North American Water^Mites INTRODUCTION Fewer than fifty species of water-mites were known from North America in 1900. Now more than two hundred and seventy species are known, largely through the work of Dr. Ruth Marshall. During her forty years' study of the group Miss Marshall amassed a collec- tion containing abundant material of nearly every species known from this continent. In addition to the type material of her own species, the Marshall Collection contains most of the Wolcott types, paratypes from Lavers, and a few types of species described from North America by Lundblad, Koenike, and Karl Viets. This col- lection was deposited in Chicago Natural History Museum in 1945. A listing of the types in the Marshall Collection was started and, as the work progressed, it was apparent that with a little expansion a full listing of the North American water-mites could be prepared. The species represented by type material in the Marshall Collection are indicated by the designation "[Marshall Collection]" following the citation. A detailed listing of the types is not possible at present for two reasons. Types of the first few species described by Miss Marshall were destroyed in a fire and subsequent neotype selections have not been published. In most of the descriptions, the type series was not clearly indicated and a formal designation of the holo- type was not made. Further clarification of the type material should be undertaken through revisionary studies. The synonymies in the check list represent, as far as is possible to ascertain, the views of Miss Marshall as expressed in her papers, and, in a few cases, in her notes. Subgenera were rarely indicated by her, hence they can be listed in only a few cases. Furthermore, most authors have defined the subgenera in the course of limited faunistic studies, with the result that general usage of subgenera is difficult. Also, the understanding of the Nearctic fauna is so limited that the use of subgenera is not particularly helpful in most cases. The subgenera of Hydrachna and Arrenurus are obvious exceptions. It is suggested (Lundblad, 1944) that intergradation between the subgenera Truncaturus, Megaluracarus, and Micruracarus of the 29 30 FIELDIANA: ZOOLOGY, VOLUME 35 genus Arrenurus is a basis for suppressing the use of these categories. The definition of the subgenera is, in respect to the few marginal forms, clearly arbitrary. Regardless of the decision in this matter, it is obvious that each of the subgenera indicates a phyletic line and is of great practical value in breaking up a genus of tremendous size. In a few cases there is uncertainty about the selection of genero- types, a question on which I do not feel qualified to pass judgment. Current usage by European workers has been followed in these cases. Viets (1949) gives a full discussion of the two major name changes affecting the species considered here. Atractides must be applied in place of Megapus and the species that have been included in Atractides must be referred to under the name Torrenticola. This unfortunate change calls for changing the family name Atractideidae to Torrenticolidae. The genus Acercus must now be referred to under the name Tiphys. Families of water-mites have been defined entirely by European investigators. The system adopted today was outlined in the papers of Thor, but it has been modified and developed through the re- search of Viets and Lundblad. Lundblad's classification (1941b) has been followed here because it is the most recent complete listing of the genera. It differs only slightly from that of Karl Viets (1936). The forty families of water-mites, although closely related, cannot be assigned to an inclusive taxonomic category. Many authors have chosen to cite Hydrachnellae or Hydracarina (Latinized names for water-mites) in the same fashion as a taxonomic category. Since there is general agreement that the group is an ecological and not a phyletic one, such a practice seems illogical and misleading. The various systems for grouping the water-mites with the prostigmatid mites suffer from the lack of any critical information on the internal and skeletal anatomy. I am aware that much critical study is necessary to clarify the status of many of the groups listed below. Furthermore, many genera known to occur in North America are not yet recorded in the literature. Considering these matters, this check list is offered only as a summary of our published knowledge of the North Ameri- can water-mites. The preparation of this list has been greatly facilitated by the kind consideration and helpful criticism of Rupert L. Wenzel and Henry S. Dybas. I am indebted to David R. Cook for his help in reviewing and checking the list. MITCHELL: NORTH AMERICAN WATER-MITES 31 HISTORY Before the latter part of the nineteenth century there were only a few publications on our water-mite fauna, all inadequate. The first usable paper, published by Koenike in 1895, gave identifications and descriptions of a surprisingly good collection of water-mites made by J. B. Tyrrell. Around the turn of the century Robert H. Wolcott published a few papers. His key to the genera of the world (1905) was later abridged and included in Fresh-Water Biology (1918). The classification suggested in this work is very much out of date due to the subsequent work of various European students. Between the years 1903 and 1946 Ruth Marshall published forty-one papers. Most of these papers deal with the still-water fauna of the mid-western states. Marshall's descriptions and illus- trations form a workable basis for the identification of our water- mites, but it is regrettable that the results of these studies have never been assembled in the form of larger monographs or revisions. Two other significant papers have been published: a revision of the genus Hydrachna by Lundblad (1934), and an article by Lavers (1945) on the Arrenurus of the state of Washington. Only a few brief descriptive papers on the North American water-mite fauna have appeared since 1900. Baker and Wharton (1952) have presented a key to, and synopses of, the water-mite families of the world. There are a few inconsist- encies in the presentation, because the key, translated from Karl Viets (1936), has not been modified to conform with the classification followed in the family synopses, which were taken from Vitzthum (1940-43). The most recent publication in this country is that of Pennak (1953), whose key (apparently taken from Wolcott, 1918) is preceded by an account of the biology of water-mites that is remarkably well done, considering the limitations of space. Omissions make the key of little value to the specialist, but probably serve to make the account a comprehensible and reasonably accurate introduction for the non-specialist who deals chiefly with the common genera. GENERAL WORKS None of the keys published in this country (Wolcott, 1905 and 1918; Pennak, 1953) are sufficiently complete for advanced studies of water-mites. Because of the uniformity, at least in generic representation, of the Holarctic fauna the excellent monographs on 32 FIELDIANA: ZOOLOGY, VOLUME 35 the European fauna (Viets, 1936; Motas, 1928; and Lundblad, 1927) are indispensable basic references for any advanced work on the North American water-mite fauna. The volumes published by the Ray Society (Soar and Williamson, 1925-29), though lacking in some critical detail, are frequently helpful in supplying general information. One meets with considerable difficulty in working with the mites that occur in our streams. Most of the genera are little known and many are not Holarctic; therefore, there is no single work that can be used for identifying these forms. Attention should be called to certain works as sources of special information. The remarkable morphological diversity of water- mites is clearly demonstrated in the work of Motas (1928). Since 1928, Motas and his associates have done a creditable job of de- scribing the subterranean fauna of the Balkans. Most of the work is summarized by Szalay (1949), although Motas' continued re- searches have added more forms since that summary. In addition to the fine treatments on the European fauna mentioned earlier, there are two other important faunistic studies, Karl Viets' study of the water-mites of Sumatra, Java, and Bali (1935) and the work of Lundblad (1941-44) on the South American fauna, which is a magnificently illustrated monograph. The extensive work on the African fauna has been reviewed and listed by Karl Viets (1953). Family HYDROVOLZIIDAE Thor Hydrovolziidae Thor, 1905, Zool. Anz., 28: 509. Genus Hydrovolzia Thor Generotype: Polyxo placophora Monti. Hydrovolzia Thor, 1905, op. cit., pp. 506-507. gerhardi Mitchell, 1954, Chicago Acad. Sci. Nat. Hist. Misc., no. 134, pp. 3-6, figs. 1-3. [C.N.H.M. Collection] Pplacophora Monti, 1905, Rend. 1st. Lomb. Sci. Lett., (2), 38: 170-174, pi. 1, fig. 1, pi. 2, figs. 2-14. Family HYDRACHNIDAE Leach Hydrachnides Leach, 1815, Trans. Linn. Soc. London, 11: 399-400. Genus Hydrachna Muller Generotype: Hydrachna cruenta Muller. Hydrachna Muller, 1776, Zool. Danicae Prodromus, p. 188. MITCHELL: NORTH AMERICAN WATER-MITES 33 Subgenus Hydrachna 8. str. cruenta Miiller, 1776, Zool. Danicae Prodromus, p. 190. americana Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, p. 63, pi. 3, figs. 25-27. [Marshall Collection] var. diminuata Lundblad, 1934, Ark. Zool., 28A, (3), p. 10, figs. 4a-4d. magniscutata Marshall, 