. l> A '^ '1K^ -T^N^ m-'-^' ^P'S.. W^-" * ^^; ■7' ^ ^t^fJ-.^-i'n^ ;^s4 •:• Af^ mk< ^' ■¥>. ;Jn^f\ •^ ' A> j*-^.' iJ >> / .1^ ^^#' ■;. J-^-rt*^ HARVARD UNIVERSITY. LIBRARY OF THE MUSEUM OF COMPARATIVE ZOOLOGY. i THE TEANSACTIONS OF THE LINNEAN SOCIETY OF LONDON. SECOND SERIES— VOLUME VI. ZOOLOGY. 1 ^L O N D O N: PRINTED BT TAYLOR AKD FEANCIS, RED LION COURT, FLEET STREET : SOLD AT THE SOCIETY'S APARTMENTS, BTJRLINGTOX-irOTTSE ; AXD BY LONGMANS, GREEN, AND CO., PATERNOSTER-KOAV. 1894-97. * .•<^ CONTENTS. PART I.— January, 189i. I. Eeport on Entuinostraca from the Gulf of Guinea, collected by John Buttray, B.Sc. By Thomas Scott, F.L.S., Mem. Soc. zool. France, Naturalist to the Fishert/ Board for Scotland. (Plates I.-XV.) page 1 PART II.— May, 1894. II. The Subterranean Crustacea of Neiv Zealand : with some general Bemarhs on the Fauna of Caves and Wells. By Charles Chilto>j, 3I.A., D.Sc, F.L.S., Bector, District High School, Port Chalmers, New Zealand. (Plates^'XVI.-XXIII.) 163 PART III.— August, 1894. III. On a Freshwater Schizopod from Tasmania. By George M. Thomson, F.L.S. (Plates^XXIV.-XXVI.) 285 PART IV.— February, 189G. IV. The Comparatice Morphology of the GaleodidsB. By H. M. Beenard, M.A. Cantab., F.L.S. , F.Z.S. {From the Hu.vley Besearch Laboratory, Boyal College of Science.) (Plates^XXVII.-XXXIV.) BO.! PART v.— June, 189G. V, A Bevision of the British Copepoda belonging to the Genera Brady a, Boeck, and Eetinosoma, Boeck. jB// Thomas Scott, F L.S., Mem. Soc. zool. Fratice, Naturalist to the Fishery Board for Scotland, and Andrew Scott, Fisheries Assistant, University College, Liverpool. (Platcs'xXXV.-XXXVIII.) 419 [ iv ] PART VI.— July, 1896. VI. 0)1 .sumc iietc or rai-e Phasmidye in the Collection of the British 3Iuseum. By "\V. P. KiRBY, F.L.S., F.B.S., Assistant in the Zoological Bejjarttnent, British JIuseiim, South Kensington. (Plates XXXIX. & XL.) 447 PAIIT VII.— OcTOBEii, 1896. VII. The Internal Anatomy o/Bdella. By A. D. Michael, V.P.L.S., F.Z.S., P.B.M.S. (Plates'XLI.-XLITI.) 477 PART VIII.— Pebruary, 1897. Titlepage, Contents, and Index . . .' 529 2nd Ser. ZOOLOGY.] [VOL. VI. PAET 1. THE TRANSACTIONS OF THE LINNEAN SOCIETY OE LONDON EEPOPiT ON ENTOMOSTRACA FEOM THE GULF OF GUINEA. BT TPIOMAS SCOTT, F.L.S., NATUTiALIST TO THE FISHEnV BOARD FOR SCOTLAND. LONDON: PRINTED FOB THE LINNEAN SOCIETY BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. SOLD AT THE SOCIETY'S APARTMENTS, BUULINGTON-HOUSB, PICCADILLY, \Y., AND BY LONGMANS, GKEEN, AND CO., PATERNOSTER-ROW. January 189Jd. TRANSACTIONS OP THE LINNEAN SOCIETY. I. Bejwrt oil Entomostraca from the Gulf of Ouiiiea, collected by John Rattray, J3.Sc. By Thomas Scott, F.L.S., Nattiralist to the Fishery Board for Scotland. Read 2iid February, 1893. ' (Plates I.-XV.) I HE following" Report contains a Catalogue, more or less descriptive, of all the Entomostraca obtained in the tow-net gatherings collected by Mr. John E-attray, in the Gulf of Guinea, while engaged as naturalist ou board the Telegraph Steamer ' Buccaneer.' It is not necessary that I should enter into any explanation of the causes of the delay in the publication of the Report on the Entomostraca further than to state that the collections were handed over to me early in 1891, and since then all the leisure that could be spared has been devoted to their examination aud to the preparation of the followinti? Catalogue. In the preparation of the Report the author has to acknowledge the valuable aid he has received from Professor G. S. Brady, E.R.S. He is also under great obligations to the Senatus of the University of Edinburgh for the privilege of consulting the numerous works on Natural History in the University Library, and to Mr. Webster, the Librarian, who has always been ready to help in hunting up any literature wanted. My thanks are also due to Dr. T. Wemyss Fulton, of the Fishery Board for Scotland, for the active interest he has taken in the preparation of the Report ; among other things he obtained for me the privilege of consulting the valuable Natural History Works in the Library of the Royal Society of Edinburgh. The Government Grant Committee of the Royal Society of London allocated to me the sum of £20 in 1891, and again in 1892, for the purposes of this investigation ; and this enabled me to retain the services of my son, Mr. Andrew Scott, for the preparation of the drawings that accompany and illustrate the Report, which, by their acknowledged SECOND SERIES. — ZOOLOGY, VOL. VI. 1 ■2 ME. T. SCOTT ON EXTOMOSTKACA nccuracy as well as their beauty, add greatly to its value. My son also prepared the greater number of the dissections represented by the drawings, which were necessary for the satisfactory diagnosis of the various species recorded. The Entomostraca described in the following Catalogue include species belonging to the orders Copepoda, Cladocera, and Ostracoda. The first is represented by one hundred and forty-eight species, the second by two species, and the third by twenty-four species. The great tendency to, and multiplicity of, variation observed, especially in certain groups, has caused considerable difficulty in deciding the value that should be placed on the amount of variation met with. Thougli care has been taken to avoid as far as possible attaching a higher value to these variations than they deserved, it has been necessary in not a few instances to give them specific and even generic rank, in order to dispose of them in anything like a satisfactory manner. A considerable number of more or less immature forms occurred in nearly all the tow- nettings, and were the cause of much trouble during the examination of the material ; the liability of mistaking an immatui'e specimen of one species for a member of another, and a different one, is considerable, and has to be kept constantly in view during the examination of such small organisms. Since writing this E,eport I have, through the kindness of Dr. T. Wemyss Fulton, of the Fishery Board for Scotland, been favoured with a perusal of Dr. Giesbrecbt's excel- lent work on the Mediterranean Copepoda, which has enabled me to make some alterations that will l)ring it more into conformity with recent views on the nomenckiture of that important group of the Crustacea ; while the Introductory Remarks by Mr. Rattray, which follow, will add to its completeness. Introductory Remarks. By John Rattray, B.Sc, F.R.S.E. For the opportunity of taking part in this expedition, of the results of Avhich a report on the Entomostraca is now presented, I have exclusively to thank Dr. John Murray, of H.M.S. ' Challenger ' Commission. J. Y. Buchanan, Esq., formerly chemist on board H.M.S. ' Challenger,' accompanied the expedition, and all my Avork was carried on under his immediate supervision on board the S.S. ' Buccaneer ' (Captain Thomson, R.N.R.), then in the service of the India Rubber, Gutta Percha, and Telegraph Works Co., Ld., of Silverto"v^^l, Essex, and at that time engaged in sounding-operations preliminary to the laying down of a telegraph-eable on the West Coast of Tropical Africa. Sailing from Liverpool in the S.S. ' Nubia ' in the begimiing of December 1885, the ' Buccaneer ' was joined by Mr. Buchanan and myself at Sierra Leone on December 23, and sailed at once northwards, touching on Dec. 24 at Bullama and Bassao, between the Isles de Los and Dakar, near Capo Verd, arriving at Dakar on the evening of the same day to complete preliminary arrangements for the soimding expedition, which started thence on December 29. FEOM THE GULF OF GUINEA. 3 So far as relates to the Biological collections, the equipment provided consisted of a supply of botanical paper with botanical press for the preservation of such larger plant specimens as might ])c procured on any short expeditions that might be possible on shore. Such chances were found only at rare intervals : thus gatlierings were made on the outward voyage at Madeira, in the vicinity of Fuuchal (Dec. 10), at Teneriffe, in and around Santa Cruz (Dec. 12 and March 28, 1886), at Sierra Leone (Dec. 21), at Conakoy, Isles de Los (March 17, 1886), at Dakar (Dee. 26-29), at Accra, North Coast of Gulf of Guinea (Jan. 16), at Sao Thome, Gulf of Guinea (Jan. 25 and 31 and Feb. 1, 1886), at Principe Island, Gulf of Guinea (Jan. 27), and at St. Paul de Loanda, E. coast of Gulf of Guinea (Feb. 10-17). On Dec. 13 some algse and shells were procured at Las Palmas, Gran Canaria, a landing for a few hours only being possible. During the brief calls at Bullama and Bassao on Dec. 21, the time Avas entirely occupied in the collecting of marine specimens either floating on the very muddy waters of these parts or occurring on the beach ; the visits paid to Libreville, Gaboon Biver, on January 28, and to Bananah Creek, Congo Iliver, on February 7, were so brief that no landing could be effected. So far as relates to Phanerogams, the best gatherings were made in and about Santa Cruz and at Sao Thome ; a considerable number of Thalamiflorse were found at both ; Papaveracege and Coniferte especially at Santa Cruz ; Malvaceae especially at Sao Thome. At the latter Legiuninous, Kosaceous, Crassulaceous, Myrtaceous, Onagraceous, Samy- daceous, and Cucurbitaceons CalycifiorfE were well represented ; at the former were gathered some Ficoidefi) and Uml)ellifera- not obtained at the latter. At St. Paul de Loanda, Leguminous and Myrtaceous Calyciflorse only were found, e. g. especially Indigofera, Uialium, Ccesalpiaia, Civtalaria, Tamarindus, and Psidium. Of Fpigynous Monopetaloid Compositte more were obtained at Santa Cruz than at Sao Thome ; but, on the other hand, more hypogynous specimens at the latter than at the former, the Jasminacese, Apocynaccne, and Convolvulacete predominating. Again, Apetake, Nycta- ginacese, Amarantaceai, Urticacea?, Euphorbiacese, and Monocotyledones — especially Connacese, Cyperacea^, and Gramineae — were found most abundantly at Sao Thome. Most Filices were obtained from Principe Island, including particularly species of Nephrolepis, Nephrodium, Polypodlum, and many young forms. At Dakar and at St. Paul de Loanda the coast-flora was poor, owing to the vast stretches of sand ; at the former were observed species of Argemonc, Ihena, Vigua, Cassia, AlMzzla, Seshunia^ Jussicea, Selioti-opium, Clerodendron, Hgptis, Scirpus, CIdorls, Pennisetum, Peiiicllkwia, Andropogou, Ccnchrus, not obtained at the latter, which, on the other hand, yielded species of Sesuvmm, Slda, Trlbuhis, Ilonetia, Indigofera, Psidium, Pluchea, Dichoma, Ipomcea, Boerhaavia, Bougainvlllea, Centema, Pupalia, Phyllanthus, Euphorhiu, Panicum, Sporoholiis, Enigrostis, Aristida, &c., not found at Dakar. Much difficidty was experienced in protecting specimens against the hot moist atmosphere of the tropics, and recourse was ultimately had to having them deposited near the furnaces of the steamer. This at length proved effective, but was accompained by the accumulation of much dust, which might, however, have been largely avoided by wrajjpin'-- in fine muslin, had that been available. 1* 4 ME. T. SCOTT ON ENTOMOSTEACA Among Algte specially noteworthy were the exuberant growths of Corallinge near Las Palmas, attached to a soft sandstone on a narrow isthmus joining the volcanic sections of the island, and of Pad'ma (Adanson) on the beach, about 3 miles from Dakar, at the far side of the bay surrounding Goree Island. Per the preservation of zoological specimens the following means were at hand : — methylated spirit, alsolute alcohol, glycerine, benzole, ether, chloroform, acetic acid, ammonia, hydrochloric acid, sulphuric acid, nitric acid, corrosive sublimate, caustic potash, osmic acid, chromic acid, j)icric acid, iodine, picrocarmine, hsematoxylin, Canada balsam; with accessories such as slides, cover-glasses, watch-glasses, porcelain dishes, spirit-lamj), camel-hair brushes, needles, spatulas, two nets of varying degrees of fineness, a tank-box, shrimp-ti*awls, mud-bags, and specimen bottles. Some 200 bottles of 4-oz. capacity, in addition to several boxfuls of others of larger sizes. At the end of the work all the available bottles were filled, and as many others as could be obtained empty from. the supplies of the ship. Many micro-preparations were made of the products of the soundings, of which 411 were taken during the cruise, and of the contents of the tow-nets at various points. Larger specimens, such as species of Pisces, were procured from native fishermen at St. Paul de Loanda, and for these the tank-box proved very u.seful. Larger Crustacea, of which a few were fouud on shore, were preserved in spirit at once. Numerous shells of Mollusca were obtained dry ; but one of the most important departments of the work was the preservation of the more delicate Arthropoda (Copepoda, Amphipoda, Schizopoda, &c.), Ascidia, ova, fish-larvce, Sag'Uta, &c., found in the tow-net gatherings. Por these the methods adopted were essentially those practised at the zoological stations of Naples * and elsewhere. Por delicate objects, Prof. E. R. Lankester had recommended, in a letter to Dr. John Murray, two plans : (a) corrosive sublimate followed by dilute then stronger alcohol, and (/3) ^ per cent, osmic acid, or this mixed with very dilute chromic acia or acetic acid, giving a short exposure of 1 to 2 minutes according to size : this to be followed by alcohols of increasing strength. The latter method was recommended for Olione and other Pteropoda ; it was adopted but rarely, owing to the difficulty of prose- cuting many different methods in a limited amount of space (the laboratory at command being quite small, but very compact) the combined chrom-osmic or aceto-osmic plans were not tried at all : the former method was freely used. For the Radiolaria the osmic acid process also proved of use, it had been recommended by Hartwig and by Haeckel ; but a glycerine medium to follow it was not employed because of the unsuitability of its refractive index to that of the E-adiolarian skeleton. For preserving the products of the tow-net pure alcohol was never adopted ab initio, but acidulated alcohol was tried, following the directions of Paul Mayer and Whitman, viz. 70 or 80 per cent, alcohol with a small addition of pure hydrochloric acid and a trace of picric acid. The specimens were subsequently washed with strong spirit to remove the acid, and preserved in spirit. Again, the picrosulphuric acid method following * Mayer, Mittheil. zool. Stat. Neap. ii. (1S31) p. 1 ; Journ. Eoy. Micr. Soc. u. s. ii. (1882) p. 866. FROM THE GULF OF GUINEA. 