caused me much concern and I still regard its status in Central America as somewhat questionable. The species has been reported from Mexico, Brazil, Dutch Guiana, and Venezuela. I am convinced that it has often been confused with M. gladiola (Walckenaer). Some of the specimens assigned to this species and to M. gladiola may well belong to other species, perhaps undescribed. I seem to have sound reasons for including the species among the Central American forms treated in this paper but I have had only one specimen for careful study and that was not in prime condition. The following facts are taken from this specimen : Female hypotype. Total length to posterior border of abdo- men between posterior spines 8.5 mm. (considerably larger than described by previous workers). The general form of the body 414 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY is shown in Figures 50 and 51. The carapace is somewhat gib- bous just behind the central fovea ; the sternum is finely rugulose and moderately convex but is not raised into a distinct cone as in M. gladiola (Walckenaer). The legs are badly fragmented and unmeasurable in this specimen. The spines appear as shown in Figures 50 and 51 and agree well with descriptions given by other authors who have had numerous specimens with which to work. The features of the epigynum are given in Figures 52-54. Males are still unknown. The hypotype female is from San Jose, Costa Rica, with no date of collection given. Micrathena funebris (Banks), 1898 (Figures 55-59) Acrosoma funebre Banks, 1898 M. funebris Petrunkeviteh, 1911 M. funebris Reimoser, 1917 M. funebris Chamberlin, 1924 M. fimebris Boewer, 1942 Al. funebris Bonnet, 1957 Only the female of this species is known but there are now numerous specimens of this sex in the Museum of Comparative Zoology representing parts of the Banks and Chamberlin collec- tions. Two of the specimens in the Banks collection are labelled "cotypes." In view of the brevity of the original description and the lack of accompanying figures, one of the "cotypes" has been selected and described in accord with my usual procedure. Female hypotype. Total length 6.825 mm. Carapace 2.275 mm. long, 1.592 mm. wide opposite second coxae where it is widest; more slender than in many species (Fig. 55). Without additional noteworthy features. Eyes. Eight in two rows as usual; median eyes and laterals on low tubercles ; viewed from above, both rows recurved ; viewed from in front, anterior row gently recurved and posterior row procurved, both measured by centers ; central ocular quadrangle wider behind than in front in ratio of 4 : 3, wider behind than long in ratio of 16 : 13. Ratio of eyes AME : ALE : PME : PLE = 7.5 : 5.5 : 10 : 6. AME separated from one another by eleven-sevenths of their diameter, from ALE by a little more than four diameters. PME separated from one another by about 1.5 times their diameter, from PLE by three diameters. CHICKERING : MICRATHENA IN CENTRAL AMERICA 415 Laterals separated from one another by nearly the diameter of ALE. Height of clypeus nearly equal to twice the diameter of AME. Chelicerae. Apparently as usual in the genus. Impossible to view the fang groove without serious injury to specimen. Maxillae. Without noteworthy features. Lip. Wider than long in ratio of 10 : 7 ; deeply grooved in basal fourth. 55 57 External Anatomy of Micrathena Figures 55-59, M. funebris Figure 60, M. furcula Fig. 55. Body of female, dorsal view. Fig. 56. Abdominal spines at posterolateral angle. Figs, fw-59. Epigynum from below, from posterior view, and in profile from right side, respectively. Fig. 60. Body of female in dorsal view. Sternum. Elongate scutiforni; longer than wide at anterior end in ratio of 23 : 18 ; sternal suture proeurved ; with low tubercles at anterolateral corners ; with a prominent tubercle at posterior end ; not extended between fourth coxae which are separated by about one-third of their width. 416 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Legs. 4123. Width of first patella at "knee" .255 mm., tibial index of first leg 13. Width of fourth patella at "knee" .242 mm., tibial index of fourth leg 12. Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters) Apparently the leg spines were present in the usual manner but are now mostly lacking. Abdomen. The general form of this part of the body is best shown in Figures 55 and 56. There are no anterior spines on the abdomen but six are present as shown. The color pattern appears to be characteristic and shows only minor variations among the numerous specimens from islands in the Gulf of California. Other features as usual in the genus. Epigynum. Strongly tubercular; somewhat distinctive (Figs. 57-59). Color in alcohol. In general, very dark brown or black with a rather distinctive pattern of white spots on the dorsum ; essen- tially as described by the author of the species and with little change after long preservation. Type locality. The original specimens came from Calmalli Mines, Sierra San Nicolas, and Mazatlan, Mexico (Tristan). The hypotype is from Mazatlan. There are many specimens from islands in the Gulf of California in the Chamberlin collection. Micrathena furcula (O. P. -Cambridge) ,1890 (Figures 60-66) Acrosoma furcula O. P.-Cambridge, 1890 A. furcula Keyserling, 1892 M. furcula Simon, 1895 M. furcula F. P.-Cambridge, 1904 M. furcula Petrunkevitch, 1911 .1/. furcula Eeinioser, 1917 M. furcula Banks, 1929 M . furcula Eoewer, 1942 M. furcula Bonnet, 1957 CHICKERING : MICRATHENA IN CENTRAL AMERICA 417 Only the female has been known up to the present time. Now however, with the finding of immature males with a copious sup- ply of hair as well as other revealing features the male can be positively identified. Banks was the first to report the female from Panama. Female hypotype. Total length 11.375 mm. Carapace quite typical of the genus except that it is largely covered by a copious growth of long yellowish silky hair. The abdomen is also well supplied with hair but this is of a darker color and largely confined to the lateral margins and especially to the posterior furcula. The color as noted among the specimens avail- able for study is quite variable but follows rather closely the External Anatomy of Micrathena Figures 61-66, If. furcula Figs. 61-63. Epigynum from below, in posterior view, and in profile from tight side, respectively. Fig. 64. Body of male in dorsal view. Fig. 65. Palpal patella, tibia, and tarsus. Fig. 66. Palpal tarsal basal hook. description given by the author of the species. The form of the abdomen (Fig. 60) should make identification certain. The characteristics of the epigynum are shown in Figures 61-63. 418 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Male allotype. Total length 4.94 mm. Carapace 2.145 mm. long, 1.820 mm. wide opposite interval between second and third coxae where it is widest ; without any dorsal swellings ; markedly narrowed opposite first coxae (Fig. 64). Eyes. Eight in two rows as usual ; ocular tubercles prominent, especially the laterals; viewed from above, both rows recurved; viewed from in front, anterior row gently recurved, posterior row procurved ; central ocular quadrangle wider behind than in front in ratio of 9 : 8, about as long as wide behind. Ratio of eyes AME : ALE : PME : PLE = 5.5 : 4 : 6.5 : 3.5. AME separated from one another by slightly more than their diameter, from ALE by three diameters. PME separated from one another by a little less than their diameter, from PLE by nearly three diameters. Laterals separated from one another by nearly the radius of AME. Height of clypeus equal to about 2.5 times the diameter of AME ; clypeus very receding. Chelicerae. With low basal tubercle in front ; unable to observe fang groove and teeth without serious injury to specimen. Maxillae. Without noteworthy features. Lip. Wider at base than long in ratio of 4 : 3 ; transversely and shallowly grooved ; with sternal suture procurved. Sternum. Elongate scutiform ; widest between second coxae; longer than wide in ratio of about 3:2; considerably and irregu- larly corrugated ; narrowly extended between fourth coxae which are only slightly separated. Legs. 4123. ' Width of first patella at "knee" .17328 mm., tibial index of first leg 12. Width of fourth patella at "knee" .15162 mm., tibial index of fourth leg 11. Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters) There is a moderately well developed ventral distal retrolateral hook on the first coxa and the corresponding short prolateral groove and ridge on the second femur. The first two legs are notably spiny, especially on the ventral and prolateral surfaces of the tibiae but the detailed placement seems not to be essential to the adequate description of the allotype. The ventral spines CHICKERING : MICRATHENA IN CENTRAL AMERICA 419 on the two anterior tibiae are short and robust. Trichobothria are conspicuous on the tibiae. Palp. Both patella and tibia are short with the latter relatively broad ; the shape of the basal tarsal hook is shown in Figure 66 ; other tarsal features are shown in Figure 65. Abdomen. With a moderately well developed dorsal scutum; 2.9 mm. long; 1.46 mm. wide in middle; only moderately flat- tened; other features fairly typical of males of the genus (Fig. 64). Color in alcohol. Carapace a rich medium brown with fine black dots ; legs generally yellowish brown but the first two pairs of femora are darker brown like the carapace. Sternum brown, mottled with black. Abdomen: dorsum with a color pattern essentially as represented in Figure 64. The darkly colored areas are a deep brown, nearly black; the lighter areas are yellowish beneath the scutum but white around the margin ; laterally there is a series of seven white elongated spots ; the venter is a complex of irregular blackish and brown spots and streaks. The color pattern in mature males is probably quite variable. As already pointed out, one important clue to proper identification of the male is the copious supply of hair in immature specimens. Type locality. The holotype female came from Guatemala. The hypotype female is from Barro Colorado Island, C. Z., July, 1936. The allotype male is from Barro Colorado Island, C. Z., July, 1934. Two immature males are in my collection from the same locality, June, 1939. Several mature females have been taken on Barro Colorado Island, C. Z., on the following dates: July, 1924 (Banks). July-August, 1936. Micrathena gladiola (Walckenaer). 1841 (Figures 67-71) Acrosoma aculeata C. L. Koeh, 1836 (preoccupied) Plcctana gladiola Walckenaer, 1841 A. flaveolum Keyserling, 1892 M. gladiola F. P.