1927, Trans. Amer. Micros. Soc., 46: 271-272, pi. 7, figs. 8-11. [Marshall Collection) var. reducta Lundblad, 1934, Ark. Zool., 28A, (3), pp. 13-14, figs. 6a-6e, pi. 1, fig. 8, pi. 2, fig. 16. var. separata Lundblad, 1934, op. cit., p. 15, figs. 5e-5h, pi. 1, fig. 5, pi. 2, fig. 15. Subgenus Scutohydrachna Viets Generotype: Hydrachna dorso&cutaia Viets, 1933, Zool. Anz., 103: 162-164, figs. 1-3. Scutohydrachna Viets, 1933, Zool. Anz., 103: 162. Chitohydrachna Habeeb, 1950, Natural. Canad., 77: 116. crenulata Marshall, 1930, Trans. Wis. Acad. Sci., 25: 247, pi. 5, figs. 6-7. [Mar- shall Collection] ?ennishonensis Habeeb, 1950, Natural. Canad., 77: 116-117, figs. 7-11. [C.N.H.M. Collection] hutchinsoni Lundblad, 1934, Ark. Zool., 28A, (3), pp. 20-21, figs. lOa-lOe. rotunda Marshall, 1930, Trans. Wis. Acad. Sci., 25: 246-247, pi. 5, figs. 4-5. [Marshall Collection] Subgenus Diplohydrachna Thor Generotype: Acarus globosa Geer, 1778, Mem. hist, ins., 7: 146-147, pi. 9, figs. 11-12. Diplohydrachna Thor, 1916, Rev. Ruisse Ent., 16: 46-47. conjecta Koenike, 1895, Rev. biol. nord. Fr., 7: pp. 145-146, pi. 8, figs. 9-11. i microscutata Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, p. 65, pi. 3, figs. 28-30. [Marshall Collection] hungerfordi Lundblad, 1934, Ark. Zool., 28A, (3), pp. 23-25, figs. 13a-13/ f 18-19. Subgenus Tetrahydrachna Lundblad Generotype: Hydrachna miliaria Berlese. Tetrahydrachna Lundblad, 1934, Ark. Zool., 28A, (3), p. 30. miliaria Berlese, 1888, Bull. Soc. Ent. Ital., 20: 219. I bilunata Marshall, 1931, Trans. Wis. Acad. Sci., 26: 314, pi. 8, figs. 26-27. [Marshall Collection] Subgenus Rhabdohydrachna Viets Generotype: Hydrachna comosa Koenike, 1896, Zool. Anz., 19: 359-360. Rhabdohydrachna Viets, 1931, op. cit., 93: 184. 34 FIELDIANA: ZOOLOGY, VOLUME 35 canadensis Marshall, 1929, (female only), Univ. Toronto Stud., Biol. Ser., no. 33, pp. 63-64, pi. 3, figs. 21, 22, 24. [Marshall Collection] geographies Miiller, 1776, Zool. Danicae Prodromus, p. 190 (Palearctic). form americana Lundblad, 1934, Ark. Zool., 28A, (3), pp. 30-32, figs. 16o-16. hesperia Lundblad, 1934, Ark. Zool., 28A, (3), pp. 38-41, figs. 21a-21d, pi. 2, fig. 13. marshallae Lundblad, 1934, op. cit., pp. 34-35, 18a-18/. [Marshall Collection] canadensis Marshall, 1929, (male only), Univ. Toronto Stud., Biol. Ser., no. 33, pp. 63-64, pi. 3, figs. 20, 23. [Marshall Collection] stipata Lundblad, 1934, Ark. Zool., 28A, (3), pp. 35-38, figs. 19a-19ff, figs. 20a- 20c, pi. 2, figs. 9-11. Family LIMNOCHARIDAE Kramer Limnocharidae Kramer, 1877, Arch. Naturg., 43, (Bd. 1), pp. 242-244. Genus Limnochares Latreille Generotype: Acarus aquaticus Linnaeus. Limnochares Latreille, 1796, Precis des caracteres des insectes, p. 181. Subgenus Limnochares s. str. aquatica Linnaeus, 1758, Syst. nat., p. 617. Subgenus Cyclothrix Wolcott Generotype: Limnochares crinita Koenike, 1899, Abh. Senckenb. naturf. Ges., 21: 313-318, pi. 21, figs. 23-29. Cyclothrix Wolcott, 1905, Trans. Amer. Micros. Soc., 26: 185. americana Lundblad, 1941, Zool. Anz., 133: 155. natans Lavers, 1941, Univ. Wash. Pub., Biology, 12: 3-6, pi. 1, figs. 1-3. ?acadiensis Habeeb, 1950, Natural. Canad., 77: 114, 116, figs. 1-3. [C.N.H.M. Collection] Family EYLAIDAE Leach Eylaides Leach, 1815, Trans. Linn. Soc. London, 11 : 399. Genus Eylais Latreille Generotype: Hydrachna extendens Muller, 1776, Zool. Danicae Prodromus, p. 190. Eylais Latreille, 1796, Precis des caracteres des insectes, pp. 182-183. abitibiensis Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, pp. 60-62, pi. 1, figs. 1-4. [Marshall Collection] extendens Muller, 1776, Zool. Danicae Prodromus, p. 190. bakeri Marshall, 1946, Trans. Wis. Acad. Sci., 36: 357, pi. 4, figs. 37-38. [Marshall Collection] MITCHELL: NORTH AMERICAN WATER-MITES 35 desecta Koenike, 1897, Abh. naturw. Ver. Bremen, 14: 288-289. falcata Koenike, 1897, op. cit., p. 288. gibberipons Viets, 1910, op. cit., 20: 171-173, figs. 5-6. hirsutipalpis Marshall, 1946, Trans. Wis. Acad. Sci., 36: 357-358, pi. 4, figs. 42-43. [Marshall Collection] infundibulifera Koenike, 1897, Abh. naturw. Ver. Bremen, 14: 284-285. marshallae Koenike, 1912, Trans. Royal Canad. Inst., 9: 286-288, pi. 1, figs. 8-11, pi. 2, fig. 10. rimosa Piersig, 1899, Zool. Anz., 22: 65-66, fig. 6. triangulifera Koenike, 1897, Abh. naturw. Ver. Bremen, 14: 289-290. Infundibulata Lundblad, 1941, Zool. Anz., 133: 155. robust a Marshall, 1946, Trans. Wis. Acad. Sci., 36: 358, pi. 4, figs. 44-46. [Mar- shall Collection] Family PROTZIIDAE Viets Protziidae Viets, 1926, Zool. Anz., 69: 196. Genus Calonyx Walter Generotype: Partnunia lauta Walter, 1906, Zool. Anz., 30: 571-572. Calonyx Walter, 1907, op. cit., 31 : 298. Protzia Marshall, 1931, Trans. Wis. Acad. Sci., 26: 312-313. Sporadoporus Wolcott, 1905, Trans. Amer. Micros. Soc., 26: 191. ions tans Marshall, 1943, op. cit., 62: 323, pi. 4, figs. 30-34. [Marshall Collection] ovata Marshall, 1931, Trans. Wis. Acad. Sci., 26: 312-313, pi. 7, figs. 9-12. [Marshall Collection] Genus Partnuniella Viets Generotype: Partnuniella thermalis Viets. Partnuniella Viets, 1938, Verhandl. Int. Verein. Limnol., 8, (Tome 3), p. 214. thermalis Viets, 1938, op. cit., pp. 215-219, figs. 1-5. [Marshall Collection] var. paucipora Viets, 1938, op. cit., p. 219, figs. 6-7. [Marshall Collection] Family CLATHROSPERCHONIDAE Lundblad Clathrosperchonidae Lundblad, 1936, Zool. Anz., 115: 30. Genus Clathrosperchon Lundblad Generotype: Clathrosperchon crassipalpis Lundblad, 1936, op. cit., p. 30. Clathrosperchon Lundblad, 1936, op. cit., p. 30. americanus Habeeb, 1953, Leafl. Acad. Biol., no. 1, p. 1, figs. 1-5. 36 FIELDIANA: ZOOLOGY, VOLUME 35 Family HYDRYPHANTIDAE Thor Hydryphantidae Thor, 1900, Nyt. mag. naturvid., 38: 263. Genus Hydryphantes Koch Generotype: Acarus ruber Geer. Hydryphantes Koch, 1842, Ubers. Arachnidensystems, 3: 30. multiporus Marshall, 1930, Trans. Wis. Acad. Sci., 25: 247-248, pi. 5, figs. 1-3. [Marshall Collection] ruber Geer, 1776, Mem. hist, ins., 7: 141-146, pi. 9, figs. 3-9. novatus Viets, 1949, Abh. naturw. Ver. Bremen, 32: 311. novus Viets, 1939, Arch. Hydrobiol., 36: 75. var. mozleyi Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, pp. 68-69, pi. 2, figs. 12-13. [Marshall Collection] tenuabilis Marshall, 1926, Univ. Iowa Stud. Nat. Hist., 11: 33, pi. 2, fig. 9, pi. 3, figs. 16-18. [Marshall Collection] Genus Thyas Koch Generotype: Thyas venusta Koch, 1836, Deutschl. Crust., Myr., Arachn., Heft 5, no. 18. Thyas Koch, 1836, op. cit. stolli Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 194-196, pi. 2, figs. 29-32. [Marshall Collection] Genus Marshallothyas Cook Generotype: Marshallothyas asopos Cook, 1953, Proc. Ent. Soc. Wash., 55: 306, figs. 1-10. Marshallothyas Cook, 1953, op. cit., p. 305. asopos Cook, 1953, op. cit., p. 306, figs. 1-10. [C.N.H.M. Collection] Genus Panisus Koenike Generotype: Panisus michaeli Koenike, 1896, Zool. Anz., 19: 356-357. Panisus Koenike, 1896, op. cit., p. 356. cataphracta Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 196-198, pi. 2, figs. 33-35. Genus Lundbladia Viets Generotype: Lundbladia feuerborni Viets, 1929, Zool. Anz., 86: 50-52. Lundbladia Viets, 1929, op. cit., pp. 49-50. muscicola Mitchell, 1953, Amer. Midi. Nat., 49: 162-165, 15 figs. [C.N.H.M. Collection] Genus Panisopsis Viets Generotype: Thyas vigilans Piersig, 1896, Zool. Anz., 19: 441. Panisopsis Viets, 1926, op. cit., 66: 147. pedunculata Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 192-194, pi. 1, figs. 24-28. [Marshall Collection] MITCHELL: NORTH AMERICAN WATER-MITES 37 Family THERMACARIDAE Sokolow Thermacaridae Sokolow, 1927, Zool. Anz., 73: 20. Genus Thertnacarus Sokolow Generotype: Thermacarus thermobius Sokolow, op. cit., pp. 11-20, figs. 1-13. Thermacarus Sokolow, 1927, op. cit., pp. 11-20. nevadensis Marshall, 1928, Psyche, 35: 93-95, pi. 3, figs. 1-9. [Marshall Col- lection] Family HYDRODROMIDAE Viets Hydrodromidae Viets, 1936, Tierwelt Deutschlands, Teil 31-32, pp. 139-140. Diplodontidae Lundblad, 1927, Zool. bidrag Uppsala, 11: 408. Genus Hydrodroma Koch Generotype: Hydrachna despiciens Miiller. Hydrodroma Koch, 1842, Ubers. Arachnidensystems, 3: 32. Diplodontus auct. (nee Dugs). americanus Marshall, 1926, Univ. Iowa Stud. Nat. Hist., 11: 33, pi. 1, fig. 4, pi. 2, fig. 8, pi. 3, figs. 13-15. [Marshall Collection] despiciens Mviller, 1776, Zool. Danicae Prodromus, p. 190. Family PSEUDOHYDRYPHANTIDAE Viets Pseudohydryphantidae Viets, 1926, Zool. Anz., 69: 196. Genus Pseudohydryphantes Viets Generotype: Pseudohydryphantes parvulus Viets, 1907, Abh. naturw. Ver. Bremen, 19: 142-145, figs. 1-4. Pseudohydryphantes Viets, 1907, op. cit., p. 142. la ti pal pus Marshall, 1924, Trans. Amer. Micros. Soc., 43: 245-246, pi. 14, figs. 44-45. [Marshall Collection] orbicularis Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, pp. 67-68, pi. 4, figs. 36-38. [Marshall Collection] Family TEUTONIIDAE Lundblad Teutoniidae Lundblad, 1927, Zool. bidrag Uppsala, 11 : 409-410. Genus Teutonia Koenike Generotype: HygrobatescometesKoch, 1837, Deutschl. Crust., Myr., Arachn., Heft 10, no. 23. Teutonia Koenike, 1889, Zool. Anz., 12: 104. lunata Marshall, 1924, Trans. Amer. Micros. Soc., 43: 245, pi. 14, figs. 48-50. [Marshall Collection] 38 FIELDIANA: ZOOLOGY, VOLUME 35 Family SPERCHONIDAE Thor Sperchonidae Thor, 1900, Nyt. mag. naturvid., 38: 264. Genus Sperchonopsis Piersig Generotype: Sperchon verrucosus Protz. Sperchonopsis Piersig, 1897, Sitzungs. naturf. Ges. Leipzig, 