[ 221 ] VII. SUliVET OF FISHING-GROUNDS, WEST COAST OF IRELAND, 1890-1891. X.-REPORT ON THE CRUSTACEA SOHIZOPODA OF IRELAND. By ERNEST AV. L. HOLT, and W. I. BEAUMONT, B.A., Cantab. (Plate XVI.) COMMUNICATED BT DR. E. F. SCHAEFF. [Rend Apeil 19, Received for Publication 'SIxy 30, 1899. Published Apbil 30, 1900.] When the Survey terminated in 1891 all the collections, with the exception of certain duplicates other\yise disposed of by the Society, were handed over to the National Museum. A great deal of the material remained still unexamined, or had only been roughly sorted by one of us during the survey. This was especially the case with the smaller Crustacea and other minute forms taken in fine-meshed nets of various descriptions. We have recently been able, by the permission of Dr. R. F. Scharff, to examine a number of bottles containing such gatherings, and now present the results of our observations in so far as concerns the Schizopoda. At the same time, since the energies of the Society are once more directed to the marine zoology of the country, we have endeavoured to compile as complete a list of Irish members of the group as can be obtained from all the material in the national collection, and from the meagre literature of the subject. Such a list, imperfect as it certainly is, cannot fail to be useful as a basis for future observations. It has been brought as far as possible up to date, while in press, by observations made at the Society's Marine Laboratory during the present 3'ear, and by the examination of the " Oceana" Collection. Though in themselves of no commercial value, the Schizopoda form a most important item in the food of fishes, while the observed conditions of their distri- bution, and the pelagic or partially pelagic habit of at least some of the species appear likely to yield results of interest, were the subject adequately studied. Norman's admirably useful synopsis of the British membersf is sufficiently recent to enable us to confine our introductory remarks to a brief comparison of -\ " British Schizopoda of the families LophogastridK and Euphausidfe." Aim. Maij. Nat. Hist., S. 6, i.\., 1892, p. 454, and "British Mysida>," ihld., x., 1892, p. 143. TR.\NS. ROY. DUB. SOC, N.S. VOL. VII., PAET VII. 2 I 222 Holt & Beaumont — Siwveu of Fishing-firouuds, W. Coast of Ireland^ 1890-91, the Irish fauna, as we at present know it, with that of the British Isles generally. Norman's list contains one species of Lophogastridse, seven of Euphausidse, and thirty-three of Mysidte. Of the Euphausida?, Boreoplumsia inermis (Kr5yer), B. Raschil (M. Sars), Thysanoessa longkaudata (Kroyer), and Nematoscelis megalops^ G. 0. Sars, have not yet been taken in Irish waters. Nematoductijlus h'dopis, Caiman, a recent addition to the family from deep water off the S.W. of Ireland, cannot yet be included in the British fauna, since it lias only been taken at 1020 fathoms, or 20 fathoms below the line of soundings which constitutes Noi-man's western boundary of our zoological dominions. The same remark applies to Eucopia australis ; and these species will probably be met, as predicted by Norman in the case of Biiphausia pellucida, Dana, within the British area. Recent observations have altered Norman's list of British species of Mysidse in personnel, but not in number, Siriella frontalis, M.-Edw., having been expunged from the list, while Dasymysis [AcantJiomysis) longicornis, M.-Edw., has been added thereto. We can find no record of the following species from Irish waters, nor are they represented in our material : — Siriella norvcgica, G. O. Sars. S.jaltensis, Czern. S. Brooki, Norman. Erythrops Goesii, G. 0. Sars. B. elegans, G. 0. Sars. Schistomysis Heller i [G. 0. Sars). S. Parker/, Norman. As some set-off to these deficiencies, we are able to add two species to the British list, viz. Parerythrops ohesa, G. 0. Sars, and Mysidella typica, G. 0. Sars. Two 'species, S. norvegica and E. elegans, have been recorded by AValker from the Irish Sea.f It seems improbable that they are absent from the coast of county Down, and, in fact, the observed differences in the British and Irish lists are unlikely to survive a proper investigation of the Irish area. The Society's surveying expeditions were concerned with the fishing-grounds, at that time in many cases unexplored. These grounds are mostly at considerable depths, and comparatively little time was available for inshore operations witli nets suit- able for the capture of Mysidee and tlie like. Hence it is by no means remarkable that the littoral forms, which are a large proportion of the above list, do not f Though the localities o£ some of Walker's records from the Irish Sea are actually nearer to the Irish than to the English coast, the deep channel to the westward of tlie Isle of Man appears to be the natural line of demarcation between Great Britain and Ireland. Report on ihe Crusfacea Hc.ldzopoda of Irelind. 223 appear in the collection. The bulk of the survey material was taken in bags of mosquito-netting suspended inside the large beam trawl. This is, apparently, a most efficacious method of collecting SchizojDods, but has the disadvantage of injuring the specimens on account of the strain against the meshes resulting from the comparatively high speed at which the trawl is hauled, and the frequent irrup- tion of large fish, crabs, sand, and other injurious matters. Mosquito-netting is, moreover, rather coarse for such small creatures as Erytlirops elcgans, &c., and this must be borne in mind in considering the evidence afforded by our record of the numbers of different species taken in the several hauls. In the systematic list it will be understood that we adopt Norman's classifica- tion and synonymy, unless the contrary is expressly stated. Further, in the brief account which we have given of the distribution, it has seemed to us desirable to condense the references by ascribing to Norman (A. M. N.*) those records, whether original or compiled, which appear in his paper. In some cases we have condensed the record still further, as by substituting " E. and W. Scotland" for various localities on both coasts. Professor Sars' work is too well known to need mention here ; while Norman has himself ackowledged the assistance of Mr. Thomas Scottf and others in the communication of British forms. The most important paper, after Norman's, dealing with Irish Schizopoda, is that of Mr. A. O. Walker.J Records other than Irish, which have appeared subsequent to Canon Nj. — 8 miles off Achill Head, 13th April, 1899 (many specimens in stomach of mackerel from surface drift-net). Ilusetwi, Dublin. — No. 114, 1896. Whitepool Bay, Co. Antrim, per Mr. R. Welch. A number of specimens cast ujd on the beach. Previous Irish Records.— 0& Valentia (A. M. N.*) : Valenlia Harbour (A. 0. W.*) : off N. of Ireland (Herdman). Distribution. — East and west coasts of Scotland (A. M. N.*): Irish Sea and North Channel (Herdman). Norway, Faroe Channel, &c. ; N.E. America (A. M.N.*): Bay of Biscay (Caullery) : N.E. America (Herdman). The presence of these Schizopods in the stomach of a ground-fish like Pris- tiurus affords fairly conclusive proof that they are not at all times pelagic in habit. The specimens from off the Skelligs may have been taken either at the bottom or during the ascent of the net, and the same remark would seem to apply to creatures taken in any ordinary net which cannot be opened and closed at given depths. Professor Herdman obtained his material entirely at the siu-face by means of the pumps of an Atlantic liner (Trans. Liverpool Biol. Soc, sii., 1898, p. 33); and it is noteworthy that the species was only met with off the coasts of the European and American continents, and not in the central part of the Atlantic. t Euphautia pellucida, Daua ; Stylocheiron sp. See Note jidded in Press, p. 250. Report on the Crustacea Schuopoda of Ireland. 