-Cambridge, 1904 M. gladiola Petrunkevitch, 1911 M. gladiola Reimoser, 1917 M. fl areola Petrunkevitch, 1925 .1/. gladiola Roewer, 1942 M. gladiola Bonnet, 1957 In collections made available to me I have found much con- fusion regarding the identification of this species. I have found 420 bulletin: museum of comparative zoology it assigned to other species and other species assigned to it. I am convinced that the group of species to which this belongs should be carefully studied, especially after more careful collect- ing is done within its area of distribution. In view of the uncer- tainties surrounding the species, I am relying quite largely upon the descriptions and identifications of both F. P. -Cambridge and Keyserling. The most significant features of the species, taken from a specimen collected at Bugaba, Panama, appear to be the following : The carapace is uniformly convex, not raised behind the median fovea ; lateral eyes are on a low tubercle ; fang groove with four teeth on promargin and three on retromargin; sternum very convex, raised into a distinct cone ; epigynum with features as shown in Figures 69-71 taken from a specimen External Anatomy of Miorathena Figures 67-71, M . gladiola Fig. 67. Abdomen of female in dorsal view. Fig. 68. Abdominal spines at posterolateral angle from left side. Figs. 69-71. Epigynum from below, in posterior view, and in profile from right side, respectively. studied by F. P. -Cambridge in the British Museum (Natural History) ; femora finely granulose and with minute setigerous granules in front and beneath ; abdominal spines as shown in Figures 67 and 68. The species is quite well known from a few places in Central America, northern South America, and some of the West Indies nearest to South America. The male is still unknown. CHICKERING : MICRATHENA IN CENTRAL AMERICA 421 IMtcrathena gracilis ( Walekenaer) , 1805 (Figures 72-77) Epeira gracilis Walekenaer, 1805 Pie ei ana gracilis Walekenaer, 1841 Acrosomal matronale C. L. Koch, 1845 E. rugosa Hentz, 1850 A. rugosum Emerton, 1884 M icrathena gracilis Simon, 1895 M. matronalis Simon, 1895 .1/. gracilis F. P. -Cambridge, 1904 A. gracilis Banks, 1909 M. gracilis Petrimkevitch, 1911 M. gracilis Reimoser, 1917 M. gracilis Chickering, 1931 M. nigrior Chamberlin and Ivie, 1936. New synonymy. M. gracilis Eoewer, 1942 H. gracilis Kraus, 1955 M. gracilis Bonnet, 1957 This species is widely distributed from the northern United States through Central America to Brazil. It has been figured and described many times but males remain scarce in collections and there is some evidence of confusion of these with males of other species. Only two males have been found thus far in the collections from Central America. The only record from Panama is that of M . nigrior Chamberlin and Ivie, 1936. This is reported to have come from my collection of 1928 but it seems odd that it has not appeared in any of my numerous collections taken since that date. Female hypotype. Total length 13 mm., including the prom- inent bases of the chelicerae. Cephalic part of the carapace cpiite prominent : both lateral ocular tubercles and median ocular tubercles moderately prominent ; central ocular quadrangle only slightly wider behind than in front, longer than wide behind in ratio of 8 : 7. Sternum with a pointed tubercle at posterior end. Femora densely granulose with setigerous tubercles. Fang groove with four teeth along the promargin and three along the retromargin. Abdomen very tall; with five pairs of spines (Fig. 72) which should aid greatly in identification. Epigynum more distinctive than usual in the genus (Figs. 73-74). Male hypotype. Total length 6.11 mm. Abdomen extremely long and slender; strongly chitinized; with a pair of segmental divisions at posterior end, the second of which bears a pair of 422 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY stout terminal spines (Fig. 75). The legs appear to lack the modified spines so frequently present in the males of the genus. The first coxa lacks the ventral hook and the second femur also lacks the ridge and groove so frequently present. The chief palpal features are shown in Figures 76-77. Collection records. The female hypotype is from Patulul, Gua- temala, January, 1912 (W. M. Wheeler). The male hypotype is from Orizaba, Mexico, with no date given. Other female speci- mens studied by me are from: Granada, Nicaragua (C. F. Baker); Polvon, Nicaragua; Tampico, Mexico, 1913 (H. L. Locke); Vera Cruz, Mexico; San Jose, Tamaulipica, Mexico, July, 1930 (Bartlett and Dice) ; Uricuajo, Costa Rica (Biolley and Tristan). One record only from Panama: M. nigrior Cham- berlin and Ivie. External Anatomy of Micrathena Figures 72-77, M. gracilis Fig. 72. Abdomen of female, dorsal view. Figs. 73-74. Epigynum in posterior and profile views, respectively. Fig. 75. Dorsal view of body of male. Fig. 76. Left palpal tarsus. Fig. 77. Palpal tarsal basal hook, more enlarged. (.MUCKERING: MICRATIIENA IN CENTRAL AMERICA 423 Micrathena granulata F. P. -Cambridge, 1904 (Figures 78-82) ^[. granulata Petrunkevitch, 1911 M. granulata Eeimoser, 1917 M. granulata Boewer, 1942 .1/. granulata Bonnet, 1957 Male hypotype. Total length 4.16 mm. General form as shown in Figure 78. Legs with ordinary and unnoteworthy spination except for the first femora which, apparently, have a group of clasping spines near the distal end (Fig. 79). The first coxa 80 82 79 External Anatomy of Micrathena Figures 78-82, M. granulata Fig. 78. Dorsal view of body of male. Fig. 79. Distal end of left first femur; ventral view. Figs. 80-82. Three different views of left palpal tibia and tarsus showing denticulated basal tarsal hook. lacks a ventral hook and the second femur lacks the correspond- ing ridge and groove. Palp: the tarsal hook is very distinctive, being broadly extended, concave, apically recurved, and set with many minute denticles (Figs. 80-82). Color in alcohol: Legs, 424 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY cephalothorax, and mouth parts all light reddish brown with variations ; abdomen dorsally yellowish with irregular whitish patches (Fig. 78). For a time it was thought that M. granulata was the missing male of M. catenulata. Recently a male belonging to this species was found with females clearly belonging to M. funebris (Banks) collected on Coronados Island, Gulf of California. At present it would seem that 31. granulata F. P. -Cambridge could be the missing male for either M. catenulata F. P. -Cambridge or M. funebris (Banks). On the other hand, perhaps this species be- longs with some other of the numerous species known only from females. This condition again emphasizes the need for careful collecting and close observation over the whole area occupied by this genus. Collection records. F. P. -Cambridge had the species only from Teapa, Mexico. The male hypotype is from Chiapas, Escuintla, Mexico with no date of collection given. I have a second speci- men taken with the hypotype and another from Coronados Is- land, Gulf of California, May 18, 1921. These three are all in the collection of the Museum of Comparative Zoology at Harvard College. ^o v Micrathena horrida ( Taczanowski) , 1873 (Figures 83-88) Acrosoma horrida Taczanowski, 1873 A. mammiUata Butler, 1873 A. longicauda Keyserling, 1892. New synonymy. M. mammiUata F. P. -Cambridge, 1904 A. longicauda O. P. -Cambridge, 1890. New synonymy. M . longicauda F. P. -Cambridge, 1904. New synonymy. A. mammiUata Banks, 1909 M. horrida Petrunkevitch, 1910 M. horrida Petrunkevitch, 1911 H. mammiUata Petrunkevitch, 1911 M. longicauda Petrunkevitch, 1911. New synonymy. M. horrida Reimoser, 1917 M. longicauda Reimoser, 1917. New synonymy. M. horrida Petrunkevitch, 1925 M. longicauda Petrunkevitch, 1925. New synonymy. M. longicauda Banks, 1929. New synonymy. A. mammiUata Banks, 1929 31. mammiUata Bryant, 1940 M. horrida Roewer, 1942 CHICKERING : MICHATHENA IN CENTRAL AMERICA 425 M. longicauda Koewer, 1942. New synonymy. M. horrida Bonnet, 1957 M. longicauda Bonnet, 1957. New synonymy. Until recently it has seemed unsafe to American araneologists to synonymize M. mammillata (Butler) with M. horrida (Tacz- anowski). It now seems to me that the synonymy as indicated is External Anatomy of Micrathena Figures 83-88, M. horrida Fig. 83. Dorsal view of body of female. Figs. 84-85. Epigynum in posterior view, and in profile, right side, re- spectively. Fig. 86. Dorsal view of body of male. Fig. 87. Left palpal tibia and tarsus of male. Fig. 88. Male palpal tibia and basal tarsal hook to show form of latter. 426 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY fully justified. F. P. -Cambridge suggested that 31. longicauda (0. P.-Cambridge) might be the male of M. mammillata (But- ler). Banks (1929) was quite convinced that this was so but he continued to list them separately. Miss Bryant (]940) recog- nized the male of M. mammillata but did not synonymize it with M. longicauda. The species appears to be closely related to M. gracilis (Walck.) ; this conclusion is based upon a comparison of both sexes of both species. Female hypotype. Total length 8.9 mm., including the prom- inent bases of the chelicerae. Very strongly chitinized. Carapace with raised cephalic part ; only slightly raised behind median fovea. Sternum convex but without a posterior tubercle as seen in M. gracilis. The femora are excessively provided with seti- gerous tubercles. Abdomen : with seven pairs of marginal spines the first of which extends from the anterior margin over the posterior lateral corners of the carapace (Fig. 83) ; there are also numerous lateral tubercles beneath the marginal spines (five on each side in the hypotype) subject to considerable variation among the many specimens available ; the epigynum is strongly tubercular (Figs. 84-85) ; there is also a prominent, median, chitinized tubercle just posterior to the cone surrounding the spinnerets. Male hypotype. Total length 4.85 mm. Very long and slender ; strongly chitinized (Fig. 86). Abdomen with a trilobate pos- terior termination ; the trilobate termination bears four small but definite spines. Legs without especially modified spines; femora one and two with numerous small setigerous tubercles ; patellae one and two quite dilate on retromargin ; coxa one without any ventral hook and femur two without the corresponding ridge and groove. Features of the palp with tarsal hook shown in Fig- ures £7-88. The shape of the abdomen and the palpal features furnish the best means of identification of the male of the species. Collection records. Male and female hypotypes are from Barro Colorado Island, C. Z., July and August, 1950, respectively. The species is widely distributed from the southern United States through Central America to several countries in northern South America and the West Indies. It occurs in my collections from many localities in Panama and is abundant on Barro Colorado Island. CHICKERING : MICRATHENA IN CENTRAL AMERICA 427 Micrathena inaequalis F. P. -Cambridge, 1904 (Figures 89-93) Acrosoma inaequalis Banks, 1909 M. inaequalis Petrunkevitch, 1911 M. inaequalis Beimoser, 1917 M. inaequalis Chickering, 1936 M. inaequalis Boewer, 1942 M. inaequalis Bonnet, 1957 F. P. -Cambridge (1904) had this species from Costa Rica and Guatemala. Banks (1909) had it from Costa Rica. I reported it from Panama in 1936 but at that time the specimens in my possession were all immature and may have been wrongly iden- tified. Now I can definitely record the species