22-23: 52. Pseudosperchon Marshall, 1933, Trans. Amer. Micros. Soc., 52: 37. ovalis Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, pp. 66-67, pi. 4, figs. 31-33. [Marshall Collection] verrucosa Protz, 1896, Zool. Anz., 19: 23-25, figs. 1-3. Genus Sperchon 1 Kramer Generotype: Sperchon squamosus Kramer, 1879, Arch. Naturg., 45, (Bd. 1), pp. 2-5, pi. 1, figs. la-Id. Sperchon Kramer, 1877, op. cit., 43, (Bd. 1), p. 240. crassipalpis Marshall, 1933, Trans. Amer. Micros. Soc., 52: 37, pi. 7, figs. 1-3. [Marshall Collection] glandulosus Koenike, 1886, Zeit. Wissen. zool., 43: 279-284, pi. 9, figs. 17-24. jasperensis Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, pp. 65-66, pi. 2, figs. 14-15. [Marshall Collection] parmatus Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 202-204, pi. 2, figs. 40-41. tenuipalpis Koenike, 1895, op. cit., pp. 204-206, pi. 2, figs. 42-47. Family LEBERTIIDAE Thor Lebertiidae Thor, 1900, Nyt. mag. naturvid., 38: 264. Genus Lebertia Neuman Generotype : Lebertia insignis Neuman, 1880, K. Svenska Vetenskap. Handl., n. ser., (4), 17, (3), pp. 69-70, pi. 8, fig. 4. Lebertia Neuman, 1880, op. cit., pp. 68-69. artaacetabula Marshall, 1912, Trans. Amer. Micros. Soc., 31: 227, pi. 27, figs. 1-3. [Marshall Collection] distincta Marshall, 1914, Trans. Wis. Acad. Sci., 17: 1301, pi. 93, figs. 21-23. [Marshall Collection] martisensis Marshall, 1943, Trans. Amer. Micros. Soc., 62: 408-410, pi. 3, figs. 23-25. [Marshall Collection] needhami Marshall, 1943, op. cit., p. 408, pi. 3, figs. 28-30. [Marshall Collection] ontarioensis Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, pp. 70-71, pi. 5, figs. 46-47. [Marshall Collection] 1 Four new forms of Sperchon, S. breiirostris ssp. scabriosus, S. mitchelli, S. glandulosus canadensis, and S. plumifer acadiensis, are proposed by Habeeb (Leafl. Acad. Biol., no. 1, p. 8). Each form is described in less than fifty words and unillustrated. These descriptions do not satisfy the requirements of Article 25c of the International Code of Zoological Nomenclature. MITCHELL: NORTH AMERICAN WATER-MITES 39 parmata Marshall, 1912, Trans. Amer. Micros. Soc., 31: 226-227, pi. 27, figs. 4-5, pi. 28, figs. 6-7. [Marshall Collection] porosa Thor, 1900, Nyt. mag. naturvid., 38: 273. quinquemaculosa Marshall, 1929, Proc. Indiana Acad. Sci., 38: 315, 317, figs. 5-8. [Marshall Collection] setosa Koenike, 1912, Trans. Roy. Canad. Inst., 9: 294-295, pi. 2, fig. 20. tau-insignita Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 201-202 (in part). tyrrelli Koenike, 1912, Trans. Roy. Canad. Inst., 9: 290-293, pi. 1, fig. 16. pi. 2, figs. 13-15. tau-insignita Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 201-202 [ (in part). wolcotti Koenike, 1912, Trans. Roy. Canad. Inst., 9: 292-294, pi. 1, figs. 17-18, pi. 2, fig. 19. tau-insignita Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 201-202 ! (in part). wyomingensis Marshall, 1933, Trans. Amer. Micros. Soc., 52: 39-40, pi. 8, figs. 16-17. [Marshall Collection] Genus Oxus Kramer Generotype: Oxus oblongus Kramer, 1879, Arch. Naturg., 45, (Bd. 1), pp. 5-7, pi. 1, figs. 2a-2c. Oxus Kramer, 1877, op. cit., 43, (Bd. 1), pp. 240-241. connatus Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, pp. 71-72, pi. 4, fig. 35. [Marshall Collection] elongatus Marshall, 1929, op. cit., p. 72, pi. 4, fig. 34. intermedius Marshall, 1926, Univ. Iowa Stud. Nat. Hist., 11 : 31, pi. 1, figs. 1-3. [Marshall Collection] Genus Frontipoda Koenike Generotype: Hydrachna musculus M tiller, 1776, Zool. Danicae Prodromus, p. 191. Frontipoda Koenike, 1891, Zool. Anz., 14: 19. americana Marshall, 1914, Trans. Wis. Acad. Sci., 17: 1300-1301, pi. 92, figs. 1-8. [Marshall Collection] Genus Gnaphiscus Koenike Generotype : Gnaphiscus setosus Koenike, 1898, Zool. Anz., 21 : 262-263. Gnaphiscus Koenike, 1898, loc. cit. Occident alls Marshall, 1924, Trans. Amer. Micros. Soc., 43: 247, pi. 13, figs. 36-40, pi. 14, figs. 51-55. [Marshall Collection] Family TORRENTICOLIDAE Oudemans Torrenticolidae Oudemans, 1941, Zool. Anz., 136: 178. Atractidaeidae Thor, 1902, op. cit., 25: 408. 40 FIELDIANA: ZOOLOGY, VOLUME 35 Genus Torrenticola Piersig Generotype: Atractides anomalus Koch, 1837, Deutschl. Crust., Myr., Arach., Heft 11, no. 10. Torrenticola Piersig, 1897, Sitzungs. naturf. Ges. Leipzig, 22-23: 155. Atractides auct. (nee Koch). calif ornicus Marshall, 1943, Trans. Amer. Micros. Soc., 62: 315-316, pi. 2, figs. 14-16. [Marshall Collection] compact us Marshall, 1943, op. cit., p. 315, pi. 3, figs. 25-26, pi. 4, fig. 27. [Mar- shall Collection] ellipsoidalis Marshall, 1943, op. cit., pp. 308-310, pi. 2, figs. 11-13. [Marshall Collection] geographicus Marshall, 1943, op. cit., p. 314, pi. 3, figs. 21-24. [Marshall Collection] indistinct us Marshall, 1929, Proc. Indiana Acad. Sci., 38: 317, 319, figs. 16-18. [Marshall Collection] jordanensis Marshall, 1930, Trans. Wis. Acad. Sci., 25: 248-249, pi. 6, figs. 12-14. [Marshall Collection] mercedensis Marshall, 1943, Trans. Amer. Micros. Soc., 62: 310, 312, pi. 2, figs. 9-10. [Marshall Collection] oblongatus Marshall, 1943, op. cit., p. 316, pi. 4, figs. 28-29, pi. 5, fig. 40. [Mar- shall Collection] obovatus Marshall, 1943, op. cit., pp. 316, 318, pi. 5, figs. 35-39. [Marshall Collection] occidentalis Marshall, 1933, op. cit., 52: 40, pi. 7, figs. 5-7. [Marshall Collection] sierrensis Marshall, 1943, op. cit., 62: 307, pi. 1, figs. 1-4. [Marshall Collection] simulans Marshall, 1933, op. cit., 52: 40, pi. 7, figs. 8-10. [Marshall Collection] tahoei Marshall, 1943, op. cit., 62: 308, pi. 1, figs. 5-7. [Marshall Collection] waddellicus Marshall, 1943, op. cit., pp. 312, 314, pi. 3, figs. 17-20. [Marshall Collection] Genus Testudacarus Walter Generotype: Testudacarus tripeltatus Walter, 1928, Rec. Indian Mus., 30: pp. 75-78, figs. 8-10. Testudacarus Walter, 1928, op. cit., p. 75. americanus Marshall, 1943, Trans. Amer. Micros. Soc., 62: 320, pi. 6, figs. 46-48. [Marshall Collection] minimus Marshall, 1943, op. cit., p. 322, pi. 6, figs. 43-45. [Marshall Collection] Family LIMNESIIDAE Thor Limnesiidae Thor, 1900, Nyt. mag. naturvid., 38: 265. Genus Limnesia Koch Generotype : Limnesia fulgida Koch. Limnesia Koch, 1842, Ubers. Arachnidensystems, 3: 27. Limnesiopsis Piersig, 1897, Sitzungs. naturf. Ges. Leipzig, 22-23: 52. MITCHELL: NORTH AMERICAN WATER-MITES 41 anomala Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 207-208, pi. 2, figs. 49-53. subsp. marshallae Viets, 1938, Zool. Anz., 121: 134-135. anomala Marshall, 1932, (male only), Trans. Wis. Acad. Sci., 27: 346, pl. 7, fig. 7. coerulea Lundblad, 1941, Zool. Anz., 133: 158. columbica Marshall, 1924, Trans. Amer. Micros. Soc., 43: 239-240, pl. 11, figs. 9-12. [Marshall Collection] cornuta Wolcott, 1903, op. cit., 24: 89-92, pl. 12, figs. 1-5. [Marshall Collection] fulgida Koch, 1835, Deutschl. Crust., Myr., Arachn., Heft 2, no. 19. histrionica Wolcott, 1903, Trans. Amer. Micros. Soc., 24: 92-95, pl. 12, figs. 6-7. wolcotti Piersig, 1905, Zool. Centr., 12: 198. koenikea Piersig, 1894, Zool. Anz., 17: 151. maculata Muller, 1776, Zool. Danicae Prodromus, p. 191. americana Piersig, 1905, Zool. Centr., 12: 198. elliptica Marshall, 1924, Trans. Amer. Micros. Soc., 43: 240, pl. 11, figs. 13-14. [Marshall Collection] marshallae Viets, 1938, Zool. Anz., 121: 134-135. anomala Marshall, 1927, Trans. Amer. Micros. Soc., 46: 213, pl. 7, figs. 5-6. anomala Marshall, 1932, Trans. Wis. Acad. Sci., 27: 346, pl. 7, figs. 6-8. hutchinsoni Lundblad, 1941, Zool. Anz., 133: 158. marshalliana Lundblad, 1952, Ark. Zool., (2), 3: 525. marshallae Lundblad, 1941, Zool. Anz., 133: 157. paucispina Wolcott, 1903, Trans. Amer. Micros. Soc., 24: 98-100, pl. 13, figs. 10-11. [Marshall Collection] protractipora Lundblad, 1941, Zool. Anz., 133: 157. undulata Muller, 1781, Hydrachnae aquis Danicae, p. 80, pl. 11, fig. 1. var. californica Lundblad, 1941, Zool. Anz., 133: 158. wawaseea Marshall, 1929, Proc. Indiana Acad. Sci., 38: 315, figs. 9-11. [Marshall Collection] Genus Tyrrellia Koenike Generotype: Tyrrellia circularis Koenike. Tyrrellia Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 198-199. circularis Koenike, 1895, op. cit., pp. 199-201, pl. 2, figs. 36-38. var. monensis Marshall, 1940, Trans. Wis. Acad. Sci., 32: 386, pl. 1, figs. 5-7, pl. 2, fig. 15. [Marshall Collection] ovalU Marshall, 1932, op. cit., 27: 342-343, pl. 8, figs. 18-21. [Marshall Col- lection] Family PONTARACHNIDAE Thor Pontarachnidae Thor, 1929, Nyt. mag. naturvid., 67, pl. 7. 