225 Nyctiphanes Coucliii (Bell). Plato XVI., fig. 1 ; and fig. I., p. 226. Thysanojioda Couchii, Bell, "British Stalk-eyed Crustacea,'' 18.53, p. 346. Bell's figure, the only drawing of the species with which wc are acquainted, is on a very small scale, and not wholly satisfactory. By the kindness of Mr. C. Green, B.A. (T.C.D.), we are able to give a more detailed illustration of the whole animal, the subject in this case being a male from Valentia Harbour. We are indebted to Mr. M. F.Woodward for a dissection and draAving of the branchial apparatus of the same specimen, and of the copulatory processes of the first pleopods of this and the preceding species. We take tlie subjoined diagnosis, with slight verbal alteration, from Norman. Carapace without lateral spines, its lobes not jiroduced over the eyes. Rostrum broadly and bluntly triangular, concealing the base of the eye-stalks. A spine over tlie base of the telson and a small siniple ventral preanal spine. In the male the antennulcs, in addition to the usual reflexed membranous leaflet at the end of the first joint, have another reflexed membranous leaflet at the end of the second joint of the peduncle, the distal portion of the leaflet being cut into digitated processes. The copulatory apparatus of the inner plate of the first pleopod (fig. I., p. 226, 8) in a specimen of 12 mm. is not unlike that of N. australis, G. 0. Sars {cf. Sars, Challenger Report, xiir., PI. xxi., fig. 6). It is much less complicated than in full-grown N. norvegica [cf. fig. I., 9). We have had no opportunit}^ of exami- ning males of the last-named species at sizes corresponding to what appears to be the fully-developed condition of N. Couchii. (See Note added in Press, p. 250.) Not in the Survey Collection. Valentia Harbour, surface, September 30th, 1898, per Miss C. Delap. Previous Irish Record. — Off Valentia (A. M. N.*). Distribution. — Banff ; coast of Cornwall (A. M. N.*) : off Penlee Point, and in Cawsand Bay, Plymouth : Firth of Tay (per W. T. Caiman). Genus Thysanoessa, F. Brandt. Thysanoessa neglecta (Ki'oyer). Survey. — Station 130, Kenm are river, off Sneem, 24 fathoms, mud. March 30th, 1891 (in net attached to trawl, day-time). Station 144, west of Inishmore, Aran Islands, about 45 fathoms, April 7th, 1891 (in large tow-net, near surface, midnight). 226 Holt & Beaumont — Survei/ of Fkhing-groiinds, W. Coast of Ireland, 1890-91. I'lO. I. -5. The five anterior gills of the right side of Nijctiphanes Couchii, 3 , \2 mm., arranged in the natural order. 6. The sixth gUl, with luminous organ and exopodite, of the same specimen. 7. The seventh thoracic appendage of the same specimen. Three of the external gill-plumes have been cut off. 8. Inner plate of the first pleopod of the same speci- men. 9. Inner plate of the first pleopod oiyyctiphaiics norregica, S , 3o mm., from Upper Loch Fyne. All figures drawn to the same scale with camera hicida. Report on the Crustacea Schisopoda of Irclnml. 227 The numerous specimens of St. 144 were taken while theS.S. "Harlequin" was tending on some local boats engaged in experimental mackerel-fishing. Some mackerel were caught, but their food was not examined. Marine Laboratory . — 4 miles west of High Island, Co. Galway, surface and bottom tow-nets at night, 16th June, 1899, and very common in stomachs of mackerel from surface drift-nets about tlie Bofin islands during the same month. No Previous Irish Record. Distribution.— Aberdeen ; Firth of Forth; Loch Seaforth (A. M. N.*) : off Hebrides ; mouth of English Channel (Ortmann). Norway; Finmark; Siberia; N.K. America (A. M. N.*) : Bay of Biscay (Caullcry)" Genus— NEMATOBACTYLUS, Caiman. Nematodactylus boopis, Caiman. Calman, Trans. R. I. Acad., xxxi., 1896, p. 17, PL ii. Off S.W. of Ireland, 1020 fathoms (Caiman). The species is not definitely British, as Norman's limit is the 1000 fathoms line. It is mentioned here for purposes of conveuience. Genus— EUCOPIA, Dana. Eucopia australis, Dana. Calmax, Trans. R. I. Acad., xxxi., 1896, p. 1.5. Off S.W. of Ireland, 1020 fathoms (Caiman). This is a cosmopolitan species from the deep water of the oceans ; Caiman considers that its occurrence at or near the surface must be regarded as exceptional. It has not yet been taken actually within the limits of the British area. Family.— MYSID^. Sub-family. — Siriellin^. Genus Siriella, Dana. Siriella Clausii, G. 0. Sars. Not in the Survey Collection. Marine Laboratory. — Blacksod Bay, 29th March, 1899, 6-8 fathoms; Inisbofin Harbour, 4th to 18th August, 1899, very common in surface and midwater nets at night, but not found, perhaps on account of abundance of drift-weed, during the day. Previous Irish Record. — S.E. of Ferry pier, Valeutia Harbour (A. 0. W.*) Distribution.— Loch Fyne (A. M. N.*) : off Plymouth. f Mediterranean (A. M. N.*). f A Sirlulla of rather abnormal character, from Start Bay, is also probably referable to this species. 328 Hoi/r & Beaumont — Survey of Fishing-grounds, W. Coast of Ireland, 1890-91. Siriella armata (Milne- Edwards). SirieUit intermedia, Gouiret, Aim. iliis. Hist. Nat. Mavs., iii., 1889, llera. v., p. 183, Pis. xvii. xvin. Survey. — Blacksod Bay, August 6tli, 1890. Station 1-15, Killeany Bay, Aran, April 8th, 1891. Killeany Bay, July 26th, 1890. 3Iarine Laboratory. — Mouth of Killeany Bay, 25th March, 1899 ; Blacksod Bay, 29th March, 1899; Ballynakill Harbour, 15th May, 1899; Bofin Harbour, August, 1899 (common among weeds, but only one young example in tow-net with S. Clausii\ Museum, Dublin. — No. 195, 1895. Roundstone. Previous Irish Record. — Valentia Hai'bour (A. O. W.*). Distribution. — E. and W. Scotland ; Isle of Man ; S. and S.W. England (A. M. N.*): Irish Sea (A. O. W.). Trieste, Guletta (A. M. N.*) : Marseilles (Gourret): Brittany; Gulf of Lyons (Pruvot): off Vlieland, North Sea (Ehrenbaum). Jersey (A. M. N.*). We have recently shown [Ann. Mag. Nat. Hist., s. 7, March, 1899, p. 151) that British records of *S'. frontalis refer in realit^^ to *S'. armata, there being no evidence of the occurrence of the former within the British area. The variability of certain characters, noted in Plymouth examples of S. armata, is equally present in Irish specimens. We believe that S. intermedia, Gourret, from Marseilles, is separated by its discoverer from S. armata on quite insufficient grounds. The least unimportant distinction that we can discover in the text is the relative shortness of the rostrum ; but this disappears in the light of Gourret's own remark (ojo. ciY., p. 182) that Marseilles examples of ^S*. armata have a shorter rostrum than is figured by Sars. Pruvot, who enumerates in liis list both S. armata and 3Iysis Griffithsice, Bell, may intend thereby to convey the intimation that he rejects Norman's view of the identity of these species with eacli otlier. On the other hand the entrj' may be no more than evidence of carelessness of compilation. Sub-family. — GASTROsACCiNiE. Genus Gastrosaccus, Norman. Gastrosaccus spinifer (Goes). Survey. — Station 223, Loughrosmore Bay, 9 to 4 fathoms, sand. IMny 21.st, 1891. Marine Laboratory. — Blacksod Bay, 29th March, 1899. Report on the Crustacea Schizopoda of Ireland. 229 3fuseum, Duhlm. — No. 195, 1895. Roundstone. Previous Irish Records. — Port Magee entrance, Valentia Harbour (A. 0. W.*): at surface, off N. and. N.E. Ireland (Herdman). Distribution. — E. and W. Scotland ; Whitby ; Starcross (A. M. N.*) : Dogger Bank (T. S.) : Irish Sea (A. 0. W.). Sweden ; Denmark ; mouth of the Seine (A. M. N.*) : Heligoland, coasts of Germany and S. Norway (Ehrenbaum) : Channel Islands (Walker and Hornell). Gastrosaccus sanctus (Van Beneden). Survey. — Station 145, Killeany Bay, Aran. April 8th, 1891. 3Iarine Lahoratori] . — Mouth of Killeany Harbour, 25th March, 1899 ; off Bofin Harbour, 17 fathoms, 17tli July, 1899 ; Bofin Harbour, 4th and 5th August, 1899, common in surface tow-nets at night, but only one specimen found, in a bottom net, during the day time. No Previous Irish Record. Distribution. — Irish Sea (A. 0. W.) : Plymouth (W. Garstang!): Jersey (A. M. N.*). Belgium ; Boulonnais; Naples; Goletta (A. M. N.*) : Black Sea ; Sea of Azov (Sowiuski, 1894, 1895). Most of the sjjecimens from Bofin have practically no trace of the upturned processes of the hind margin of the carapace, though agreeing in other respects with- the type. The same peculiarity has been observed in material from Plymouth, and appears to require further attention. Genus Haplostylus, Kossmann. This genus is distinguished from Gastrosaccus by the rudimentary condition of the inner branch of the third pleopod of the male. Forwardly directed lobes of the posterior margin of the carapace are invariably absent. f Haplostylus Normani (G. 0. Sars). Gastrosaccus Norxiiani, G. 0. Sars, et auct. Not in the Surveij Collection. Irish Record.