5 Kleinenberg's * formula, as adopted by Mayer f , that is, without the addition of creosote, was often used, because of its reported high degree of penetrability for chitinized structures. The fixing agent was simply added to the sea-water, and this was subse- quently succeeded by increasing strengths of spirit. Mayer's J pier o- hydrochloric acid method was only employed a few times. Corrosive sublimate was extensively used, and was found to be of special service on account of the rapidity of its action. Lang's § methods were simplified and accelerated by adding a little of the solid salt to the sea-water ; the hot solution of the salt was never adopted, though it has been recommended for Sagitta, Copepoda, ScqMrina, and other Arthropod larvte. In a few cases, following Carnoy || , a trace of acetic acid was added to the corrosive solution. The mercuric salt was removed by subsequent washing — the mode of filtration was found of advantage from its speed and cleanliness — and successive treatment with progressive strengths of spirit. The animals were in all cases, where preservation was required, killed as rapidly as possible after capture, with a view to the obtaining of good results for structural purposes. Tow-net collections were made throvighout the whole course of the voyage ; the total number of these was, however, somewhat less than the total number of soundings, because (1) soundings were sometimes taken with much speed in shallow depths, and the delay of the steamer was therefore brief ; (2) tow-net gatherings could not continuou.sly be obtained by night and by day, save only at intervals. During work only one net was really lost through the snapping of gear belonging to the net itself, a few others, usually in deep water, w^ere lost on account of the breaking of the cable upon which they were attached. The majority of the gatherings were made in the upper strata of the water, or say down to 25 fathoms ; but deep-sea nets were repeatedly used. The deepest w^ere wrought at 360 and t60 fathoms on January 22, in lat. 1° 55' 5" N., long. 5° 55' 5" E. Prof. Chrystal's double-hooped net was used at a depth of 260 fms., but the collection obtained was small. On Feb. 5, in lat. 4° 26' 7" S., long. 10° 1' 8" E., two nets were set adrift at 235, 185, and 85 fathoms attached to balloon buoys in a S. ^ W. current of 0-54 knots ; and, again, similarly on Feb. 22, in lat. 5° 59' 4" S., long. 3° 49' 4" E., a series of nets were exposed at 30, 40, 70, 100, 130, 160, 190, and 200 fms.,— the temperatures at these respective depths being 6r-3 F., 59"-3 F., 57°-5 F., 55° F., 52°-5 F., 49° F., and 46°"7 F. ; but in heaving up, after an exposure of 7 hours, the cable snapped, and all but the uppermost were lost. Three more deep-sea nets were lost by the breaking of a steel rope attached to an anchor-dredge in lat. 5° 5 1' S., long. 11° 48' W., when, out of 1780 fms. of rope, 1675 fms. were lost together with the anchor-dredge, weighing 5 cwt. 2 qrs. 14 lbs. These accidents were specially to be regretted by reason of the opportunities * Foster and Balfour, Embryol. t Journ. Roj'. llicr. Soc. n. s. ii. (1882) p. 867. + Mittheil. zool. Stat. Neap. 1881, p, 5. § Zool. Anzeig. 1878, p. 79. II La Biol. Celhilaire, p. It.j. Q ME. T. SCOTT ON ENTOMOSTRACA they presented for ascertaining something of life at these depths. In lat. 0' 7' 8" S., lono-. 14° 28' 6 " "W., nets were employed at intervals down to 100 fms. on March 10 ; and again on March 11, down to 76 fms., in lat. 0° 0' 7" N., long. 13° 4' W. The time of exposure of tow-nets varied with circumstances and opportunities from 20 minutes to 7 hours (the latter when sent adrift from the ship). Inshore nets taken at Conakoy, Isles de Los, Bullama, Bassao, Dakar, Accra, off Little Bassam, in the vicinity of the suhmarine gully known as the " bottomless pit," Porto Novo, Libreville (Gaboon River), Bananah Creek (Congo River), and St. Paul de Loanda were always at or near the surface. Of special interest is the series procured during soundings in the vicinity of the Congo canon, where gyrations of the water, accompanied by the production of coarse bubbles of foam, were very evident on the surface of the sea. For Ascidia, Prof. Herdman had recommended three plans, all of which were employed, viz. : (1) picric acid and alcohol ; (2) osmic acid and alcohol ; and (3) picric acid alone, without alcohol, for Saljjcs and Doliolmn. Some were also preserved in glycerine, without either picric acid or spirit to prevent opacity. Por living specimens of sclero- dermic corals, of which only a few were obtained, the corrosive sublimate treatment was employed. No Hydrozoa were preserved, according to Pagenstecher's * method, by the use of sodium chloride and alum succeeded by stronger and stronger alcohols. Por the Peridinidffi, of which several were obtained, Gcza Entz'sf recommendation of glycerine was not followed, though tried, chiefly on account of refractive considerations. Porifera have been treated by Keller % with osmic and chromic acids, the former of the strength of -^-(,- to ro pei' cent., the latter very dilute ; but of these, the only repre- sentatives obtained were found on the shore at Ascension Island, and were immediately placed in spirit. Subjoined is a list of the positions of the 48 stations of the expedition, where the best available means were adopted for obtaining collections, with the sru'face temperature observed at each : — Station I. Dec. 29, 1885, lat. l.r 48' N., loug. 19° 18' W. (75° F.). II. Jan. 1, 1886, lat. 7° 54 N., long. 17° 25' W. (82°-2 F.). lat. 7° 1' N., long. 15° 54 W. (82°-9 F.). lat. 7° 33' N., long. 15° 18' W. (83° F.). lat. 7° 20' N., long. 13° 26' W. (83°-2 F.). lat. 7° 8' N., long. 13° 27' W. (83°-4. F.). lat. 5° 48' N., long. 14° 20' W. (85°-5 F.). lat. 3° 57' 2" N., loug. 7° 42' 8" W. (82°-8 F.). Here a S.E. current down to 150 fms. SJ III. 3> % IS IV. }y s, >1 V. iy 4, » VI. J) yy }> VII. }f 5, » VIII. }> 9, * Zeitschr. wiss. Zool. xvii. (1S67) p. 379. t Zool. Anzeig. 1881, p. 575. X Zeitschr. wiss. Zool. xxx. p. 568. FEOM THE GCJLF OF GUINEA. Station IX. Jau.10,1886, lat. 3° 0' 8" N., long. 7^ 43' W. (83° F.). Station in and near outer edge of Guinea current. Water ultramarine. lat. 3° 58' N., long. 3° 12' W. (83°-7 F.). lat. 5° 15' 4" N., long. 3° 10' E. (83°-2 F.). lat. 4° 12' 7" N., long. 3° 57' 5" E. (82°-7 F.). A strong N.N.W. current 2 to 3 fms. deep, and under it a strong current in opposite direction, lat. 3° 55' 3" N., long. 4° 7' 3" E. (83°-2 F.). lat. 2^ 20' 2" N., long. 5' 7' 8" E. (82°-2 F.). lat. 1° 55' 5" N., long. 5= 55' 5" E. (82°-9 F.). Current N. 37'= W.= 0-72 knots, lat. 0'' 38' 6" N., long. 6" 25' 8" E. (82'"-9 F.). lat. 0° 21' 1" N., long. 7° 33' E. (83'' F.). lat. 1= 22' 2" S., long. 7° 45' E. (81°-4 F.). lat. 1° r/ 2" S., long. 8° 10' 4" E. (83° F.). lat. 1° 1' 2" S., long. 8° 19' 7" E. (82°-8 F.). lat. 2° 39' S., long. 8° 58' E. (81°-7 F.). A floating island near this, lat. 2° 47' S., long. 8° 46' E. (82°-7 F.). lat. 4° 26' 7" S., long. 10^ 1' 8" E. (82°-l F.). Current S. 4 W.=0-54 knots. X. „ 13, XL „ 19, XII. „ 20, XIII. „ „ XIV. „ 21, XV. „ 22, XVI 23 XVII. „ 29, XVIII. Feb. 3, XIX. „ „ ^Y.v. „ „ XXI. „ 4, XXII. „ „ XXIII. „ 5, , XXIV. ,, XXV. , XXVI. „ XXVII. „ XXVIII. „ XXIX. „ XXX. „ XXXI. „ XXXII. „ XXXIII. „ XXXIV. „ XXXV. „ XXXVI. „ XXXVII. XXXVIII. „ XXXIX. XL. XLI. „ XLII. „ XLIII. „ XLIV. „ XLV. „ XLVI. „ XLVII. „ XLVIII. „ 6, „ lat. 5° 54' S., long. 11° 33' E. (82= F.). 0 „ 19, „ 20, „ 21, !> !> 90 „ 23, 24 or; ,, ~j, 26 „ 27, „ 28, Mar. 5, „ 6, „ 7, 0 „ 10, „ 11, „ 12, „ 13, lat. 5° 55' 8" S., long. 11° 50' 3" E. (84°-2 F.), lat. 8° 8' 2" S., long. 12° 29' 4" E. (79°-8 F.). lat. 5° 9' S., long. 10° 43' E. (82°-3 F.). lat. 5° 51' 7" S., long. 8° 36' 5" E. (83°-3 F.). lat. 5° 47' 7" S., long. 6° 49' 5" E. (82°-2 F.). lat. .5° 50' 9" S., long. 5° 1' 4" E. (81°-7 F.). lat. 5° 59' 4" S., long. 3° 49' 4" E. (83° F.). lat. 6° 2' 2" S., long. 1° 50' 7" E. (81°-8 F.). lat. 5° 58' 1" S., long. 0'^ 1' 5" E. (81° F.). lat. 5° 58' 5" S., long. 1° 24' 1" W. (81° F.). lat. 5° 59' 5" S., long. 3° 24' 5" W. (80° F.). lat. 6° 0' 7" S., long. 5° 5' 4" W. (81° F.). lat. 6° 3' 4" S., long. 6° 27' 2" W. (85°-5 F.). lat. 3° 58' 6" S., long. 8° 11' W. (79°-8 F.). lat. 5° 56' 3" S., long. 9' 32' 6" W. (80°-6 F.). lat. 5° 54' S., long. 11° 48' W (81° F.). lat. G 0' 3" S., long. 13° 24' 9" W. (81° F.). lat. 3° 59' S., long. 13° 28' W. lat. 2° 42' 2" S., long. 14° 43' 4" W. (81°-5 F.). lat. 0"^ 1' 6" S., long. 15<= 56' 5" W. (81' F.). lat. 0° 7' 8" S., long. 14° 28' 6" W. (81°-6 F.). lat. 0° 0' 7" N., long. 18° 4' W. (80°-8 F.). lat. 1° 17' 6" N., long. 13° 54' 4" W. (82°-3 F.). lat. 3° 3' 4" N., long. 1 5° 0' 9" W. (83°-l F.). Current W. byS. true. (At Loanda.) ME. T. SCOTT ON ENTOMOSTEACA Part I. COPEPODA. The material from which the Copepoda noticed in this Report were ohtained w^as collected chiefly hy means of tow-nets worked at the surface and at various depths (under surface) from 2 to 460 fathoms, and a few were shore gatherings. The material was contained in 149 hottles, which represented ahout as many separate gatherings. Lists of species ohtained in some of the more important gatherings are appended to these introductory remarks {vide p. 13). Comparatively few of the species were generally distributed throughout the area examined, or were of frequent or common occurrence in the tow-nettings. The following were among the most common and most widely distributed species in the collection : — Eacalanus attenuatus, Bldncalanus cormitus, TJucUna vulgaris, EiichcBta mariua, Temora stylifera, Corycmus varius, Corycceus speciosus, and Onccea obtusa. On the other hand, a considerable number of species, though obtained in gatherings from localities all over the area examined, were uncommon or rare in the collections in which they occurred — Eucalanus setiger and Pleuromma abclominale may be given as examples. Other species, though observed in comparatively few gatherings, were yet moderately common in those in which they did occur — Kemicalanus longicoriiis is a striking example of this. Tliis species was observed in comparatively few gatherings, but in one of these no fewer than 80 fairly perfect specimens were obtained ; in contrast to this, it may be stated that scarcely half a dozen sjoecimens of Ilemicalani were observed in the whole of the ' Challenger ' collections. Several species, as Acartia sinnicaudata, Olthona miuuta, Amyriione Andreici, Ilyopsyiliis affiiiis, and some other Harpactids, were obtained in gatherings from inshore and brackish-water localities, as, for example, from a shore collection at Accra and at Sao Thome Island, and in surface-gatherings from Bananah Creek at the mouth of the River Congo, and from Loanda Harbour. A few fish-para- sites, including the pretty Messella, were also observed, and are described in this Report, Many of the species occurred more frequently in the surface tow-nettings collected during the night than in tliose collected^during the day, while in the under-surface tow- nettings they were of more frequent occurrence in those collected during the day than in those collected during the night. This will be observed by referring to the classified list of species. FEOM THE GULF OF GUINEA. 9 The following Table exhibits some points of interest respecting the general distribution of species in surface and uuder-suri'ace, and in day and niglit, collections: — Table I. — Description of the Tow-net Gatherings. C „ d -3 J3 ■T3 „ . a -S ?! i a -g c -g X i c -S bo ■5 en . ^ . 5 tie ' ,2 "5 _0 sl H o Si ■n o .2 & o o o . cT bo 11= dj O ;- o *, — 5- bO !_£ s © s c = o = ^- S.S STj; (h bO 3 O ■;= a .S 03 1 at o ■'^ ts -2 o J O s 3 S a © (» c - o (D bO n . ■r -t-s ^ != bO o © .5 ^ t 2^ o _© ff- © =- !» S a 111 © •5 'o p^ © © t: a| .a rt .s a verage number of spe eacli of the day t gatherings. aximum number of in any one of the da net gatlierings. inimum number of spe any one of the day 1 gatherings. perage number of spe each of tlie night t gatherings. aximum number of in any one of the nigl net gatherings. inimum number of spe any one of the night t gatherings. ^ stand rca). jEtidius armatus, Brady. Temora stylifera (Dana). Aeartia laxa, Dana. Phaenna spinifera, Clans. Oithona Challengeri, Brady. * SajjhlrinLlla is now known to be the male form of CopfVi'rt, of which there are several species. 14 Mli. T. SCOTT ON ENTOMOSTEACA Miracia efferata, Dana. Machairopus (?) idyoides, Brady. Setella gracilis, Dana. Corycaeus varius, Dana. speciosus, Dana. Oncaja obtusa {Dana). Oncaea gracilis (Dana). Copilia mirabilis, Dana. Lubbockia squDlimana, Glaus. Saphiriiia metallina, Dana. Sapbirinella stylifera {Lubhod'). List IV.— Tow-net Gathering No. 14-, surface, lat. 5° 58' N., long. 14° 20' W., January 5tli. Collected in the evening after darkness set in. Calanus valgus, Bradi/. propinquus, Brad;/. Eucalanus attenuatus, Dana. Rhincalanus corniitus, Dana. Leuckartia flavicornis, Claiis. TJndina vulgaris, Dana. Euchirella messinensis (Chins). Scolecitbrix Danse (Lubhocl-). Eucheeta marina (Prestandrea). Candace pachydactyla, Dana. Pontcllopsis villosa, Brady, Pontellina plumata, Dana. Labidoeera detruncata, var. intermedia, n. var. Oithona setigera, Dana. Miracia efferata, Dana. Setella gracilis, Dana. Corycoeus varius, Dana. speciosus, Dana. pellucidus, Dana. Oncaea obtusa, Dana. Copilia mirabilis, Dana. Sapbirina ovalis, Dana. Saphiriuella stylifera (Lubbock). List V.— Tow-net Gathering No. 21, 50 fathoms, Station 9 (lat. 3^ 0' 8" N., long. 7° 43' W.), January 10th. Collected at noon. Temperature (corrected) of water at 50 fathoms 59°-59 P., sp. gr. 1-02G32. Eucalanus setiger, Brady. attenuatus, Dana. spinifer, n. sp. Ehincalanus cornutus, Dana, Hemicalanus longicornis. Clans. Augaptilis longicaudatus (Glaus). Leuckartia flavicornis, Claus. Scolecitbris Danae (Lubbock). Bradyi, Giesbreclit. ctenopus, Gu'sbreclit. tenuipes, n. sp. Eucbaeta marina (I'restandrea), Hcssei, Brady, var. similis, n. var. Candace pacbydactyla, Dana, intermedia, n. sp. Acartia laxa, Dana, Clausocalanus arcuicornis (Dana), Temora stylifera (Dana), Phaenna spinifera, Clans. Pontellina plumata (Dana), Oithona Challengeri, Brady, Euterpe gracilis, var. armata, n. var. Miracia efferata, Dana, Clytemuestra rostrata (Brady). Setella gracilis, Dana. CorycEeus varius, Dana, speciosus, Dana. pellucidus, Dana. limbatus, Brady. Oncaea obtusa, Dana. gracilis, n. sp. mediterranea (Claus). Copilia mirabilis, Dana. Saphiriua metallina, Dana, Saphiriuella stylifera (LubbocJc). PEOM THE GULF OF GUINEA. 15 List VI.— Tow-net Gathering No. 29, 13th. Collected hetween 8 a.m sp. gr. 1-02606. Calanus valgus, Bradif. gracilis, Dana. Paracalanus parvus (Claus). Eucalanus setiger, Bradij. attenuatus, Dana. f;piinfer, n. sp. Khiuoulauus cornutus, Dana. Hemicalanus mucrouatus, Clans. Calocalanus pavo (Dana). Heterocliaita spinifrons, Claus. Leuckartia flavicornis, Clans. TJndiua vulgaris, Dana. Scolecithrix Dante {Luhbocl-). ctenopus, G-ieshrecM. Eucha?ta marina {Prestandrea). hebes, Giesbrecht. .^tidius armatus, Brady. Clausooalanus furcatus (Bradi/). Centropages violaceus, Claws. 25 fathoms, lat. 3° 58' N., long. 3° -12' W., January and 1 P.M. Temperature at 25 fathoms 67°"7 F., ilecynocera Clausi, /. C Thompson. Candace pachydactyla, Dana. Acartia laxa, Dana. Pontellina plumata (Dana). Miracia efFerata, Dana. Clytemnestra rostrata (Brady). Setella gracilis, Dana. Corycseus varius, Dana. spcciosus, Dana. — • pellucidus, Dana. venustus, Dana. Onciea obtusa, Dana. Copilia mirabilis, Dana. Saphirina opaca, Lubbock. splendens, Dana. metallina, Dana. Sapliirinella stylifera (Lidibock). Clausocalanus arouicornis (Dana). List VII.~Tow-net Gathering No. 16, 30 fathoms, lat. 3° 22' 5" N., long. 4" 11' 8" E. January 20th. Collected about 7 p.m. Calanus valgus, Brady. propiuquus, Brady. gracilis, Dana. Eucalanus setiger, Brady. attenuatus, Dana. llhincalanus cornutus, Dana. Hemicalanus longicornis, Clan.t. • mucronatus, Claus. Pleuromma abdominale (Luhhoch). Leuckartia flavicornis, Claus. Undlna vulgaris, Dana. EuchircUa messinensis (Claus). Scolecitbrix Danae (Lidiboclc). Euchaeta marina (Prestandrea). ^tidius armatus, Brady. Temora stylifera (Dana). Centropages furcatus (Dana). Mecyuocera Clausi, I. C. Thompson. Candace pectinata, Brady. Acartia laxa, Dana. Oithona Challengeri, Brady. • setigera, Dana. Microsetella atlantica, Brady ■.^- Boberfson. Clytemnestra rostrata (Brady). Setella gracilis, Dana. CorycKus varius, Dana. spcciosus, Dana. limbatus, Brady. Oncaja obtusa (Dana). Copilia mirabilis, Dana. Lubbockia squillimana, Claus. Saphirina ovalis, Dana. opaliua, Dana. opaca, LuhbocJc. metallina, Dana. Saphirinolla stylifera (Lubbocl-). 16 MR. T. SCOTT ON ENTOMOSTKACA List VIII.