42 FIELDIANA: ZOOLOGY, VOLUME 35 Genus Pontarachna Philippi Generotype: Pontarachna punctulum Philippi, 1840, Arch. Naturg., 6, (Bd. 1), pp. 191-193, pi. 4, figs. 4-5. Pontarachna Philippi, 1840, op. cit., p. 193. cruciata Hall, 1912, Pomona Coll., Rep. Laguna Mar. Lab., 1: 183-184, fig. 102. Family HYGROBATIDAE Koch Hygrobatides Koch, 1842, Ubers. Arachnidensystems, 3: 7. Genus Hygrobates Koch Generotype: Hygrobates lutescens Koch, 1841, Deutschl. Crust., Myr., Arachn., Heft 37, no. 13. Hygrobates Koch, 1837, op. cit., Heft 10, no. 8. decaporus Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 215-216, pi. 3, figs. 62-63. exilis Koenike, 1895, op. cit., pp. 213-215, pi. 3, figs. 60-61. longipalpis Hermann, 1804, Mem. Apterolog., p. 55, pi. 3, fig. 1, pi. 9, fig. P. ruber Marshall, 1926, Univ. Iowa Stud. Nat. Hist., 11: 32, pi. 1, figs. 5-7. multiporus Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 216-217, pi. 3, fig. 64. [Marshall Collection] neooctoporus Marshall, 1926, Univ. Iowa Stud. Nat. Hist., 11: 34. [Marshall Collection] octoporux Marshall, 1924, Trans. Amer. Micros. Soc., 43: 238-239, pi. 11, figs. 1-5. occidentalis Marshall, 1943, op. cit., 62: 414, pi. 4, figs. 39-41. [Marshall Collection] Genus Atractides Koch Generotype: Atractides spinipes Koch, 1837, Deutschl. Crust., Myr., Arachn., Heft 11, no. 16. Atractides Koch, 1837, loc. cit. Megapus Neuman, 1880, K. Svenska Vetenskap. Handl., n. ser., (4), 17, (3), pp. 63-64. crassipalpis Koenike, 1909, Abh. naturw. Ver. Bremen, 19: 246. ovalis Koenike, 1895, op. cit., 13: 211-212, pi. 3, figs. 58-59. nodipalpis Thor, 1899, Arch. Math. Naturv., 21, (5), pp. 39-40, pi. 17, figs. 120-121 (Palearctic). var. americanus Marshall, 1943, Trans. Amer. Micros. Soc., 62: 414-415, pi. 4, figs. 31-34. [Marshall Collection] spinipes Marshall, 1933, op. cit., 52: 41, pi. 7, figs. 18-20. parviscutus Marshall, 1915, Trans. Amer. Micros. Soc., 34: 186, pi. 6, figs. 1-4. [Marshall Collection] orthopes Marshall, 1915, op. cit., p. 187, pi. 6, figs. 10-12. ?phenopleces Marshall, 1915, op. cit., pp. 186-187, pi. 6, figs. 5-9. [Marshall Collection] stun- con sis Marshall, 1927, op. cit., 46: 274-275, pi. 8, figs. 16-19. [Marshall Collection] MITCHELL: NORTH AMERICAN WATER-MITES 43 Family UNIONICOLIDAE Oudemans Unionicolidae Oudemans, 1909, Tijdschr. Ent., 52: 60. Genus Unionicola Haldeman Generotype: Unionicola crassipes Miiller. Unionicola Haldeman, 1842, Zool. Contr., 1: 1. Atax Koch, 1842, tlbers. Arachnidensystems, 3: 7. abnormipes Wolcott, 1898, Zool. Bull., 1: 280-281, fig. 2. [Marshall Collection] aculeatus Koenike, 1890, Zool. Anz., 13: 139-140. sayi Piersig, 1901, Das Tierreich, 13: 213. adensameri Thon, 1901, Ann. Naturhist. Hofmus., 16: 31-35, pi. 3. arcuata Wolcott, 1898, Zool. Bull., 1: 284-285, fig. 5. [Marshall Collection] campelomaicola Marshall, 1935, Univ. Toronto Stud., Biol. Ser., no. 39, pp. 99-102, figs. 1-5. [Marshall Collection] crassipes Miiller, 1776, Zool. Danicae Prodromus, p. 189. figuralis Koch, 1836, Deutschl. Crust., Myr., Arachn., Heft 7, no. 10. fossulatus Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 221-222, pi. 3, figs. 68-71. indistinctus Wolcott, 1898, Zool. Bull., 1 : 281-282, fig. 3. [Marshall Collection] intermedia Koenike, 1882, Abh. naturw. Ver. Bremen, 7: 265-266 (Palearctic). var. wolcotti Piersig, 1900, Zool. Anz., 23: 211-212. [Marshall Collection] pectinatus Wolcott, 1898, Zool. Bull., 1: 280, fig. 1. [Marshall Collection] serratus Wolcott, 1898, op. cit., pp. 282-283, fig. 4. [Marshall Collection] stricta Wolcott, 1898, op. cit., pp. 283-284. [Marshall Collection] t umidus Wolcott, 1898, op. cit., p. 285, fig. 6. [Marshall Collection] ypsilophora Bonz, 1783, K. Deutsche Akad. Naturf . Halle, nova acta Leopoldana, 7: 52, pi. 1, figs. 1-4. haldemani Piersig, 1900, Zool. Anz., 23: 212. formosa Dana and Whelpley, 1836, Amer. Jour. Sci., (1), 30: 357-358, figs. 1-8. Genus Najadicola Piersig Generotype: Unionicola ingens Koenike. Najadicola Piersig, 1897, Zool. Anz., 20: 59-60. ingens Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 219-220, pi. 3, figs. 65-67. Genus Neumania Lebert Generotype: Hydrachna spinipes Miiller, 1776, Zool. Danicae Prodromus, p. 189. Neumania Lebert, 1879, Bull. Soc. Vaud. Sci. Natur., 16: 357. armata Marshall, 1922, Trans. Wis. Acad. Sci., 20: 209, pi. 3, figs. 11-13. [Mar- shall Collection] muttkowskii Marshall, 1922, op. cit., p. 208, pi. 2, fig. 10 (in part). [Marshall Collection] 44 FIELDIANA: ZOOLOGY, VOLUME 35 distincta Marshall, 1922, Trans. Wis. Acad. Sci., 20: 210-211, pi. 4, figs. 20, 23. [Marshall Collection] brevibrachiala Marshall, 1922, op. cit., p. 211, pi. 4, figs. 24-25. [Mar- shall Collection] okobojica Marshall, 1926, Univ. Iowa Stud. Nat. Hist., 11: 31, pi. 2, figs. 11-12. [Marshall Collection] extendens Marshall, 1922, Trans. Wis. Acad. Sci., 20: 209, pi. 3, figs. 14-16. [Marshall Collection] punctata Marshall, 1922, (female only), op. cit., pp. 211-212, pi. 4, fig. 29. [Marshall Collection] fragilis Marshall, 1922, op. cit., p. 208, pi. 2, figs. 7-9. [Marshall Collection] hickmani Marshall, 1933, op. cit., 28: 46, pi. 4, figs. 41-43. [Marshall Collection] kodiakica Marshall, 1924, Trans. Amer. Micros. Soc., 43: 246, pi. 14, figs. 42-43. [Marshall Collection] longiseta Marshall, 1924, op. cit., p. 243, pi. 12, fig. 23, pi. 13, fig. 26. [Marshall Collection] ovata Marshall, 1922, Trans. Wis. Acad. Sci., 20: 206-207, pi. 2, fig. 1. papillator Marshall, 1922, op. cit., pp. 209-210, pi. 3, figs. 17-20, pi. 4, fig. 21. [Marshall Collection] pubescens Marshall, 1929, Proc. Indiana Acad. Sci., 38: 319, figs. 1-4. [Marshall Collection] punctata Marshall, 1922, (male only), Trans. Wis. Acad. Sci., 20: 211-212. [Marshall Collection] semicircularis Marshall, 1922, op. cit., p. 207, pi. 2, figs. 2-3. [Marshall Col- lection] tenuipalpis Marshall, 1922, op. cit., pp. 207-208, pi. 2, figs. 4-6. [Marshall Collection] muttkowskii Marshall, 1922, op. cit., p. 208, pi. 2, fig. 10 (in part). [Mar- shall Collection] Pvernalis Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 218-219. Genus Koenikea Wolcott Generotype: Koenikea concava Wolcott (male only). Koenikea Wolcott, 1900, Trans. Amer. Micros. Soc., 21: 189-190. Tanaognathus Wolcott, 1900, op. cit., pp. 193-194. alata Lundblad, 1943, K. Svenska Vetenskap. Handl., 20, (5), p. 15, fig. 7. concava Wolcott, 1900, (male only), Trans. Amer. Micros. Soc., 21: 190-193, pi. 11, figs. 15, 17, 19, pi. 12, fig. 24. [Marshall Collection] haldemani Viets, 1930, Zool. Anz., 92: 268-272, figs. 6-8. marshallae Viets, 1930, op. cit., pp. 267-271, figs. 1-5. spinipes Wolcott, 1900, Trans. Amer. Micros. Soc., 21: 194-197, pi. 12, figs. 25-28. [Marshall Collection] wolcotti Viets, 1930, Zool. Anz., 92: 266. [Marshall Collection] concava Wolcott, 1900, (female only), Trans. Amer. Micros. Soc., 21: 190-193, pi. 11, figs. 18, 20-21, pi. 12, fig. 23. [Marshall Collection] MITCHELL: NORTH AMERICAN WATER-MITES 45 Genus Huitfeldtia Thor Generotype: Huitfeldtia rectipes Thor. Huitfeldtia Thor, 1898, Arch. Math. Naturv., 20, (7), pp. 1-2. rectipes Thor, 1898, op. cit., pp. 4-5, pi. 5, figs. 1-7. Family FELTRIIDAE Thor Feltriidae Thor, 1929, Nyt. mag. naturvid., 67, pi. 7. Genus Feltria Koenike Generotype: Feltria minuta Koenike. Feltria Koenike, 1892, Zool. Anz., 15: 323. minuta Koenike, 1892, op. cit., pp. 323-324, figs. 3-4. Family PIONIDAE Thor Pionidae Thor, 1900, Nyt. mag. naturvid., 38: 265. Genus Wettina Piersig Generotype: Tiphys podagricus Koch, 1837, Deutschl. Crust., Myr., Arachn., Heft 11, no. 9. Wettina Piersig, 1892, Zool. Anz., 15: 408-410. primaria Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, p. 83, pi. 4, figs. 39-41. [Marshall Collection] Genus Hydrochoreutes Koch Generotype: Spio ungulata Koch. Hydrochoreutes Koch, 1837, Deutschl. Crust., Myr., Arach., Heft 11, no. 11. ungulatus Koch, 1835, op. cit., Heft 5, no. 17. Genus Tiphys Koch Generotype: Tiphys sagulatus Koch, 1837, Deutschl. Crust., Myr., Arachn., Heft 11, no. 7. Tiphys Koch, 1835, op. cit., Heft 5, no. 19. Acercus Koch, 1842, Ubers. Arachnidensystems, 3: 23. Laminipes Piersig, 1901, Zool. Anz., 24: 219-220. diversus Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, pp. 83-84, pi. 5, figs. 48-50. [Marshall Collection] simulans Marshall, 1924, Trans. Amer. Micros. Soc., 43: 244, pi. 14, figs. 46-47. [Marshall Collection] torris Muller, 1776, Zool. Danicae Prodromus, p. 191. var. americanus Marshall, 1937, Trans. Wis. Acad. Sci., 30: 237, pi. 8, figs. 58-61. 46 FIELDIANA: ZOOLOGY, VOLUME 35 Genus Pionopsis Piersig Generotype: Hydrachne lutescens Hermann, 1804, Mem. Apterolog., p. 57, pi. 6, fig. 7. Pionopsis Piersig, 1894, Zool. Anz., 17: 215-216. latilamellis Marshall, 1924, Trans. Amer. Micros. Soc., 43: 244, pi. 13, figs. 32-34. [Marshall Collection] Genus Pionacercus Piersig Generotype: Pionacercus leuckarti Piersig, 1894, Zool. Anz., 17: 213-214, figs. 1-2. Pionacercus Piersig, 1894, op. cit., p. 213. novus Marshall, 1924, Trans. Amer. Micros. Soc., 43: 244-245, pi. 13, fig. 35, pi. 14, fig. 41. [Marshall Collection] Genus Piona Koch Generotype: Nesaea rosea Koch, 1837, Deutschl. Crust., Myr., Arachn., Heft 10, no. 7. Piona Koch, 1842, Ubers. Arachnidensystems, 3: 13. Curvipes Koenike, 1891, Zool. Anz., 14: 19-20. americana Marshall, 1929, Trans. Wis. Acad. Sci., 24: 401-404, pi. 9, figs. 1-9. [Marshall Collection] carnea Koch, 1836, Deutschl. Crust., Myr., Arachn., Heft 8, no. 24. neocarnea Marshall, 1924, Trans. Amer. Micros. Soc., 43: 241, pi. 12, figs. 15-17. [Marshall Collection] conglobata Koch, 1836, Deutschl. Crust., Myr., Arachn., Heft 8, no. 9 (Pale- arctic). var. wisconsinensis Marshall, 1935, Trans. Wis. Acad. Sci., 29: 284, pi. 10, figs. 43-47. [Marshall Collection] constrictus Wolcott, 1902, Trans. Amer. Micros. Soc., 23: 222-226, pi. 30, figs. 14-18. [Marshall Collection] coronis Wolcott, 1902, op. cit., pp. 208-210, pi. 29, figs. 1-2. [Marshall Collection] crassus Wolcott, 1902, op. cit., pp. 246-249, pi. 33, figs. 57-60. [Marshall Collection] debilis Wolcott, 1902, op. cit., pp. 234-235, pi. 32, figs. 44-46. [Marshall Col- lection] exilis Wolcott, 1902, op. cit., pp. 210-213, pi. 29, figs. 3-8. [Marshall Collection] guatemalensis Stoll, 1887, Biol. Centr.