from the high- lands of western Panama. External Anatomy of Micrathena Figures 89-93, M. inaequalis Fig. 89. Dorsal view of body of female. Fig. 90. Posterolateral abdominal spines; posterior view. Figs. 91-93. Epigynum from below, in posterior view, and in profile from right side, respectively. Hypotype female. Total length 7.8 mm. Carapace raised both before and behind the median fovea. Sternum moderately con- vex ; with a series of low marginal tubercles. Abdomen : there 428 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY is a pair of sharply pointed spines reaching far over the cara- pace ; there is also a pair of short marginal spines somewhat behind the middle ; the abdomen extends far laterally at the posterior border and there terminates in a pair of spines on each side (Figs. 89-90). These eight spines seem to be typical of the species but small lateral marginal spines may also occur on some specimens. The degree to which the large posterior lat- eral spines are separated is also, apparently, at least somewhat variable in the general population. Characteristics of the epigy- num are shown in Figures 91-93. Collection records. In addition to the earlier records of the species from Costa Rica and Guatemala I can now add the following from Panama : El Valle, July, 1936 ; Boquete. Chiriqui, July, 1939; El Volcan, Chiriqui, August, 1950. The hypotype fe2iiale is from Boquete, July, 1939. The male is un- known. MlCRATIIEXA INSOLITA Sp. 110V. (Figures 94-98) Apparently the holotype had recently completed its last moult and was not yet well chitinized. It is, however, in good condi- tion for describing. Female holotype. Total length 4.55 mm. Carapace largely covered by the anterior marginal abdominal spines and project- ing anterior end of the abdomen itself ; about 2.08 mm. long and about 1.625 mm. wide opposite interval between second and third coxae where it is widest; median thoracic fovea obscure; regularly and gently arched dorsally from PME to posterior declivity with no marked gibbosity as in many species in the genus. Eyes. Eight in two rows as usual ; viewed from above, both rows recurved ; viewed from in front, both rows procurved, pos- terior row strongly so ; central ocular quadrangle wider behind than in front in ratio of about 3 : 2, wider behind than long in ratio of about 18 : 13. Ratio of eyes AME : ALE : PME : PLE = 7 : 7 : 8 : 7 (laterals somewhat oval). AME separated from one another by a little more than 1.5 times their diameter, from ALE by nearly six times their diameter. PME separated from one another by slightly more than 2.5 times their diameter, from PLE by about 5 times their diameter. Laterals separated from one another by about the radius of ALE. Height of clypeus equal to 1.5 times the diameter of AME. (MUCKERING : MICRATIIENA IN CENTRAL AMERICA 429 Chcliccrae. Parallel, moderately robust ; as usual in the genus. Unable to see fang- groove because of fragility of the holotype. Maxillae and Lip. Apparently as usual in the genus and with- out noteworthy features. External Anatomy of Micrathena Figures 9-4-98, M. insolita Fig. 94. Dorsal view of body of female. Fig. 95. Posterior end of abdomen ; seen from posterior surface. Figs. 9(i-98. Epigynum from below, from a somewhat posterior view, and in profile from right side, respectively. Sternum. Quite convex; without tubercles; posterior coxae separated by about half their width. Legs. 4123. Width of first patella at "knee" .2274 mm., tibial index of first leg 12. Width of fourth patella at "knee" .2373 mm tibial index of fourth leg 13. Femora Patellae Tibiae Metatarsi (All measurements in millimeters) Tarsi Totals 430 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Legs with few spines; details of spination seem to be unnote- worthy. Abdomen. Measured with anterior and posterior spines, as long as entire body. Three pairs of spines as indicated in Fig- ures 94-95. Perhaps the most striking feature is the extreme extension of the anterior pair of spines. Epigynum. Features of this organ essentially as shown in Fig- ures 96-98. This organ lies so close to the chitinized cone sur- rounding the spinnerets that it is impossible to view it from the posterior surface in the usual manner. Color in alcohol. Legs generally yellowish ; first two pairs with a dorsal brown stripe on femora, patellae, tibiae, and metatarsi with the tarsi entirely brown ; second two pairs of legs similarly colored except the brown stripe is changed to a large spot of irregular shape. Carapace yellowish in anterior half with brown dots and a narrow brown median stripe; posterior half with brown dots closely crowded together. Abdomen: dusky yellowish dorsally with black stripes and spots as suggested in Figure 94 ; posterior and lateral surfaces yellowish with irregular black stripes. Type locality. Female holotype from Porto Bello, Panama, August, 1936. There are no paratypes and the male is unknown. MlCRATHENA MACFARLANEI Sp. UOV. (Figures 99-102) Female holotype. Total length from AME to middle of pos- terior margin of abdomen 11.05 mm. Carapace about 4 mm. long (considerably overlapped by abdomen), 3.185 mm. wide opposite posterior border of second coxae where it is widest ; quite strongly gibbous just posterior to well defined median fovea ; with paired dorsolateral foveae very faintly indicated ; gently raised just posterior to PMB. Eyes. Eight in two rows as usual ; viewed from above, both rows moderately recurved; viewed from in front, anterior row slightly recurved, posterior row slightly procurved, all measured by centers. Central ocular quadrangle wider behind than in front in ratio of about 19 : 17 ; wider behind than long in ratio of about 19 : 16. Ratio of eyes AME : ALE : PME : PLE = 6.5 : 4.5 : 7 : 4.5. AME separated from one another by ten-thir- teenths of their diameter, from ALE by about 4 times their diameter. PME separated from one another by slightly more than their diameter, from PLE by four times their diameter. CHICKERING : MICKATIIENA IN CENTRAL AMERICA 4:.U Laterals separated from one another by slightly less than one- fourth of the diameter of one of them. Height of elypeus equal to slightly more than the diameter of AME. Chelicerae. Robust; gibbons in front near base. Promargin of fang groove with four teeth, relromargin with three robust teeth. Maxillae and Lip. Typical of females of the genus; details regarded as unnoteworthy. Sternum. Sternal suture procurved; anterolateral tubercles moderately well developed, others hardly tubercular, more rounded ridges ; continuous posteriorly with a sclerite extending between fourth coxae which are separated by two-fifths of their width. cT%E\ External Anatomy of Micrathena Figures 99-102, M. macfarlanei Fig. 99. Dorsal view of body of female. Figs. 100-102. Epigynum from below, in posterior view, and in profile from right side, respectively. Legs. 4123. Width of first patella at "knee" .520 mm., tibial index of first leg 10. Width of fourth patella at "knee" .520 mm.. tibial index of fourth leg 12. 432 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters) Setigerous tubercles numerous on legs; true spines few; first femora with a series of six or seven very short prolateral spines. Abdomen. Plump and full ; somewhat convex dorsally ; general form and five pairs of spines as shown in Figure 99. Epigynum. Essentially as shown in Figures 100-102. Color in alcohol. Legs with varying shades of reddish brown. Carapace with a narrow, median, dusky brown stripe from be- tween PME to near median fovea; with a broad, broken, dusky brown, dorsolateral stripe on eacli side leaving the margins yel- lowish. Sternum dark brown. Lip dark brown, nearly black, with a yellowish tip. Maxillae dark brown with anterior and median margins yellowish. Chelicerae : fang and tips of basal segments dark brown, elsewhere yellowish. Abdomen: dorsal region almost white with black ' ' punctures ' ' ; second, fourth, and fifth spines reddish at bases with more or less black striping; lateral sides and venter a variegated black and yellowish. Type locality. Female holotype from Barro Colorado Island, C. Z., August, 1954; one mature paratype female and several immature females from the same localitv, July, 1936 and June, 1939. MlCRATHENA MACILENTA Sp. 110 V. (Figures 103-109) Note : The two specimens treated under the name M. macilenta sp. nov. were formerly believed to belong to the species named M. parallela (O. P.-Cambridge) but a careful comparison with the type of the latter species in the British Museum (Natural History) has shown this to be an error and so they must be regarded as representing a species new to science. One is selected, therefore, as the holotype and described in accord with my usual procedure. Male holotype. Total length 3.95 mm. Carapace 1.76 mm. long; somewhat overlapped by abdomen ; 1.30 mm. wide slightly behind second coxae where it is widest; .66 mm. tall just behind well developed median fovea where it is tallest. CHICKERING : MICRATHENA IN CENTRAL AMERICA 433 Eyes. Eight in two rows as usual ; ocular tubercles only mod- erately developed; viewed from above, both rows strongly re- curved; viewed from in front, anterior row slightly procurved, posterior row strongly procurved, all measured by centers. Cen- tral ocular quadrangle wider behind than in front in ratio of 11 : 9, wider behind than long in ratio of 22 : 19. Ratio of eyes AME : ALE : PME : PLE = 7:6:8: 5.5. AME sep- arated from one another by slightly less than their diameter, External Anatomy of Micratliena Figures 103-109, M. macilenta Fig. 103. Dorsal view of body of male. Fig. 10-4. Left palpal tarsus. Fig. 105. Left first femur; prolateral view. Fig. 106. Distal end of left second femur and patella ; prolateral view. Fig. 107. Dorsal view of left palpal tibia. Figs. 108-100. Two views of left palpal cymbium and basal tarsal hook. from ALE by nearly two and one-third times their diameter. PME separated from one another by their diameter, from PLE by two and one-half times their diameter. Laterals separated from one another only by a well defined line. Height of clypeus equal to about one and one-fifth times the diameter of AME. 434 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Chclicerae, Maxillae, and Lip. All apparently quite typical of males of the genus. Teeth along fang groove not observed because of fragility of the holotype. Sternum. Only slightly convex; slightly rugulose; without definite tubercles; continued as a narrow sclerite between coxae laterally and as a fairly broad, thin sclerite between fourth coxae which are separated by about one-third of their width. Legs. 1423. Width of first patella at "knee" .17328 mm., tibial index of first leg 11. Width of fourth patella at "knee" .15162 mm., tibial index of fourth leg 13. Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters) The ventral, distal, retrolateral hook on first coxa and the cor- responding ridge and groove on the proximal prolateral surface of the second femur are moderately well developed. There are numerous spines on legs; those with most significance appear to be on the first and second femora essentially as shown in Figures 105-106. Palp. General features as shown in Figures 104, 107-109. Re- sembles that of M. parallela (O. P. -Cambridge) with which the species was formerly confused. Abdomen. Much flattened dorsoventrally ; the only evidence of suppressed spines shows at posterior end where two pairs of small tubercles occur ; other features as usual in males of the genus (Fig. 103). Color in alcohol. Legs and mouth parts variable shades of yellowish ; not distinctive. Carapace yellowish in the center, brownish elsewhere. Abdomen : dorsum nearly white throughout center with irregular black marginal stripes as shown in Figure 103; venter dusty yellowish with gray patches in regions of booklungs. Paratype follows the color pattern of the holotype very closely. Type locality. Male holotype from Barro Colorado Island, C. Z., July, 1934; one paratype male from the same locality, August, 1950. and one taken in December, 1957. The female is unknown. CHECKERING : MICRATHENA IN CENTRAL AMERICA 435 Micrathena militabis (Fabricius) , 1775 Aranea militaris Fabricius, 1775 A. militaris Olivier, 1789 Plectana militaris WaJckenaer, 1841 Acrosoma militaris Butler, 1873 A. mil Hare Banks, 1898 M. militaris Petrunkevitch, 1911 .1/. militaris Eeimoser, 1917 M. militaris Petrunkevitch, 1930 M . militaris Eoewer, 1942 M. militaris Bonnet, 1957 Banks (1898), with some uncertainty, reported this species from Margarita Island, Lower California. The single specimen now in the Museum of Comparative Zoology from Margarita Island and labelled M. militaris (Fabr.) is a specimen of M. sexspinosa (Halm). Another specimen from Western Mexico with a similar label is a female of M. sagittata (Walck.). I am assuming, therefore, that M. militaris (Fabr.) has not yet been found in Central America. Micrathena mitrata (Hentz), 1850 (Figures 110-116) Acrosoma mitrata Hentz, 1850 A. mitrata Emerton, 1884 A. reduvianum McCook, 1893 A. mitrata Banks, 1898 A. mitrata Emerton, 1902 M. mitrata F. P. -Cambridge, 1904 M. reduviana Petrunkevitch, 1911 M. mitrata Eeimoser, 1917 H. mitrata Eoewer, 1942 M. mitrata Kaston, 1948 .1/. mitrata Levi, 1954 M. mitrata Bonnet, 1957 The female of this species is well known from many localities in the United States. It has also been reported from Mexico and, doubtfully, from Cuba (Franginillo). The male, apparently, has not been carefully studied and appears to be scarce in collections. In general, the specimens from the United States studied by me agree well with those from Mexico in the British Museum (Nat- ural History). The hypotypes have been selected from collec- tions made in Canton, North Carolina, and kept in the Museum 436 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY of Comparative Zoology. There is no date of collection given but the specimens have been in preservation a long time. Female hypotype. Total length 4.55 mm. Probably the best means of identification is the presence of two pairs of postero- lateral abdominal spines (Fig. 110). Prominent spines are lack- ing elsewhere but there are many small lateral spinules usually 115 External Anatomy of Hicrathena Figures 110-116, M. mitrata Fig. 110. Dorsal view of body of female. Figs. 111-113. Epigynum from below, in posterior view, and in profile from right side, respectively. Fig. 114. Dorsal view of body of male. Fig. 115. Left palpal tarsus of male. Fig. 116. Palpal tibia and basal tarsal hook of male, more enlarged. CHICKERING : MICRATIIENA IN CENTRAL AMERICA 437 not mentioned in descriptions. The lateral spinules appear to be less evident in the specimens from Mexico than among those from the United States which I have had an opportunity to study. In some of the specimens in the British Museum (Natu- ral History) from Mexico there appeared to be a tendency for the anterolateral corners of the abdomen to be somewhat extended. The epigynum is obscurely distinctive (Figs. 111-113). Male hypotype. Total length 3.25 mm. Abdominal spines are completely suppressed in the male (Pig. 111). Features of the palp are difficult to determine and present in drawings because of long preservation, minute size, and some deterioration, but Figures 115-116 are believed to give the most important charac- teristics. The coxal hook and corresponding femoral groove and ridge are poorly developed. MlCRATIIENA MIRIFICA sp. 110V. (Figures 117-121) Male holotype. Total length 4.03 mm. Carapace 1.69 mm. long; 1.495 mm. wide opposite interval between second and third coxae where it is widest ; considerably overlapped by anterior end of abdomen ; median fovea only slightly behind middle ; median region nearly level from PME to posterior declivity ; with lateral margins regularlv rounded to cephalic region (Fig. 117). Eyes. Eight in two rows as usual; viewed from above, both rows recurved ; viewed from in front, anterior row nearly straight, posterior row procurved, all measured by centers. Cen- tral ocular quadrangle only slightly wider behind than in front, slightly longer than wide behind. Ratio of eyes AME : ALE : PME : PLE = 7:5:7:5 (laterals somewhat angular). AME separated from one another by slightly less than their diameter, from ALE by about 2.5 times their diameter. PME separated from one another by slightly less than their diameter, from PLE by about three times their diameter. Laterals separated from one another by about one-third of their diameter. Height of clypeus equal to about 1.5 times the diameter of AME. Clypeus quite receding. Median ocular tubercle quite prominent ; lateral ocular tubercles moderately prominent. Chelicerae, Maxillae, and Lip. Quite as usual in males of the genus and without noteworthy features. 438 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Sternum. Nearly flat ; without noteworthy features. Pedicel with pointed tubercle projecting forward toward posterior end of sternum. Posterior coxae separated by a little more than half their width. Legs. 1423. Width of first patella at "knee" .166 mm., tibial index of first leg 10. Width of fourth patella at "knee" .154 mm., tibial index of fourth leg 14. Femora Patellae Tibiae Metatarsi (All measurements in millimeters) Tarsi Totals Spines: first femur without special clasping spines; first tibia with long, robust, prolateral, and ventral spines as shown in Figure 120; second tibia with short, robust, prolateral, and ventral spines as shown in Figure 121. Without coxal hook and femoral ridge and groove. 117 118 External Anatomy of Miorathena Figures 117-121, M. mirifiea Fig. 117. Dorsal view of body of male. Fig. 118. Left palpal tibia and tarsus. Fig. 119. Left palpal patella, tibia, and basal tarsal hook. Figs. 120-121. Left first and second tibiae, respectively; ventral view. CIIICKERING : MICRATIIENA IN CENTRAL AMERICA 439 Palp. The tibia is simple, without spines or special modifica- tions. Other palpal features, including tarsal hook, shown in Figures 118-119. Abdomen. Wholly without spines; considerably flattened dor- soventrally; with form as shown in Figure 117. Color in alcohol. Legs yellowish brown above with small dusky patches ; lighter below. Carapace light brown in center with broad, darker brown lateral stripes. Abdomen nearly white dor- sally with black markings as suggested in Figure 117. Sternum yellowish with a large black spot in posterior half. Color pattern of paratypes like that of holotype. Type locality. Male holotype and one paratype from Barro Colorado Island, C. Z., July, 1950; one additional paratype from the same locality, July, 1939. MlCRATIIENA MODICA sp. 110Y. (Figures 122-126) Male holotype. Total length 4.29 mm. Carapace 1.625 mm. long; 1.43 mm. wide just behind second coxae w 7 here it is widest; thoracic part regularly rounded laterally; .585 mm. tall just behind the moderately well marked central fovea where it is tallest ; considerably overlapped by anterior border of abdomen. Eyes. Eight in two rows as usual ; lateral ocular tubercles mod- erately well developed; central ocular tubercle hardly existent. Viewed from above, both rows rather strongly recurved ; viewed from in front, anterior row gently recurved, posterior row clearly procurved, all measured by centers. Central ocular quad- rangle only slightly wider behind than in front, almost exactly as long as wide behind. Katio of eyes AME : ALE : PME : PLE =8 : 6 : 8.5 : 6. AME separated from one another by nearly their diameter, from ALE by about three-halves of their diameter. PME separated from one another by about their diameter, from PLE by about twice their diameter. Laterals separated from one another by a broad line. Height of elypeus equal to about nine-eighths of the diameter of AME. CheHcerae, Maxillae, and Lip. Apparently quite typical of males in the genus. Teeth along the fang groove not observed because of fragility of the holotype. Sternum. Only slightly convex; tubercles almost completely suppressed ; posterior end extended between fourth coxae which are separated by about two-thirds of their width. 440 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Legs. 1243. Width of the first patella at "knee" .19494 mm., tibial index of first leg 9. Width of fourth patella at "knee" .15162 mm., tibial index of fourth leg 9. The ventral distal retrolateral hook on first coxa and the corre- sponding proximal prolateral groove and ridge on the second femur are all lacking in this species. The legs are all quite spiny but the modified spines appear to be most important on the first femur (Fig. 123). Probably a considerable degree of variation in the spination will be noted when a series of these males is available for study. 