— Tow-net Gathering No. 55, 10 fathoms, lat. 1° 55' 5" N., long 5° 55' 5" E., January 22nd. Collected during the middle of the day. Temperature (corrected) of the water 81°-98 P., surface sp. gr. 1-02358. Paracalanus parvus (Claus). Eucalanus attenuatus, Dana. Euchasta marina {Prestandrea). Clausooalamis furcafcus {Brady). Temora stylifera (Dana). Ceiitropages furcatus (Dana). violaceus, Clans. Candaoe pectinata, Brad//. Pontellina plumata (Dana). Oithona Challengeri, Brady. Miraoia efferata, Dana. Setella gracilis, Dana. Corj-ciEus varius, Dana. speoiosus, Dana. pellucidus, Dana. Oncsea obtusa (Dana). Copilia mirabilis, Dana. 8aphirina ovalis, Dana. insqualis, Dana. opaoa, Lubbock. Saphirinella stylifera (Lubbock). List IX. — Tow-net Gathering No. 57, 30 fathoms. Locality, date, and time of collection the same as List VIII. Temperature of the water 63°-98 F. Calamis valgus, Brady. propiiKjuus, Brady. gracilis, Dana. Paracalanus parvus (Claus). Eucalanus attenuatus, Dana. Ehincalanus cornutus, Dana. Hcmicalanus longicornis, Claus. Calocalanus pavo (Dana). plumulosus (Claus). Heterochieta splnifrons, Claus. Leuckartia flavicornis, Claus. Undina vulgaris, Dana. Scoleeithrix Danre: (Lubbock). minor, Brady. Bradyi, Giesbrcchf. ctenopus, Oksbreclit. Euchajta marina (Prestandrea). ^tidius armatus, Bradif. Clausocalanus furcatus (Brady). arcuicornis (Dana). Temora stylifera (Dana). longicornis (^I'dller). Mecynooera Clausi, /. C. TJiompson. Centropagos furcatus (Dana). Candace pachydactyla, Dana. intermedea, n. sp. truucata, Dana. Acartia laxa, Dana. Pontellina plumata, Dana. Oithona Challengeri, Brady. Microsctella atlantica, Brady Sf Robertson. Miracia efferata, Dana. Setella gracilis, Dana. Coryeasus varius, Dana. speciosus, Dana. ■ pellucidus, Dana, limbatus, Brady. venustus, Dana. Onea?a obtusa (Dana). Copilia mirabilis, Dana. Lubbockia squillimana, Claus. Sapliirina ovalis, Dana. metallina, Dana. Saphirinella stylifera (Lubbock). List X. — Tow-net Gathering No. 59, 60 fathoms. Locality, date, and time of collection the same as List VIII. Temperature of water 60°-25 P., sp. gr. 1-02029. Eucalanus setigcr, Brady. Hoterochoeta spinifrons, Claus. Ehincalanus cornutus, Dana. Leuckartia flavicornis, Claus. Pleuromma abdominale (Lubbock). Euchasta hebes, Gieshrecht. FROM THE GULF OF GUINEA. 17 Candace pachydactyla, Dana. yEtidius armatus, Bradif. Phaemia spiniter, Claus. Oithona ChaUengeri, Brady. Corycseus varius, Daim. Coryea3us spcciosus, Dana. Copilia mirabilis, Dana. Saphirina metallina, Dana. Saphirinella stylifcra (Luhhoch). List XI. — Tow-net Gathering No. 60, 160 fathoms. Locality, date, and time of collection the same as List VIII. Temperature about 50° F. Paraoalanus parvus (Clans). Undina vulgaris, Dana. Euchseta marina (Prestandrea). Temora stylifcra {Dana). Centropages violaceus, Claus. Pontcllina phimata, Dana. Labidocera dctruncata, var. intermedia. Miracia etferata, Dana. SetelJa gracilis, Dana. Corycseus varius, Dana. Corycseus speciosus, Dana. pellucidus, Dana. Onea;a obtusa (Dana). Copilia mirabilis, Dana. Saphirina ovalis, Dana. inaequalis, Dana. opaoa, Lubbock. splendens, Dana. Saphirinella stylifcra (Lubbock). List XII.— Tow-net Gathering No. 61, 260 fathoms, the same as List VIII. Temperature Calanus valgus, Brady. gracilis, Dana. Eucalanus attenuatus, Dana. Rhincalauus cornutus, Dana. Hemicalanus longieornis, Claus, Pleuromma abdominalis (L\d)bock). Heterochaeta spinifrons, Claus. Leuckartia flavicornis, Claus. Scolecithrix Danse (Lubbock). Bradyi, Giesbrechi. ^tidius armatus, Bradij. Euchseta marina (Prestandrea). Candace pectinata, Bradi/. Locality, date, and time of collection of water about 46° F. Candace pachydactyla, Dana. Pontellina plumata, Dana. Oithona ChaUengeri, Bradij. Miracia eiferata, Dana. CorycKus varius, Dana. speciosus, Dana. pellucidus, Dana. limbatus, Brady. OncEea obtusa (Dana). Copilia mirabilis, Dana. Saphirina serrata, Brady. Saphirinella stylifera (Lubbock). Saphirella abyssicola, nov. gen. et sp. List XIII. — Tow-net Gatbering No. 62, 360 fathoms. Locality, date, and time of collection the same as List VIII. Temperature of water about 43° F. Calanus propinquns, Brady. Paracalanus parvus ( Clans). Eucalanus attenuatus, Dana. Rhincalanus cornutus, Dana. Hemicalanus longieornis, Claus. longicaudatus, Claus. plumosus, Claus. Augaptilis bectieus, Giesbrechi. SECOND SERIES. — ZOOLOGY, VOL. VI. Calocalanus pavo (Dana). Pleuromma abdominale (Lubbock). princeps, n. sp. Leuckartia flavicornis, Claus. Undina vulgaris, Dana. Scolecithrix Dana? (Lubbock). longieornis, n. sp. liradyi, Giesbrechi. 18 MR. T. SCOTT ON ENT0310STRACA Scolecithrix tenuipes, n. sp. Amallophora dubia, nov. gen. et sp. Euchiieta marina (Prestandrea). harbata, Brady. jEtidius armatus, Brady. armiger, Gieshrecht. Clausocalanus arcuicornia (Dana). Phyllopus bidentatua, Brady. Temora stylifera (Datia). Candace tnincata, Dana. Acartia laxa, Dana. MormoniUa pbasma, Gieshrecht. Phaiinna spinifera, Glaus. Pontellina plumata, Dana. Oithona Challeiigeri, Brady. setiger, Dana. Miracia efferata, Dana. Setella gracilis, Dana. ^gisthus longirosh-is, n. sp. Corycseus varius, Dana. speciosus, Dana. ■ pellucidus, Dana. limbatus, Brady. obtiisus, Dana. Onca^a obiusa (Dana). gracilis (Dana). Copilia mirabili.s, Dana. Lubbockia squillimana, Glaus. Saphirina iutequalis, Dana. ■ ■ metallina, Dana. Sapbirinella stylifera (Luhhock). List XIV. — Tow-net Gathering No. 63, 400 fathoms. Locality, date, and time of collection the same as List VIII. Calanus propincjuus, Brady. gracilis, Dana. Paracalanus parvus (Clans). Eucalanus attenuatus, Dana. Khincalanus cornutus, Dana. Hemicalanus longicornis, Glaus. Pleuromma abdominale (Lubhock). Heterocha^ta siiiuifrous, Glaus. Leuckartia flavicornis, Claws. Undina viilgaris, Dana. Eucbirella mcssiucnsis (Glaus). Amallophora dubia, nov. gen. tt sp. magna, n. sp. Euchfet-a marina (Preslandrea). Eucha^ta Hcssci, var. similis, n. var. jEtidius armiger, Oieshrecht. Temora longicornis (Midler). Candace varicans, Gieshrecht. Oithona Challengeri, Brady. Microsetclla atlantica, Brady df Bohertson. Longipedia minor, T. Sf A. Scott. Clytemnestra rostrata, Brady. Setelia gracilis, Dana. Coryceeus varius, Dana. speciosus, Dana. venustus, Dana. Oncoea obtusa (Dana). (?) Saphirina nigromaculata, Glaus. List XV.— Tow-net Gathering No. 08, 20 fathoms. Off Sao Thome Island (lat. 3° 34' N., long. 0° 30' 4" E.). Collected after midday, January 23rd. Calanus valgus, Brady. propinquus, Brady. gracilis, Dana. Eucalanus attenuatus, Dana. Khincalanus cornutus, Dana. Hemicalanus longicornis, Glaus. mucronatus, Glaus. Augaptilis hecticus, Gieshrecht. Eattrayi, n. sp. Pleuromma abdominale (Luhhocl'). Heterochoeta spinifrons, Glaus. Leuckartia flavicornis, Glaus. Undina vulgaris, Dana. Scolecithrix Dan^ (Luhhoch). Bradyi, Gieshrecht. ctenopus, Gieshrecht. Euchaeta marina (Prestandrea). ■?, sp. ^tidius armatus. Clausocalanus arcuicornis (Dana). Temora stylifera (Dana). Mecyuocera Clausi, /. G. Thonipson. rKO.M THE GULF OF GUINEA. 19 Oandaee pectinata, Brady. pachydactj'la, Dana. truncata, Dana. I'ontellina plumata, Dana. Stenhelia aocraensis. Setella gracOis, Dana. Corjcaeus variiis, Dana. speciosus, Dana. pellucidus, Dana. Cor3'caeus limbatus, Brady. Onca;a obtusa {Dana). Copilia mirabilis, Dana. Lubbockia squillimana, Ohms. Saphirina ovalis, Dana. opaca, LtMock. nietallina. Dana. Sapbirinella stylifera (Luhlocl-). List XVI.— Tow-net Gathering No. 71, 15 fatlioms, lat. 0° 28' 7" N. Collected al)out 6 p.m., January 23rd. long. 6° 35' 2" E. Calanns valgus, Brady. proi)inquiis, Dana. gracilis, Dana. ParacalaDus parvus (Claus). Eucalanus attenuatus, Dana. llhincalanus cornutus, Dana. Hemicalanus lougieornis, Clans. Hctcrochasta spiuifrons, Claus. Undina vulgaris, Dana. Scolecithrix Danse (IaMocJc). Bradyi, GieshrecJd. Euchaeta marina {Prestandrea). hebes, Gieshrecht. Clausocalanus fureatus (Brady). Temora stylifera {Dawi). longicornis, Midler. Centropages \-iolaceus ( Glaus). Candace pacbydactyla, Dana. intermedia, n. sp. Acartia laxa, Dana. Pontelliua jilumata, Dana. Uithona Challeiigeri, Brady. Microsetella atlantica, Brady ^- Robertson. Miracia efferata, Dana. Clytemnestra rostrata (Brady). Setella gracilis, Dana. Coryca'us varius, Dana. speciosus, Dana. pellucidus, Dana. limbatus, Brady. venustus, Dana. Oncasa obtusa (Dana). Copilia mirabilis, Dana. Lubbockia squillimana, Claus. Saphirina iuEequalis, Dana. opalina, Dana. opaca, LiMock. splendens, Dana. Saphirinella stylifera (Luhbock). List XVII. — Tow-net Gathering No. 82, surface. Collected about midnight, January 28th. Calanus valgus, Brady. Paracalauus parvus (Claus). Eucalanus attenuatus, Dana. lihincalanus cornutus, Dana. Leuckartia flavicornis, Claus. Undina vulgaris, Dana. Euchseta marina (Prestandrea). Temora stylifera (Dana). longicornis, Muller. Centropages fureatus (Dana). Candace pectinata, Brady. iuteimedia, n. sp. Pontellina plumata, Dana. lat. 0° 22' 8" N., long. 8' 33' 2" E. Sp. gr. of the water 1-02237. Oithoua Challengeri, Brady. Microsetella atlantica, Brady ^- Moberfson. Euterpe gracilis, var. armata, n. var. Clytemnestra rostrata (Brady). Setella gracilis, Dana. Corycaeus varius, Dana. speciosus, Dana. pellucidus, Dana. obtusus, Dana. Oncoea obtusa (Dana). Saphirina ovalis, Dana. inajqualis, Dana. 20. Ml{. T. SCOTT ON EJNTOMOSTEACA List XVIII. — Tow-net Gathering No. 91, shore (low tide), Sao Thome Island. Collected during- the day, January 31st Laophonte pygm^a, n. sp. Machairopus idyoidos, Brady. longipes, n. sp. List XIX.— Tow-net Gathering No. 92, surface, lat. 0° 7' & N., long. 6° 59' 2" E. Collected February 2nd, shortly after midday. Calanus valgus, Brady. Temora stylifera (Dana). Pontellina plumata, Dana. Oithona Challcngeri, Brady. Microsetella atlantica, B. ijj- R. Miraoia efferata, Dana, Corycoeus varius, Dana. speciosus, Dana. pellucidus, Dana. venustus, Dana. obtusus, Dana. Oucuia obtusa (Dana). List XX. — Tow-net Gathering Collected Febr Calanus valgus, Brady. Rhincalauus cornutus, Dana. Leuckartia flavicornis, Claus. Undina vulgaris, Dana. Seolecitbrix Bradyi, Giesbrecht. Euchaita liebes, Gvshrecht. Temora stylifera {Dana). loDgicornis (Mailer). Candace intermedia, n. sp. Labidocera acutifroas (Dana). Pontelliua plumata, Dana. Oithona Challengeri, Brady. Euterpe gracilis, var. armata, n. var. No. 97, surface, lat. 0° 45' 8" S., long. 7° 37' 4" E. uary 3rd, shortly after midnight. Microsetella atlantica, Brady 4' Robertson. Miracia efferata, Dana. Clyta;muestra rostrata (Brady). Setella gracilis, Dana. Corycoeus varius, Dana. speciosus, Dana. pellucidus, Dana. limbatus, Brady. venustus, Dana. Onca;a obtusa (Dana). Lubbockia squillimana, Claus. Saphirina iuKiqualis, Dana. serrata, Brady. List XXL— Tow-net Gatliering No. 113, 30 fathoms. Station 23 (lat. 4° 26' 7" S., 11 A.M. and 3 p.m., Eebruary 5th. Tempera- This gathering contained a greater number species, than any other in the collection. long. 10° r 8" E.). Collected between ture 82°-l F., sp. gr. at noon 1-U2347. of individual specimens, though not of Calanus propinquus, Brady. gracilis, Dana. tonsus, Brady. Eucalanus setigcr, Brady. • attenuatus, Dana. Rhiucalanus cornutus, Dana. Hemicalanus longicornis, Claus. mucrouatus, Claus. Heterochaeta spinifrons, Claus. Undina vulgaris, Dana, Euchirella mcssinensis (Claus). Seolecitbrix Danas (Lubbock). Euchseta marina (Prestandrea). barbata, Brady. Candace pectinata, Brady. pacbydactyla, Dana. intermedia, n. sp. — ■ — truncata, Dana. Acartia laxa, Dana. Phaenna spinifera, Claus. FROM THE GULF OF GUIjNEA. 21 Labidocera acutifrons (Dana). Pontella securitcra, Bradij. Oithona Challengeri, Brady. Corycseus varius, Dana. speciosus, Dana. Oncaja obtusa (Dana). gracilis (Dana). Copiliii mirabilis, Da?ia. Copilia quadrata, Dana. Rattrayi, n. sp. Lubbockia squillimana, Claus. Sapbiriua ina^qualis, Dana. scrrata, Brady. splcndcns, Dana. metalliua, Dana. Sapbiriiiella stylLfcra (Lubbock). List XXII. — Tow-net Gathering No. 119, 235 fathoms, Station 23. Date and hour of collection the same as last. ] -02648. Calanus valgus, Brady. propiuquus, Brady. gracilis, Dana. Eucalanus atteuuatus, Dana. spinifer, n. sp. Rhincalanus coniutus, Dana. Hemicalanus longicornis (Claus). plumosus, Claiis. Plouromma abdominale (Lubbock). Heterochajta spinifrons, Claus. Leuckartia fiavicornis, Claus. Scolecithrix minor, Brady. Eucha3ta marina (Prestandrea). uEtidius armatus, Brady. Mecynocera Clausi, /. C. Thompson. Acartia lasa, Dana. Mormonilla j)hasma, Oicsbrecht. At 200 fathoms the temperature was 55° E., sji. gr. Euterpe gracilis, var. armata, n. var. Microsetella atlantiea, Brady 4 Roherison. Miracia efferata, Dana. Clytemnestra rostrata (Brady). Setclla gracilis, Dana. .^ilgisthus longirostris, n. sp. Oncaea obtusa (Dana). gracilis (Dana). Corycaeus varius, Dana. speciosus, Dana. Copilia mirabilis, Dana. Lubbockia squillimana, Claus. Saphirina splendens, Dana. metallina, Dana. Saphirinella stylifcra (Lubbock), Artotrogus abyssioolus, n. sp. List XXIIL— Tow-net Gathering Xo. 133, surface, lat. 6° 29' 4" S., long. 11° 24' 8" E. Collected at 7.30 p.m., February 8th. Sp. gr. at 8 p.m. 1-02398. Paracalanus parvus (Clai(s). rieuromma abJominale (fyubhock). Leuckartia flavieurnis, Claus. Undina vulgaris, Dana. Scolecithrix Dana; (Lubbock). Temora dubia (Lubbock). longicornis (Miiller). Centropages brachiatus, Dana. furcatus, Dana. Candace pachydactyla, Dana. intermedia, n. sp. Pontellopsis villosa, Brady. Pontella seourifer, Brady. inermis, Brady. Oithona seligera, Dana. Microsetella atlantiea, Brady ^ Robertson. Coryca3us varius, Dana. ■ speciosus, Dana. obtusus, Dana. Oncaea obtusa (Dana). Lubbockia squillimana, Claris. 22 MK. T. SCOTT ON ENTOMOSTRACA List XXIV. — Tow-net Gathering No. 137, sur Collected at 5 a.m., February 9th. Calanus valgus, Brady. • piopiiiquus, Brady. Paracalauus parvus (Clans). Eucalanus atteiiuatus, Dana. Khincalanus cornutus, Dana. Undina vulgaris, Dana. Soolecithrix Danas (Lubbock). Euehseta marina (Prestandrea). Temora dubia (LubbocJc). longicornis (Muller). Candace pectinata, Brady. Acartia lasa, Dana. Pontellopsis villosa, Brady. Labidocera acutifrons (Dana). face, lat. 7° 38' S., long. 12° 3' 3" E. Sp. gr. at 1 A.M. 102623. Pontella securifer, Brady. inermis, Brady. Oithona plumifeia, Dana. Coryeteus spociosus, Dana. pelluoidus, Dana. limbatus, Brady. Oncsea obtusa (Dana). Copilia mirabilis, Dana. Lubbockia squillimana, Claus. Sapbirina inaequalis, Dana. opalina, Dana. ■ splendens, Dana. Sapbirinella stj'lifera (LubbocJc). List XXV. — Tow-net Gatherings Nos. 141, 142, 143, 144, and 145, surface, Loanda Harbour. Collected during the afternoon, February 13th and 15th. Surface-tem- perature at noon on the 13th was 78°'2 F. ; at noon on the 15th the surface-temperature of the seaward part of the Harbour, where all the tow-net gatherings, except No. 141, w^ere collected, was 79°'2 F. Few species were observed in any of the Loanda Harbour gatherings. Eucalanus attenuatus, Dana. Temora longicornis (AliiUi'r). Ceutropages brachiatus, Dana. furcatus, Dana. Acartia plumosa, n. sp. Paracartia dubia, n. g. et sp. spiuicaudata, n. g. et sp. Oitbona setigera, Dana. minuta, n. sp. Longipedia minor, T. cj- A. Scott. Euterpe gracilis, var. armata, n. var. Corycoous obtusus (Dana). Hersiliodes Livingstoni, n. sp. Lichomolgus propinquus, n. sp. COPEPODA. INDEX TO GENERA AND SPECIES. age Acartia, Dana 65 Clausi, Giishrccht 67 denticornis, Brady 66 laxa, Da7ia 65 plumosa, n. sp 66 .^gisthus, Giesbrecht 104 longirostris, u. sp 104 Page jEtidius, Brady 70 armatus, Brady 70 armiger, Giesbrecht 71 Amallophora, nov. subgen 54 dubia, n. sp 55 magna, n. sp 55 robusta, n. sp 56 Page Amallophora typica, n. sp 54 Amymone, Claus 94 Andrewi, n. sp 94 Artotrogus, Boecl- 128 abyssicolus, n. sp 128 Augaptilis, Giesbrecht 34 hecticus, Giesbrecht 35 ¥EOM THE GULF 0¥ GUINEA. 