— 0^ Valentia (A. M. N.*). Distribution. — Rockall (A. M. N.*). Plymouth. Mediterranean (A. IM. N.*). f We are indebted to Mr. W. T. Calmau for the reference on which our diagnosis is founded. TEANS. EOr. DUB. SOC, N.S. VOL. VII., PAET VII. 2 K 230 Holt & BKAUJroNX — Surveij of Fishlnfj-groiinds, W. Coast of Ireland, 1890—91. Genus Anchialus, G. O. Sars. Anchialus agilis, G. 0. Sars. Surveij. — Station US, Ballinskelligs Bay, 32 to 28 fathoms, soft mud. August 21st, 1890. Station 121a, off Ballycottin, 41 fathoms, sand. August 28th, 1890. No Previous Irish Record. Distribution.— ?\yn\0Mi\\ (A. M. N.* !). Naples; Messina (A. M. N.*): Channel Islands (Walker and Hornell). Sub-family. — liETEROMYSiNiE. Genus Heteromysis, S. I. Smith. Heteromysis formosa, S. I. Smith. Not in the Survey Collection. Irish Record. — Valentia Harbour, shore (A. 0. W.*). Distribution.— Y'lvih. of Forth, Guernsey (A. M. N.*). Plymouth (W. Garstang !). Norway ; coast of United States (A. M. N.*). Sub-family. — Leptomysin^. To include a new-comer, Parerythrops obesa, G. O. Sars, Norman's synopsis of this sub-family may conveniently be altered by substituting '^ 3Iale toith at least the second to fifth pairs of pleopods greatly developed and adapted for sivimming ,''^ for " male with all the pleopods, etc.''^ Genus Erythrops, G. 0. Sars. Erythrops serrata, G. 0. Sars. Survey. — Station 115, off the Skelligs, 62 to 52 fathoms, mud and sand. August 20th, 1890. Station 143, west of Inishmore, Aran, 46 to 44 fathoms. April 7th, 1891. Station 125, 40 miles west of Bolus Head, 115 fathoms. March 23rd, 1891. The contents of the surface and bottom tow-nets of Station 125 were accidentally mixed. Obvious derivatives of the bottom are sand, small crabs, and bivalve shells. Two much-damaged Schizopods are almost certainly also from the bottom. One of them, a headless, limbless, and macerated specimen, with a broken telson, is Ixeport on the Crustacea Hchizopoda of Ireland. 231 only recognisable from one of the inner uropods, whicli has the inner margin finely serrulated throughout. This character appears to be confined to E. serrata. In other respects the uropod conforms equally to this species. Previous Irish Records.— 0& Valentia, 80 to 100 fathoms (A. M. N.*): Mr. A. 0. Walker has recorded the species from Station 115, having no doubt received specimens accidentally mixed with Amphipods, etc., from tlie same haul. Distribution.— Shetland ; Moray Firth; Firth of Forth (A. M. N.*) : Loch Fyne (T. S.): Irish Sea (A. 0. W.). Norway, 30 to 200 fathoms (G. 0. S.): Denmark (A. M. N.*). It would appear, from the examination of Irish specimens, that existing descriptions of this species requii'e modification. We find that the serrulation of the inner uropod, a character hitherto held to be of unreservedly specific value, is by no means constant; but is, in fact, practically confined to females and imma- ture males. In females, of which thirty were examined, the serrulation was invariably well-marked. In the male it appears to be lost with maturity, as testified by the perfection of the pleopods, and particularly by the full development of the setae of the copu- latory process of the antennule. Thus, of fifty-six males, twenty-four are devoid of serrulation on the inner uropods, and twenty of these, in which the antennules remain uninjured, have the setae fully developed. The remaining thirty -two males have the inner uropod serrulated ; in twenty- five the setffi of the antennule are undeveloped ; in two the sette are minute ; in one the setae are about half -grown. In the remaining four the antennules are not available. A length of 10 mm., from the tip of the antennal scale to the extremity cf the uropod, approximately represents, for our specimens, the greatest length of males with serrulated uropods. We considered it possible that the above remarks might be of purely local application, the absence of serrulation being a racial, rather than a specific, character. Sars' figures (Monogr. over Mysider, Tab. ii.) could not be taken as evidence, since it was not certain that the serrulated uropod of his figure 11 was taken from the same individual of which the anterior parts, with fully developed setfe, are shown in his figure 10. However, we have since found in the Museum some specimens of E. serrata from the Asbjornsen collection, which appear to have been named by Professor Sars himself. One of them is a mature male, and its inner uropods are as innocent of serrulation as in the case of examples from the West of Ireland. The Asbjornsen specimens are from Lofoten. (See Note, p. 250.) It is possible that these facts are quite familiar to Professor Sars, but if he has published any modification of his original diagnosis, it has escaped our notice. 2K2 232 Holt & Beaumont — Survey of Fishing-grounds, W. Coast of Ireluml, 1890-91. Genus Parerythrops, G. 0. Sars, Monog. over Mysider, Pt. I., ncc Pt. III. Nematopus, G. 0. Sars. Eges short, not flattened, nearly globose, remote from each other ; pigment of dull fulvous colour, not soluble in spirits. Antennal scale very short ; external margin not ciliated, terminating in a spine-point. Legs of moderate length, rather robust; tarsus of (about?) three articulations, besides the stout nail. Telson elongate, sub-triangular ; lateral margins entire ; apex narrowly truncate, beset with four slender S2:)ines and two set£E. Pleopods in female small, simple ; in male first pair small, simple ; remaining pairs biramous, natatory. (Abbreviated from G. 0. Sars.) Parerythrops obesa, G. 0. Sars. PI. XVI., figs. 2, 3. Parerythrops obesa, G. 0. Sars, Carcinolog. Bidrag. Norg. Faun., I. Monog. over Mysider, 1870, p. 41. Carapace of about equal horizontal width throughout, the greatest width Ijeing much more than half the length ; anterior margin produced so as to form nearly a right angle. Pleon less than half as wide as cephalothorax, its last segment longer than the otiiers. Eges large, sub-globose ; internal margin but slightly emarginato. Antennule, peduncle a little longer than tlie eye ; its distal articula- tion longer than the united length of the two proximal. Antennal scale a little longer than peduncle of antennule, sub-rhomboidal, about three times as long as wide ; outer margin terminating in a spine, beyond which the linguiform apex is produced so as to occupy nearly half the length of the scale. Telson nearly equal in length to the last segment of abdomen ; elongate, sub-triangular, greatest width much less than length ; lateral margins nearly straight ; apex very narrow, squarely truncate ; outer pair of terminal spines not half as long as the inner pair. Uropods, outer about one-third longer than inner ; the latter with about 20 strong spines occupying the greater part of its inner margin. Pigment uf adult bright red. Length of adult female about 13 mm., of male about 14 mm. (After G. O. Sars.) Survey. — Station 115. Off the Skelligs, 62 to 52 fathoms, mud and sand. August 20th, 1890. No Previous British Record. Distribution.— Norway ; Lofoten ; Finmark, 30 to 200 fathoms (G. 0. S.). Ueport on the Crustacea Schisopofla nf Ireland. 