122 25 External Anatomy of Micrathena Figures 122-126, M. modica Dorsal view of body of male. Left first femur ; ventral view. Fig. 124. Left palpal tibia and base of tarsus with tarsal hook. Fig. 125. Left palpal tibia and tarsus. Fig. 126. Another view of basal tarsal hook. Fig Fig i oo 123. CHICKERING : MICRATHENA IN CENTRAL AMERICA 441 Palp. General features shown in Figures 124-126. The hasal tarsal hook resembles those of certain other species but is also somewhat distinctive. The tibia is conservative and without special features. Abdomen. General features as shown in Figure 122. Much flattened dorsoventrally ; with no indication of suppressed spines. Color in alcohol. Legs and mouth parts in varying shades of brownish and yellowish colors; details regarded as unessential. Carapace with a yellowish brown central stripe and a broad dusky brown stripe on each side as indicated by stippling in Figure 122. Abdomen : with many white subchitinous flecks on dorsum together with dark markings also as indicated in Figure 122. Type locality. Male holotype is from Summit, Canal Zone, July, 1950. One paratype male from Barro Colorado Island, C. Z., July, 1950 ; one immature male from El Volcan, Chiriqui, August, 1950 showing short spines at posterior end of abdomen. The female is unknown. MlCRATHENA MOLESTA sp. nOV. (Figures 127-132) Note : The holotype specimen described below was found in the Nathan Banks collection in the Museum of Comparative Zoology. It was filed with two other specimens and labelled M . triserrata F. P. -Cambridge. I have carefully compared the holotype with those specimens assigned to M. triserrata F. P. -Cambridge in the British Museum (Natural History) and have been compelled to decide that they do not belong together. For this reason, but somewhat hesitantly, I have been compelled to consider the species new to science and, therefore, I am describing the holotype in accord with my usual procedure. Female holotype. Total length 6.825 mm. Carapace about 2.21 mm. long; 1.82 mm. wide opposite the interval between second and third coxae where it is widest; 1.40 mm. tall at level of marked gibbosity just behind the central fovea which is well defined ; with three pairs of dorsolateral foveae also well defined (Fig. 127). Eyes. Eight in two rows as usual ; viewed from above, pos- terior row moderately recurved, anterior row strongly so. Viewed from in front, anterior row gently recurved, posterior row gently procurved, all measured by centers. Central ocular quadrangle 442 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY wider behind than in front in ratio of about 6 : 5, wider behind than long in ratio of 15 : 14. Ratio of eyes AME : ALE : PME : PLE = 9.5 : 7.5 : 11 : 6. AME separated from one another by a little less than their diameter, from ALE by a little less than 2.5 times their diameter. PME separated from one another by a little more than their diameter, from PLE by about five-thirds of their diameter. Laterals separated from one another by about one-fourth the diameter of PLE (a deformity has removed the PLE far away from the ALE on the right side). Height of elypeus equal to about the radius of AME. 131 External Anatomy of Micrathena Figures 127-132, M. molettta Fig. 127. Dorsal view of body of female. Fig. 128. Posterior end of abdomen from behind. Fig. 129. Eight lateral view of posterolateral corner of abdomen. Figs. 130-132. Epigynum from below, in posterior view, and in profile from right side, respectively. Chelicerae, Maxillae, and Lip. All apparently quite typical of the genus and with details regarded as unnoteworthy. Sternum. A simple scutiform; sternal suture nearly straight; anterolateral tubercles moderately developed, others hardly indi- cated; not continued between fourth coxae which are separated by about one-third of their width. CHICKERING : MICRATHENA IN CENTRAL AMERICA 443 Legs. 4123. Width of first patella at "knee" .22743 mm., tibial index of first leg 11. Width of fourth patella at "knee" .23826 mm., tibial index of fourth leg 13. Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters ) With few spines on legs ; exact number and placement not re- garded as essential for adequate description ; with many seti- gerous tubercles. Abdomen. General form as shown in Figures 127-129. The holotype has eight pairs of spines as shown ; one of the paratypes has the same number but the other has the three small lateral spines on each side represented only by tubercles. Epigymim. Essentially as shown in Figures 130-132. One paratype agrees well with the holotype in this respect but the other does not, perhaps because of immaturity. Color in alcohol. Carapace a reddish brown with lateral sides dusky as indicated by stippling in Figure 127. Sternum a lighter reddish brown. Legs and mouth parts with varying shades of reddish brown. Abdomen : dorsum almost entirely yellowish with small white subchitinous flecks; the numerous "punctures" are reddish brown. Type locality. Holotype female together with two paratype females from Tablazo, Costa Rica. Apparently collected by Prof. Tristan during the early part of the present century and re- ported as M. triserrata F. P. -Cambridge (Banks, 1909). The male is unknown. Micrathena parallela (O. P. -Cambridge) , 1890 (Figures 133-137) Acrosoma parallelum O. P. -Cambridge, 1890 A. parallelum Keyserling, 1892 M. parallela F. P.-Cambridge, 1904 M. parallela Petrunkevitch, 1911 M. parallela Reimoser, 1917 M. parallela Petrunkevitch, 1925 M. parallela Roewer, 1942 M. parallela Bonnet, 1957 444 BULLETIN: MUSEUM OE COMPARATIVE ZOOLOGY The Pickard-Cambridges (1890, 1904) reported this species from Panama and Guatemala. Keyserling (1892) mentions hav- ing numerous specimens from Guatemala. The species has not yet appeared in my collections and my only opportunity to study it came during my period of work in the British Museum (Natu- ral History) in the summer of 1958. The type material now consists of parts of four specimens from which the following facts have been taken. Apparently there are no highly modified femoral spines in this species such as frequently occur in males of the genus ; some variation in respect to tibial spines has been noted among the available specimens but the ventral spines on the first and second tibiae are probably fairly typical (Figs. 134- 135) ; there is some discoloration from long preservation but in 133 External Anatomy of Micrathena Figures 133-137, M. parallela Fig. 133. Dorsal view of body of male. Fig. 134. Ventral spines of first tibia. Fig. 135. Ventral spines of second tibia. Fig. 13G. Palpal tarsus. Fig. 137. Base of palpal tarsus with another view of basal tarsal hook. general the color is a dull reddish brown with carapace lighter in head region and along central region ; abdomen is irregularly CIIICKERING : MICRATHENA IN CENTRAL, AMERICA 445 yellowish through the center and much darker on lateral sides ; the body is much flattened dorsoventrally with lateral sides nearly parallel ; the first coxa has the ventral hook well developed and the second femur is provided with the corresponding groove and ridge ; Figures 136-137 show the most important features of the palpal basal tarsal hook and other parts of the palpal tarsus. The female is unknown. MlCRATHENA PATRUELIS (C. L. Koch), 1839 (Figures 138-145) Acrosoma patruele C. L. Koch, 1839 Plectana patruela Walekenaer, 1841 P. reduviana Walekenaer, 1841 M. reduviana Simon, 1895 M. patruelis F. P. -Cambridge, 1904 M. reduviana F. P. -Cambridge, 1904 A. patruele Banks, 1909 M. patruelis Petrunkevitch, 1911 M. patruelis B-eimoser, 1917 M. patruelis dickering, 1931 .]/. retracta Chambeiiin and Ivie, 1936. New synonymy M. patruelis Boewer, 1942 M. patruelis Bonnet, 1957 It is quite apparent that much confusion concerning this species has existed in the past and I fear it is not yet entirely re- moved. I am quite certain that M. retracta Chamberlin and Ivie is the same as the species regarded as M. patruelis (C. L. Koch), but I am not entirely satisfied that the latter, as now understood, is one species alone. Kraus (1955) has recently identified M. saceata (C. L. Koch), 1836 among his collections from El Salva- dor. It seems to me that this raises the whole question of rela- tionships between these two species and it is my opinion that all available collections of both species should be carefully studied in an endeavor to clarify the whole matter. At present I cannot do better than to consider all specimens which I have had an opportunity to study as belonging to M. patruelis (C. L. Koch) as I have indicated. Female hypotype. Total length 6.305 mm. Carapace only slightly raised behind median thoracic fovea ; lateral margins with numerous setigerous tubercles. Sternum moderately convex; lateral tubercles extending toward intervals between second and third coxae, third and fourth, and both fourth coxae quite 446 BULLETIN: MUSEUM OP COMPARATIVE ZOOLOGY marked. Abdomen with a pair of very short anterolateral tuber- cles where spines so often occur in many species; with a pair of posterolateral spines on each side with the upper one robust and External Anatomy of Micratlwna Figures 138-145, M. patruelis Fig. 138. Dorsal view of body of female. Fig. 139. Abdominal spines at posterolateral corner. Figs. 140-142. Epigynum from below, in posterior view, and profile from right side, respectively. Fig. 143. Dorsal view of body of male. Fig. 144. Palpal tibia and tarsus of male. Fig. 145. Palpal tibia and basal tarsal hook in different view. CHICKERING : MICRATHENA IN CENTRAL AMERICA 447 projecting dorsally and the lower one much smaller and directed posteriorly (Figs. 138-139) ; lateral margins and more dorsal of the abdominal spines with minute denticles. Epigynum as shown in Figures 140-142. Color in alcohol : Carapace and legs with varying shades of brown ; sternum dark brown ; abdomen nearly white above because of subchitinous granules but with dark brown or black margins; venter and lateral sides dark brown with many lighter stripes. Considerable variation has been noted among available specimens in respect to color pattern. General appearance shown in Figure 138. Male hypotype. Total length 3.77 mm. First and second femora with long spines above but only a terminal pair below ; with many setigerous tubercles. First and second tibiae with numerous modified spines. Only one prolateral spine on first and second patellae as compared to two on each as mentioned by F. P. -Cambridge. The usual coxal hook and femoral groove and ridge are present. Palpal features are shown in Figures 144-145.^ Collection records. The species has been reported from Mexico, through Central America and into northern South America. 1 have it for study from several parts of Panama, Honduras, Nicaragua, Costa Rica, and Mexico. The male and female hypo- types are both from Barro Colorado Island, C. Z., August, 1936 and July, 1954, respectively. Micrathena petersi (Taczanowski) , 1872 Aorosoma petersi Taczanowski, 1872 A. petersi Keyserling, 1898 M. petersi F. P. -Cambridge, 1904 M. petersi Petrunkevitch, 1911 M. petersi Reimoser, 1917 M. petersi Banks, 1929 .1/. petersi Roewer, 1942 M. petersi Bonnet, 1957 Taczanowski described this species from Guiana. Keyserling recorded it from Guatemala and described it from an immature female. 1 have many immature specimens of M. sexspinosa (Hahn) which closely resemble Keyserling 's figures and descrip- tion. The specimens identified by Banks (1929) are all immature and, according to my present view, all belong to M. sexspinosa (Hahn). For these reasons I am not regarding M. petersi (Tac- zanowski) as a Central American species. 