-Amer., 13: 11-12, pi. 10, figs. 2-26, pi. 11, figs. l-l/. inconstans Wolcott, 1902, Trans. Amer. Micros. Soc., 23: 241-243, pi. 32, fig. 47, pi. 33, figs. 48-50. [Marshall Collection] insularis Marshall, 1924, op. cit., 43: 243, pi. 12, fig. 24, pi. 13, figs. 30, 31. [Marshall Collection] interrupta Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, pp. 81-82, pi. 6, figs. 59-60. [Marshall Collection] linguaplax Crowell, 1953, Amer. Midi. Nat., 50: 426-431, figs. 1-12. [C.N.H.M. Collection] MITCHELL: NORTH AMERICAN WATER-MITES 47 medius Wolcott, 1902, Trans. Amer. Micros. Soc., 23: 229-231, pi. 31, figs. 30-31. [Marshall Collection] nodata Miiller, 1776, Zool. Danicae Prodromus, p. 191 (Palearctic). var. latigenitalia Marshall, 1924, Trans. Amer. Micros. Soc., 43: 242, pi. 12, fig. 22, pi. 13, figs. 27-29. [Marshall Collection] ?fuscatus Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 209. obturbans Piersig, 1896, Zool. Anz., 19: 439-440. pugilis Wolcott, 1902, Trans. Amer. Micros. Soc., 23: 213-216, pi. 29, figs. 9-12. [Marshall Collection] reighardi Wolcott, 1902, op. cit., pp. 235-239, pi. 32, figs. 35-38. [Marshall Collection] rotunda Kramer, 1879, Arch. Naturg., 45, (Bd. 1), p. 12, pi. 1, fig. 6. rubrapes Marshall, 1924, Trans. Amer. Micros. Soc., 43: 241-242, pi. 12, figs. 18-21. [Marshall Collection] setiger Wolcott, 1902, op. cit., 23: 243-246, pi. 33, figs. 51-56. [Marshall Col- lection] socialis Marshall, 1930, op. cit., 49: 343-344, pi. 39, figs. 5-10. [Marshall Col- lection] spinulosus Wolcott, 1902, op. cit., pp. 226-229, pi. 31, figs. 24-29. [Marshall Collection] triangularis Wolcott, 1902, op. cit., 23: 220-222, pi. 31, figs. 32-33. [Marshall Collection] turgidus Wolcott, 1902, op. cit., pp. 216-220, pi. 30, figs. 19-23. [Marshall Collection] wolcotti Marshall, 1937, Trans. Wis. Acad. Sci., 30: 235-236, pi. 7, figs. 49-52. [Marshall Collection] Genus Forelia Haller Generotype: Arrhenurus variegator Koch, 1837, Deutschl. Crust., Myr., Arachn., Heft 12, no. 24. Forelia Haller, 1882, Mitt, naturf. Ges. Bern, 1881, Heft 2, pp. 58-59. Tiphys Wolcott, 1905, Trans. Amer. Micros. Soc., 26: 214-215. liliacea Muller, 1776, Zool. Danicae Prodromus, p. 190. ovalis Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, pp. 78-79, pi. 5, figs. 42-45. [Marshall Collection] Family AXONOPSIDAE Viets Axonopsidae Viets, 1929, Zool. Anz., 80: 169. Genus Albia Thon Generotype: Albia stationis Thon. Albia Thon, 1899, Zool. Anz., 22: 100-101. caerulea Marshall, 1927, Trans. Amer. Micros. Soc., 46: 277, pi. 9, figs. 25-27. [Marshall Collection] Pstationis Thon, 1899, Zool. Anz., 22: 101-102. 48 FIELDIANA: ZOOLOGY, VOLUME 35 Genus Brachypoda Lebert Generotype: Hydrachna versicolor Miiller, 1776, Zool. Danicae Prodromus, p. 191. Brachypoda Lebert, 1879, Bull. Soc. Vaud. Sci. Natur., (2), 16: 340, 374. Brachypoda Habeeb, 1953, Leafl. Acad. Biol., no. 1, p. 9 (in part). setosicauda Habeeb, 1953, op. cit., p. 12, figs. 26-27. ssp. acuticauda Habeeb, 1953, op. cit., p. 12, fig. 28. Genus Axonopsis Piersig Generotype: Hydrachna complanata Miiller, 1776, Zool. Danicae Prodromus, p. 191. Axonopsis Piersig, 1893, Zool. Anz., 16: 310. setoniensis Habeeb, 1953, Leafl. Acad. Biol., no. 1, p. 9, figs. 23-25. Genus Ljania Thor Generotype : Ljania bipapillata Thor. Ljania Thor, 1898, Arch. f. Math. Naturv., 20, (13), p. 3. bipapillata Thor, 1898, op. cit., p. 3 (Palearctic). ssp. purpurea Habeeb, 1953, Leafl. Acad. Biol., no. 1, p. 9. Genus Neoaxonopsis Lundblad Generotype: Neoaxonopsis odontogaster Lundblad, 1938, Zool. Anz., 122: 38-39. Neoaxonopsis Lundblad, 1938, op. cit., p. 38. Brachypoda Habeeb, 1953, Leafl. Acad. Biol., no. 1, p. 9 (in part). pilositarsa Habeeb, 1953, Leafl. Acad. Biol., no. 1, p. 9, figs. 20-23. unguitarsa Habeeb, 1953, op. cit., pp. 9, 12, figs. 29-30. Genus Aturus Kramer Generotype: Aturus scaber Kramer, 1875, Arch. Naturg., 43, (Bd. 1), pp. 309-310, pi. 8, fig. 3. Aturus Kramer, 1875, op. cit., p. 309. acadiensis Habeeb, 1953, Leafl. Acad. Biol., no. 1, p. 15. canadensis Habeeb, 1953, Natural. Canad., 80: 274-275. deceptor Habeeb, 1953, op. cit., pp. 275-276. droueti Habeeb, 1953, Leafl. Acad. Biol., no. 1, p. 15. estellae Habeeb, 1953, op. cit., p. 2, figs. 6-11. formosus Habeeb, 1953, op. cit., p. 4, figs. 12-14, 18. pallidus Habeeb, op. cit., p. 4. mirabilis Piersig, 1897, Sitzungs. naturf. Ges. Leipzig, 22-23: 157. scaber Koenike, 1895, Abh. naturw. Ver. Bremen. 13: 186-191, pi. 1, fig. 23. projector Habeeb, 1953, Natural. Canad., 80: 275. MITCHELL: NORTH AMERICAN WATER-MITES 49 Family MIDEIDAE Viets Mideidae Viets, 1929, Zool. Anz., 80: 169. Genus Midea Bruzelius Generotype: Hydrachna orbiculata Muller, 1776, Zool. Danicae Prodromus, p. 190. Midea Bruzelius, 1854, Biskrif. ofver Hydrachnider, p. 35. determina Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, pp. 84-85, pi. 7, figs. 62-66. [Marshall Collection] expansa Marshall, 1940, Trans. Wis. Acad. Sci., 32: 138-139, pi. 4, figs. 26-30. [Marshall Collection) Family MIDEOPSIDAE Thor Mideopsidae Thor, 1928, Zeits. Morph. Okol. Tiere, 11: 109. Genus Mideopsis Neuman Generotype: Hydrachna orbicularis Muller. Mideopsis Neuman, 1880, K. Svenska Vetenskap. Handl., n. ser., (4), 17, (3), p. 67. americanus Marshall, 1940, Trans. Wis. Acad. Sci., 32: 140-141, pi. 1, figs. 1-4. [Marshall Collection] fibrosa Lundblad, 1941, Zool. Anz., 133: 159-160. lamellipalpis Lundblad, 1941, op. cit., p. 159. orbicularis Muller, 1776, Zool. Danicae Prodromus, p. 190. rosea Lundblad, 1941, Zool. Anz., 133: 159. Genus Xystonotus Wolcott Generotype: Xystonotus asper Wolcott. Xystonotus Wolcott, 1900, Trans. Amer. Micros. Soc., 21: 185-186. asper Wolcott, 1900, op. cit., pp. 186-189, pi. 10, figs. 8-14. [Marshall Collection] reelfootensis Hoff, 1944, Jour. Tenn. Acad. Sci., 19: 234-238, pi. 1, figs. 1-10. [Marshall Collection] I Family KRENDOWSKIJIDAE Lundblad Krendowskijidae Lundblad, 1930, Zool. bidrag Uppsala, 13: 56-58. Genus Krendowskia Piersig Generotype: Krendowskia latissima Piersig, 1895, Zool. Anz., 18: 147-148. Krendowskia Piersig, 1895, op. cit., pp. 147-148. similis Viets, 1931, op. cit., 93: 42-44, figs. 12-14. 50 FIELDIANA: ZOOLOGY, VOLUME 35 Genus Geayia Thor Generotype: Geayia venezuelae Thor, 1897, Bull. Mus. d'Hist. Nat., 3: 12-13, figs. 1-6. Geayia Thor, 1897, op. cit., pp. 11-12. Krendowskia Wolcott, 1900, Trans. Amer. Micros. Soc., 21: 178-181. Krendowskia Wolcott, 1905, op. cit., 26: 193. ovata Wolcott, 1900, Trans. Amer. Micros. Soc., 21: 181-185, pi. 9, figs. 1-7. [Marshall Collection] Family ARRENURIDAE Thor Arrenuridae Thor, 1900, Nyt. mag. naturvid., 38: 266. Genus Arrenurus Duges Generotype: Arrenurus viridis Dugs, 1834, Ann. Sci. Nat. (Zool.), (2), 1: 154-156, pi. 10, figs. 18-21. Arrenurus Dugs, 1834, op. cit., pp. 154-156. Steganaspis Wolcott, 1901, Trans. Amer. Micros. Soc., 22: 105-106. Subgenus Truncaturus Thor Generotype: Arrenurus paluster Thor, 1900, Nyt. mag. naturvid., 38: 380- 382, pi. 8, figs. 25-27. Truncaturus Thor, 1900, op. cit., pp. 379-380. kenki Marshall, 1944, Amer. Midi. Nat., 31: 631, 633, pi. 1, figs. 1-2, 6. [Mar- shall Collection] Subgenus Micruracarus Viets Generotype: Arrhenurus forpicatus Neuman, 1880, K. Svenska Vetenskap. Handl., n. ser., (4), 17, (3), p. 90, pi. 6, figs. 2. Micruracarus Viets, 1911, Zool. Anz., 38: 504. acutus Marshall, 1908, Trans. Amer. Micros. Soc., 28: 92, pi. 8, figs. 14-16. [Marshall Collection] bicaudatus Marshall, 1908, op. cit., p. 91, pi. 7, figs. 8-10. [Marshall Collection] couleensis Lavers, 1945, op. cit., 64: 233-234, pi. 1, figs. 1-4. [Marshall Col- lection] crenellatus Marshall, 1908, op. cit., 28: 90-91, pi. 8, figs. 11-13. [Marshall Collection] infundibularis Marshall, 1908, op. cit., pp. 93-94, pi. 8, fig. 20, pi. 9, figs. 21-22. [Marshall Collection] laticaudatus Marshall, 1908, op. cit., pp. 95-96, pi. 9, figs. 23-25. [Marshall Collection] lyriger Marshall, 1908, op. cit., pp. 94-95, pi. 9, fig. 26, pi. 10, figs. 27-28. [Mar- shall Collection] montifer Marshall, 1908, op. cit., pp. 96-97, pi. 10, figs. 29-31. [Marshall Collection] MITCHELL: NORTH AMERICAN WATER-MITES 51 muttkowskii Marshall, 1940, Trans. Wis. Acad. Sci., 32: 144, pi. 4, figs. 33-35. [Marshall Collection] pseudosetiger Marshall, 1921, Trans. Amer. Micros. Soc., 40: 170, pi. 9, figs. 4-6. [Marshall Collection] setiger Marshall, 1910, op. cit., 29: 97-98. rotundus Marshall, 1908, op. cit., 28: 89-90, pi. 7, figs. 1-4, pi. 9, fig. 128. [Mar- shall Collection] scutulatus Marshall, 1908, op. cit., p. 93, pi. 8, figs. 17-19. [Marshall Collection] setiger Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 178-182, pi. 1, figs. 11-13. ovalis Marshall, 1908, Trans. Amer. Micros. Soc., 28: 90, pi. 7, figs. 5-7. [Marshall Collection] Subgenus Megaluracarus Viets Generotype: Hydrachna globator Muller, 1776, Zool. Danicae Prodromus, p. 188. Megaluracarus Viets, 1911, Zool. Anz., 38: 504. apetiolatus Piersig, 1904, Zool. Centr., 11: 210. corniger Marshall, 1903, Trans. Wis. Acad. Sci., 14: 155-156, pi. 15, fig. 7, a-e, aphelocercus Lavers, 1945, Trans. Amer. Micros. Soc., 64: 248, pi. 4, figs. 33-38. [Marshall Collection] belonocercus Lavers, 1945, op. cit., pp. 238-239, pi. 1, figs. 7-12. [Marshall Collection] birgei Marshall, 1903, Trans. Wis. Acad. Sci., 14: 158-159, pi. 16, fig. 10, a-/, pi. 17, fig. 10, e. [Marshall Collection] capillatus Marshall, 1908, Trans. Amer. Micros. Soc., 28: 101-102, pi. 12, figs. 43-45. cardiacus Marshall, 1903, Trans. Wis. Acad. Sci., 14: 153-154, pi. 17, fig. 5, d-i, pi. 18, fig. 5, a-c. [Marshall Collection] cornicularis Marshall, 