233 The species is added to tlie British Fauna on the evidence of a single female, so much battered that some of the generic characters cannot be observed. The telson, however, remains available, and is of a form only met with, so far as we know, in the genera Parerythrops and Metererythrops {vide figs. 2, 3). In distinguishing between the three known species, P. obesa, 31. robusta, S. I. Smith, and P. ahyssicola, G. 0. Sars, the small size of the eyes in the last named is a very obvious character. The two first have large eyes of about the same size and form. So far as we can determine, in the absence of the adjacent appendages, and from the defective condition of tlie cephalothorax, the eyes in our specimen are too large to permit of its being assigned to P. ahi/ssicola. Moreover, the outline of the facetted area agrees, on the testimony of Sars' figures, rather with P. obesa tlian with P. abyssicola. While in other characters the latter closely resembles P. obesa, 31. robusta differs from either in having a much more elongate telson. In our specimen it is about equal to the last segment of the abdomen ; in 31. robusta it is about one-third as long as the entire pleon. Minor differences observed by Sars in the characters of the antennules, antenna! scales, and legs are of no use to us, as our specimen has lost all these appendages. P. obesa and P. abyssicola are not separated by any very well-marked charac- ters of the telson, but, although the lateral margins of this structure are rather more curved than in Sars' figure of P. obesa, they agree with that species rather than with P. abyssicola. The proportions of the terminal sjjines are also in harmony with P. obesa rather than with P. abyssicola {cf. Sars, op. cit., PL in., fig. 18, PL xxviii., figs. 9, 10, PL XXIX., figs. 7, 8). The single inner uropod which remained entire in our specimen was broken in manipulation, but has been carefully reconstructed by Mr. Green (fig. 3). At present it has fewer spines than in any of Sars' species, but some have almost certainly been broken off. Genus Mysidopsis, G. 0. Sars. Mysidopsis didelphys (Norman). Survey. — Station 115. Off the Skelligs, 62 to 52 fathoms, mud and sand. August 20th, 1890. Station 125. 40 miles west of Bolus Head, 115 fathoms. March 23rd, 1891. We have already mentioned, under E. serrata, the accidental mixing of the contents of the bottom and surface nets of Station 125. The bottle contains a mangled specimen, apparently a M3^sidopsis, and probably referable to this species. The total length is about 7 mm. The cephalo-thoracic shield is displaced ; the trunk is much macerated ; the legs have disappeared, except the 234 Holt & Beaumont — Survey of Fishing-r/rounds, W. Coast of Ireland, 1890-91. exopodite of one. The eyes are large, of a pale reddish colour. What remains of one antennal scale has the chai'actcrs of the genus. The pleopods are simple. Tlie telson is broken off rather short, but the proximal spines of the lateral margins are rather few, as in 31. didelphjs rather than M. angiista. There is a single spine on the ventral side of the otocyst, a character common to these two species. The size of the eyes, the lateral margins of the telson, and the some- what robust form of tlie whole animal are sufficient, as we think, to justify our determination. From Station 115, in addition to sixteen mature and half-grown specimens, we have two which are quite small. They can be referred without difficulty to the same species as the larger ones, and serve, by comparison, to confirm our determination of the mangled example from Station 125. 31. didelplvjs is recorded by Sars from 50 to 150 fathoms, whereas 31. aiigusta has not yet been taken below the 50 fathom line. Previous Irish Record. — Off Valentia (A. M. N.*). Distribution. — Shetland; Firth of Clyde ; Loch Fyne ; Moray Firth ; Firth of Forth ; off Tynemouth (A. M. N.*). Norway ; Denmark (A. M. N.*). Mysidopsis gibbosa, G. 0. Sars. Survey. — Station 118, Ballinskelligs Bay, 32 to 28 fathoms, soft mud. August 21st, 1890. Ilaritie Laloratory. — Fahy Bay, Ballynakill, 5th March and 18th May, 1899. 3Iuseum, Duhlin. — No. 195, 1895. Roundstone. Previous Irish Records. — Valentia (A. M.N.*): Valentia Harbour (A. 0. W.*). Distribution.— Log\\ Fyne ; Firth of Forth (A. M. N.*): Plymouth (W. Garstang !) : Start Bay : Irish Sea, Port Erin (A. 0. W.). Norway; Denmark; Mediterranean (A. M. N.*). Mysidopsis angusta, G. 0. Sars. Survey. — Station 118, Ballinskelligs Bay, 32 to 28 fathoms, soft mud. August 21st, 1890. Station 1-18, 7 miles S.S.W. of Gregory Sound, Aran, 38 fathoms, sand. April 9th, 1891. Previous Irish Record. — Valentia Harbour (A. 0. W.*}. Distribution.— E. and W. Scotland (A. M. N.*) : Dogger Bank (T. S.): Start Bay, and off Plymouth. Norway ; Naples (A. M. N.*). Report on the Crustacea Scliisopoda of Ireland. 235 Mysidopsis hibernica, Norman. PI. XVI., figs. 4, 5. Survey. — Station 115, off the Skelligs, 62 to 52 fathoms, mud and sand. August 20th, 1890. L^ Previous Record. — Valentia (A. M. N.*). The species has hitherto been known from a pair of examples captured by Norman in Dr. Jeffrey's yacht " Ospre)^," at Valentia in 1870. No note was made of the "circumstances as to the dei^th, etc.," under which they were obtained, so that our record furnishes the first exact information on this point. The length is given by Norman as 15 mm. Our solitary example is considerably smaller; and, if only young examples were present at the time we were fishing, many may have escaped through the meshes of the mosquito-net bag. As usual, the anterior appendages are rather defective, the antennal scales having disappeared, and the antennules being more or less denuded of sette. Hence the characters of these appendages are not available for specific diagnosis. The telson and the inner uropod (figs. 4, 5) are, as we think, in sufficiently close agreement with Norman's diagnosis {Ann. Mag. Nat. Hist., s. 6, October, 1892, p. 165, pi. ix., figs. 2, 3, 4) to warrant us in referring the specimen to 31. hibernica. It will be noticed, how- ever, that the apex of the telson diverges slightly from the type. In Norman's figure there is shown but a slight emargination of the posterior border between the inner pair of terminal spines, whereas Mr. Green's drawing shows that the Skelligs specimen has a distinct notch in this position ; while the terminal spines (the longer of which have lost their points) are by no means symmetrical. Slight variations and abnormalities of this structure must be quite familiar to every student of the family. If Norman's figures 2 and 3 {loc. cit.) are drawn to the same scale, the telson must, relatively to the length of the inner uropod, be rather shorter in the Skelligs example than in the type. We believe that we have evidence, from the analogy of other members of the family, that such a difference is often explicable by the size of the specimens, the length of the telson tending to increase with age. In our specimen the lateral margins of the telson have fewer spines than are shown in Norman's figure, as, indeed, might be anticipated from its small size {cf. especially Schistomysis spiriMs). The typical structure of the telson cannot be held to be certainly known until more specimens have been examined. Although the asymmetry of the Skelligs example suggests abnormality, it is quite possible that a notch in the jjosterior border is more usual than a simple emargination. 336 Holt & BiiAdMONr — Survey of Flshing-ij rounds, W. Coast of Ireland, 1890-91. Genus Leptomysis, G. 0. Sars. Leptomysis gracilis, G. 0. Sars. Survey — Station 118. Ballinskelligs Bay, G fathoms, sand. 21st August, 1890. Station 121a. Inside the Nymph Bank, off Ballycottin, 41 fathoms, sand. 28th August, 1890. Station 130. Kenmare river, off Sneem, 24 fathoms, mud. 30th March, 1891. No Previous Irish Record. Distribution.— E. Scotland ; Shetland (A. M. N.*) : Plymouth (W. Gar- stang !). Norway; Boulonnais, France (A. M. N.*) : North Sea, central parts (Ehren- baum). L. gracilis does not figure in Walker's records from the Irish Sea, so that a considerable gap occurs in the recorded distribution of this species on the British coasts. On the south and east coasts of England the gap is possibly due to want of observation, but it is much less likely that any Schizopod, abundant on the W. coast of England and Scotland, should escape the attention of Mr. Walker and Mr. Thomas Scott. An abnormal example in the Irish collection has one large median terminal spine on the telson, and two large postero-lateral spines, which each appear to have been separated from the median by one (possibly two) small spines, now missing. Many lateral spines have been lost by the telson, and the antennal scales are imperfect, but the hispid skin and characteristic rostrum sufficiently associate the specimen with L. gracilis. Leptomysis mediterranea, G. 0. Sars. Survey — Station 145. Killeany Bay, Aran. 8th April, 1891. A single specimen, 18 mm. long, caught in a small calico trawl. The large number of setse on the distal joints of the antennal scales is noteworthy = 12 on the internal, 16 on the external border. Ilarine laloratory. — Mouth of Killeany Bay, 25th March, 1899. No Previous Irish Record. Distribution. — Channel Islands; Starcross, Devon (A. M. N.*): Plymouth (W. Garstang !). Spain; Mediterranean (A.M.N.*): Heligoland (Ehrenbaum). Report on the Crustacea Schkopoda of Ireland. 