448 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Micrathena quadriserrata F. P. -Cambridge, 1904 (Figures 146-149) M. quadriserrata Petrunkevitch, 1911 M. quadriserrata Reimoser, 1917 M. quadriserrata Banks, 1929 M. quadriserrata Roewer, 1942 M. quadriserrata Bonnet, 1957 F. P. -Cambridge (1904) had the original specimens from Guatemala; Banks (1929) recorded it from Panama; I have col- lected it in Panama on several occasions. It has been reported from South America but there seems to be some uncertainty about the exactness of the identifications from this part of the world. The male remains unknown as an adult. Female hypotype. Total length 6.37 mm. The carapace is very- gibbous behind the median fovea. The sternum is slightly convex. Abdomen : there is a pair of long anterior spines extending far over the carapace ; two pairs of small lateral marginal spines ; the abdomen is bifurcated posteriorly and each bifurcation is subdivided into four fairly robust spines (Fig. 146). The most important epigynal features are shown in Figures 147-149. The External Anatomy of Micrathena Figures 146-149, M. quadriserrata Fig. 146. Dorsal view of body of female. Figs. 147-149. Epigynum from below, in posterior view, and in profile from right side, respectively. CHICKERING : MICRATHENA IN CENTRAL AMERICA 449 most common color pattern is suggested in Figure 146; the un- stippled areas are white and the stippled areas are black or gray ; numerous specimens show that the color pattern is highly vari- able ; in some the whole dorsum is black. In a specimen in the British Museum (Natural History), collected in Joinville, Brazil, there were a total of nine pairs of spines because of the multipli- cation of small lateral spines to four on each side. The number and placement of spines in Panamian specimens seem to be quite consistent. I have several immature males in my collection which I am, for the present, regarding as the missing males in this species but none is sufficiently mature to warrant description. Collection records. The species has been recorded from both Guatemala and Panama in Central America and from Brazil and Venezuela in South America. I have taken the species repeatedly on Barro Colorado Island, C. Z., at France Field, and at Fort Sheridan, C. Z. MlCRATHENA SACCATA (C. L. Koch), 1836 Acrosoma saccatum C. L. Koch, 1836 Plectana saccata Walckenaer, 1841 M. saccata Simon, 1895 M. saccata Petrunkevitch, 1911 M. saccata Beimoser, 1917 M. saccata Boewer, 1942 M. saccata Kraus, 1955 M. saccata Bonnet, 1957 Until recently this species has been considered exclusively South American in distribution. Kraus (1955) reported it from several localities in El Salvador. Of course, caution is indicated here but it seems probable that the species has been confused with M. patruelis (C. L. Koch) which it very closely resembles and which is probably very common in El Salvador. For these reasons I am not regarding the species as definitely established in Central America. Micrathena sagittata ( Walckenaer ) , 1841 (Figures 150-156) Plectana sagittata Walckenaer, 1841 Epeira spinea Hentz, 1850 Acrosoma bovinum Thorell, 1859 A. bovinum Thorell, 1868 450 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY A. spineum Emerton, 1884 A. spineum McCook, 1893 A. spineum Emerton, 1902 M. sagittata F. P.-Cambridge, 190-4 M. sagittata Petrunkeviteh, 1911 .1/. sagittata Reimoser, 1917 M. sagittata Petrunkeviteh, 1930 M. sagittata Roewer, 1942 M. sagittata Kaston, 1948 M. sagittata Levi, 1954 M. sagittata Bonnet, 1957 This species has been figured and at least partially described many times but the male is not easily separated from that of several other species. M. sagittata is widely distributed through- out the United States, Central America, West Indies, and the northern parts of South America. Female hypotype. Total length 8.45 mm. The cephalic portion of the carapace is prominently raised ; considerably gibbous behind the median fovea. The sternum is quite convex ; with three pairs of lateral tubercles ; the posterior end is strongly tubercular between the bases of the fouith coxae. Abdomen: with a pair of long anterior spines arising from dorsolateral positions (not anterior border) and extending far forward but not closely contiguous to the carapace ; a pair of short lateral, somewhat re- curved spines arise a little behind the middle ; a pair of long- robust posterolateral spines ; each of the latter has a small cusp at its base (often lacking in certain specimens) (Fig. 150). The epigynum is more distinctive than usual ; the free part of the scape appears very different than in most species when viewed in profile (Figs. 151-153). Color in alcohol: dorsum of abdomen largely yellowish with the long spines reddish at bases and black at tips; lateral sides of abdomen with broken stripes of yellow and black ; the cephalothorax is reddish brown with a conspicu- ous whitish yellow margin. Male hypotype. Total length 4.5 mm. The shape of the body seems to vary somewhat among numerous specimens but the shape of the hypotype is shown in Figure 154 and is regarded as fairly typical. The color is dark brown dorsally with obscure whitish spots as indicated by the unstippled areas. Palp : the tibia is provided with two robust spines, a feature not usually shown in descriptions or published figures ; the tarsal hook is rather distinctive (Figs. 155-156). There is no ventral coxal hook on the first coxa and no proximal prolateral groove or CHICKERING : MICRATHENA IN CENTRAL, AMERICA 451 ridge on the second femur (eight males from North Carolina and Colombia examined). Some specimens show the abdominal spines, so conspicuous in females, as plainly suppressed spines in the form of tubercles thus changing the form of the abdomen considerably. This was especially true of the South American forms. 1 5 O 151 External Anatomy of Micrathena Figures 150-156, M. sagittata Fig. 150. Dorsal view of body of female. Figs. 151-153. Epigynum from below, in posterior view, and in profile from right side, respectively. Fig. 154. Dorsal view of body of male. Fig. 155. Left palpal tibia and tarsus. Fig. 156. Left palpal tibia and basal tarsal hook in different, view. Collection records. F. P. -Cambridge had the species from Mexico and Guatemala. Specimens from Mexico and Costa Rica are in the collection in the Museum of Comparative Zoology at Petrunkevitch (1930) has recorded it from Harvard College 452 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Puerto Rico. I found numerous specimens from northern South America in the British Museum (Natural History). It is well known from many parts of the United States. It has not, how- ever, appeared in my Panamanian collections. The male hypo- type is from Balsam Gap, North Carolina, August, 1930; the female hypotype is from Vera Cruz, Medias Aquas, Mexico, with no date of collection given. Micrathena SCHREIBERSI (Perty), 1833 (Figures 157-168) Acrosoma schrcibersi Perty, 1833 A. spinosum C. L. Koch, 1836 Plectana macracantha Walckenaer, 1841 M. schrcibersi Simon, 1895 M. schrcibersi F. P.-Cambridge, 1904 .1/. schrcibersi Petrunkevitch, 1911 M. schrcibersi Beimoser, 1917 A. schreibersi Banks, 1929 M. coleophora Chamberlin and Ivic, 1936. New synonymy. M. schrcibersi Boewer, 1942 M. schrcibersi Bonnet, 1957 This is a well known and strikingly beautiful species charac- teristic of South America but now known to be one of the most common members of the genus in Panama. Banks, apparently, had the male properly identified but he did not report it in his paper (1929). M. coleophora Chamberlin and Ivie is, quite plainly, the male of this species. Female hypotype. Total length, including the posterior abdom- inal spines and the somewhat protruding bases of the chelicerae, 14.3 mm. The size appears to be quite variable as determined from a study of a large number of individuals. There are ten spines on the abdomen (Fig. 157). The head portion is strongly raised and the carapace is moderately swollen behind the median fovea. The sternum is only moderately convex with the anterior border swollen into a low transverse ridge. The epigynum is quite distinctive (Figs. 158-160). The color in alcohol is fairly typical of the species in general ; the legs are a rich dark brown ; the carapace is a similar brown with a yellowish-white margin ; the abdomen is yellowish-white in the middle of the dorsum with nearly black margins ; the anterior spines are white with the second pair nearly black ; the fourth pair is bright red with black tips ; the posterior pair is nearly black. The color pattern, CIIICKERING : MICRATIIENA IN CENTRAL AMERICA 453 External Anatomy of Micrathena Figures 157-160, M. schreibersi Fig 1 . 157. Dorsal view of body of female. Figs. 158-160. Epigynum from below, in posterior view, and in profile (right side and somewhat more enlarged), respectively. however, is highly variable as noted in a large series. One speci- men from Colombia, for example, had bright yellow legs and a very dark body. Male hypotype. Total length 5.395 mm. The shape and gen- eral appearance (Fig. 161) should serve to identify the males of this species without much difficulty. The color is reddish brown with variations. The abdomen is rounded behind and con- stricted near the middle. Ventral spines on the first and second tibiae are shown in Figures 167-168. Palp : the tibia appears to be rather distinctive in shape ; the basal tarsal hook and other im- portant features of the palpal tarsus are shown in Figures 162- 166. There is no ventral hook on the first coxa and no corre- sponding groove and ridge on the second femur. Collection records. The species has been reported from numer- ous localities in South America, Mexico, and Panama. It is probably widely distributed through Central America. It ap- pears to be one of the two most common species of the genus on 454 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Barro Colorado Island, C. Z., but is much less common elsewhere in Panama where I have collected. Both sexes are in my collec- tion from Barro Colorado Island taken from June to August, 1934, 1936, 1939, 1950, 1954 and also in January 1958. I also have it from C. Z. Forest Reserve, 1939: France Field, C. Z., August, 1939 ; Peluca Hydrographic Station, Boqueron River, Panama, July, 1950. External Anatomy of Micrathena Figures 161-168, M. scJireibersi Fig. 161. Dorsal view of body of male. Figs. 162-163. Left palpal tarsus and basal tarsal hook; two different views. Fig. 164. Basal palpal tarsal hook ; seen from distal end of tarsus. Figs. 165-166. Two different views of left palpal patella and tibia. Figs. 167-168. Eight first and second tibiae, respectively, showing spines; seen in ventral view. CHICKERING : MICRATHENA IN CENTRAL AMERICA 455 Micrathena serrata F. P. -Cambridge, 1904 (Figures 169-173) M. serrata Petrunkevitch, 1911 M. serrata Beimoser, 1917 M. serrata Checkering, 1936 .If. serrata Boewer, 1942 M. serrata Bonnet, 1957 This species seems to be very uncommon in collections. I had my first opportunity to study the species carefully during my period of work in the British Museum (Natural History) in the summer of 1958. The species was reported from Barro Colorado Island in my collection of 1934 (1936) but the specimens are not now in the collection and, hence, the correctness of the identifica- tion cannot now be determined. Female hypotype. The following facts are taken from a cotype in the British Museum (Natural History) : Total length from External Anatomy of Micrathena Figures 169-173, H. serrata Fig. 169. Dorsal view of body of female. Fig. 170. Spines at posterolateral corner of abdomen; right side. Figs. 171-173. Epigynum from below, and in posterior view, and in profile from right side, respectively. 