1908, Trans. Amer. Micros. Soc., 28: 112-113, pi. 14, figs. 68-70. [Marshall Collection] elevatus Marshall, 1914, Trans. Wis. Acad. Sci., 17: 1301-1302, pi. 1, figs. 12-15, pi. 2, fig. 16. elongatus Marshall, 1924, op. cit., 21: 214, pi. 7, figs. 6-7, pi. 8, figs. 14-15. [Marshall Collection] expansus Marshall, 1908, Trans. Amer. Micros. Soc., 28: 107-108, pi. 13, figs. 53-55. [Marshall Collection] invaginatus Lavers, 1945, op. cit., 64: 246, 248, pi. 3, figs. 27-32. [Marshall Collection] kincaidi Lavers, 1945, op. cit., pp. 242, 244, pi. 3, figs. 22-26, pi. 6, fig. 63. [Mar- shall Collection] krameri Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 182-185, pi. 1, figs. 16-20. laversi Marshall, 1944, Amer. Midi. Nat., 31: 633, 635, pi. 2, figs. 7-11, pi. 3, fig. 17. [Marshall Collection] longicaudatus Marshall, 1908, Trans. Amer. Micros. Soc., 28: 111-112, pi. 14, figs. 65-67. [Marshall Collection] mamillanus Marshall, 1908, op. cit., pp. 98-99, pi. 10, figs. 32-34, pi. 11, fig. 35. [Marshall Collection) UBRAOT 52 FIELDIANA: ZOOLOGY, VOLUME 35 manubriator Marshall, 1903, Trans. Wis. Acad. Sci., 14: 151-152, pi. 15, fig. 3, 6, pi. 16, fig. 3, a, c, d, pi. 17, fig. 3, e, f. [Marshall Collection] marshalli Piersig, 1904, Zool. Centr., 11: 210. globator Marshall, 1903, Trans. Wis. Acad. Sci., 14: 148-150, pi. 14, fig- 1, a-g, pi. 15, fig. 1, e. megalurus Marshall, 1903, op. cit., pp. 150-151, pi. 14, fig. 2, 6, c, e, f, pi. 15, fig. 2, a, d. [Marshall Collection] var. intermedius Marshall, 1940, op. cit., 32: 147-148, pi. 5, figs. 41-44. [Marshall Collection] morrisoni Marshall, 1904, op. cit., 14: 523-524, pi. 40, fig. 2, a-d. parallellatus Marshall, 1903, op. cit., 14: 154-155, pi. 16, fig. 6, a-c, pi. 17, fig. 6, d, pi. 18, fig. 6, e. [Marshall Collection] prominulus Marshall, 1908, Trans. Amer. Micros. Soc., 28: 108-109, pi. 13, figs. 56-60. [Marshall Collection] pseudocaudatus Piersig, 1905, Zool. Centr., 12: 185. caudatus Marshall, 1904, Trans. Wis. Acad. Sci., 14: 521-523, pi. 40, fig. 1, a-c. pseudoconicus Piersig, 1904, Zool. Centr., 11: 210. conicus Marshall, 1903, Trans. Wis. Acad. Sci., 14: 158, pi. 18, fig. 9, a-d. pseudocylindratus Piersig, 1904, Zool. Centr., 11: 210. cylindratus Marshall, 1903, Trans. Wis. Acad. Sci., 14: 156-157, pi. 17, fig. 8, a-d. rawsoni Marshall, 1929, Univ. Toronto Stud., Biol. Ser., no. 33, p. 86, pi. 7, figs. 67-70. [Marshall Collection] rectangularis Marshall, 1908, Trans. Amer. Micros. Soc., 28: 110, pi. 14, figs. 61-63. [Marshall Collection] rheophilous Lavers, 1945, op. cit., 64: 239, pi. 2, figs. 13-17, pi. 4, fig. 43. [Mar- shall Collection] scutuliformis Marshall, 1908, op. cit., 28: 100, pi. 11, figs. 39-42. [Marshall Collection] semicircularis Piersig, 1904, Zool. Centr., 11: 210. securiformis Marshall, 1903, Trans. Wis. Acad. Sci., 14: 152-153, pi. 18, fig. 4, a-c. simulans Marshall, 1921, Trans. Amer. Micros. Soc., 40: 169, pi. 10, figs. 17-21. [Marshall Collection] solifer Marshall, 1908, op. cit., 28: 99, pi. 11, figs. 36-38. [Marshall Collection] tahoei Marshall, 1910, op. cit., 29: 100-101, pi. 1, fig. 7, pi. 2, figs. 11-14, pi. 3, fig. 3. [Marshall Collection] un if or mis Marshall, 1921, op. cit., 40: 169, pi. 9, figs. 1-3. [Marshall Collection] wardi Marshall, 1940, Trans. Wis. Acad. Sci., 32: 148, pi. 6, figs. 52-54. [Marshall Collection] Subgenus Arrenurus s. str. anu-r it-anus Marshall, 1908, Trans. Amer. Micros. Soc., 28: 126-128, pi. 21, figs. 112-117. [Marshall Collection] var. mucronatus Lavers, 1945, op. cit., 64: 255-256, pi. 5, fig. 50. [Marshall Collection] MITCHELL: NORTH AMERICAN WATER-MITES 53 amplus Marshall, 1908, Trans. Amer. Micros. Soc., 28: 122-123, pi. 20, figs. 102-105. [Marshall Collection] auricularis Lavers, 1945, pp. cit., 64: 258, 260, pi. 5, figs. 51-53, pi. 6, figs. 60-62. [Marshall Collection] auris Lavers, 1945, op. cit., pp. 260-261, pi. 6, figs. 55-58. [Marshall Collection] bleptopetlolatus Cook, 1954, op. cit., 73: 48, 50, pi. 1, figs. 3, 7. [C.N.H.M. Collection] cascadensis Lavers, 1945, op. cit., 64: 253, pi. 5, figs. 44-49. [Marshall Col- lection] cum pact ills Marshall, 1908, op. cit., 28: 120, pi. 18, figs. 93-95. [Marshall Collection] dentipetiolatus Marshall, 1908, op. cit., p. 117, pi. 16, fig. 81, pi. 17, figs. 82-83. [Marshall Collection] drepanophorus Cook, 1954, op. cit., 73: 51-52, pi. 1, fig. 8, pi. 2, fig. 22, pi. 3, fig. 23. [C.N.H.M. Collection] falcicornis Marshall, 1908, op. cit., 28: 121-122, pi. 19, figs. 96-98. [Marshall Collection] fissicorniformis Cook, 1954, op. cit., 73: 50, pi. 1, figs. 2, 4. [C.N.H.M. Col- lection] fissicornis Marshall, 1908, op. cit., 28: 130, pi. 22, figs. 125-127. [Marshall Collection] flabellifer Marshall, 1908, op. cit., pp. 125-126, pi. 22, figs. 122-124. [Marshall Collection] gennadus Cook, 1954, op. cit., 73: 54, pi. 3, figs. 27-28. [C.N.H.M. Collection] hungerfordi Cook, 1954, op. cit., p. 52, pi. 2, figs. 14-16. [C.N.H.M. Collection] interpositus Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 176-178, pi. 1, figs. 6-10. angustocaudatus Marshall, 1908, Trans. Amer. Micros. Soc., 28: 116, pi. 16, figs. 77-79. [Marshall Collection] laticornis Marshall, 1908, op. cit., p. 122, pi. 19, figs. 99-101. [Marshall Col- lection] lautus Koenike, 1895, Abh. naturw. Ver. Bremen, 13: 172-176, pi. 1, figs. 1-5. magnicaudatus Marshall, Trans. Amer. Micros. Soc., 28: 123-124, pi. 20, figs. 106-108. [Marshall Collection] major Marshall, 1908, op. cit., pp. 128-129, pi. 21, figs. 118-120, pi. 22, fig. 121. [Marshall Collection] maryellenae Cook, 1954, op. cit., 73: 57, pi. 4, figs. 40, 44. [C.N.H.M. Collection] neosuperior Cook, 1954, op. cit., p. 56, pi. 4, figs. 37-38. [C.N.H.M. Collection] pinguisomus Cook, 1954, op. cit., pp. 44, 46, pi. 1, figs. 9, 12. [C.N.H.M. Collection] pistillatus Marshall, 1908, op. cit., 28: 119-120, pi. 18, figs. 90-92. [Marshall Collection] planus Marshall, 1908, op. cit., pp. 115-116, pi. 16, figs. 75-76. [Marshall Collection] subsp. ventropetiolatus Lavers, 1945, op. cit., 64: 250-251, pi. 4, figs. 39-42, pi. 6, fig. 59. [Marshall Collection] platy-rotundo-cuspidator Mxinchberg, 1951, Arch. Hydrobiol., 45: 383-388, figs. 1-8. 54 FIELDIANA: ZOOLOGY, VOLUME 35 pleopetiolatus Marshall, 1944, Amer. Midi. Nat., 31 : 635, 637, pi. 3, figs. 12-16. [Marshall Collection] pollictus Marshall, 1910, Trans. Amer. Micros. Soc., 29: 106-107, pi. 1, figs. 9-10, pi. 3, figs. 25-28. [Marshall Collection] pseudosuperior Cook, 1954, op. cit., 73: 55-56, pi. 4, figs. 41-42. [C.N.H.M. Collection] reflexus Marshall, 1908, op. cit., 28: 117-118, pi. 17, figs. 84-86. [Marshall Collection] serratus Marshall, 1919, op. cit., 38: 276, pi. 29, figs. 1-7. [Marshall Collection] superior Marshall, 1908, op. cit., 28: 124-125, pi. 20, figs. 109-111. [Marshall Collection] tacomaensis Marshall, 1924, Trans. Wis. Acad. Sci., 21: 213-214, pi. 7, figs. 1-5. [Marshall Collection] tetratumuli Munchberg, 1953, Zool. Jahrb. (Syst.), 82: 51-56, figs. 1-9. trifoliatus Marshall, 1908, Trans. Amer. Micros. Soc., 28: 115, pi. 15, figs. 72-74. [Marshall Collection] wallensis Cook, 1954, op. cit., 73: 57-58, pi. 4, figs. 36, 43. [C.N.H.M. Collection] wolcotti Marshall, 1908, pp. cit., 28: 118-119, pi. 17, fig. 87, pi. 18, figs. 88-89. [Marshall Collection] Incertae sedis The names listed below represent species that cannot be entered in the modern taxonomic system because of the inadequacy of the descriptions. The species are listed in alphabetical order. Arrhenurus acerformis Marshall, 1924, Trans. Wis. Acad. Sci., 21: 215, pi. 8, figs. 8, 9, 13. [Marshall Collection] Arrhenurus hirsutus Marshall, op. cit., p. 215, pi. 8, figs. 10-12. [Marshall Col- lection] [This and the previous species of Arrenurus are based only on females and cannot be properly entered into the generic system.] Hydrachna coccinea Haldeman, 1843, Proc. Acad. Nat. Sci. Philadelphia, 1: 196. [Probably Hydryphantidae.] Hydrachna nebulosa Haldeman, op. cit., p. 196. [Not Hydrachna.} Hydrachna pyriformis Dana and Whelpley, 1836, Amer. Jour. Sci., (1), 30: 358-359, pi. 1, fig. 9. [Probably Unionicola.} Hydrachna scabra Haldeman, 1843, Proc. Acad. Nat. Sci. Philadelphia, 1: 184. [ Hydryphantes?] Hydrachna triangularis Say, 1821, Jour. Acad. Nat. Sci. Philadelphia, 2: 59. [Probably Unionicola.