237 Leptomysis lingvura, G. 0. Sars. Leptomysis Martoni, P. Gourret, "Eevision d. Crust, podophthalm. Golfe de Marseille."— Auii. Miis. Hist. Nat. Marseille, in., 1889, Mem. v., p. 185 ; pi. xviii., figs. 8-14. /S'«n'f^.— Station 118. Ballinskelligs Bay, 32 to 28 fathoms, soft mud. 21st August, 1890. Miisetim, Dublin. — No. 195, 1895. Rounclstone. Previous Irish Records. — Lough Kay, Valentia ; Dingle Bay (A. O. W.*). Distribution. — Firth of Forth (T. S.): Loch Fyne ; Northumberland; Durham; Starcross (A. M. N.*): Irish Sea, Port Erin and Colwyn Bay (A. 0. W.): Plymouth. Norway; Boulomiais; Mediterranean; Black Sea (A. M. N.*) : N.-W. France (Pruvot. L. Marioni.). While Leptomysis sardica (G. 0. Sars) is considered by Norman to be merely a small race of L. lingvura, it would appear, from the remarks of the same observer, that typical examples of the latter occur in the Mediterranean (Adriatic), as well as in the Atlantic. We see no reason to doubt the accuracy of Norman's views as to the identity of the two species. We further believe that L. Marioni, of Gourret, is not to be distinguished from L. lingvura by any characters of specific moment. It docs not appear that the author was acquainted with Sars' Norwegian monograph, nor is it certain that the distinctions which are drawn between L. sardica and L. 3Iarioni are based on the examination of a series of the latter sufficiently numerous to eliminate the probability of the occurrence of intermediate varieties, L. sardica appears to have been known to Gourret only from the figures of Sars, and in the case of an appendage not figured for L. sardica, comparison has been somewhat futilely instituted with L. mediterranea. The mandible is figured and comj^ared with that of L. mediterranea, as figured by Sars. The difference would be the more remarkable if Gourret's drawing were not obviously taken from a specimen distorted in manipulation. In the position in which they are shown the anterior denticulations of the cutting edge have no very obvious function. We have examined the mandibles of L. lingvura, and consider it possible that Gourret's figure 8, pi. xviii., may have been based on a distorted appendage of similar structure. The anterior denticulations, though very different in position, are not widely dissimilar from those of L. Marioni (as figured). The distinctive characters of the outer process of the antennule in L. Marioni do not appear to us of much importance, and, in so far as concerns the length of the first joint of the process, Gourret's species would seem to resemble L. lingvura. We suppose that a comparison of the first maxilla3 of L. 3farioni and L. sardica contains a clerical error, whereby the latter species has been substituted TKiMS. EOr. DUB. SOC, N.S. VOL. Til., PART VII. 2 L 238 Holt & Bkaumont — Snrvri/ of Fishinri-groumls, W. Coast of Ireland, 1890-91. for L. mediterranean since Sars neither figures this appendage of L. sardica nor includes a description of it in the diagnosis of the species. "With regard to the second maxilla L. mediierranea is the species selected for comparison. The differences noted as distinguishing L. Marioni are less strongly marked, as far as Gourret's figure appears from the whole context to be reliable, when the last-named species is compared with L. lingvura. The outer processes (fouets) of the second maxillte of a specimen examined are somewhat conical, and have but few marginal set^e. The maxillipeds are stated to differ slightly from those of L. mediterranean but in the case of the second pair such difference appears only to bring them more into conformity with L. lingvura. The inner uropod of L. Ilarioni, if notably different from that of L. sardica, is certainly distinguishable from that of L. lingvura in no important particular. The spinulatlon of the telson in L. 3Iarioni is undoubtedly different from that which typically obtains in L. lingvura. In the latter there are two (in L. sardica three) small median spines, bordered by a large spine on each side. Each large spine is separated laterally from another large spine by three (in L. sardica four) smaller ones. In L. 3Iarioni there are eight small median spines, of which the two most central are rather larger than the rest. Lateral to these on cither hand are two large spines separated by seven smaller ones. The difference in size between the larger and smaller spines is much greater in L. Marioni than In L. lingvura; and the distinction between the two forms in this particular is, in effect, that the four large spines of the extremity of the telson are separated by more numerous and smaller spinulcs in L. 3Iarioni than in L. lingvura. The analogy of other forms, notably Siriella armata, inclines us to distrust most strongly the specific value of such a distinction, based on the examination of an unknown and possibly small number of examples ; the more especially since the supposed differences in other parts appear altogether trivial, not to say illusory. L. 31arioni may therefore be relegated, for the present, to the synonymy of L. lingvura, or may, at most, be held to be a race of the latter characterised by difference of the number of splnules on the terminal portion of the telson. Sub-family. — Mysin.e. Genus Hemimysis, G. 0. Sars. Hemimysis Laniornee (Couch). Not in the Surveg Collection. Marine Lahoratory. — Blacksod Bay, C-8 fathoms, 29th March, 1899. Two specimens, pigment bright red. iVo Previous Irish Uccord. Report on the Crustacea ScJrizopoJa of Ireland. 239 Distribution. — Falmouth ; Plymouth ; Sealiam ; N. Wales ; E. and W. Scot- land (A. M. N.*). Norwa}^ ; Sweden ; Denmark ; Naples ; Black Sea (A. M. N.*). Genus Macropsis, Gr. 0. Sars. (See Note added in Press, p. 250.) Genus Macromysis, A. Wliitc. Macromysis flexuosa (Miiller). Not in the Survey Collection. Marine Laboratory. — Aran; Blacksod Bay ; Ballynakill ; Inisbofin ; 1899. Museum, Dublin. — No. 85, 1893, Bantry Bay, per A. Ti. C. Newburgh. No. 122, 1892, Bantry Bay. No. 122, 1892, Dunbeacon Harbour, Bantry Bay. No. 122, 1892, S.W. of Ireland. Unregistered. Dunbeacon Harbour; Broadhaven, 1873; Merrion, Co. Dublin, per G. Y. Dixon. Previous Irish Records. — "All our coasts" (A. M. N.*). Distribution. — British coasts. Atlantic coasts of the European continent; Baltic; Black Sea (?), (A.M.N.*). Of all British M3^sidiB with which wo are acquainted, the genus Macromysis appears to present the greatest difficulty in the determination of the species, on account of the unsatisfactory nature of the characters by wliich 31. flexuosa and 31. neglecta have been separated by Sars and Norman. Were it not for the high authority of these observers, we might be inclined, witli little ceremony, to relegate one species to the synonomy of the other, a proceeding hardly justified by our experience of the family. We must, however, admit that we have never seen a really typical specimen of 31. neglecta as redefined by Norman. The distinctive characters of the two may be summarised (from Norman) as follows : — 31. neglecta. 31. flexuosa. Antennal scale. — Ca. 5 times as long as 7 to 8 times as long as broad ; more broad ; not twice the length of than twice the length of 2;)eduncle peduncle of antennule ; ajoex of antennule ; apex scarcely ex- extending twice tlie length of tending beyond spine, spine of external margin. Tarsus. — 5-articulate, lasti-articulate. C-articulate, last 5-articulate. Telson.—QMi -l- of total length, very Cleft ^ of total length, moderately narrow and constricted at base; open; 21 to 27 lateral spines. 18 to 20 lateral spines. Length. — 20 mm. 25 mm. 2L2 2i0 Hoi.T & BeaUiMONT — Siirrc// of Fishing-r/roitnds, W. Coast r>f Irrland, 1890—91. The above characters, if constantly found associated in individuals, Avould certainly enable us to name specimens either M. flcxuosa or M. neglecta, leaving to higlier autliorities the task of deciding whether or no the somewliat minute differ- ences enumerated were really of specific moment. However, in the Irish examples, the characters prove to be mixed in individuals or compromised by the occurrence of intermediate conditions. The number of joints in the tarsus lias the appearance, on jDaper, of a well- defined character, and it may be easy for an expert to count the joints in all examples. We ourselves have often experienced the greatest difiiculty in this matter, since the proximal articulation is often so faintly indicated, even under a moderately high power, that it is impossible to decide whether it is entitled to rank. Moreover, the number of joints often varies in the anterior legs of the same individual, as may be seen by the following figures : — Articulations of tarsus of legs ^ from in front backwards. '\ Specimen. Specimen. A. 6, 6, 6, 5, 5, 4. I. 5, 5, 6, 5, 5, 4. B. 5, 5, 6, 5, 5, 4. t "^ .