456 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY chelicerae to posterior end of abdomen (exclusive of posterior spines) 7.47 mm.; length to tip of posterior spines 8.07 mm. Carapace 2.28 mm. long, 2.08 mm. wide at level of interval be- tween second and third coxae where it is widest. Height of clypeus slightly less than diameter of AME. Carapace consider- ably raised behind conspicuously rounded central fovea ; with three pairs of dorsolateral foveae (Fig. 169). Viewed from in front, anterior row of eyes slightly recurved, posterior row slightly procurved. Chelicerae with four teeth along promargin of fang groove and three along retromargin. Sternum only slightly convex; with posterior end slightly tubercular. Abdo- men: extends forward over the carapace a moderate extent; general form and seven pairs of spines as shown in Figures 169- 170. Features of the epigynum shown in Figures 171-173. The species would seem to be closely related to M. duodecimspinosa (0. P. -Cambridge). The male is unknown. Collection records. The original specimens were all from the highlands of Chiriqui, El Volcan, Panama. I have recently found two specimens in the Banks collection in the Museum of Com- parative Zoology from La Verbena, Costa Rica, (Tristan) which appear to belong to this species. Micrathena sexspinosa (Hahn), 1822 (Figures 174-180) Epeira sexspinosa Hahn, 1822 E. furcata Hahn, 1822 Acrosoma sexspinosa Hahn, 1834 Plectana squamosa Walckenaer, 1841 A. obtusospinosa Keyserling, 1863 Keyserlingia coimigera O. P. -Cambridge, 1890. New synonymy. A. calcaratum O. P.-Cambridge, 1890 A. obtusospinum Keyserling, 1892 A. calcaratum Keyserling, 1892 A. sedes Getaz, 1893 M . sexspinosa Simon, 1895 M. obtusospina F. P.-Cambridge, 1904 M. cornigera F. P.-Cambridge, 1904. New synonymy. M. sedes F. P.-Cambridge, 1904 A. obtusispina Banks, 1909 A. sexspinosa Banks, 1909 M. obtusospinosa Petrunkevitch, 1911 M. sexspinosa Petrunkevitch, 1911 M . sedes Petrunkevitch, 1911 CHICKERING : MICRATIIENA IN CENTRAL AMERICA 457 M. cornigera Petrunkeviteh, 1911. New synonymy. M. cornigera Beimoser, 1917. New synonymy. M. sexspinosa Beimoser, 1917 M. cornigera Petrunkeviteh, 1925. New synonymy. M. obtusispina Banks, 1929 M. cornigera Banks, 1929. New synonymy. M. sexspinosa Petrunkeviteh, 1930 M. cornigera Boewer, 1942 M. sexspinosa Boewer, 1942 M. sexspinosa Kraus, 1955 M. cornigera Bonnet, 1957. New synonymy. It now seems necessary to accept the complicated synonymy the essentials of which are given above but I cannot regard M. forcipata (Thorell) as a synonym for M. sexspinosa (Halm) as Reimoser (1917), Roewer (1942), and Bonnet (1957) have done. The Cuban specimens of M. forcipata (Thorell) are clearly dis- tinct from M. sexspinosa (Ilahn), as I shall try to show in a forthcoming paper. The specimens labelled M. sedes (Getaz) in the Museum of Comparative Zoology are, in my opinion, all immature females of M. sexspinosa (Halm). Immature females have four pairs of abdominal spines and then, with the last moult the pair between the surviving two pairs of dorsolateral spines is often suppressed. Usually remains of these suppressed spines can be found even in fully matured specimens. Banks (1929) concluded that his A. cornigera 0. P. -Cambridge was the male of M. sexspinosa but he did not formally synonymize it with the latter. Other bibliographers have continued to keep the two separate. Now I think we can be certain of the synonymy as I have given it above. Female hypotype. Total length 16.25 mm. The cephalic part of the carapace is strongly raised ; the median fovea is a shallow groove rather than a pit. The sternum is quite convex ; it bears paired tubercles opposite coxae one to three and a posterior tubercle extends between fourth coxae. The femora, especially the first two, are well supplied with setigerous tubercles. The features of the epigynum are shown in Figures 175-177. Abdo- men : with three pairs of well developed spines and with another pair represented by tubercles as shown in Figure 174. Color : The carapace is a rich dark reddish brown with a whitish margin ; dorsal ly the abdomen is a mosaic of whitish spots and streaks intermixed with reddish and black spots and streaks; the inter- mixture is quite variable but rather characteristic of the species. 458 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Male hypotype. Total length 5.59 mm. General form as shown in Figure 178. Color: the dorsal surface is a mahogany brown with light spots and light margin as indicated in the figure. The most distinctive feature appears to be the long curved process belonging to the tarsal hook ; this and other palpal fea- tures are shown in Figures 179-180. The coxal hook and the corresponding femoral ridge and groove are all lacking. External Anatomy of Micrathena Figures 174-180, M. sexspinosa 178 Fig. 174. Body of female; dorsal view. Figs. 175-177. Epigynum from below, in posterior view, and in profile from right side, respectively. Fig. 178. Body of male ; dorsal view. Fig. 179. Palpal tibia and tarsus of male. Fig. 180. Basal tarsal hook. CHICKEBING : MICRATHENA IN CENTRAL AMERICA 459 Collection records. The male and female hypotypes are from Barro Colorado Island, C. Z., July and August, 1954, respec- tively. The species is well known from many localities in Central America, South America, and the West Indies. It appears to be one of the two most abundant species on Barro Colorado Island. Micrathena spinulata F. P. -Cambridge, 1904 (Figures 181-184) If. spinulata Petrunkevitch, 1911 M. spinulata Reimoser, 1917 M. spinulata Roewer, 1942 M. spinulata Bonnet, 1957 This species seems to be extremely rare in collections. Ap- parently it has not been recorded since the original specimens were collected in Mexico and studied by the author of the species. He had only females. During my period of work in the British Museum (Natural History) in the summer of 1958 I found the specimens studied by the author and identified the individual used for F. P. -Cambridge's drawings. This speci- men should be regarded as the lectotype and indicated as such. 181 i 184 External Anatomy of Micrathena Figures 181-184, M. spinulata Fig. 181. Abdomen of female; dorsal view. Figs. 182-184. Epigynum from below, in posterior view, and in profile from right side, respectively. Lectotype. Total length 6.175 mm. Color pattern essentially as given by the author of the species but I have noted consider- able variation in the pattern among the various available speci- mens. The median thoracic fovea is well defined together with 460 BILLETIN: MUSEUM OF COMPARATIVE ZOOLOGY three pairs of dorsolateral foveae. Sternum only slightly con- vex; only slightly raised opposite the coxae. There are six ab- dominal spines but all are hardly more than spinules (Pig. 181). The epigynum is similar to that of M. gracilis (Pigs. 182-18-1). The species is still only known from Mexico and, as far as I have been able to learn, only from the original collections. Micrathena striata F. P. -Cambridge, 1904 (Figures 185-188) M. striata Petrunkeviteh, 1911 M. striata Reimoser, 1917 M. striata Eoewer, 1942 .1/. striata Bonnet, 1957 This is another very rare species in collections. My only op- portunity to study it also came during my period of work in the British Museum (Natural History) in the summer of 1958. It seems highly probable that I was able to identify the specimen 185 External Anatomy of Micrathena Figures 185-188, M. striata Fig. 185. Abdomen of female; dorsal view. Figs. 186-188. Epigynum from below, in posterior view, and in profile from right side, respectively. CHICKERING : MICRATHENA IN CENTRAL AMERICA 461 which the author of the species used as a basis for his description and I have indicated that this should be designated the lectotype. Numerous specimens from Guatemala are available for study. The total length is about 8 mm. The carapace has a well defined central fovea but no dorsolateral foveae. The sternum is essen- tially like that of M. spinulata. The abdominal spines and gen- eral form of the abdomen are shown in Figure 185. The essen- tial features of the epigynum are shown in Figures 186-188. The color of the abdomen is yellow with a series of narrow black lateral lines. The species is apparently known only from Guate- mala and only from the female. MlCRATHENA SUBFLAVA Sp. nOV. (Figures 189-193) Female kolotype. Total length from AME to posterior border of abdomen 8.515 mm. Carapace considerably overlapped by abdomen; about 2.925 mm. long; 2.405 mm. wide opposite inter- val between second and third coxae where it is widest ; strongly gibbous just behind the well defined median fovea ; without well defined dorsolateral foveae. Eyes. Eight in two rows as usual ; viewed from above, both rows moderately recurved ; viewed from in front, anterior row gently recurved, posterior row gently procurved, all measured by centers. Central ocular quadrangle slightly wider behind than in front, slightly wider behind than long. Ratio of eyes AME : ALE : PME : PLE = 10 : 8.5 : 12 : 8. AME separated from one another by four-fifths of their diameter, from ALE by four times their diameter. PME separated from one another by five-sixths of their diameter, from PLE by ten-thirds of their diameter. Height of clypeus equal to three-fifths of the diameter of AME. Chelicerae. Robust, quite gibbous in front; typical of females in the genus. With a well defined fang groove having four teeth along the promargin and three along the retromargin (some variation noted between right and left sides). Maxillae and Lip. Quite typical of the genus ; details regarded as uimoteworthy for adequate description of the species. Sternum. Moderately convex; with seven tubercles as com- monly occur in the genus ; continued between fourth coxae which are separated by about three-fourths of their width. 462 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Legs. 4123. Width of first patella at "knee" .29241 mm., tibial index of first leg 10. Width of fourth patella at "knee" .30324 mm., tibial index of fourth leg 12. Femora Patellae Tibiae Metatarsi (All measurements in millimeters) Tarsi Totals With many setigerous tubercles on legs but only a few spines with details of spination regarded as unnoteworthy. 193 External Anatomy of Alicrathena Figures 189-193, M. subflava Fig. 189. Body of female; dorsal view. Fig. 190. Spines at posterolateral angle of abdomen; lateral view. Figs. 191-193. Epigynum from below, in posterior view, and in profile from right side, respectively. CHICKEBING : MICRATHENA IN CENTRAL AMERICA 463 Abdomen. General features as shown in Figures 189-190. Con- siderably flattened dorsoventrally ; only slightly concave in mid- dle of posterior dorsal region ; with nine pairs of short spines as figured but the first pair of lateral marginal spines is often reduced to blunt tubercles in paratypes. A prominent tubercle or short robust spine lies on each side of the chitinous cone sur- rounding the spinnerets. Epigynum. The general characteristics of this organ are shown in Figures 191-193. Color in alcohol. Legs, in general, a dull brown with some variations; sternum a dusky yellow; carapace yellowish with fine brownish dots. Abdomen: main part of dorsum yellowish with variations ; irregularly black along the lateral margins and posterior border; lateral sides with narrow broken black stripes alternating with yellowish stripes; region of epigynum and cone around spinnerets reddish brown. Type locality. Ilolotype female from Barro Colorado Island, C. Z., August, 1950. Several paratype females from the same locality: June, 1934; June-August, 1936; June, 1939; July- August, 1954. The male is unknown. Micrathena subspinosa F. P. -Cambridge, 1904 (Figures 194-197) M. subspi7iosa Petrunkevitch, 1911 M. subspinosa Reimoser, 1917 M. subspinosa Roewer, 1942 M. subspinosa Bonnet, 1957 The correct treatment of this species is not at all clear. 