} Hydrachna tricolor Packard, 1871, Amer. Jour. Sci., (3), 1: 108. [There is no clue to the genus of this species in the description.] Hydrachna 5-undulata Haldeman, 1843, Proc. Acad. Nat. Sci. Philadelphia, 1 : 184. [Limnesia?] Steganaspis arrenuroides Wolcott, 1901, Trans. Amer. Micros. Soc., 22: 105-109, pi. 21, figs. 1-6. [A larval description that cannot be placed in a taxonomic system that is based on adult characters.] Unionicola humerosa Haldeman, 1842, Zool. Contr., 1, (1), p. 2, pi. 1, fig. 11. Unionicola lactea Haldeman, 1842, op. cit., p. 1, pi. 1, figs. 6-8. MITCHELL: NORTH AMERICAN WATER-MITES 55 Unionicola lugubris Haldeman, 1842, Zool. Contr., 1, (1), p. 2. Unionicola oviformis Haldeman, 1842, op. cit., p. 1, pi. 1, figs. 1-5. Unionicola personata Haldeman, 1842, op. cit., p. 2, pi. 1, fig. 10. I'nionicola proximo Haldeman, 1842, op. cit., p. 2. Unionicola reticulata Haldeman, 1842, op. cit., p. 3, pi. 1, fig. 9. Unionicola symmetrica Haldeman, 1842, op. cit., p. 2. Unionicola unicolor Haldeman, 1842, op. cit., p. 3. [The preceding nine species are all defined on color differences. I agree with Wolcott (1899, p. 233) that these species are likely to be U. ypsilophora Bonz.] Rejected Records Records of Old World species from the New World that cannot be verified or properly assigned are listed here. Leidy, 1883, Proc. Acad. Nat. Sci. Phila., 35: 44-46. Atax [Unionicola} bonzi Claparecle is cited and probably represents an erroneous identification. There is no other record of the species from the New World. Crowell, 1952, Jour. Elisha Mitchell Sci. Soc., 68: 191-196, 2 pis. Seven Pale- arctic species are recorded for the first time from North America. Neither the illustrations nor the text gives significant specific features. I have examined the slides and cannot see specific characters. Atractides (Torrenticola) anomalus, op. cit., p. 192. Aturus intermedius, op. cit., p. 193. Hygrobates fluviatilis, op. cit., pp. 192-193. Lebertia natans, op. cit., p. 192. Megapus (Atractides) walteri, op. cit., p. 193. Sperchon longirostris, op. cit., p. 192. Sperchon squamosus, op. cit., p. 191. Bergstrom, 1953, Trans. Amer. Micros. Soc., 72: 157-162. Forty species are listed, four of them recorded from North America for the first time. Many of the specimens on which these records are based have been examined and the technique of slide preparation is such that reliable specific identifications are impossible. I reject all the records but list only the species new to North America. Eylais wilsoni, op. cit., p. 158. Fiona nodata, op. cit., p. 161. Puma nodata laminata, op. cit., p. 161. Fiona uncata, op. cit., p. 161. Additional Type Material in the Marshall Collection The species listed below were described by Marshall from outside of North America and are represented by type material in the Marshall Collection. Arrenurus asiaticus Marshall, 1919, Trans. Amer. Micros. Soc., 38: 276-277, pi. 29, figs. 8-10 China. Arrenurus distinclus Marshall, 1919, op. cit., p. 277, pi. 30, figs. 14-16 China. Arrenurus epimerosus Marshall, 1919, op. cit., pp. 278-279, pi. 31, figs. 25-28 Brazil. 56 FIELDIANA: ZOOLOGY, VOLUME 35 Arrenurus geei Marshall, 1921, Trans. Amer. Micros. Soc., 40: 172, pi. 11, figs. 26-29 China. Arrenurus habanicus Marshall, 1927, Trans. 111. Acad. Sci., 19: 198 Cuba. Arrenurus maderius Marshall, 1919, Trans. Amer. Micros. Soc., 38: 279, pi. 31, figs. 29-32 Brazil. Arrenurus merrilli Marshall, 1919, op. cit., pp. 277-278, pi. 30, figs. 17-18 Brazil. Arrenurus pisciscaudapetiolatus Marshall, 1928, Trans. Wis. Acad. Sci., 23: 605, pi. 15, figs. 20-25 China. Arrenurus quadricornicus Marshall, 1919, Trans. Amer. Micros. Soc., 38: 279-280, pi. 31, figs. 33-37 British Guiana. Arrenurus scapulatus Marshall, 1910, op. cit., 29: 98-99, pi. 1, figs. 2-6 Belgian Congo. Arrenurus soochowensis Marshall, 1921, op. cit., 40: 171, pi. 11, figs. 22-25 China. Arrenurus triconicus Marshall, 1919, op. cit., 38: 278, pi. 30, figs. 19-24 British Guiana. Arrenurus valencius Marshall-, 1919, op. cit., p. 277, pi. 29, figs. 11-13 Venezuela. Hydrachna nova Marshall, 1928, Trans. Wis. Acad. Sci., 23: 601-602, pi. 13, figs. 1-4 China. Hydrachna simulans Marshall, 1928, op. cit., p. 602, pi. 14, figs. 16-18 China. Koenikea indistincta Marshall, 1936, Carnegie Inst. Wash. Pub., no. 457, p. 134, figs. 1-5 Yucatan. Limnesia koenikei var. asiatica Marshall, 1928, op. cit., p. 604, pi. 14, figs. 13-15 China. Neumania cenotea Marshall, 1936, Carnegie Inst. Wash. Pub., no. 457, pp. 133-134, figs. 6-8 Yucatan. Neumania geei Marshall, 1928, Trans. Wis. Acad. Sci., 23: 603-604, pi. 14, figs. 10-12 China. Fiona erratica Marshall, 1940, Trans. Amer. Micros. Soc., 59: 377-378, pi. 2, figs. 8-11 Argentina. Fiona marianaensis Marshall, 1927, Trans. 111. Acad. Sci., 19: 198 Cuba. Fiona pearsei Marshall, 1936, Carnegie Inst. Wash. Pub., no. 457, pp. 134-135, figs. 9-14 Yucatan. Xystonotus torrei Marshall, 1927, Trans. 111. Acad. Sci., 19: 198-199 Cuba. BIBLIOGRAPHY BAKER, EDWARD W., and WHARTON, G. W. 1952. An introduction to Acarology. 8+465 pp., 377 figs., 1 col. pi. Mac- millan and Co., New York. BERGSTROM, DAVID W. 1953. Hydracarina from the Rocky Mountain region. Trans. Amer. Micros. Soc., 72: 157-162. BERLESE, ANTONIO 1888. Acari Austro-Americani. Bull. Soc. Ent. Ital., 20: 171-222, 9 pis. BONZ, CHRISTOPHORI 1783. Observatio Dr. J. Christophori Gottlieb Bonz. K. Deutsche Akad. naturf. zu Halle, nova acta Leopold., 7: 52-53, 1 pi. BRUZELIUS, RAGNAR MAGNUS 1854. Biskrifning ofver Hydrachnider, spm forekomma inom Skane. Aka- demisk Afhandling. Inaugural dissertation submitted to the faculty of Lund. 66 pp., 5 pis. (Paper not seen.) COOK, DAVID R. 1953. Marshallothyas, a new genus belonging to the subfamily Thyasinae. Proc. Ent. Soc. Wash., 55: 305-308, 10 figs. 1954. Preliminary list of the Arrenuri of Michigan. Part I. The subgenus Arrenurus. Trans. Amer. Micros. Soc., 73: 39-58, 4 pis. CROWELL, ROBERT M. 1952. New records of rheophilic water-mites from northwestern North Carolina. Jour. Elisha Mitchell Sci. Soc., 68: 191-196, 2 pis. 1953. Morphology and developmental stages of Fiona linguaplax n. sp. (Hydracarina: Pionidae), a water-mite from North Carolina. Amer. Midi. Nat., 50: 426-432, 14 figs. DANA, JAMES D., and WHELPLEY, JAMES 1836. On two American species of the genus Hydrachna. Amer. Jour. Sci., (1), 30: 354-359, 1 pi. DUGES, ALFREDO 1884. Atax alzatei. La Naturaleza, 6: 344-347, 1 pi. DUGES, ANTONIO 1834. 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Op. cit., 21: 177-200, 4 pis. 1901. Description of a new genus of North American water mites, with ob- servations on the classification of the group. Op. cit., 22: 105-117, 1 pi. 1902. The North American species of Curvipes. Op. cit., 23: 201-256, 5 pis. 1903. The North American species of Limnesia. Op. cit., 24: 85-107, 2 pis. 1905. A review of the genera of the water mites. Op. cit., 26: 161-243, 10 pis. 1918. The water-mites (Hydracarina). In Fresh-Water Biology, H. B. WARD and G. C. WHIFFLE, Editors, pp. 851-875, 34 figs. New York. Index Current names and principal references in roman type, synonyms in italic type abitibiensis Mars., 34 abnormipes Wolc., 43 acadiensis Hab. (Aturus), 48 acadiensis Hab. (Limnoch.), 34 acadiensis Hab. (Sperch.), 38 Acarus L., 33, 34, 36 Acercus Koch, 30, 45 acerformis Mars., 54 aculeatus Koen., 43 acuticauda Hab., 48 acutus Mars., 50 adensameri Thon, 43 alata Ldbl., 44 Albia Thon, 47 americana Ldbl. (Hydrach.), 34 americana Ldbl. (Limnoch.), 34 americana Mars. (Frontip.), 39 americana Mars. (Hydrach.), 33 americana Mars. (Fiona), 46 americana Piers. (Limnes.), 41 americanus Hab. (Clath.), 35 americanus Mars. (Arren.), 52 americanus Mars. (Atract.), 42 americanus Mars. (Hydro.), 37 americanus Mars. (Mideop.), 49 americanus Mars. (Testud.), 40 americanus Mars. (Tiphys), 45 amplus Mars., 53 angustocaudatus Mars., 53 anomala Koen. (Limnes.), 41 anomala Mars. (Limnes.), 41 anomalus Crow. (Torrent.), 55 anomalus Koch (Torrent.), 40 apetiolatus Piers., 51 aphelocercus Lav., 51 aquatica L., 34 arcuata Wolc., 43 armata Mars., 43 ARRENURIDAE, 50 arrenuroides Wolc., 54 Arrenurus Duges, 29, SO, 31, 47, 50, 52, 54, 55 artaacetabula Mars., 38 asiatica Mars., 56 asiaticus Mars., 55 asopos Cook, 36 asper Wolc., 49 Alax Koch, 43, 55 ATRACTIDAEIDAE, 30, 39 Atractides auct., 30, 40, 55 Atractides Koch, 30, 42, 55 Aturus Kram., 48, 55 auricularis Lav., 53 auris Lav., 53 AXONOPSIDAE, 47 Axonopsis Piers., 48 bakeri Mars., 34 belonocercus Lav., 51 bicaudatus Mars., 50 bilunata Mars., 33 bipapillata Thor, 48 birgei Mars., 51 bleptopetiolatus Cook, 53 bonzi Leidy, 55 Brachypoda Hab., 48 Brachypoda Leb., 48 brevibrachiata Mars., 44 brevirostris Koen., 38 caerulea Mars., 47 californica Ldbl., 41 calif ornicus Mars., 40 Calonyx Walt., 35 campelomaicola Mars., 43 canadensis Hab. (Aturus), 48 canadensis Hab. (Sperch.), 38 canadensis Mars. (Hydrach.), 34 capillatus Mars., 51 cardiacus Mars., 51 carnea Koch, 46 cascadensis Lav., 53 cataphracta Koen., 36 caudatus Mars., 52 cenotea Mars., 56 Chitohydrachna Hab., 33 circularis Koen., 41 Clathrosperchon Ldbl., 35 CLATHROSPERCHONIDAE, 35 coccinea Hald., 54 coerulea Ldbl., 41 columbica Mars., 41 cometes Koch, 37 comosa Koen., 33 compactilis Mars., 53 compactus Mars., 40 complanata Miill., 48 concava Wolc., 44 conglobata Koch, 46 conicus Mars., 52 conjecta Koen., 33 66 INDEX 67 connatus Mars., 39 constans Mars., 35 constrictus Wolc., 46 cornicularis Mars., 51 corniger Mars., 51 cornuta Wolc., 41 coronis Wolc., 46 couleensis Lav., 50 crassipalpis Koen. (Atract.), 42 crassipalpis Ldbl. (Clath.), 35 crassipalpis Mars. (Sperch.), 38 crassipes Mlill., 43 crassus Wolc., 46 crenellatus Mars., 50 crenulata Mars., 33 crinita Koen., 34 cruciata Hall, 42 cruenta Mull., 32, 33 Curvipes Koen., 46 cylinaratus Mars., 52 Cyclothrix Wolc., 34 debilis Wolc., 46 decaporus Koen., 42 deceptor Hab., 48 dentipetiolatus Mars., 53 desecta Koen., 35 despiciens Duges, 37 determina Mars., 49 diminuata Ldbl., 33 DIPLODONTIDAE, 37 Diplodontus auct., 37 Diplohydrachna Thor, 33 distincta Mars. (Leb.), 38 distincta Mars. (Neum.), 44 distinctus Mars. (Arren.), 55 diversus Mars., 45 dorsoscutata Viets, 33 drepanophorus Cook, 53 droueti Hab., 48 elevatus Mars., 51 ellipsoidalis Mars., 40 elliptica Mars., 41 elongatus Mars. (Arren.), 51 elongatus Mars. (Oxus), 39 ennishonensis Hab., 33 epimerosus Mars., 55 erratica Mars., 56 estellae Hab., 48 exilis Koen. (Hygro.), 42 exilis Wolc. (Fiona), 46 expansa Mars., 49 expansus Mars., 51 extendens Mull. (Eyl.), 34 extendens Mars. (Neum.), 44 EYLAIDAE, 34 Eylais Latr., 34, 55 fakata Koen., 35 falcicornis Mars., 