- . n^ ^-5 (") • C. 5, 6, 6, 6, 5, -. 6 4 ■"* X. Au anterior leg, 4. D. 5-6 (?), X, -, 6, 6, 5. 5 5 6 L. -, -, X, X, 5, 4. o E. 5, —^^' 6, 5-6(?), 5,4-5 (??). 4 •5-6 (?), ■ 6 M. 4-5(?), 5, 5, 5, 5 (?), ^. F. 5, 5-6(??), 5-6(?), 5, 5, 4. ^^ ^^-1 G. 5, 6 (?), 6 (?), 5, 5 (?), 4. N. x, 5, a leg anterior to last 4. If the presence of a sixth articulation is a crucial point of distinction, A to J must be M. flcxuosa, while L to N are 31. neglecta. The specimens are enumer- ated in the order of size, A to K measui-ing 24 to 15 mm. (including antennal scales and telson) ; L to M 13 to 12 mm. In the case of ScJiistomysis ornata, Norman, in deciding P. Kervillei to be a synonym of the first-named species, attaches no importance to the extra joint of the tarsus present, but apparently not invariably, in large specimens. We cannot see why the character should have greater value in Macromysis, in which, indeed, we have given some little evidence that the number of joints may increase with the age or size of the specimen ; although since M and N are fully developed males, it be not correlated to sexual maturity. f Two figures separated by a hyphen and followed by a note of interrogation indicate that the exis- tence of the larger number of articulations (six in 5-6 ?) is doubtful. The doubt is greater where two notes of interrogation are employed. A single figure followed by a note of interrogation means that the proximal articulation was observed, but only iudistinctly formed. Figures shown as fractions (%\ refer to a pair of legs. Ueport on the Crustacea Sohizopoda of Ireland. 241 The relations of the antennal scale to the jieduncle of the antennule give results as follows : — A. antenual scale fully double the length of the peduncle of the antennule; C. distinctly more than double; D. about double ; E. barely double ; F. somewhat less than double ; CI. barely double ; H. about double ; I. distinctly less than double ; J. scales both perfect, but of unequal length : the longer one about double the length of the peduncle of antennule ; K. slightly less than double ; M. slightly less than double ; N. distinctly less than double. The relative length and breadth of the scale can only be ascertained by isolating this appendage. In the few cases in which this has been done, the breadth has proved to be about one-sixth of the length. Such a proportion is intermediate between the conditions of 31. Jlexuosa and M. neglccta. In shape, on comparison with Sars' figures, the antennal scale appears to incline to the condition of the last-named species. Specimens C and D have the apex of the scale as in 31. Jlexuosa ; in A the shape is intermediate ; in B and K the scale is imperfect ; in the remaining specimens the shape approaches 31. neglecta. But, as far as one can judge without detaching the scale, the width is in all cases intermediate. At what point of constriction the cleft of the telson may be held to incline to one species rather than to the other is difficult to decide, but comparison with Sars' figures appears to range our examples as follows (the fraction indicates the length of the cleft in the total length of the telson) : — A. ca. -. " neglecta " ; B. ca. ~. " neglecta " ; c. c ^o ^. " neglecta''' ; E. -. ^^ Jlexuosa^' ; 6 F. ^. " neglecta " ; H. intermediate ; 1 '■ 6' '■ itG)' K. 7:. "Jlexuosa " ; 6 L. ^- "Jlexuosa " ; 1 N. ca. ^. "Jlexuosa." The lateral spines of the telson are : — 20 ^•21' B. 24; c. 22; E. 21 ; 23 F • 23' 21 22' G. H. 22 ; 24 ^•245 20 "^- 21' K. 22; 20 ^•21' 20 ''•23' 20 2l" The preceding details may be summed up in a table showing to which species the individuals incline in the characters of different parts. 212 Holt & Bkaumont — Surveij of Fishing-groumh., W. Coast of Ireland, 1890—91. The net result appears to us to prove that if M. flcxuosa and 31. neglecta have been rightly separated, their distinctive characters have been very imperfectly defined. As the species stand at present, the Irish examples which we have seen are typical of neither. Two characters, those of the tarsus and of tlie lateral spines of the telson, are almost certainly variable with the size of the example. Macromysis neglecta (G. 0. Sars). As appears from our remarks under the preceding, we have great doubts as to the validity of this species, f Our doubts appear to be shared by Ehrenbaum. Specimens have been recorded under this name as follows : — Irish Record. — Valentia Harbour (A. 0. W.*). Distribution. — Loch Fyne ; Starcross ; Plymouth; North Wales; Guernsey (A. M. N.*} ; Irish Sea (A. O. W.). Norway; Denmark (A. M. N.*) : Heligoland (Ehrenbaum). f In the museum are four .speoimeus from tlie Asbjomsen collection (Cliristiania) named by Professor Sars. We have examined them in so far as was possible without isolating the appendages. They consist of two males, 16 and 17 mm. ca., including antennal scales and uropods, and two females, 17 and 20 mm. In each of the four we have found at least one leg with the tarsus 6-articulate. The two males have 22 lateral spines on the telson, a number in excess of that assigned to the species by Norman, but perhaps. Report on the Crustacea Schizojwda of Ireland. 243 Macromysis inermis (Rathke). Not in the Survey Collection. Ilarine Lahoratorij. — Inisbofin Harbour, -itli and 5th August, 1899, surface towuet at niglit. Young examples, apparently referable to this species. Irish Record. — Valentia Harbour (A. 0. W.*). Distribution. — Shetland ; east and west coasts of Scotland ; Northumberland ; Plymouth (A. M. N.*) ; North Wales ; Isle of Man (A. O. W.). Norway; Sweden; Denmark; Baltic; Murmau Sea; Spitzbergen (A. M.N.*) : Heligoland (Ehrenbauni). Genus Schistomysis, Norman. Schistomysis spiritus, Norman. Survey. — Station 115, off the Skelligs, C2 to 52 fathoms, mud and sand. August 20th, 1890. Station 223, Loughrosmore Bay, Co. Donegal, 9 to 4 fathoms, sand. Slay 21st, 1891. No Previous Irish Record. Distribution. — Shetland; Durliam; Banff; Firth of Forth; Jersey (A. M. N.*) : Plymouth (W. Garstang !) : Irish Sea, Puffin Island (A. 0. W.). Norway; North Sea; Denmark; Holland; Boulonnais, France (A. M. N.*). The gathering from Station 223 contains a specimen of 10 mm., and a num- ber of smaller immature forms. The spines of the inner uropod, in the latter, are comparatively few in number and consequently much less crowded than in the adult condition. In the specimen of 10 mm. (and in one of 12 mm. from Plymouth) the spines are still less dense than in tlie adult, but have the characteristic ai'range- ment. Other characters, which need not be detailed, leave no doubt as to the specific determination. Schistomysis ornata (G. O. Sars). Survey. — Station 118, Ballinskelligs Bay, 32 to 28 fathoms, soft mud. August 2 1st, 1890. Station 121rt, inside the Nymph Bank, off Ballycottin, 41 fathoms, sand. August 28th, 1890. Station 130, Keumare River, off Sneem, 24 fathoms, mud. March 30th, 1891. covered by Sars' diagnosis (20 ca.). We have compared the otolith of the larger specimen of each sex with that of a M.flexuosa from Christiania Tjord, and are unable to detect any proportional difference in size. In so far as concerns the characters of the antennal scales, and of the cleft of the telson, the determination appears to be in harmony with the descriptions of the two species. 2-44 Holt &, Beaumont — Sitrven of Fishing-firoimds, W. Coas^t of Ireland, 1890—91. Station 148, seven miles S.S.W. of Grregoiy Sound, Aran, 38 fathoms, sand. April 9th, 1891. Marine Laboratory. — Blacksod Bay, 6— 8 fathoms, 29th March, 1899. Numerous examples, divergent in some characters from the type. We have observed the same peculiarity in specimens from the estuary of the Tamar, and propose to revert to the matter on a future occasion. Previous Irish Bccords. — Off Valentia (A. M. N.