23 Page A ugaptilis longicaudatus ( Clatis) 34 Eattrnyi, n. sp 36 Bradya, Boeck 02 brevicornis, n. sp 02 Calanus, Leach 24 comptus, Dtnia 26 gracilis, Dana 25 propiiKjuus, Braihj 25 tonsus, Brailif 25 valgus, Brad;/ 24 Caligus, MiiUer 120 bengoensis, n. sp 130 dubius, n. sp 130 Murrayanus, n. sp 120 (?) Tbymni, Da,i,( 120 Calocalanus, Gksbrecht 37 pavo (Dana) 37 plumulosus {Claus} 30 Candace, Dana 60 intermedia, n. sp 61 pacbydactyla, Dana CO pectinata, Brad if Gl truncata, Dana 63 varicaus, Gieshredit 62 Centropages, Kroi/er 77 brachiatus (Dana) 77 furcatus (Dana) 77 violaceus (Ckins) 78 Clausooalanus, Gieshredit .... 72 arcuicornis (Dana) 73 furcatus (Bradif) 72 latipes, n. sp 72 Cletodes, Brady OS linearis (Clauf) 08 Clytemnestra, Dana 106 rostrata (Brady) 106 Copilia, Dana 113 denticulata, n. sp 114 Fultoni, n. sp 114 mirabilis, Dana 113 quadrata, Dana 113 Corycieus, Dana 110 limbatus, Brady Ill obtusus, Dana. 112 pellucidus, Dana 110 speeiosus, Dana 112 varius, Dana 110 venustus, Dana Ill Cyclopicera, Brady 127 Page Cjxlopicera lata, Bradi/ 127 Dactylopus, Claus 08 latipes, n. sp 00 propinquus, n. sp 90 Ectinosoma, Beecl- 02 Chrystali, n. sp 02 Eucalanus, Dana 28 attenuatus, Dana 28 setigor, Brady 30 spinifer, n. sp 20 Euchffita, Philippi 57 australis, Brady 58 barbata, Brady 58 gigas, Brady 58 hebes, Gieshredit 50 var. valida, nov. var. . . 60 Hessci, Brady, var. similis. 58 nmrin'O. (Prestandrca) .... 57 pulchra (Luhhodc) 57 EuchireUa, Gieshredit 45 messinensis (Claus) 45 Euterpe, Claus 03 gracilis, Claus, var. artnata, n. var 03 Harpacticus, M.-Edwards .... 102 ehelifer (Midler), var 102 Hemicalanus, Chius 32 longicornis, Claus 32 mucronatus, Claus 33 plumosus, Claus 33 Hersiliodes, Canu 118 Livingstoni, n. sp 118 Hessella, Brady 131 cylindrica, Brady 131 Heterocalanus, n. gen 30 serricaudatus, n. sp 40 HeteroohKta, Claus 43 spinifrons, Claus 43 Ilyopsyllus, Brady ^ Robertson . 101 affinis, n. sp 101 Labidocera, Lidjhodc 82 acutifrons, Dana 85 acutum, Dana 85 Darwinii, Luhhodc S3 detruncata, Dana, var. . . S3 Laophonte, Philippi 96 brevicornis, n. sp 07 longipes, n. sp 06 pygmtea, n. sp 97 Page Laophonte sorrata (Claus) .... 96 Leuckartia, Claus 44 flavicoruis, Claus 44 Lichomolgus, Thorcll 1 20 congoeusis, n. sp 120 Longipedia, Claus 91 minor, T. l}- A. Scott .... 91 Lubbockia, Claris 115 squillimana, Claus 115 Machairopus, Brady 104 idyoides, Brady 104 Mecynocera, /. C. Thompson . 80 Clausi, /. C. Thompson . . 80 Microsetella, Brady ^f- Robertson. 01 atlautiea, Brady c|- Robert- son 91 Miraeia, Dana 102 efferata, Dana 102 minor, n. sp 102 Mormonilla, Gieshredit 64 phasma, Giesbrccht 64 Nogagus, Leadi 1 30 validus, Dana 130 Oitbona, Baird 89 Challengeri, Brady 89 minuta, n. sp 90 plumifera, Dana 89 setigera, Dana 91 Onoasa, Philippi 116 gracilis (Dana) 116 mediterranea (Claus) .... 117 obtusa (Dana) IIG Pachysoma, Claus 119 punctatum, Claus 110 Paracalanus, Botd- 26 parvus {Clans) 26 pygmseus (Claus) 27 Paracartia, u. gen 68 dubia, n. sp G9 spinicaudata, u. sp 69 Phaenna, Claus 81 spinilera, Claws 81 Phyllopus, Brady 74 bidentatus, Brady 74 Pleuromma, Claus 41 abdomiuale (Lubbod) .... 41 gracile, Claus 42 princeps, n. sp 42 Poutclla, Dana 85 24 ME. T. SCOTT ON ENTOMOSTEACA Page Pontella inermis, Brady 85 mediterraiica (Claus) .... 86 securifera, Bnidij 86 Pontellina, Dana 88 plumata, Dana 88 Pontellojjsis, Brady 87 ■villosa, Brady 87 Pontopsyllus, n. g 131 elongatus, n. sp 131 Pseudanthessius, Claris 121 propinquus, n. sp 12) Rhincalanus, Dana 30 aculeatus, n. sp 31 cornutus, Dana 30 SaphireUa, n. gen 126 abyssicola, u. sp 126 Saphirina, /. C. Thompson .... 122 inaequalis, Dana 122 Page Saphirina mctallina, Dana .... 125 opaca, LubhocJc 124 opalina, Dana .• ■ • • 123 ovalis, Dana 122 serrata, Brady 123 sinuicauda, Brady 125 splendens, Dana 124 Siphiriuella, Clans 126 stylifera (Luhhoch) 126 Scolecithrix, Brady 47 Bradyi, Giesbrecht 51 ctenopus, Giesbrecht 48 Dante (Lidiboek) 49 dubia, Giesbrecht 5.3 latipes, n. sp. . . . longicornis, n. sp. major, n. sp. ... 50 52 Page Scolecithrix minor, Brady ... 50 securifrons, n. sp 47 tenuipes, n. sp 48 tumida, n. sp 52 Sctella, Dana 109 gracilis, Dana 109 Stenhelia, Boech 95 accraensis, n. sp 96 Temora, Baird 75 longicornis {MiUler) .... 76 stylifera {Dana) 75 Temoropia, n. gen 79 mayumbaensis, n. sp 79 Thalestris, Claas 100 forficula, Claus 100 Undina, Dana 44 vulgaris, Dana 44 Section I. GNATHOSTOMA, ThoreU. Family CALANID^. Genus Calanus, Leach. 1819. Calanus, Leach^ Diet. Nat. Sci. vol. xiv. Art. Entomostraca. Calanus valgus, Brady. 1883. Calanus valgus, Brady, ' Challenger' Copepoda, p. 33, pi. iii. figs. 1-7. Habitat. Station 2 (lat. 7° 54' N., long. 17° 25'W.),in 5 and 25 fathoms, tow-nettings, January 1st (night collection). Lat. 3° 58' N., long. 3° 42' W., in 25 and 50 fathoms, tow-nettings, January 13th (day collections). Banauah Creek, Mouth of the Congo, surface tow-netting ^day collection). Lat. 7° 51' G"-8, long. 11° 11' 7" E., surface tow-netting (night collection), &c. This species was obtained in 55 tow-nettings, 21 of which were surface nettings and 31 under-surface nettings : 5 of the surface and 22 of the under-surface nettings were day collections, while 19 surface and 11 under-surface nettings were night collections, as shown in the annexed formula : — f 5 day collections, r 24 surface 1 19 night ditto. Tow-nettmgs 55 < . -.^ , ,.^, I 31 under-surface / ^^ day ditto. 1 11 night ditto. The under-surface tow-nettings ranged from 5 to 260 fathoms. Calanus valgus was taken in the open sea, where the specific gravity of the water was 1-02620, and the FEOM THE GULF OF GUINEA. 25 temperature 82°'2 P., and at Bananali Creek, where the sp. gr. of the water was 1-00870 and the temperature 82° F. It was also captured at a depth of 260 fathoms (as recorded above), where the temperature of the water was about 16° F. This species is thus apparently able to exist under very varied conditions, as regards the density and tem- perature of the water. It also appeared to be generally distributed throughout the area examined, but was more plentiful near, and south of, the Equator. The flexed position of the right fifth foot of the male, referred to by Dr. Brady in his Eeport on the ' Challenger ' Copepoda, was also observed in many of ' Buccaneer ' specimens. Calanus peopinqtjus, Brady. 1883. Calanus propinquus, Brady, op. cit. p. 34, pi. ii. figs. 1-7, pi. xiv. figs. 10, 11. Habitat. Lat. 1° 55' 5" N., long. 5° 55' 5" E., 360 fathoms, day collection, January 22nd. Station 23, surface and 235 fathoms, day collections, February 5th. This species, though only satisfactorily identified in tow-nettings from the localities described, may have occurred in others. Usually I was unable to identify this Calanus with certainty, except by carefully dissecting the specimens ; hence the probability of its being of more frequent occurrence in the collection than the few localities given for it would seem to indicate. Calanus tonsus, Brady. 1883. Calanus tonsus, Brady, op. cit. p. S-i, pi. iv. figs. 8, 9. Eahltat. In a tow-netting from Station 23, a surface gathering. The large and tumid first abdominal segment seems to be a fairly good character of this species. Calanus gracilis, Dana. 1852. Calanus gracilis, Dana, Crust. U.S. Expl. Exped. p. 1078, pi. Ixxiv. fig. 10. 1883. Calanus gracilis, Brady, op. cit. p. 35, pi. v. figs. 1-6, and pi. xlvi. fig. 1. Habitat. Station 2, 5 fathoms, night tow-netting, January 1st. Station 3, 25 fathoms, January 2nd (day collection). Lat. 3° 22' 5" N., long. 4° 11' 8" E., 30 fathoms, January 20th (night collection). Station 21, surface, February 3rd (day collection). Station 23, surface and 235 fathoms (the first a day, the other a night collection). Calanus gracilis was obtained in 19 tow-nettings — 4 of these were surface gatherings and 15 were under-surface gatherings. 2 of the surface and 12 of the under-surface tow- nettings were day collections, while 2 of the surface and 4 of the under-surface were night collections, as in the formula : — 2 day collections. 1. ..• -,n( ^^'^'^^"^ I 2 night ditto. Tow-nettmgs 19 -^ ^-.^i ,-.. ( 15 under-surface | ^^ day ditto. l 4 night ditto. The under-surface tow-nettings ranged from 5 to 160 fathoms. Though frequent in a few of the gatherings in which it occurred, Calanus gracilis was not a common species, SECOND SERIES. — ZOOLOGY, VOL. VI. 4 26 ME. T. SCOTT ON ENTOMOSTEACA l)ut was> nevertlieless, -widely though sparingly distributed throughout the greater part of the area examined. The specimens obtained were mostly females, and were readily distinguished from the other species of Calanns by the long anterior antenntie and the peculiar terminal spine of the first swimming-feet. ? Calanus comptus, Dana. (PI. V. figs. 46-50; PI. VI. figs. 1-5.) 1853. Calanus comptus, Dana, Crust. U.S. Expl. Exped. p. 1050, pi. Ixxii. fig. 2a. Hale. Length, exclusive of tail-setae, 3'3 mm. Body composed of sis segments, the first as long as the entire length of the other five. Anterior antennae scarcely longer than the cephalothorax, 23-jointed, and very sparingly setiferous ; the proportional lengths of the joints are nearly as in the formula : — 36 . 6 . 6 . 7 . 8 ■ 8 . 7 ■ 8 . 11 . 12 ■ 13 . 17 . 18 . 20 . 20 ■ 21 . 22 . 22 . 18 ■ 10 . 18 . 19 . 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23' Posterior antennae and mouth-organs nearly as in Calanus fimnarcliicus. The first four pairs of swimming-feet closely resemble those of Cal. gracilis, Dana, the peculiar terminal spine of the outer branches of the first pair in both species being almost identical. The fifth pair also resemble those of that species, as figured in the ' Challenger ' Copepoda, except that the small secondary branch is 3-jointed. Abdomen short, 5-jointed, the second segment rather longer than any of the others. Caudal stylets short. Habitat. Lat. 6° 34' N., long. 12° 39' W,, surface collection. One or two specimens only were obtained. This Calamis so closely resembles Calanus gracilis in many respects that I am inclined to consider it as simply a variety of that species. Genus Paracalanus, Boeck (1864). Paracalantjs parvus (Claus). (PI. I, figs. 9-14.) 18G3. Calanus parvus, Claus, Die freilebendeu Copepoden, p. 173, t. xxvi. figs. 10-14, t. xxvii. figs. 1-4. 1864. Paracalanus parvus, Boeck, Oversigt Norges Copepoder, p. 232. Length 1"12 mm. Cephalothorax elongate-ovate, rounded in front and behind. Anterior antennae reaching to the end of the caudal stylets, 24-jointed ; the proportional lengths of the joints are as follow (antennae the same in both sexes) : — 35 ■ 25 ■ 12 . 12 . 10 . 10 . 12 ■ 13 . 10 . 10 . 10 . 13 . 12 . 13 . 15 . 15 . 15 . 15 . 15 . 15 . 13 . 14 . 15 . 27 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24* Posterior antennae and mouth-organs as in Calanns. The inner branch of the first pair of swimming-feet 2-jointed, about as long as the first two joints of the outer branch ; the basal joint of the peduncle bears a stout plumose seta near the inner distal angle. The basal joints of both branches of the fourth pair are small, the second and third joints of the inner branch and tlie second joint of the outer branch are furnished on the side with an armature of spines as in the figure (fig. 11), and the outer margin of the last joint of the outer branch is distinctly dentate from the base to the first marginal TEOM THE GULF OF GUINEA. 27 spine. All the first four pairs of swimming-feet liave the inner margins of both branches furnished with long plumose hairs. The fifth feet in the male are 1-branched — the right short, 3-jointed, and terminating in two short spines of unequal length ; the left 5-jointed, apparently hinged between the first and second joints ; length of the joints subequal, the last terminating in two small spines. Fifth pair of feet in the female 1-branched, 2-jointed, the last joint much narrower than the first and terminating in one long and one short spiniform setse. Bahltat. Lat. 6° 34' N., long. 12° 39' W., surface, January 6th (day collection). Off Accra, 3 fathoms, January 15th (night collection). Lat. 1" 55' 5" N., long. 5° 55' 5" E., 10, 20, 30, 360, and 160 fathoms, January 22nd (day collection). Station 18, surface tow-netting, February 3rd (day collection). Station 21i (off the mouth of the Congo River), surface tow-netting, February 6th (day collection). Lat. 5° 9' 8" S., long. 11° 10' 4" E., surface tow-netting, February 19th (day collection), &c. Paracalanus parvus occurred in 19 tow-nettings, 29 of which were surface and 20 under-surface gatherings. The under-surface tow-nettings ranged from 2^ to 460 fathoms. 11 of the surface and 16 of the under-surface tow-nettings were day col- lections, while 18 surface and 4 under-surface were night collections, as in the formu.la : — r 11 day collections, r 29 surface 1 18 night ditto. Tow-nettmgs 49 < ^-.n ^ v^i. \ 20 under-surface X ^^ ^^^ ^^^^^O" I 4 night ditto. This species was comparatively frequent in all the gatherings in which it was observed. Paracalanus pyoai^L's (Claus). (PL I. figs. 1-8.) 1863. Calanus pijffnueus, Claus, Die freilebenden Copepoden, p. 74. Female. Length 7 mm. (l-36th of an inch). Body robust, composed of four segments, the first being fully twice the entire length of the outer three ; rostrum short, stout, prominent. Anterior antennae reaching beyond the cephalothorax, 24-jointed, sparingly setiferous ; sette mostly small, except towards the extremity, where there are several moderately long hairs ; the proportional lengths of the joints are as shown in the formiila : — 30 ■ 6 ■ .5 ■ 5 ■ .5 . 5 . 5 . 5 ■ G ■ 7 . 8 . 8 ■ 8 ■ 8 ■ 8 . 7 ■ S . 11 ■ 8 ■ 12 ■ U ■ 12 . lo . 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24' Posterior antennoe small, provided with moderately long setse; the primary branch composed of two nearly equal joints ; secondary branch fully half the length of the other ; 7-jointed, the third, fourth, and fifth joints very short, the others longer and subequal. Mouth-organs as in Paracalanus j^arcus. The swimming-feet are also similar to those of that species, but differ in their armature, especially in having the second as well as the last joints of the outer branches of the second, third, and fourth pairs serrate on the outer margin, in the terminal spines being proportionally smaller, and in both branches 4* 28 ME. T. SCOTT ON ENTOMOSTEACA of the fourth pair being more slender. The fifth pair resemble those of Faracalanus parvus, but are proportionally stouter and have much shorter terminal spines. Abdomen small, composed of four segments, the second and third segments very short. Caudal stylets nearly as long as the last abdominal segment, breadth about half the length ; apical setse four. No males were observed. Rahitat. Lat. 3° 57' 2" N., long. 7° 42' 8" W., 2 fathoms, January 9th (night collection). Libreville, Gaboon River, surface, January 28th (day collection). Bananah Creek, Congo River, surface, February 7th (day collection). Comparatively few specimens of Faracalanus pygmceus were obtained. Genus Eucalantjs, Dana. Eucalanus and Calarms (iu part), Dana, Crust. U.S. Expl. Exped. (1852). ElJCALANUS ATTENUATUS, Dana. 1852. Calanus attenuatus, Dana, loc. cit. p. 1080, pi. Ixxv. fig. 2. 1856. Calanus mirabilis, Lubbock, Trans. Entom. Soc. vol. iv. pi. v. figs. 1-6. 