53 Feltria Koen., 45 FELTRIIDAE, 45 feuerborni Viets, 36 fibrosa Ldbl., 49 figuralis Koch, 43 fissicorniformis Cook, 53 fissicornis Mars., 53 5-undulata Hald., 54 flabellifer Mars., 53 fluviatilis Crow., 55 forpicatus Neum., 50 Forelia Haller, 47 formosa D. and W., 43 formosus Hab., 48 fossulatus Koen., 43 fragilis Mars., 44 Frontipoda Koen., 39 fulgida Koch., 40, 41 fuscatus Koen. (Fiona), 47 Geayia Thor, 50 geei Mars. (Arren.), 56 geei Mars. (Neum.), 56 gennadus Cook, 53 geographica Mull. (Hydrach.), 34 geographicus Mars. (Torrent.), 40 gerhardi Mitch., 32 gibberipons Viets, 35 glandulosus Koen., 38 globosa Geer, 33 globator Mars. (Arren.), 52 globator Mull. (Arren.), 51 Gnaphiscus Koen., 39 guatemalensis Stoll, 46 habanicus Mars., 56 haldemani Piers. (Union.), 43 haldemani Viets (Koen.), 44 hesperia Ldbl., 34 hickmani Mars., 44 hirsutipalpis Mars., 35 histrionica Wolc., 41 hirsutus Mars., 54 Huitfeldtia Thor, 45 humerosa Hald., 54 hungerfordi Cook (Arren.), 53 hungerfordi Ldbl. (Hydrach.), 33 hutchinsoni Ldbl. (Hydrach.), 33 hutchinsoni Ldbl. (Limnes.), 41 Hydrachna Leach, 29, 31, 32, 33, Sit, 37, 39, 1*3, ^6, 48, 49, 51, 54, 56 HYDRACHNIDAE, 32 Hydrochoreutes Koch, 45 Hydrodroma Koch, 37 HYDRODROMIDAE, 37 Hydrovolzia Thor, 32 HYDROVOLZIIDAE, 32 Hydryphantes Koch, 36, 54 HYDRYPHANTIDAE, 36, 54 Hygrobates Koch, 57, 42, 55 HYGROBATIDAE, 42 68 FIELDIANA: ZOOLOGY, VOLUME 35 inconstans Wolc., 46 indistincta Mars. (Koen.), 56 indistinctus Mars. (Torrent.), 40 indistinctus Wolc. (Union.), 43 infundibularis Mars., 50 infundibulata Ldbl., 35 infnndibulifera Koen., 35 ingens Koen., 43 insignis Neum., 38 insularis Mars., 46 intermedia Koen. (Union.), 43 intermedius Crow. (Aturus), 55 intermedius Mars. (Arren.), 52 intermedius Mars. (Oxus), 39 interpositus Koen., 53 interrupta Mars., 46 invaginatus Lav., 51 jasperensis Mars., 38 jordanensis Mars., 40 kenki Mars., 50 kincaidi Lav., 51 kodiakica Mars., 44 Koenikea Wolc., 44, 56 koenikea Wolc., 41 koenikei Piers. (Limnes.), 53 krameri Koen., 51 Krendowskia Piers., 49 Krendowskia Wolc., 50 KRENDOWSKIJIDAE, 49 lactea Hald., 54 lamellipalpis Ldbl., 49 laminata Bergs., 55 Laminipes Piers., 45 laticaudatus Mars., 50 laticornis Mars., 53 latigenitalia Mars., 47 latilamellis Mars., 46 latipalpus Mars., 37 latissima Piers., 49 lauta Walt. (Galon.), 35 lautus Koen. (Arren.), 53 laversi Mars., 51 Lebertia Neum., 38, 55 LEBERTIIDAE, 38 leuckarti Piers., 46 liliacea Mull., 47 Limnesia Koch, 40, 54, 56 LIMNESIIDAE, 40 Limnesiopsis Piers., 40 Limnochares Latr., 34 LIMNOCHARIDAE, 34 linguaplax Crow., 46 Ljania Thor, 48 longicaudatus Mars., 51 longipalpis Herm. (Hygro.), 42 longirostris Crow., 55 longiseta Mars., 44 lugubris Hald., 55 lunata Mars., 37 Lundbladia Viets, 36 lutescens Koch (Hygro.), 42 lutescens Herm. (Pionops.), 46 lyriger Mars., 50 maculata Miill., 41 maderius Mars., 56 magnicaudatus Mars., 53 magniscutata Mars., 33 major Mars., 53 mamillanus Mars., 51 manubriator Mars., 52 marianaensis Mars., 56 marshallae Koen. (Eyl.), 35 marshallae Ldbl. (Hydrach.), 34 marshallae Ldbl. (Limnes.), 41 marshallae Viets (Koen.), 44 marshallae Viets (Limnes.), 41 marshalli Piers. (Arren.), 52 marshalliana Ldbl., 41 Marshallothyas Cook, 36 maryellenae Cook, 53 martisensis Mars., 38 medius Wolc., 47 Megaluracarus Viets, 29, 51 megalurus Mars., 52 Megapus Neum., 30, 42, 55 mercedensis Mars., 40 merrilli Mars., 56 michaeli Koen., 36 microscutata Mars., 33 Micruracarus Viets, 29, 50 Midea Bruz., 49 MIDEIDAE, 49 MIDEOPSIDAE, 49 Mideopsis Neum., 49 miliaria Berl., 33 minimus Mars., 40 minuta Koen., 45 mirabilis Piers., 48 mitchelli Hab., 38 monensis Mars., 41 montifer Mars., 50 morrisoni Mars., 52 mozleyi Mars., 36 mucronatus Lav., 52 multiporus Mars. (Hydry.), 36 multiporus Koen. (Hygro.), 42 muscicola Mitch., 36 musculus Miill., 39 muttkowskii Mars. (Arren.), 51 muttkowskii Mars. (Neum.), 43, 44 Najadicola Piers., 43 natans Crow. (Leb.), 55 natans Lav. (Limnoch.), 34 nebulosa Hald., 54 needhami Mars., 38 Neoaxonopsis Ldbl., 48 neocarnea Mars., 46 neooctopprus Mars., 42 neosuperior Mars., 53 INDEX 69 Nesaea Koch, 46 Neumania Leb., 43, 56 nevadensis Mars., 37 nodata Bergs. (Fiona), 55 nodata Mull. (Fiona), 47 nodipalpis Thor, 42 nova Mars. (Hydrach.), 56 novatus Viets (Hydry.), 36 novus Viets (Hydry.), 36 novus Mars. (Pionac.), 46 oblongatus Mars., 40 oblongus Kram., 39 obovatus Mars., 40 obturbans Piers., 47 occidentalis Mars., 42 occidentalis Mars. (Gnaph.), 39 occidentalis Mars. (Torrent.), 40 octoporus Mars., 42 odontogaster Ldbl., 48 okobojica Mars., 44 ontarioensis Mars., 38 orbicularis Mars. (Pseudohy.), 37 orbicularis Miill. (Mideop.), 49 orbiculata Mull., 49 orthppes Mars., 42 ova/is Koen. (Atrac.), 42 ova/is Mars. (Arren.), 51 ovalis Mars. (Forel.), 47 ovalis Mars. (Sperch.), 38 ovalis Mars. (Tyrr.), 41 ovata Mars. (Galon.), 35 ovata Mars. (Neum.), 44 ovata Wolc. (Geayia), 50 oviformis Hald., 55 Oxus Kram., 39 pallidus Hah., 48 paluster Thor, 50 Panisopsis Viets, 36 Panisus Koen., 36 papillator Mars., 44 parallellatus Mars., 52 parmata Mars. (Leb.), 39 parmatus Koen. (Sperch.), 38 Partnunia Piers., 35 Partnuniella Viets, 35 parviscutus Mars., 42 parvulus Viets, 37 paucipora Viets, 35 paucispina Wolc., 41 pearsei Mars., 56 pectinatus Wolc., 43 pedunculata Koen., 36 personata Hald., 55 pheno pieces Mars., 42 pilositarsa Hah., 48 pinguisomus Gook, 53 Fiona Koch, 46, 55, 56 Pionacercus Piers., 46 PIONIDAE, 45 Pionopsis Piers., 46 pisciscaudapetiolatus Mars., 56 pistillatus Mars., 53 placophora Monti, 32 planus Mars., 53 platy-rotundo-cuspidator Miinch., 53 pleopetiolatus Mars., 54 plumifer Thor, 38 podagricus Koch, 45 pollictus Mars., 54 Polyxo Monti, 32 Pontarachna Phil., 42 PONTARACHNIDAE, 41 porosa Thor, 39 primaria Mars., 45 projector Hab., 48 prominulus Mars., 52 protractipora Ldbl., 41 Protzia Mars., 35 PROTZIIDAE, 35 proximo Hald., 55 pseudocaudatus Piers., 52 pseudoconicus Piers., 52 pseudocylindratus Piers., 52 Pseudohydryphantes Viets, 37 PSEUDOHYDRYPHANTIDAE, 37 pseudosetiger Mars., 51 Pseudosperchon Mars., 38 pseudosuperior Cook, 54 pubescens Mars., 44 pugilis Wolc., 47 punctata Mars., 44 punctulum Phil., 42 purpurea Hab., 48 pyriformis D. and W., 54 quadricornicus Mars., 56 quinquemaculosa Mars., 39 rawsoni Mars., 52 rectangularis Mars., 52 rectipes Thor, 45 reducta Ldbl., 33 reelfootensis Hoff, 49 reflexus Mars., 54 reighardi Wolc., 47 reticulata Hald., 55 Rhabdohydrachna Viets, 33 rheophilous Lav., 52 rimosa Piers., 35 robusta Mars., 35 rosea Ldbl. (Mideop.), 49 rosea Koch (Piona), 46 rotunda Mars. (Hydrac.), 33 rotunda Kram. (Piona), 47 rotundus Mars. (Arren.), 51 ruber Geer (Hydry.), 36 ruber Mars. (Hygro.), 42 rubrapes Mars., 47 sagulatus Koch, 45 sayi Piers., 43 scaber Kram. (Atur.), 48 70 FIELDIANA: ZOOLOGY, VOLUME 35 scaber Koen. (Atur.), 48 scabra Hald., 54 scabriosus Hab., 38 scapulatus Mars., 56 Scutohydrachna Viets, 33 scutulatus Mars., 51 scutuliformis Mars., 52 securiformis Mars., 52 semicircularis Piers. (Arren.), 52 semicircularis Mars. (Neum.), 44 separata Ldbl., 33 serratus Mars. (Arren.), 54 serratus Wolc. (Union.), 43 setosicauda Hab., 48 setiger Koen. (Arren.), 51 setiger Mars. (Arren.), 51 setiger Wolc. (Fiona), 47 setoniensis Hab., 48 setosa Koen. (Leb.), 39 setosus Koen. (Gnaph.), 39 sierrensis Mars., 40 similis Viets, 49 simulans Mars. (Arren.), 52 simulans Mars. (Hydrac.), 53 simulans Mars. (Tiph.), 45 simulans Mars. (Torrent.), 40 socialis Mars., 47 solifer Mars., 52 soochowensis Mars., 56 Sperchon Kram., 38, 55 SPERCHONIDAE, 38 Sperchonopsis Piers., 38 spinipes Koch (Atract.), 42 spinipes Mars. (Atract.), 42 spinipes Wolc. (Koen.), 44 spinipes Mull. (Neum.), 43 spinulosus Wolc., 47 Spio Koch, 45 Sporadoporus Wolc., 35 squamosus Crow. (Sperch.), 55 squamosus Kram. (Sperch.), 38 stationis Thon, 47 Steganaspis Wolc., 50, 5| stipata Ldbl., 34 stolli Koen., 36 stricta Wolc., 43 sturgeonensis Mars., 42 superior Mars., 54 symmetrica Hald., 55 tacomaensis Mars., 54 tahoei Mars. (Arren.), 52 tahoei Mars. (Torrent.), 40 Tanaognathus Wolc., 44 tau-insignita Koen., 39 tenuabilis Mars., 36 tenuipalpis Koen. (Sperch.), 38 tenuipalpis Mars. (Neum.), 44 Testudacarus Walt., 40 tetratumuli Munch., 54 Teutonia Koen., 37 TEUTONIIDAE, 37 Tetrahydrachna Ldbl., 33 Thyas Koch, 36 THERMACARIDAE, 37 Thermacarus Sok., 37 thermalis Viets, 35 thermobius Sok., 37 Tiphys Koch, 30, 45 Tiphys Wolc., 47 torrei Mars., 56 Torrenticola Piers., 30,40,55 TORRENTICOLIDAE, 30, 39 torris Mull., 45 triangularis Say (Hydrac.), 54 triangularis Wolc. (Fiona), 47 triangulifera Koen., 35 tricolor Pack., 54 triconicus Mars., 56 trifoliatus Mars., 54 tripeltatus Walt., 40 Truncaturus Thor, 29, 50 tumidus Wolc., 43 turgidus Wolc., 47 tyrrelli Koen., 39 Tyrrellia Koen., 41 uncata Bergs., 55 undulata Mull., 41 unguitarsa Hab., 48 ungulata Koch, 45 unicolor Hald., 55 uniformis Mars., 52 Unionicola Hald., 43, 5,4, 55 UNIONICOLIDAE, 43 valencius Mars., 56 variegator Koch, 47 venezuelae Thor, 50 ventropetiolatus Lav., 53 venusta Koch, 36 vernalis Koen., 44 verrucosa Protz., 38 versicolor Mull., 48 vigilans Piers., 36 viridis Duges, 50 waddellicus Mars., 40 wallensis Cook, 54 walteri Crow., 55 wardi Mars., 52 wawassee Mars., 41 Wettina Piers., 45 wilsoni Bergs., 55 wisconsinensis Mars., 46 wolcotti Koen. (Leb.), 39 wolcotti Mars. (Arren.), 54 wolcotti Mars. (Fiona), 47 wolcotti Piers. (Limnes.), 41 wolcotti Piers. (Union.), 43 wolcotti Viets (Koen.), 44 wyomingensis Mars., 39 Xystonotus Wolc., 49, 56 ypsilophora Bonz, 43, 55