*) : Port Magee entrance, Valentia Harbour, 15 fathoms (A. O. W.*). Distribution. — Shetland; east Scotland; Durham; Liverpool Bay (A. M. N.*): Irish Sea (A. 0. AV.) : Dogger Bank (T. S.): off Plymouth and Tamar estuar3\ Norway ; Denmark ; Holland ; N. W. France (A. M. N.*) : Baltic, North Sea (Ehrenbaum). Scliistomysis arenosa (CI. 0. Sars). Not in the Survey Collection. Marine Laboratory. — Off the White Strand, Ship Sound, Inisbofin, 2-5 fathoms, 20th and 22nd July, 1899, very abundant. No Previous Irish Record. Distribution. — Starcross, Devon (A.M.N.*): Plj-mouth (W. Garstang!): Mediterranean (A. M. N.*). Genus Mysis, Latreille. Mysis relicta, Lov^n. Museum, Dublin. — Lough Neagh, near mouth of Antrim river, per Dr. R. F. Scharff. Previous Irish Record. — Lough Neagh (A. M. N.*). 3Iysis chamwleon, recorded by Bell, on the authority of W. Thompson, from the stomachs of pollen in Lough Neagh, can only be referable to this species. Distribution. — Lakes Venern, Vettern, Malar, etc., Sweden; Lake Mjosen, Norway; Lake Onega, Russia; Lake Ladoga, Putko, etc., Finland; northern part of Gulf of Bothnia; Lakes Michigan and Superior, in America (A. M. N.*). Lough Neagh appears to be regarded by geologists as due to a comparatively late subsidence of the basalt of the Bann valley, but the exact period is disputed. It may be presumed that 31. relicta did not enter the Lough by the navigation canal ; it certainly cannot have ascended the Bann, which is in places much too rapid to permit of such an achievement. The most closely allied marine species is M. ocidata, the sub-Arctic habitat of which is perhaps of some importance in considering the age of the Lough. tteport on the Crustacea Sc/iiso/ioda of Ireland. 245 Genus Neomysis, Czerniavsky. Neomysis vulgaris (J. V. Thompson). JVoi in the Survey Collection. Irish Records. — River Lee, up to Cork and Cove (J. V. Thompson) : Belfast Lough (W. Thompson). Distribution. — " All round our coast in brackish water " (A. M. N.*). European Atlantic coasts (except Spain and Portugal) ; Baltic ; White and Murman Seas ; Black Sea(?) (A. M. N.*) : Bouches du Rhone (A. F. Marion in Hit.) Dasymysis, gen. no v. Synon. Acanthomysis, Czerniavsky. — Monogr. Mysid. imprimis Imperii Eossici, 1882, Fuse. I., p. 134. Skin hispid. Antennal scale lanceolate, setiferous on both margins. Tarsus with about three articulations and a slender nail. Telson linguiforui, entire ; proximal part of lateral margins naked, or with a few spines near the base ; distal parts of margin densely armed with numerous unequal lanceolate spines. In the male, the first, second, and fifth pleopods are like those of the female ; the third is hardly at all modified ; the fourth with a peduncle and two branches, the inner as usual in Mysinaj; the outer narrowly cylindrical, somewhat flexuous, bi-articulate, the proximal joint elongate, the distal very short and beset with two short subequal setiform flagella. Type. Mysis longicornis, Milne-Edwards.— " Hist. Nat. Crust.," 1837, ii., p. 459, pi. xxvL, figs. 7-9. G. 0. Sars— " Middelhav. Mysider," 1877, p. 22, pis. 9, 10, = Acanthomysis platy^ens, Czerniavsky, op. cit. p. 137. The genus Acanthomysis, instituted by Czerniavsky, with M. longicornis (G. 0. Sars) as the type, cannot be retained, since it is stated that the pleopods are as in Mysis, the type being thus excluded. The genus Mysis, as restricted by Czerniavsky himself, contains the species 31. relicta, M. ocidata, M. mixta, and several others of more doubtful value. The three which we have named have the pleopods very different from those of M. longicornis. The third pleopod of the male has a well-developed basal joint, and two distinct, if short, branches. The fourth pleopod of the male has the outer branch multi-articulate, and much stouter than in M. longicornis (cf. G. 0. Sars, " Monog. over Mysider," pp. 69, TRANS. EOT. DUB. SOC, N.S. VOL. VII., PAUI Vil. . 2 M 2-46 Holt & Beaumont — Surveij of Fishing -grounds, W. Coast of Ireland, 1890—91. 73, 76, pis. xxxi.— xxxiii.). In so far as the pleopods are concerned M. longicornis might be included in the genus Neomysis, from which, however, it is dis- tinguished by other characters. Dasymysis longicornis (M.-Edw.), 3Igsis longieorni's, Milne-Edwards, loc. cit. ? 3Igsis longicornis, Heller, " Crust, pod. Siidl. Europ.," 1863, p. 302. 3I//sis longicornis, Gr. 0. Sars, loc. cit. AcantJiomgsis platydens, Czerniavsky, loc. cit. Acanthomysis longicornis, Czerniavsky, op. cit., "Ease. III.," p. 75. Acanthomijsis spinosissima, Czerniavsky, op. cit., " Fasc. I.," p. 135, pis. xxxi., xxxii. Form narrow and slender, abdomen nearly straiglit. Skin hispid in all parts. Rostrum obtusely angular. Eyes large, pyriform, widely separate, extending well beyond the lateral margin of carapace. Peduncle of antcnnule rather elongate, the second joint dorsally produced into a forwardly-directed process; the last joint rather tumid and nearly equal in length to the first. Antennal scale but slightly extending beyond peduncle of antennule, narrowly lanceolate in form, its extremity divided from the rest by an oblique suture. Tarsus about three-articulate, the proximal articulation the longer, nail slender but distinct. Tebon elongate, entire ; widely dilate at the base, thence suddenly constricted ; the posterior part narrowly linguiform, and densely armed at the margin with numerous, unequal, lanceolate, straight or slightly curved spines, their extremities with a distinct axial marking, f Inner uropod hardly longer than telson, narrowly lancolate, base swollen ; otocyst oval, large ; inner margin in region of otoc3^st beset with a row of spines of gradually increasing size. Outer uropod one-fourth longer than inner, very narrow, with a slight outward curve, apex obliquely truncate. Male, with the Jpurth pleopod not reaching the posterior extremity of the sixth segment. Length of female scarcely 9 mm. Pigment blackish-brown, not abundant. Survey. — Station 118, Ballinskelligs Bay, 32 to 28 fathoms, soft mud. 21st August, 1890. Previous Irish Record. — None. f The external ctitinous sheath of the spine is suddenly thickened toTvards the distal end, the lumen being thus reduced in such a way as to present the appearance of an axial line. This character (also present in L. apiops (?) ) appears to have suggested to Mr. Walker that the extremity of the spine is trigonal. Report on the Crustacea Schizopoda of Ireland. 247 Distribution.— ^t^rt Bay, Devon : off Plymouth (E. W. L. H. and W. I. B.). Irish Soa (A. 0. W.). Naples (M.-Edvv., G.O.S., Czerniavsky): Alg-eria(?) (Lucas). We found this species extremely abundant in Start Bay in 1898, f while later in the same year a single specimen was recorded from the Irish Sea by Mr. Walker.J Our present record deals with material collected nine years ago, so that it is improbable that the appearance of the species in British collections is due to a recent extension of range. Mr. Walker speaks of the difficulty of distinguishing this form from Leptomijds apiops^ G. O. Sars, but the latter has a smooth skin, while that of D. longicornis is most conspicuously hispid. The synonymy of the species is chiefly the result of the misplaced industry of Czerniavsky, who, mistrusting the identity of Sars' species with the imperfectly defined M. longicornis of Milne-Edwards, changed the specific name of the former to A. plat)jdens^ while nevertheless including Milne-Edwards' species in the genus of which Sars' species was made the ty])e. At the same time a new species, A. spinosissima, was erected for the recej)tion of specimens, also from the Bay of Naples, which do not appear to us to differ from the type in any essential feature. Since no note is made of the character of the skin in Czerniavsky's dichotomic table [op. cit., p. 137), it may be presumed that A. spinosissima is as hispid as D. longicornis. In the same table the dimensions of the two species have been transposed, A. spinosissima being in fact founded on specimens considerably smaller than those described by Sars. To this difference in size may, perhaps, be ascribed such discrepancies (other than those of slight abnormality of the telson^, cf. PI. XXXI., fig. 19) as Czerniavsky was able to detect. Sub-family. — Mysidellin^. Genus Mysidella, G. 0. Sars. Body short and robust. Eges well developed or rudimentary. Antennal scale small, lanceolate, setose on both margins. Peduncle of antennule in male with only a very small hirsute lobe. Lahriim obtuse in front, produced behind into two unequal lobes, 3Iandihle large, the incisive extremity very much dilate and flattened, in the form of a blade without a trace of teeth or spines. First maxilla, its processes strongly incurved ; the outer large, compressed, sub-spathulate, with obliquely t Joimi. M. B. A., N. S., v., 1898, p. 344. % Ann. Ei'p. Port Erin Biol. Stat., 1898, p. 15. 