1883. Eucalanus attenuatus, Brady, op. cit. p. 38, pi. ii. figs. 8-10, pi. vi. figs. 1-8. Habitat. Station 2, 5, 25, and 50 fathoms tow-nettings, January 1st (night collections). Station 9, 25 and 50 fathoms tow-nettings, January 10th (day collections). Station 14, 10 fathoms tow-netting, January 21st (night collection). Lagoon Island, Sao Thome, surface tow-netting, January 28th (night collection). Station 23, surface, 10, 20, 85, 135, 185, and 235 fathoms tow-nettings, February 5th (day collections). Bananah Creek, Congo River, surface tow-netting, February 7th (day collection). Loanda Ilarbour (seaward), surface, February 15th (day collection). This was one of the more common and generally distributed sj)ecies in the ' Buccaneer ' collections. It occurred in 89 tow-nettings, 41 of these being surface and 48 under- surface gatherings. The under-surface tow-nettings ranged in depth from 2 to 460 fathoms. 18 of the surface and 35 of the under-surface gatherings were collected during the day, while 23 of the surface and 13 of the under-surface were collected during the night, as in the formula: — 18 day collections. r 18 day collectic -41 surface \ 23 night ditto. Tow-nettings 89- Us under-surface J 3-^ "^"^^ ^^^^^'O- 1 13 night ditto. Eucalanus attenuatus was taken at the surface in the open sea, the specific gravity of the water being 1-02543 and temperature 85°-5 F., and at 360 fathoms with the tem- perature of the water at about 43° F. It was taken off the mouth of the Congo River, where the specific gravity of the water was 1-01984 and the temperature 82° F. (the colour of the water here, — lat. 6° 54' 3" S., long. 11° 33' E., — was "brownish olive-green to amber-brown "), and at Bananah Creek, where the specific gravity was only 1'00870. It will be observed from these records that this Eucalanus is able to live in water of very varied character, as regards density and temperature. A species capable of existing FEOM THE GULF OF GUINEA. 29 under such a diversity of conditions might be expected to have a wide distribution, and such is the case witli this Eucalamis. Dana has recorded it from the Pacific and China Seas. In the ' Challenger ' Report it is recorded from the Malayan and Australasian Seas. Sir John Lubbock has recorded it from the Bay of Biscay * and Mr. I. C. Thompson from Madeira and the Canary Islands f. Prof. Claus records a Calanella from the Mediteranean, which Dr. Brady thinks is " in all probability identical with the present species." EUCALANUS SPINIFER, n. sp. (PI. I. figs. 15-23.) Length 5"5 mm. Forehead triangular ; rostrum as in Eucalanus attenuatus ; postero- lateral angles produced and spiniform ; anterior antennae 22-jointed, reaching to the extremity of the caudal stylets, the proportional lengths of the joints are nearly as follows : — 40 ■ 11 . 11 ■ 12 . 12 . 13 . 20 . 18 . 20 . 2-5 . 29 . 27 . 29 . 29 . 29 . 26 . 29 . 27 . 24 . 2.3 . 13 . 10 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22" The secondary branch of the posterior antennae small, 7-jointed, the two basal and the terminal joints longer than the others, both branches furnished with numerous plumose hairs. The secondary branch of the mandible-palp 3-jointed, stouter and nearer the distal end of the large basal part than that of E. attenuatus; both branches furnished with a number of long hairs, those of the secondary branch being setiferous from the middle to near the extremity (fig. 17). Anterior and posterior foot-jaws as in E. attenuatus. The inner branches of first pair of swimming-feet 2-jointed, joints subequal; the following three pairs as in Eucalanus attenuatus. Fifth pair of feet in the male 1-branched, each branch 4-jointed, the last joint terminating in a long somewhat curved spine ; on tlie inner margin and near the base of the spine springs a stout plumose hair, the length of which exceeds that of the terminal spine. Abdomen very short and 3- jointed, the basal joint as long as the other two together. Caudal stylets nearly as long- as the last two abdominal segments, each stylet furnished with five plumose hairs, the inner one being about half the length of the other four, which are about equal. Habitat. Station 9, 50 fathoms tow-netting, January 10th (day collection). Lat. 5"" 10' N., long. 3° 56' 2" W., inshore surface tow-netting, January 12th (night collection). Lat. 3° 58' N., long. 3' 42' W., 25 fathoms tow-netting, January 13th (day collection). Lat. 1° 55' 5" N., long. 5° 55' 5" E., 35 fathoms tow-netting, January 22nd (day collection). Lat. 4° 26' 7" S., long. 10° 1' 8" E., 238 fathoms tow-netting, February 5th (day collection). The tow-nettings from the localities described were the only gatherings in which this Eucalanus was observed, but, though its distribution was limited, a considerable number of specimens were obtained. Its chief and most apparent distinctive characters are the spiniform lateral angles of the last thoracic segment and the form of the male fifth feet. Eucalanus spinifer is also a larger and more robust species than Eucalanus attenuatus, which it closely resembles. * Trans. Entom. Soc. vol. iv. pt. 2, p. 10. t Trans. Linn. Soc. 30 ME. T. SCOTT ON ENTOMOSTRACA EuCALANUS SETIGER, Brady. 1883. Eucalanus sethjer, Brady, op. cit. p. 39, pi. iii. figs. 8-15. Sahitat. Station 2, 50 fathoms, January 1st (night collection). Station 9, 50 fathoms, January 10th (day collection). Off Accra, surface and 3 fathoms tow-nettings, January 16th (day collection). Lat. 0° 45' 8" S., long. 7° 37' 4" E., surface tow-netting, Eehruary 2nd (night collection). Bananah Creek, Congo River, surface tow-netting, February 7th (day collection), &c. Eucalanus setiger was observed in 32 tow-nettings, 15 of which were surface and 17 under-surface gatherings. The under-surface tow-nettings were from various dej)ths, ranging from 3 to 60 fathoms. Of the surface gatherings 10 of them were day, and 5 (including 1 close inshore) were night collections. Of the under-surface gatherings, 11 were day and 6 were night collections, as in the formula : — f 10 day collections. n. ,,. „r 15 surface -y 5 ^igi,t ditto. Tow-nettmgs 32-< ^ ,, ^ ,.^ 1 17 under-surface | ^^ ^^^ '^^tto. 1 6 night ditto. By comparing this with other formula it will be observed that Eucalanus setiger occurred in a proportionally greater number of day surface tow-nettings than do the majority of the species recorded in this Report, the occurrence of which is frequent enough to admit of comparison. This difference may only be due to accidental causes ; nevertheless it seems of sufficient interest to be worth noting, as possibly indicating less susceptibility to the influence of daylight or sunlight than those species which occur more frequently in night than in day surface collections. Eucalanus setiger, like Eucalanus attenuatus, seems able to exist under very varied conditions as regards the density and temperature of the Avater : it was obtained in the open sea at Station 2 (50 fathoms), the density of the water being about 1*02020 and temperature (corrected) 56°-85 E. ; at Station 23 (surface), density 1'02347 and temperature 82°-l E. ; and at Bananah Creek, where the density of the water was only 1"00870. This may readily Ije distinguished from the other Eucalani of this Report by its smaller size and by lateral setoe on the last two thoracic segments. Genus Rhincalanus, Dana (1852). Rhincalanus cornuttjs, Dana. 1852. Rhincalanus cornutus, Dana, loc. cit. p. 1083, pi. Ixxvii. figs. 2a-d. 1883. Rhincalanus cornutus, Brady, op. cit. ]). 11, pi. vii. figs. 1-10. Eahitat. Station 3, 100 fathoms tow-netting, January 2nd (day collection). Station 9, 25 and 50 fathoms tow-nettings, January 10th (day collection). Station 14, 10 and 20 fathoms, January 21st (night collection). Lat. 1° 55' 5" N., long. 5° 55' 55" E., 30, 60, 260, 360, and 460 fathoms tow-nettings, January 22nd (day collections). Station 23, surface, and 10, 20, 85, 135, 185, and 235 fathoms tow-nettings, Eehruary 5th (day collections), &c. FEOM THE GULF OF GUINEA. 31 This species was observed in 70 tow-nettings, 29 of these were surface and 41 under- surface gatherings. The under-surface comprised tow-nettings from various depths from 3 to 400 fathoms. 9 of the surface and 30 of the under-surface tow-nettings were collected during the day, while 20 surface and 11 under-surface Avere collected during the night, as shown by the formula : — ( 9 day collections. rr ff .J29 surface | 20 night ditto. Tow-nettmgs 70 < , , . i il under-surface / '^" '^^^ ^^i^to. 1 11 night ditto. The superficial and bathymetrical distribution of BJdncalanus cormitus was co-extensive with tlie area examined, except that, unlike either Eucalanus attenuatus or setiger, it was not obtained in any gathering from Bauanah Creek or Loanda Harbour, where the specific gravity approximates so closely to that of fresh water. I have not observed a single specimen among the large number that have passed through my hands that could be ascribed to Rldiicalanus gigas, Brady. Ehincalanus actjleatus, n. sp. (PL II. figs. 11-21.) Length about 3'25 mm. (exclusive of tail-setae, which were fully 1 mm. in leno-th). Body ovate, attenuate towards the head. Forehead produced forward into a strongly spiniform rostrum. The postero-lateral angles of the last thoi*acic segment are produced backward into spine-like processes. The anterior antennae long and slender, reaching to beyond the caudal stylets, 21-jointed ; the proportional lengths of the joints are nearly as follows : — 170 . 42 ■ 17 ■ 18 . 14 . 14 ■ 10 . 9 . 9 . 12 ■ 13 . 45 . 54 ■ 59 . 72 . 85 . 82 . 82 . 80 . 80 . 30 1 2 3 4 5 fi 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21' The anterior antennae are sparingly setiferous. The secondary branch of the posterior antennae about two-thirds the length of the primary branch, 6-jointed, the first joint fully half as long as the second, the third, fourth, and fifth small, the last as long as all the preceding three together ; the end of the primary branch is furnished with four long- plumose setse and a small plain one ; two plumose setas spring from the end of the last joint of the secondary branch and one from each of the preceding four joints. Mandible stout, the distal end with four teeth, three of which are close together and one separated from the others by a deep and moderately wide sinus. I failed to observe a mandible- palp. The maxilla-palp furnished with three very long sette, which are plumose from the middle. The anterior foot-jaws resemble those of Hemicakmus more closely than those of Hhincalanus. The posterior foot-jaw as in Hhincalanus cornutus, but differing in being furnished with three ciliated heart-like processes, two of which are on the under margin and near the end of the first segment and one on the upper margin of the second segment. Both branches of the first four pairs of swdmming-feet 3-jointed, the second of the two basal joints of the first feet is produced on the inside so as to form a stout process to which the inner branch is attached. A stout curved spine springs from the end of the posterior margin of the second joint of the outer branch of the second pair of swimming- 32 ME. T. SCOTT ON ENTOMOSTEACA feet, wliich is fully half as long as the next joint. The end of the last joint of the outer hranch of the first pair is furnished with a stout plumose spinous seta, while the outer hranches of the next three pairs have each a terminal falciform spine ciliated on the inner margin and finely serrate on the outer margin. Fifth pair of feet 2-branched, inner branch 1-jointed, rudimentary, and bearing at its apex a long plumose seta ; the ff outer branch 2-jointed ; an extremely long slender seta springs from the outer edge near ^ the proximal end of the second basal joint on both sides. The terminal joints of both of the outer branches bear several small spines on the outer margin and one on the inner margin. Abdomen short, 4-jointed ; second and third joints smaller than the first, subequal. Caudal stylets fully as long as the last abdominal segment, and furnished with densely plumose dark-coloured setse. Bahitat. Lat. 6° 38' N., long. 12° 37' W., 25 fathoms tow-netting, January 6th (day collection). One sj)ecimen only of this curious form was obtained. llliiihcalanus aculeatus differs somewhat from the generic characters of Rldncalanus as described by Prof. Brady in the number of joints of the anterior antennge, the compara- tively long terminal joint of the secondary branch of the posterior antennae, and in the form of the mandible and maxilla, but agrees with the other characters ; I have therefore included it in that genus. Genus Hemicalanus, Claus, 1863. Hemicalanus, Claus, Die freilcbenden Copepoden, 1863 (not Hemicalanus of Dana) ; Brady, 'Challenger' Copepoda, 1883. Hemicalanus longicornis, Claus. 1863. Hemicalanus longicornis, Claus, loo. cit. p. 179, pi. sxix. fig. 1. 1883. Hemicalanus longicornis, Brady, op. cit. p. 44, pi. ix. figs. 1-5. Habitat. Station 2, 25 and 50 fathoms, January 1st (night collection). Station 3, 100 fathoms (day collection). Station 9, 50 fathoms (day collection). Lat. 1° 55' 5" N., long. 5° 55' 5" E., 30, 260, 360, and 460 fathoms (day collections). Station 23, surface, and 10, 20, 85, 135, 185, and 235 fathoms, January 5th (day collections). Hemicalanus longicornis was obtained in 26 tow-nettings, but only one of these was from the surface, all the others were under-surface gatherings and ranged in depth from 5 to 160 fathoms. 21 of these tow-nettings (including the surface gathering) were day collections, while 5 were night collections, as shown in the formula : — 1 surface 1 day collection. 25 under-surface I ^0 day coUections. l 5 night ditto. This Hemicalanus was of frequent occurrence in some of the tow-nettings. It was very common in a gathering from 35 fathoms, collected on the 22nd January in lat. 1° 55' 5" N., long. 5 55' 5" E. ; in this gathering eighty-five perfect specimens, besides a number of others more or less damaged, were obtained. Tow-nettings 26. FROM THE GULF OF GUINEA. 33 Hemicalaktjs PLrMOSUS, Claus. (PI. II. fig. 6 ; PI. VI. fig. G.) 1863. Hemiculanus plumosvs, Claiis, Die freilebeiidcii Cojjcpotleu, p. 178, pi. xxviii. fig. 12, pi. xxix. figs. 1-7. Habitat. Station 2, 50 fathoms (night coUcetion). Lat. 6° 38' N., long. 12° 37' W., 25 fathoms (day collection). Lat. 3° 55' 3" N., long. 4' 7' 3" E., 30 fathoms (day collection). Lat. 1° 55' 5" N., long. 5° 55' 5" E., 360 fathoms (day collection). Station 23, 85 fathoms and 235 fathoms (day collections). This appears to bea sciirce species in the ' Buccaneer collections ; only a few specimens have been ol)tained. Claus {Joe. cit.) gives a very full description and some very good figures of this Hemicalanits. Hemicalamts jj^mnosua comes very near Hemicalamis orientalis, Brady, described in the ' Report on the ' Challenger ' Copepoda.' Hemicalanus mucronatus, Claus. 1863. Hemicalanus mucronatus, Claus, loc. cit. p. 179, pi. xxix. fig. 2. Length (exclusive of the tail-setse) of the specimen figured 3'8 mm. (the length varies in diiferent specimens). Body somewhat cylindrical. Head pyramidal, the apex mucro- nate^in some specimens spiniform, the postcro-Iateral angles of last thoracic segment rounded. Anterior antennse, reaching to beyond the caudal stylets, 25-jointed. The proportional lengths of the joints are represented very nearly by the annexed formula : — 40 . 10 . 15 . 17 ■ 18 ■ 18 ■ 18 . IS ■ 21 . 20 . 22 . 23 . 30 . 34 . 34 . 35 . 37 . 37 . 33 . 28 . 30 . 29 . 28 ■ 27 . 18 1 2 3 4 5 G 7 8 9 10 11 12 13 14 15 16 17 18 19 20 i!l 22 23 ^4 25" Posterior antenuaj similar to those of H. 