1 have wavered between the decision to regard it as a variant of M. duodccimspinosa (0. P. -Cambridge) and retaining it as a valid species and have finally decided on the latter course, at least for the present, i had an opportunity to study the type in the British Museum (Natural History). The author of the species gave the important features very briefly as follows : "almost precisely similar to M. 12-spinosa in general character, but the third, lower cusp on the posterior bifid spur is remote from the two main cusps in the middle of the spur behind, and thus becomes trifid. The posterior margin of the vulva, though pre- senting a minute median angle, has not a tongue-like prominence which is noticeable in 71/. 12-spinosa." Color: "similar to that of M. 12-spinosa, the posterior spurs dark brown, apically black." 464 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY The length is about 6 mm. Figure 194 is intended to show rela- tionships among the spines at the posterolateral angle of the abdomen. Figures 195-197 are intended to show the chief fea- tures of the epigynum. Known only from Guatemala and only from the female. External Anatomy of Micrathena Figures 194-197, M. subspinosa Fig. 194. Spines at posterolateral angle of abdomen ; lateral view. Figs. 195-197. Epigynum from below, in posterior view, and in profile from right side, respectively. Micrathena trapa (Getaz), 1891 Acrosoma trapa Getaz, 1891 M. trapa F. P.-Cambridge, 1904 M. trapa Petrunkevitch, 1911 AI. trapa Eeimoser, 1917 M. trapa Eoewer, 1942 M. trapa Bonnet, 1957 F. P.-Cambridge (1904) did not include any description of this species and did not include it in his keys. The brief de- scription given by Reimoser (1917) was copied from the state- ment given by the author of the species and gives little basis for its recognition. It seems probable that the species exists among others which are better known and well described. The male is unknown. I have been obliged to omit the species from further consideration in this paper. Micrathena triserrata F. P.-Cambridge, 1904 (Figures 198-201) Acrosoma triserrata Banks, 1909 M . triserrata Petrunkevitch, 1911 M. triserrata Eeimoser, 1917 CHICKERING : MICRATIIENA IN CENTRAL AMERICA 465 M. triserrata Koewer, 1942 .1/. triserrata Bonnet, 1957 Specimens in the Pickard-Cambridge collection from Guate- mala and Costa Rica have been studied and a lectotype selected. The following facts are taken from the lectotype in the British Museum (Natural History) : Total length from AME to pos- terior end of the triserrated abdominal fork 8.13 mm. Carapace with a well defined central fovea behind which is a marked gib- bosity ; there are also three pairs of dorsolateral foveae ; the head is considerably raised and separated from the thoracic part by diagonal grooves. The sternum is only slightly convex and somewhat granulose. In addition to the abdominal spines shown in F. P. -Cambridge's figures and named in bis description is, apparently, a small lateral marginal spine at base of the fork on each side (Pig. 198), but it appears to be somewhat variable. External Anatomy of Micrathena Figures 198-201, M. triserrata Fig. 198. Abdomen of female; dorsal view. Figs. 199-201. Epigynum from below, in posterior view, and in profile from right side, respectively. On the lectotype this small spine is unilateral (possibly lost in handling), barely represented in one paratype, and lacking on the third specimen. Features of the epigynum are shown in Figures 199-201. The male is unknown. The species is known only from Guatemala and Costa Rica. 460 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Micrathena uncata F. P. -Cambridge, 1904 (Figures 202-205) .)/. uncata Petruiikevitch, 1911 M. uncata Reimoser, 1917 M. uncata Roewer, 1942 M. uncata Bonnet, 1957 This is another species which appears in collections only very rarely. Apparently it has not been reported until the present time since its first appearance in the collections studied by F. P.- Cambridge (1904). I appear to have two specimens which belong here. Only males are known. Male hypotype. Total length 4.5 mm. The general appearance (Fig. 202) is similar to that of 31. parallela (O. P. -Cambridge). The first two pairs of tibiae do not have the modified short ventral spines recorded by F. P. -Cambridge ; the first pair of femora has a series of ventral and prolateral spines probably modified for clasping (Fig. 203) ; the second pair of femora seems to be devoid of these ; the ventral hook is lacking on the first coxa and the corresponding ridge and groove on the second femur are also lacking. The main features of the palpal tarsus are shown in Figures 201-205. Color: Carapace with a broad, median, light brownish stripe and a broad brown stripe on each side (Fig. 202) ; the abdomen is light yellowish dorsally and with numerous irregular white flecks and small indications of black spots at anterior and posterolateral corners. Collection records. F. P. -Cambridge had this species only from Guatemala. The hypotype and one other specimen are from Barro Colorado Island, C. Z., August, 1939. Micrathena vitiosa (O. P. -Cambridge, 1890) (Figures 206-210) Acrosoma vitiosum O. P. -Cambridge, 1890 A. vitiosum Keyserling, 1892 .1/. vitiosa F. P.-Cambridge, 1904 .1/. vitiosa Petruiikevitch, 1911 M. vitiosa Reimoser, 1917 M. vitiosa Roewer, 1942 .1/. vitiosa Bonnet, 1957 While working in the British Museum (Natural History) in the summer of 1958 I had my only opportunity to study this CHICKERING : MICRATIIENA IN CENTRAL AMERICA 467 20 203 210 External Anatomy of Miorathena Figures 202-205, M. uncata Figures 206-210, M. vitiosa Fig. 202. Dorsal view of body of male. Fig. 203. Left first femur; ventral and prolateral spines. Fig. 204. Left palpal tarsus. Fig. 205. Another view of basal tarsal hook. Fig. 206. Dorsal view of body of male (from O. P.-C). Figs. 207-208. First and second femora, respectively; ventral views. Figs. 209-210. Eight palpal patella, tibia, and tarsus; 209 especially to show form of basal tarsal hook. species. I found two specimens in the Cambridge collection and one of these should be selected as the lectotype. The Pickard- Cambridges had the species from Panama and Keyserling 468 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY (1892) reported it from Guatemala but I did not find these specimens in the Keyserling collection. The total length is about 4.5 mm. The general form of the body is shown in Figure 206. The first and second tibiae appeared to be spined in what may be termed the usual manner. The first and second femora, however, seemed to have special ventral spines as shown in Figures 207-208. The third femur also has a row of spur-like ventral spines. The most important features of the palp are shown in Figures 209-210. The tarsal hook is particularly distinc- tive. There is no ventral hook on the first coxa nor any ridge or groove on the second femur. The female is completely unknown. Micrathena zilchi Kraus, 1955 (Figures 211-213) The holotype and several mature paratypes as well as several more immature specimens were reported by Dr. Kraus in 1955 from El Salvador. I know of no mature specimens of this species in American collections. I have one immature female from Hon- duras which I am tentatively assigning to this species. Only females are known. Some of the distinctive features of the species, taken directly from the original description, may be 21 1 213 2 12 External Anatomy of Micrathena Figures 211-213, M. zilchi Fig. 211. Dorsal new of abdomen of female. Figs. 212-213. Epigynum from below and in profile, respectively. CIIICKERING : MICRATHENA IN CENTRAL AMERICA 469 given as follows : Total length 14 mm. ; central ocular quadrangle almost square ; PME larger than AME ; general shape of abdo- men and spination as shown in Figure 211; the epigynum ap- pears as shown in Figures 212-213 ; the color of the abdomen is bright, reddish yellow. The author of the species regards it as closely related to M. xanthcpyga Simon, 1895 from Venezuela. The accompanying figures have been copied directly from those furnished with the original description. SELECTED BIBLIOGRAPHY Banks, Nathan 1898. Arachnida from Baja California and other parts of Mexico. Proc. California Acad., Sci., Ser. 3, Zoology, 1(7): 205-309, 5 pis. 1909. Arachnida from Costa Rica. Proc. Acad. Nat. Sci. Philadelphia, April, 1909: 194-234. 1929. Spiders from Panama. Bull. Mus. Comp. Zool., 69: 53-96, 4 pis. Bonnet, Pierre 1957. Bibliographia Araneorum. 2. 3me partie. Toulouse: Les Artisans de l'Imprimerie Douladoure. Bryant, Elizabeth B. 1940. Cuban spiders in the Museum of Comparative Zoology. Bull. Mus. Comp. Zool., 86(7): 249-532, 22 pis. Cambridge, O. P.- and F. P.-Cambridge 1889- Arachnida- Araneida. In: Biologia Centrali- Americana. Dulau 1905 & Co., London. Chamberlin, R. V. and Wilton Ivie 1936. New spiders from Mexico and Panama. Bull. Univ. Utah, 27: No. 5, Biol, series, 3. No. 5:3-103, 17 pis. Chickering, Arthur M. 1931. Notes and studies on Arachnida. I. Araneae from the Lancetilla Valley, Honduras, I. Pap. Michigan Acad. Sci. Arts Letters, 13: 249-252. 1960. Six new species of Micrathena (Araneae, Argiopidae) from South America with notes on known species. Proc. Zool. Soc. London, 135(1) : 1-25, 78 figs. Keyserling, Graf E. von 1863. Beschreibung neuer und wenig bekannter Arten aus der Familie Orbitelae. Verh. Zool. Bot, Ges. Wien, 15: 799-856, pis. 18-21. 1892. Die Spinnen Amerikas. 4. Epeiridae. Niirnberg. Baur & Raspe. Kraus, Otto 1955. Spinnen aus El Salvador (Arachnoidea, Araneae). Abhand. Senckenberg. Naturf orsch. Ges., 493 : 1-112, 12 pis. 4-70 bulletin: museum of comparative zoology Petrunkevitch, Alexander 1911. A synonymic index-catalogue of spiders of North, Central, and South America, etc. Bull. Amer. Mus. Nat. Hist., 29: 1-809. 192.i. Arachnida from Panama. Trans. Conn. Acad. Arts Sci., 27: 51-248. 1930. The spiders of Porto Rico. Pt. 2. Trans. Conn. Acad. Arts Sci., 30: 159-355, 240 figs. Reimoser, Eduard 1917. Die Spinnengattung Micrathena Sundevall. Verh. zool.-bot. Ges. Wien, 67(%): 73-160. Roewer, C. F. 1942. Katalog der Araneae. Vol. 1. Bremen. Simon, Eugene 1892- Histoire Naturelle des Araignees. Deuxieme Edition. 2 Vols. 1903. Librarie Encyclopedique de Roret, Paris.