2 M 2 248 IIoLT & Beaumont— ^SHJvr^ of Fishing -grounds, W. Coast of Ireland, 1890-91. truncate edge set with numerous unguiforin spines ; the inner in the form of a setose tubercle. Second maxilla small and feeble. First maxilliped strong ; basal joint without an incisive lamina, second joint very short, third rather swollen; penultimate without setjB, but strongly spined at the external apex ; last joint very small and armed with a long, narrow apical spine. Legs small and feeble, sparsely setose ; tarsus with few articulations, nail inconspicuous. Incubatory pouch of female of three lobes on each side, the anterior pair rudimentary. Genital appendages of male very long, anteriorly directed, witliout setse. Pleopods rudi- mentary, simple, alike in both sexes. Telson short, anterior part of lateral margin naked, posterior part closely spined, a small apical cleft. Uropods short, subequal ; otocyst well developed. (Abbreviated from G. 0. Sars.) Mysidella typica, G. 0. Sars. (PI. XVI., figs. 6, 7.) Mysidella tijpica, G. 0. Sars, Carcinolog. Bidrag til Norges Fauna, I. Moiiogr. ATysider, Hefte III., 1879, p. 86, pis. XXXV., xxxvi. Body rather abbreviate ; cephalo-thorax short, sub-gibbous ; abdomen much more slender, cylindrical, slightly tapering, last segment short ; last two segments of cephalo-thorax exposed dorsally. Eostrum distinctly angular. Fi/es well developed, but not large, rather remote from each other, bi-ight fulvous. Peduncle of antenmde scarcely one-fourth as long as the cephalo-thorax, its basal joint short, nearly as wide as long. Antennal scale three times as long as wide, reaching by scarcely a third of its length beyond peduncle of antennule, outer margin nearly straight, inner distinctly arcuate, apex bluntly acuminate. First maxilliped with the pen- ultimate larger than the preceding joint, and armed with three teeth. Legs, first hardly longer than second maxillipeds; tarsus shorter than preceding joint, 2-articulate ; nail slender, setiform ; second to fifth legs sub-equal in length ; tarsus longer than preceding joint, 3-articulate ; posterior leg much longer than the rest, very narrow ; tarsus elongate, 3-articulate. Telson hardly one-fourth as long as abdomen, about twice as long as wide, linguiform, tapering distinctly towards the apex ; anterior half of lateral margin naked, posterior half with about eighteen closely set spines of gradually increasing length, apex obtusely rounded, with a short, narrow rectilinear cleft; each side of cleft with (about) two to four minute spines. Inner uropod a little longer than telson, about seven-eighths as long as the outer, its inner margin spined throughout (from the level of the centre of the otocyst). Colour, body pellucid with a little red pigment here and there. Length Report on the Crustacea Schizopoda of Ireland. 249 of adult female hardly exceeding 8 mm. (Abbreviated witli slight alteration from Gr. O. Sars.) Survey. — Station 115, off the Skelligs, 62 to 52 fathoms, mud and sand. August 20th, 1890 (in muslin bag attached to trawl). No Previous British Record. Distribution. — Western Norway, 50 to 150 fathoms (Gr. 0. Sars). Our material consists of two specimens, both of adult size. Though consider- ably damaged, their determination is not difficult. Mr. Green has depicted a first maxilliped of one specimen, and the telson and inner uropod of the other (figs. 6 and 7). The maxilliped has lost most of its setse. It w ill be noticed that the cleft of the telson has only two spines on one side and three on the other. Sars describes and figures four on each side, but the variation is unimportant. [Notes added in Pbess. 250 Holt & Beaumont — Survey of Fishhig-groimdSjW, Coast of Irelaml, 1890-91. NOTES ADDED IN PRESS. Euphausia pellucida, Dana. Taken in the serial tow-nets of Station 2 of Mr. George Murray's " Oceana" Expedition, 52° 45' N., 12° 27' W., 453 fathoms. An oceanic species of very wide distribution, not previouslij recorded from tvitliin the British area. Stylocheiron sp. Taken in company with the hist. No member of this genus has hitherto heeti recorded from ivithin the British area. Nyctiphanes Couchii (Bell). Evidence presented by a small example (about 6 mm. long), taken off Plymouth, points to the absence of exopods on the fifth and sixth pairs of legs in the female of this species, as in N. australis. The imperfect condition of the remaining female specimens in our possession does not permit of the complete establishment of this point. In the female N. norvegica exojiods are present on all the legs (except the last pair, which are quite rudimentary throughout the genus), as in the males of all three species. Macropsis Slabber! (Van Beneden). A single specimen taken in a sui-face tow-net at night, Inisbofin Harbour, 5th August, 1899. No Previous Irish Record. Distribution.— F'lvth of Forth ; Falmouth (A. M. N.*) : Whitsand Bay ; Tamar Estuary. Sweden ; Denmark ; Holland ; Belgium ; Mouth of the Seine ; Mediterranean ; Black Sea (A. M. N.*) : Heligoland ; German North Sea Coast (Ehrenbaum) : Channel Islands (Walker and Hornell). Erythrops serrata, G. 0. Sars. Specimens from the Clyde, communicated by Mr. W. T. Caiman, agree in particulars of serrulation of the inner uropod with the Irish examples. Report on the Crustacea Schizopoda of Ireland. 251 List showing the Coaiparative Representation of Different Species in the Survey Hauls. Station 115, 62 to 52 fathoms ; Erythrops serrata, Mijsidopsis didelphys, Mysidella typica, Mysidopsis kihernica, Parerythrops obesa, Schistomysis spiritus, Nyctiphanes norveyica, very numerous. 18. 2. 1. 1. 1. 1. Station 118, 32 to 28 fathoms :— Sckistomytis ornata, Leptomysis gracilis, Jfysidopsis angusta, Leptomysis linyvura, Dasymysis loHyicornis, Anchialus ayilis, Ifysidopsis gihbosa, Station 121 (?, 41 fathoms :- Anchialus ayilis, Leplomysis gracilis, Schistomysis nrnata, Station 125, 115 fathoms: — Ifysidopsis didelphys, . . Erylhrops serrata, many. rather less numerous. ZOca. 15 ca. 4. 2. 1. Station 1.30, 24 fathoms :— Leptomysis gracilis, Schistomysis ornata, 14. 12 or 13. 12 ca. Station 143, 46 to 44 fathoms: — Schistomysis ornata, . , 4. £rythrops serrata, . . 2. Jfysidopsis a)igiista, . . 2. Station 144, surface over 45 fathoms, ca : Thysanoessa neglecta, . , many. Station 145. 5 fathoms or less: — Siriella armata, . . 9. Gastrosaccus sanctus, . . 5. Leptomysis mediterranea, 1. Station 148, 38 fathoms : — Schistomysis ornata, . . 6. Station 223, 9 to 4 fathoms : — Schistomysis spiritiis, . . many. Gastrosaccus spinifer, . . 2. 2o2 Holt & Beaumont — Survey of Fishing-grounds, W. Coast of Ireland, 1890—91. EXPLANATION OF PLATE XVI.* Figure 1. Male of Nydiphanes Coucliii, 12 mm., from Yalentia Harbour. 2. Telson and inner uropod of Parerythrops obesa from S.W. Ireland, dorsal aspect. 3. The same, ventral aspect. 4. Telson and inner uropod of Mysidopsis hibernica from S.W. Ireland, dorsal aspect. 5. Inner uropod of same, ventral aspect. 6. Telson and inner uropod of Mysidtlla typica from 8."\Y. Ireland, dorsal aspect. 7. First maxilliped of same. [In figs. 4 to 6 the setse have been omitted.] * Owing to a misunderstanding, for which the editor is in no way responsible, the plate was allowed to go to press before certain necessary corrections had been made. The exopodite of the sixth leg (the penultimate thoracic appendage, the last being rudimentary) is not shown ; and the structure of the remaining legs is obscure, each exopodite appearing to consist of a single ciliated joint directly articulated to the rest of the limb. This erroneous impression is conveyed by the complete masking of the basal portion of the endopodites by the proximal joints of the exopodites. The gills are shown in accurate detail in fig. I., p. 226.