'plumoms. The mouth-organs are also similar to those of that species, except that the anterior foot-jaws are weaker, the spines on the second and third joints of the same foot-jaws are shorter and more slender, and the terminal setse of both anterior and posterior foot-jaws are not spiniferous or ciliated as in Hemicalanus flumosus. The swimming-feet are similar to those of Hemicalanus plumosus. Abdomen 4-jointed, first segment much larger than the others. Caudal stylets short, divergent, the terminal seta} densely p)lumose. Habitat. (1) Station 2, 50 fathoms toAv -netting, January 1st (night collection). (2) Lat. 3° qS' N., long. 3° 42' W., 25 fathoms tow-netting, January 13th (day collection). (3) Lat. 3° 22' 5" N., long. 4° 11' 8" E., 30 fathoms tow-netting, January 20th (night collection). (4) Station 14, 10 fathoms tow-netting, January 21st (night collection). (5) Lat, 6° 38' N., long. 12' 37' W., 25 fathoms tow-netting (day collection). (6) Lat. V 55' 5" E., 35 fathoms tow-netting, January 22nd (day collection). (7) Off Sao Thome Island (lat. 0° 34' N., long. 6' 30' 4" E.), 20 fathoms tow-netting, January 23rd (day collection). (8) Station 23, surface tow-netting, Eebruary 5th (day collection). Several specimens of H. mucronatus were obtained ; the size of the specimens varied to some extent, and the forehead was more spiniform in some specimens than in others. This species comes very near Hemicalanus aculeatus, Brady, in general form and in the structure of the appendages, but is much smaller than Brady's specimen. The length of the specimen described and figured in this lleport, which was one of the largest of SECOKD SEllIES. — ZOOLOGY, VOL. VI. 5 34 MK. T. SCOTT 0\ ENTOMOSTEACA the 'Buccaneer' specimens, was, as already stated, 3"8 mm.; hut Semicalamis aculeatus, Brady, measured 575 mm. in length — that is, fully half as long again as the ' Buccaneer ' specimen. It is interesting to note that while six ^^ecxes of Memicalanus (including four of Claus's Mediterranean species) have been obtained in the ' Buccaneer ' collection, only three (including one of Claus's Mediterranean species) were observed in the collections of the 'Challenger' expedition, and further, that while Hemiealaiii were of frequent occurrence in the ' Buccaneer ' tow-nettings, 85 perfect specimens, besides a number of others more or less damaged, were captured in a single tow-net gathering. The three species recorded in the ' Challenger ' Report were represented in the collection " only by about half a dozen specimens in all." Such a remarkable difference in the distribution of the Memicalani seems to indicate that their distribution is local, and that, with perhaps one or two exceptions, they prefer to frequent what is comparatively inshore water to mid-ocean. Hemic alcmus longicornis appears to be more cosmopolitan than the other species and to have a more or less general distribution throughout tropical and subtropical seas. Yet, though this SemiccdaiiHs has undoubtedly an extensive distribution, it is noteworthy that none of Dana's species can be satisfactorily ascribed to it. This might have been accounted for had it been a critical species, but the extremely long anterior antennse of Hemicalanus longicornis at once distinguish it from all other Calmiidce. Genus Augaptilis, Giesbrecht (1889). Hemicalanus, Clans (in part). Augaptilis longicaudatus (Claus). (PL I. figs. 24-26; PL II. fig. 5.) 1863. Hemicalanus longicaudatus, Claus, loc. cit. p. 179, pi. xxix. fig. 3. 1892. Au(/aptilis longicornis, Giesbrecht, Fauna unci Flora des Golfes vonNeapel (Copepodeu), p. 414, pi. 27. fig. 31 ; pi. 28. figs. 2, 8, 19, 23, 31, 3.5, 38; pi. 39. figs. 37, 48. Habitat. Station 3, 100 fathoms tow-netting, January 2nd (day collection). Lat. 1° 55' 5" N., long. 5° 55' 5" E., 360 fathoms tow-nettmg (day collection). This Augaptilis occurred only in the tow-nettings from the two localities described ; it differs from other species of Hemicalanus in the great length of the secondary branch of the posterior antennte, in the comparatively long caudal stylets, and particularly by the anterior and posterior foot-jaws being furnished with moderately long setae, which possess each a double row of short filaments with round, flat, button-like tops. These filaments (or sense-organs ?) somewhat resemble " drawing-tacks," i. e. small nails with round flat heads, used for fixing drawing-paper upon a drawing-board. There is a double row of these filaments on each seta, the filaments of each double row being usually opposite each other ; there are about 147 of these filaments in the length of a millimetre. They impart to the setae that are furnished with them a very marked and striking appearance. Prof. Claus considers them as forming an important and distinctive specific character, and refers to them in his description of the species in the following terms : — "Die Hakenhorsten der oberen imd untern Maxillarfiisse tragen zwei Reihen sehr zierlich FROM THE GULF OF GUINEA. 35 geknopftev Seitenspitzen." This form of filament appears to be peculiar to Augtqitilis longicaudatns. Another species {AnguptUis TluUrwji) described in this lleport possesses similar filaments, but the button-tops, instead of being round, are broadly crescent-shaped. Not more than about half a dozen specimens of AugaptiUs longicaudatns were obtained in the ' Buccaneer ' collections. AuGAPTiLis HECTicus, Giesbrecht. (PI. I. figs. 37-39, PI. II. figs. 1-4, 38-4i2.) 1892. AnnaptUif! hecticus, Ciesbreclit, op. cit. p. ill, pi. 27. fig. 30; pi. 28. figs. 5, 9, IG, 30, 33, 37; pi. 29. fig. 18; pi. 39. fig. 45. 1892. Hemicalanus longisetosus, Scott (MS. name). Length, exclusive of tail-setse, 2-46 mm. ; cephalothorax elongate, slender, cylindrical, subtriangularin front, rounded behind ; anterior antennye, reaching beyond the extremity of the abdomen, 25-joiuted ; the right antenna of the male 18-jointed. Tlie proportional lengths of the joints are nearly as follows : — Male. 20 . 12 . 10 . i:^ . 1 ;^. . 1 3 . 12 . 56 . 20 . 22 . IS . 17 . 19 . 22 . 35 . 29 . 18 . 18. 12 3 4 .-. li 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25. Female. 20 .8 . 8 . 8 . S . 8 . 8 . 8 . 10 . 10 . 11 . 13 . 15 . 15 . ll . 13 . lT7]5TT2TTo7roTTO . 11 . 15 . is! In the male antennae the eighth joint is rather longer than the imited lengths of the preceding four joints, and there is a distinct hinge between the fourteenth and fifteenth joints ; the fifteenth bears at the proximal end a slender hair-like appeudao-e which extends forward beyond the extremity of the joint. A densely plumose seta springs from the lower terminal angle of the sixteenth joint, and from the upper angle a rather long non-plumose spinous seta ; a second densely plumose seta, similar to that on the sixteenth, springs from the upper terminal angle of the seventeenth joint. The second and third last joints of the female anterior antennae and the left male antenna are likewise fm-nished with one or two (?) plumose sette similar to those of the male eighth antenna ; the antennae of both sexes are otherwise sparingly setiferous. The secondary branch of the posterior antennae is fully half the length of the primary branch, 6(?)-jointed, both branches with long plumose hairs ; mandible styliform, the extremity somewhat furcate, but one of the teeth nearly obsolete ; other mouth-organs as in Hemicalanus longlcornis. Five pairs of swimming-feet in both sexes, all of them 2- branched, with both branches 3-jointed ; the terminal spine of the outer branch of the fourth pair has a row of minute tubercules along its exterior margin ; the inner margin is ciliated. The middle joint of the outer branch of the right (?) fifth foot of the male bears a stout, slightly curved process on the upper part of the inner margin ; the last joint bears a short terminal spine, immediately behind which, on the inner margin, is a moderately long plumose hair ; the last joint of the outer branch of the left foot bears a long curved terminal spine, finely serrate on its inner edge ; both the inner margins are furnished with several long plumose hairs which extend beyond the terminal spine of the outer branch of the left foot. Abdomen in the male 5-jointed, in the female 4- jointed ; the length of the segments in both are subequal. Caudal stylets in the male about as long as the last two abdominal segments, and in the female about the length of the 5 * 36 ME. T. SCOTT ON ENTOMOSTEACA last segment of the abdomen. Eacli stylet is fm-nished with one extremely long seta, wliicli is longer than the cephalothorax and abdomen together ; each seta bears a dense mass of fine hairs, near, but not quite at, its extremity ; the extreme end appears to be free from hairs ; there are also three short and densely plumose setse on the exterior margin of the stylets, one near the middle and two near the extremity of each stylet. EaUtat. (1) Lat. 3° 58' N., long. 3°42' W., 25 fathoms tow-netting January, 13th (day collection). (2) Lat. 1° 55' 5" N., long. 5° 55' 5" E., 360 fathoms tow-netting, January 22nd (day collection, temperature of the water about 43° E.). (3) Off Sao Thome Island (lat. 0° 34' N., long. 6" 30' 4" E.), 24 fathoms tow-netting, January 23rd (day collection). Only two or three specimens of this interesting form were obtained. The extremely long tail-setse, \Aath the remarkable accumulation of fine hairs near their extremity, distinguish this Augaptilis at once from the other species described in this Report. AuGAPTiLis Rattrayi, n. sp. (PI. II. figs. 25-37.) Length, exclusive of tail-setse, 4'9 mm. Cephalothorax robust, seen from above broadly ovate, measuring in breadth 2'6 mm., rounded in front, the postero-lateral ano-les of the last thoracic segment also rounded. Thoracic segments five, the first as lono" as all the other four together. Every part of the integument — cephalothorax, abdomen, and appendages — is covered more or less with minute spinous hairs. Anterior antennre short, not much longer than the first thoracic segment, 24-jointed. The pro- portional lengths of the joints are nearly as follows : — 60 . 25 . 20 . 20 . 20 . 20 . 22 . 35 . 35 . 32 . 43 . 50 . 53 . 49 . 52 . 54 . 60 . 56 . 47 . 49 . 40 . 42 . 45 . 36 i 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 2r"22 23 24" The antennae are sparingly setiferous, the setge on the second, eighteenth, and twentieth joints being the longest. The posterior antennse have the basal part stout, the primary and secondary branches short, the secondary branch being shorter and more slender than the other and 7-jointed ; the last joint is rather longer than all the preceding four too'ether, and furnished at the extremity with three long setae, which are plumose from the middle. The end of the primary branch is also furnished with a number of hairs similar to those of the secondary branch. The mandibles are slender and terminate in two moderately long teeth, between which is another minvite and rudimentary one ; the mandible-palp is stout, 2-branched, one of the branches 2-, the other 4-jointed ; both branches bear several plumose hairs. The "rod-like process" of the maxillas terminates in three very long plumose hairs. Two hairs, bearing each a double row of peculiar short filaments having flat broadly crescent-shaped tops, which extend from near the distal end to about the middle of the hairs, spring from the extremity of a stout lateral appendage of the maxillse. Anterior foot-jaws stout, 5-jointed, the first two with several stout spinous hairs on the anterior margin, the last three with a number of long setae having a double row of short filaments, with flat, broadly crescent- shaped tops, each double row not extending below the middle of the seta. The posterior foot-jaw 6-jointed, the first two joints moderately stout and long, sparingly setiferous on the upper margin ; the second joint has also a long non-plumose hair attached to FROM THE GULF OF GUINEA. 37 its upper distal angle ; tlie next three joints are short and stout, and bear four long fllamentiferous setre similar to those of the anterior foot-jaws. The end joint is small and rudimentary, and terminates in one short and two long non-plumose hairs. The swimming-feet are as in Hemicalanus longicornis ; the five pairs are 2-branched and each branch 3-jointed, all of them being more or less thickly beset with short spinous hairs. The basal joint of the outer branches of the first pair bears on its posterior distal angle an elongate spine, which extends to the extremity of the last joint. The exterior distal angles of the first and second joints of the outer branches of the third and fourth pairs bear one very stout spine, having a short spinous process on each side of it at its base. Abdomen short, 3-jointed, the first joint much longer than the otherjtwo together. Caudal stylets short, somewhat divergent, each with six plumose hairs, four terminal, which are moderately long and subequal ; a smaller one on the lower outer margin, and one very slender hair near the base of the second terminal seta, counting from the inside. Habitat. (1) Station 3, 100 fathoms tow-netting, January 2nd (day collection), specific gravity of the water 1-0260S, temperature 56"-4 F. (2) Lat. G° 38' N., long. 12^ 37' W., 25 fathoms tow-netting, January 6th (day collection), sp. g. of the water (surface) l"02i00, temperature (surface) 83°-5 F. (3) Lat. 1° 55' 5" N., long. 5° 55' 5" E., 35 fathoms tow-netting, January 22nd (day collection), temperature at 30 fathoms 63°"98 F. (1) Off Sao Thome Island, lat. 0°3i'N., long. 6° 20' 4" E., 20 fathoms tow-netting, January 23rd (day collection). Only one adult specimen and a few others more or less immature were obtained ; the adult specimen is from locality (3), and is the one from which the drawings were made. The peculiar short flat-topped filaments (sense-organs ?) with which several of the hairs of the maxilla? and foot -jaws are furnished resemble those observed and described in Atlcjaptilis longiccmdahis, which Prof. Claus speaks of as " sehr zierlich geknopfte Seitenspitzen," but instead of the tops being circular like a button, as in that species, they are broadly crescent-shaped; the " bvitton-tops " are also larger than those of Augaptilis longictmdatiis. In AngaptiUs Rattrayi there are about forty button-topped filaments in the length of a millimetre, but in Aifgctptilis lofigicaitdatus the number of filaments in a millimetre is about one hundred and forty-seven. The filaments in each double row are usually opposite each other, as shown in the enlarged drawings. They give a pecuHar and striking appearance to the setse that are provided with them. Genus Calocalanus, Giesbrecht (1891). Elenco dei Copepodi pelagici,— R. Corvetta ' Vettor Pisaiii.' (Atti della Reale Accademia del Lincei, serie iv. Rendiconti, vol. v. pt. 1.) Calocalanus pavo (Dana). (PI. VI. figs. 9, 10.) 1852. Calanus jnivo, Daua, loc. cit. p. 1061, pi. 72. 1892. Calocalanus pavo, Giesbrecht, op. cit. p. 185, pis. 1, 4, 9, 36. 38 ME. T. SCOTT ON ENTOMOSTEACA Length about 7 mm. Cephalotliorax rounded in front and behind. Anterior antennae fully a half longer than the cephalothorax and abdomen together, 24-jointed, the first joint large and bearing two plumose and a few plain seta3, the last joint long and slender, furnished at its extremity with four plain setae of moderate length. The second and third last joints possess longer setae than any of the other joints ; all the joints from the eleventh to the twentieth inclusive bear each a number of small hairs on the upper margin besides the longer setae with which all the joints are more or less furnished. The proportional lengths of the joints are very nearly as in the annexed formula : — 45 . 10 . 10 . 10 . 10 . 10 . 10 . 10 ■ 11 . 11 ■ 15 ■ 15 . 17 ■ 18 . 22 ■ 24 . 27 . 28 . 29 . 30 . 25 . 24 . 20 . 87 1 2 3 4 5 6 7 8 9 lO 11 12 13 14 15 16 17 18 19 20 21 22 23 24" Secondary branch of the posterior antennse as long as the primary branch, 8-jointed ; the third and last much larger than the other joints ; both branches setiferous. Mandibles stout, the apex furnished with several more or less rudimentary teeth ; the mandible-palp well developed ; secondary branch 5(?)-jointed, shorter than the primary, the basal part furnished with three seta3 on its inner margin. Maxillae large, somewhat similar to those of Micalanus, but the basal part dilated. Foot-jaws as in Eiicalanus, but the terminal setae of first foot-jaws plain. The first four pairs of swimming-feet 2-branched, outer branches 3-jointed, the inner branch of first pair 2-, of the others 3-jointed. The outer branches of second, third, and fourth pairs only with sabre-like terminal spines ; the second joint of the outer and the second and third joints of the inner branches armed with transverse rows of spines. Fifth pair of feet in the male (?J 1- branched, branches 3-jointed, the terminal joint longer than the other two together, compressed, the extremities rounded and furnished with several long setae and two or three transverse rows of small hairs as in the figure, Abdomen very short, 3(?)- jointed. Caudal stylets extremely divergent, bearing four long spreading setae, two of which are divided to near the base. Habitat. Station 2, surface and 25 fathoms tow-nettings, January 1st (night col- lections). Station 3, 25 fathoms, January 2nd (day collection). Station 9, 50 fathoms, January 10th (day collection). Lat. 1° 55' 5" N., long. 5' 55' 5" E., 360 and 400 fathoms tow-netting, January 22nd (day collection). Station 23, 20 fathoms, February 5th (day collection). This species was comparatively frequent all over the area examined. It is readily distinguished from other Calanidce described in this Report by the remarkably divergent caudal stylets, which are at almost right angles to the abdomen. The anterior antennae and tail-setae appear to be, in this species, more than usually fragile ; not a single perfect specimen was obtained in the whole collection. The tail-setae were commonly altogether wanting or the stumps of them only remained, and the anterior antennee were, with very few exceptions, all more or less damaged. It was only after very carefully searching the tow-nettings that a few specimens were discovered that had the joints of the antennae complete ; the figure, therefore, represents the anterior antennae perfect as regards the number of joints. No specimens with perfect caudal setae were obtained. FKOM THE GULF OF GUINEA. 39 Calocalanus plumulosus (Glaus). (PI. I. %s. 35, 36; PI. VI. figs. 7, 8.) 1863. Calanus plumulosus, Claus, Die freilebenden Copciioden, p. 174, taf. xxvi. figs. 15, 16. 1892. Calocalanus plumulosus, Giesbrecht, op. cit. p. 185, pis. 3, 9, 36. Length (female) 1-3 mm. Body elongate, first segment nearly equal to twice the entire length of the other three ; postero-lateral angles of thorax rounded. Anterior antennoe, reaching somewhat beyond the extremity of the abdomen, 24.-jointed; the large basal joint bears one long plumose seta near the proximal end, the last joint is slender and equal to the combined length of the preceding two. The proportional lengths of the joints are nearly as shown in the formula : — 50 . 10 . 10 . 10 . 10 . 10 . 10 . 10 . 11 . 13 . 10 . 16 . 18 . IS . 18 . 19 . 18 . 21 . 21 . 21 . 21 . 20 . 15 . 36 i 2 3 4 5 0 7 8 0 10 11 12 13 14 15 16 17 18 19 20 21 2)i 23 24' Posterior antennae, mouth-appendages, and swimming-feet as in Calocalanus pavo. The last joint of each foot of the fifth pair is equal to half the length of the foot, and the third joint is nearly one and a half times the length of the preceding one ; the broadly rounded extremity of the last joint bears a small spine near the outer ano-le a much larger spine near the middle, and a moderately long seta near the inner ano-le • there are also two small setae near the distal end of the inner margin ; both mar^-ins of the joints are also more or less fringed with cilia (PI. I. fig. 35). Abdomen short, first segment rather tumid, the second much shorter than either the first or third, breadth of the second and third increasing towards the distal end ; the first and second have each a fringe of small serrse concentric with, and a little anterior to, the distal margin. Stylets about equal to the length of the second abdominal segment, slightly divergent, and furnished with four terminal plumose setae, and one very small seta near the extremity of the inner margin. Calocalanus plumulosus was obtained in a tow-net gathering from 30 fathoms, lal. r 55' 5" N., long. 6° 55' 5" E., collected January 22ud. Only a few specimens were observed. This species difi'ers very markedly, not only in its greater size but also in general appearance, from Calocalanus pavo ; moreover, the anterior antennae are proportionallv much shorter than in that species. The proportional lengths of the joints of the anterior antennae and fifth feet also differ considerably in the two species. Another character of the spirit specimens is the abruptly flexed abdomen, which is bent at a right angle in all those obtained. The position of the caudal stylets in Calocalanus plumulosus is almost normal, while those of Calocalanus pavo are extremely divergent. The long plumose seta on the basal joint of the anterior antennae appears also to be a character of Caloca- lanus plumulosus *. Genus Heterocalanus, nov. gen. (Provisional name.) Anterior antennae 22-jointed ; right antennae of the male resembling that of the * " Dieser " (the long basal joint of the anterior antenna?) " triigt eine kraftige, zweiseitig befiederte, gelb pigmentirte Borate." Claus, he. cit. 40 MR. T. SCOTT ON -ENTOMOSTRACA Pontellklce. Second branch of the posterior antenutc longer than the prhiiary branch, 4-jointed. Mandibles stout, broad, furnished with papilliform teeth and elongate tooth-like processes on the exterior angle ; mandible palp 2-branched, secondary branch 3-jointed. Anterior foot-jaws like those- of Ithincalanns cornutus. Posterior foot-jaws strong, 6-jointed, the two basal joints large. The first four pairs of swimming- feet have both branches 3-jointed. Pifth pair in both sexes 1-branched, those of the male dissimilar and adapted for grasping ; those of the female the same on both sides, 3-jointed, the last joint produced into a large curved spiniform process. Ovisac large. Heterocalanus serricaudatus, n. sp. (PL II. figs. 43-48; PI. III. figs. 1-7.) Length 1"15 mm. Body elongate, narrowly rounded in front, the postero-lateral angles of last thoracic segment rounded, and bearing several small spines. Anterior antennse longer than the body ; those of the female slender, 22-jointed, sparingly seti- ferous. The proportional lengths of the joints are nearly as follows : — 11 ■ 11 . 5 ■ 7 . 6 . 10 . 5 ■ (i . 10 . 12 . 14 ■ 16 ■ 18 . 18 ■ 18 . 16 . 14 . 14 . 13 . 14 . ]2 . 3 1 2 3 4 5 6 7 8 9 10 11 IL' 13 14 15 16 17 18 19 20 21 22' The right anterior antenna of the male also 22-jointed, distinctly hinged between the 18th and 19th joints, the upper margin of the 18th joint serrate ; the 11th and 12th joints are small, the 14th, 15th, and IGth dilated. The general form of the male riffht antenna somewhat resembles that of the Pontelliclce. Posterior antennae have the secondary branches longer than the primary, 4-jointed, the third joint very small, im- parting to the branch the appearance of being much constricted in the middle ; both branches furnished with numerous non-plumose hairs. Mandible stout, broad, bearing several small papillose teeth, and on the exterior angle three elongate tooth-like processes and a short plumose seta. The basal part of the mandible palp is comparatively large, and produced laterally to form the base of the secondary branch, which is 3-jointed. Both branches are furnished with a number of non-plumose hairs (PI. III. fig. 4). Anterior foot-jaws like those of Rhmcalaiius cornutus, short, obscurely 3(or 4 ?)-jointed. Posterior foot-jaws strong, 6-jointed, the two basal joints large, the other four small, subequal ; each of the fourth, fifth, and sixth joints bear interiorly a stout, elongate, blunt-pointed spine, that of the fifth being much larger than those of the other two joints ; the terminal joint is also furnished with six long plumose hairs. The first four pairs of swimming-feet are 2-branched, both branches 3-jointed. The joints of the inner branch of the first pair subequal ; the outer branch is without dagger-Hke spines at the distal angles of the joints. The first joint of the inner branch and the middle joint of the outer branch of the second, third, and fourth pairs are smaller than the other joints, and the exterior distal angles of all the joints of the outer branches bear stout dagger-like spines, which are finely serrate on both edges ; the last joint has an additional and similar spine arising from an excavation on the lower half of the outer margin. The terminal spines of the outer branches are finely serrate on the outer edge, except near the base, which is plain ; the extremity of the terminal spines is slightly curved FEOM THE GULF OF GUINEA. 41 outwards. The terminal spines of the outer branches of the first pair are more slender than those of the others ; all tlie four pairs are furnished Avith numerous stout plumose seta? on the inner marorins of both branches as well as round the extremity of the inner branches. The fifth pair in the male is 1-branchcd. The second joint of the right foot bears interiorly a small dilated process liaving a number of small spines ; the extremity of the last joint truncate ; an elongate curved appendage with a tumid base springs from the inner angle, and a stout setiferous spine from the outer angle of the extremity of the last joint. The second joint of the left foot has a long slender appendage, very faintly serrate on the inner edge. The outer angle of the third joint and the extremity of the fourth terminate in a long spinous process, and the inner edge of the base of the last joint is ciliated. The fifth pair in the female is 1-branched, the right and left are similar, and 3(or 4 ?)-jointed ; the first and second joints stout, the third short, but produced inwards into a large curved spiniform process, finely but distinctly serrate on both margins ; the last (?) joint nearly obsolete, terminating in one long plain spine and a second short one, serrate on the inner edge. Abdomen (exclusive of caudal stylets) nearly half as long as the cephalothorax, 5-jointed in the male, 4-jointed in the female ; the second, third, and fourth segments in the male, and the first, second, and third in the female, fringed posteriorly wdth a prominent row of saw-like teeth. Caudal stylets as long as the last abdominal segment, narrow, somewhat divergent, bearing each four moderately long, terminal, plumose setva, and a fifth which springs from a notch on the outer margin ; all the seta? are articulated below the proximal half; there is also a small hair between the two inner setse. Ova forming one large circular complanate cluster, containing about sixteen large ova arranged in a single layer, eleven or twelve round the circumference, the others central. Habitat. Lat. 5° 10' N., long. 3° 56' 2" "W., surface, close inshore, January 12th (night collection). Off Accra, three fathoms, January 16tb (night collection). Ofi' Appi, surface tow-netting, January 18th (day collection). Libreville, Gaboon River, in two surface tow-nettings, January 28tli (day collection). Bananah Creek, Congo River, surface tow-netting, Eebruary 8th (night collection). Seterocalanus serricaudafus appears to be more confined to inshore waters than many of the species recorded in this Report, though it seems nevertheless capable of existing under varied conditions as regards the density of the water, having been obtained in water varying in specific gravity from 1*02511 to l'0087O. Genus Pleuromma, Claus. Pleuromma, Claus, Die freilebenden Copepoden (1863). ? Mctridia, Boeck, Oversigt af Norges Marine Copepoda, 1864. ? Metridia, Brady, Monograph, British Copepoda, vol. i. 1878. Pleuromma abdominale, Claus. 1863. Pleuromma abdominah, Claus, loc. cit. p. 195, pi. v. figs. 1-6, 13, 14; pi. vi. figs. 1-10. 1883. Pleuromma abdominak, Brady, ' Challenger,' Copepoda, p. 46, pi. xi. figs. 1-13. SECOND SERIES. — ZOOLOGY, VOL. VI. 6 42 ME. T. SCOTT ON ENTOMOSTEACA Sabitat. Station 2, 25 fathoms tow-netting, January 1st (night collection). Lat. 3° 55' 3" N., long. 4° 7' 13" E., 50 fathoms tow-netting, January 20th (day collection). Off Sao Thome Island (lat. 0° 34' N., long. 6° 31' 6" E.), 20 fathoms tow-netting, Januaiy 23rd (day collection). Station 23, 235 fathoms tow-netting, Eehruary 5th (day collection). Pleuromma ahdominale was obtained in 25 tow-nettings, eight of which were surface gatherings, and seventeen under-surface, ranging in depth from 3 to 460 fathoms ; one of the surface and seven of the under-surface gatherings were day collections, the others were collected dm'ing the night, as shown in the formula : — 1 day collection. r i day collection. 8 surface | 7 ^jgj^^ collections. Tow-nettings 25 •. ^ . t^ 1 17 under-surface J ^ day ditto. I 10 night ditto. In the adult males the abdomen was usually more or less distorted, as figured by Prof. Brady in his Report on the ' Challenger ' Copepoda. The form agreeing with Pleuro^nma gracile, Claus, was obtained in a few of the tow- nettings, and the difference between it and JPlenromma ahdominale. is so marked and constant in the ' Buccaneer ' specimens that I have considered it preferable to record them separately. Pleuromma geacilb, Claus. (PI. VI. figs. 11-14.) 1863. Pleuromma gracile, Claus, loc. cit. p. 197, pi. v. figs. 7-11. 1883. ? Pleuromma ahdominale, Brady (in part), op. cit. p. 46, pi. xii. figs. 1-16; pi. xsxi. figs. 13, 14. Habitat. Lat. 1° 55' 5" N., long. 5° 55' 5" E., 250 and 360 fathoms tow-nettings, January 22nd (day collections). Lagoon, Sao Thome Island, surface. A form agreeing with the description and figures of Pleuromma gracile in ' Die frei- lebenden Copepoden ' occurred in the gatherings described ; it seems to be distinct from Pleuromma abdominals. Pleuromma princeps, n. sp. (PI. III. figs. 8-20.) Length (exclusive of tail-setae) 12 mm. Cephalothorax elongate, robust. Eorehead acute ; postero-lateral angles of the last thoracic segment produced, shortly spiniform. Left anterior antenna of male 25-jointed ; the right antenna is 22-jointed, hinged at the eighteenth joint, the proportional lengths of the joints as in the annexed formula : — Lett. 50 . 20 . 20 . 15 . 20 . 20 . 20 . 15 . 20 . 25 . 3(1 . 30 . 40 . 45 . -50 . -SO . 50 . 50 . 55 . 38 . 85 . 37 . 40 • 30 . 10. ~1~ 2 3 4 5 6 7 H 9 10 11 12 13 14 15 16 17 18 19 20 2l 22 23 24 25. night. 7u . 20 . 20 . 20 . 20 . 25 . 1« . 15 . 12 . 12 . 25 . 24 . 30 . 45 . 40 . 50 . 60 . 13 . 70 . 80 . 30 . 7 . The nineteenth joint is furnished at the distal end with a tooth-like process which extends over the base of the next joint. There are also, near the middle of the same joint, one long and one very short spine, which extend in a forward direction along the margin of the segment ; both antennae are sparingly setiferous. Posterior antennae as FEOM THE GUI.F OF GUINEA. 43 in Flevrcn.ma aldcmhwle; seta? on both branches plumose. The mouth-organs also as in P. abdominrie, but the anterior foot-jaw bears two elongate spines which spring from a prominent basal part near its extremity. The distal processes of the maxiUte appear to be less produced than in Pleuromma abdominale. The first pair of swimming- feet are smaller than the following three pairs ; the posterior outer aspect of the basal joint of the inner branch is beset with numerous fine cilia, and the outer margin of the middle joint is fringed with fine hairs. The exterior margin of the second, and the upper half of the third, segment of the outer branch are also fringed with fine hairs, while the lower half of the third segment is finely serrate. The outer branch of the second pair of swimming-feet on both sides has the first segment " deeply excavated at the base ;" the excavation is bounded interiorly by two strong, upward-directed, curved spines. There is no " thumb-like prominence " on the basal segment of the third pair of feet, as in 'Pleuromma ahdomhwle. The fourth pair of feet closely resemble the preceding pair. The last segment of the outer branch of the first pair terminates in a long stout seta, plumose on the inner margin. The outer branch of the second, tliird, and fourth pairs terminates in a moderately short, stout, sabre-like spine, the inner margin fringed with cilia, the outer margin very faintly toothed. The fifth pair of feet strongly prehensile ; one branch (the right ?) terminates in a clumsy claw-like segment. A small spine springs from near the proximal end of the penultimate segment. Tlie last segment of the other branch is furnished, on the inner side and near the base, with a moderately long, stout process, and two peculiar, stalked ap^Dendages. There is also at the base of the last segment a thin plate having a saw-like edge, and partly sur- rounded with delicate cilia ; both branches of the fifth feet are about the same leuo-th. Abdomen 4-jointed; joints subequal. Caudal stylets twice the len"-th of the last abdominal segment, and each furnished with six setae, four of them on the rounded extremity of the stylet, one on the outer margin, and a very small slender seta on the inner margin. All the setiB are densely plumose. Habitat. Lat. 1° 55' 5" N., long. 5° 55' 5" E., 360 fathoms tow-netting, January 22nd (day collection). Only one specimen — a male — of this fine species was obtained. Genus Heteroch^eta, Claus. HeterochiBta, Claus, Die fi'eilebendeu Copepodeu (1863). HETEROCHiETA SPINIFRONS, ClaUS. 1863. Heterochatd spinifrons, Claus, loc. cit. p. 182, pi. xxxii. figs. 8, 9, 14, 16. 1883. Heterochata spinifrons, Brady, Report ' Chall.' Copep. p. 49, pi. xiii. figs. 1-13. Habitat. Station 2, 25 fathoms tow-netting, January 1st (night collection). Lat. 3° 58' N., long. 3° 42' W., 50 fathoms tow-netting, January 13th (night collection). Station 14, 10 fathoms, January 21st (night collection). Off Sao Thome Island (lat. 0° 3i' N., long. 6° 30' 4" E.), 20 fathoms, January 23rd (day collection). Station 23, 235 fathoms, February 5th (day collection). 6* M ME. T. SCOTT ON ENTOMOSTRACA HeterochcBta spinifrous occurred in 20 tow-nettings ; only one of these was a surface gathering collected during the day, the other nineteen were under-surface and I'anged in depth from 5 to 4G0 fathoms ; fifteen of these were day collections, and four night collections, as shown in the formula : — r 1 sm-face 1 day collection. Tow-nettings 20 < r 15 day collections. U9 nnder-surface | 4 ^;^„^^ ^litto. This, though generally distributed, was a somewhat rare species in the ' Buccaneer ' collection. The dilated outer branches of the fourth pair of swimming-feet, with their short terminal spines, and the extremely long and slender seta of the right caudal stylet, allow of its being readily distinguished from most other species. Genus Leuckartia, Glaus. Leuckartia, Claus, Die freilebenden Copepoden (1863). Leuckartia plavicornis, Claus. 1863. Leuckartia flavicornis, Claus, loc. cit. p. 183, pi. xxxii. figs. 1-7. 1883. Leuckartia flavicornis, Brady, op, cit. p. 50, pi. xv. figs. 1-9, 16. Habitat. Station 2, 25 fathoms, January 1st (night collection). Off Accra, surface tow-netting, January 16th (night collection). Lagoon, Sao Thome Island, surface tow-netting, January 27 th (night collection). Station 23, 10, 20, 85, 135, 185, and 235 fathoms tow-nettings, February 5th (day collection). Bananah Creek, Congo River, surface tow-netting, February 7th (day collection). This Leuckartia was observed in 67 tow-uettings ; 30 of these were surface gatherings, and 37 under-surface. The under-surface tow-nettings were from various depths, from 10 to 460 fathoms. Seven of the surface and 27 of the under-surface tow-nettings were day collections, the others were night collections, as exhibited by the annexed formula : — r 7 day collections. r30 surface I 23 night ditto. Tow-nettmgs 67 < ro7 i r++ L37 under surface [ ^^ ^'^^^ d^"*^- L 10 night ditto. This species appears to have been widely distributed throughout the area examined during the ' Buccaneer's ' expedition, but comparatively few specimens were observed in the tow-nettings in which it occurred, except in those from deep water. Genus Undina, Dana. Undina, Dana, Proc. Amer. Acad. Sci. (1849). Undina vulgaris, Dana. 1852. Undina vulgaris, Dana, Crust, of U.S. Espl. Exped. p. 1092, pi. Ixxvii. fig. 8, a-d. FEOM THE GULF OF GUINEA. 45 1856. Undina longipes, Lvibbock, Trans. Entom. Soc. p. 17, pi. vi. figs. 1-5. 1883. Undina vulgaris, Brady, Report 'Cliall.' Copep. p. 53, pi. xv. figs. 11-15 ; pi. x\iii. fig. 6. Eabitat. Station 2, surface tow-ncttings, January 1st (niglit collection). Lat. 3° 58' N., long. 3° 10' W., surface tow-netting, January 13tli (day collection). Lat. 1° 55' 5" N., long. 5° 55' 5" E., 20, 35, and 460 fathoms tow-nettings, January 22nd (day collections). Lagoon, Sao Thome Island, surface tow-netting, January 27th (night collection). Station 21, surface tow-netting, February l«rt(?i»^, Lubbock), which appears to have been almost as common as Undina vulgaris in the ' Challenger ' collections, was entirely absent from the ' Buccaneer ' tow-nettings, not a trace of it being observed, though carefully sought for. Genus Euchieella, Giesbrecht (1891). Elenco del Copepodi pelagici, — R. Corvetta ' Vettor Pisani.' (Atti deUa Reale Accademia dei Lincei, serie iv. Reudicoiiti, vol. v. pt. 1, p. 330.) ? EUCHIRELLA MESSINENSIS (Claus). (PI. VI. figS. 15 & 16.) ? Undina messinensis, Claus, Die freilebendeu Copepoden, p. 187, pi. 31. Length, exclusive of tail-setae, 5 mm. Body elongate, robust. Forehead subtruncate ; postero-lateral angles of the last thoracic segment rounded and furnished with a number of hairs. Anterior antennae reaching to near the extremity of the abdomen ; the left 24-, the right 23-jointed, the proportional lengths of the joints nearly as in the annexed formula : — Eight antenna. 10 ■ 13 . 7 . 6 . 7 ■ 7 . 7 . 11 . 8 . 8 . 8 . 14 . 19 . 19 . 19 . 20 . IS . 20 . 18 . 13 . 13 . 13 . 14. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24. Left antenna. 10 . 13 . 7 . 6 . 6 . 7 . 6 . 8 .6.7.7. 8 . 14 . 15 . 20 . 19 . 20 . 18 . 20 . 17 . 14 . 13 . 11 . 14, The 3rd, 7th, 8th, 13th, 17th, and 20th joints are each furnished with a long j^lain seta. The terminal joint bears three (or four ?) long setse, two of them plumose ; there is also a plumose seta on the penultimate joint, and two stout short plumose hairs sjjring from near the end of the basal joint. The posterior antennae have the secondary branch 46 ME. T. SCOTT ON ENTOMOSTEACA large and stout, 6-joiuted, the first and last joints long, tlie intermediate very short. The small intermediate joints bear each one seta, and the extremity of the last joint three lono" plumose setse ; the primary braucli is extremely short, being almost rudimentary. Mandible stout, with nvimerous terminal papillose teeth; the exterior angle bears a strono- laterally-produced spine, which is serrate on the ujiper margin. The mandible palp is of moderate size, 2-branched, each branch with several long terminal plumose liairs. The maxUlBD are large, and bear at the extremity and on the interior margin a ]iumber of stout setiferous spines ; the external branch of the maxilla-palp very short and broad; terminal branch stout, somewhat digitiform; both branches with numerous plumose hairs. Foot-jaws as in Euchceta Hessei, except that near the extremity of the anterior foot-jaw are two setiferous spines much stouter than the others, and also two plain spinous setae on the lower extreme angle of the ultimate joint. The first four pairs of swimming-feet are similar to those of Euchceta ; the first pair resemble those of Euchceta Sessei, except that the inner branch has a lobe-like process near the base, and the outer branch a long slender terminal spine, finely serrate on the outer margin ; the outer branches of the second, third, and fourth pairs armed with a stout terminal spine, liaving about twenty strong saw-like teeth on its outer margin. The basal joint of the fourth pair bears a large bifurcate spiniform appendage ; the setse on both branches of all the four pairs are densely plumose. Abdomen short, composed of four segments, the first large, beiDg nearly as long as all the other three together. Catidal stylets short, divaricate, each with one short spine on the outer distal angle, and foiu* moderately long terminal plumose hairs ; another slender hair springs from near the inner distal angle of each stylet, and is about half the length of the others. Habitat. Station 2, 50 fathoms, January 1st (night tow-netting). Lat. 5° 58' N., long. 14° 20' W., surface gathering, January 5th (night tow-netting). Lat. 3° 22' 5" N., long. 4° 11' 8" E., 20 and 30 fathoms tow-nettings, January 20th (night collections). Lat. r 55' 5" N., long. 5° 55' 5" E., 460 fathoms tow -netting, January 22nd (day collection). Lat. 1° 29' N., long. 7° 33' 8" E., surface tow-netting, January 27th (night collection). Station 23, 30 fathoms, February 5th (day collection). Only a few specimens of this species were obtained ; they were all females, and were readily distinguished by the large forked spiniform appendage on the basal joints of the fourth pair of swimming-feet. As has been pointed out by Prof. Brady, TJiidina messi- nensis, Clans, differs from Vnclina, Dana, by the absence of the first pair of foot-jaws in the male (as described by Dr. Glaus), and by the inner branches of the first and second swinimino'-feet being only 1-jointed (Glaus, however describes the inner branch of the second pair as 2-jointed, but ia the ' Buccaneer ' specimens it was certainly only 1-jointed). In TJndina, Dana, on the other hand, the inner branches of all the swimming-feet are 3-jointed. Uiidina messlnensis has the fifth pair of feet in the male similar to those of EuchcBta pulchra, Liibbock (to which it has been doubtfully referred), but dificrs from that and all other Euchceta} kno\\Ti to me by the very rudimentary form of the primary branch of the posterior antennse. FROM THE GULF OF GriNEA. 47 Genus Scolecithrix, Brady. ScolecithrLv, Brady, Report 'Challenger' Copepoda (1883). Scolecithrix securifrons, n. sp. (PI. IV. figs. 40-56; PL V. fig. 1.) Length, exclusive of tail-setae, about 4 mm. Cepbalothorax robust, the anterior segment fully two-tbirds the length of the body. Forehead with a prominent median keel, which is continued do\Aniwards to the slightly furcate rostrum. Anterior antennse longer than the body, 23-jointed in the female, 19-jointcd in the male. The annexed formula shows very nearly the proportional lengths of the joints : — Male. 10 ■ 11 . 5 ■ 6 . 6 . 7 ■ 6 . 41 . 22 . 1.3 . 13 ■ 14 . 13 . 10 . 9 . 13 . 13 . 12 . 3 ' 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23. Female. 13 . 12 . 6 . 6 . 7 . 7 . 7 . 21 . 9 . 11 . 14 . 15 . 15 . 15 . 14 . 14 . 14 . 13 . 13 . 13 . 14 . 12 3. The long eighth joint has one or two pseudo-divisions, indicating the possible coalescence of two, if not three, smaller joints. The secondary branch of the posterior antennse is half as long again as the primary one, 5-jointed, the third and fourth joints small, the last joint with three terminal setre ; several setse spring from the vicinity of the two small joints ; the primary branch is furnished with a number of terminal setae, which, with the others, are all more or less plumose. Mandible-palp with two small branches set wide apart, and each with numerous plumose hairs. Maxillae and other mouth-organs as in Scolecithrix Dance. Pirst pair of swimming-feet small, inner branch 1-jointed, with a lobe-like appendage, terminal spine of the outer branch small. All the joints of the second and third pairs are armed with transverse curved rows of short stout spinules, and the terminal sabre-like spines of the outer branches have their exterior margin strongly and coarsely toothed. The fourth pair Avants the transverse rows of spinules, but is otherwise similar to the second and third pairs. The fifth jjaii' in the female is very small, 1-branched, 2-jointed, and with a moderately long slender, curved, terminal spine, the distal half serrate on the outer margin ; a small blunt process springs from the inner distal angle of the terminal joint, close to the base of the elongate spine ; this spine was apparently hinged to the extremity of the last joint, for in one or two specimens it was turned upAvard at a right angle to the joint, and in such a manner as to allow of its being ap]jlied to the base of the first abdominal segment. The fifth feet in the male are strongly developed ; the left foot is 1-branched, 3-jointed, with a curved finger-like process at the extremity ; the right has a slender 1-jointed inner branch, curved outwards so as to be opposed to the 2-jointed clawed terminal part of the outer branch ; the basal part to which the two branches are attached is much dilated. Abdomen in the female short, first segment larger and much wider jwsteriorly than the next; the posterior margiii of the abdominal segments in both sexes fringed with hairs. Caudal stylets short, divergent, each with four long terminal plumose setae nearly equal in length, and a small hair near the base of the inner seta. Habitat. Station 2, 50 fathoms tow-netting, January 1st (niglit collection). Lat. 7°33'N., long. 15° 18' W., 25 fathoms tow-netting, January 2nd (night collection). Lat. 1° 55' 5" N., long. 55° 55' 5" E., 360 fathoms tow-netting, January 22nd (day collection). Lat. 0° 25' 1" N., 4S ME- T. SCOTT OX ENTOMOSTRACA long. 6° 35' 2" E., 10 fathoms tow-netting, January 23rd (night collection). Station 23, 185 fathoms tow-netting, February 5th (clay collection). Kot more than one, or at most two, specimens of this Scolecitlirix were obtained in each of the tow-nettings from the localities here recorded. The prominent keeled forehead, which gives this species such a marked character, enables it to be readily distingiiished. ^S" ScOLECiTHRix CTENOPUS, Giesbrecht. (PI. V. figs. 2-9.) 1892. Scolecithrix denopus, Giesbrecht, Fauna und Flora des Golfes von Neapel (Copepoden), p. 285, pis. 13, 37. Male. Length, exclusive of tail-setse, 1'83 mm. The cephalothoras elongate, rounded in front and behind. Anterior antennae slender, reaching to the extremity of the abdomen, the left 21-, the right 20-jointed. The proportional lengths of the joints of the left antenna are nearly as follows : — 16. 16. 3. 3.3. 4. 4. 16. 5. 5. 6. 6. 6. 5. 6. 5. 6. 6. 6.6. 3 1 -J. a 4 5 6 7 S y lu 11 12 13 14 15 16 17 18 19 20 21' The sixteenth joint of the right antenna consists of two coalescent joints, but otherwise the right and left antennse are similar ; posterior antennce and mouth-organs as in Scoleci- tlirix DaiKe. The inner branch of the third pair of swimming-feet small, the terminal spine of the outer branch somewhat distorted, its outer margin being furnished with irregular but stout and prominent teeth. The fifth pair of feet has one very short 3 -jointed, and one very long, slender, 4-jointed branch, which extends beyond the extremity of the abdomen ; the last segment of the elongate branch is curved, furnished on one side with a dense fringe of hairs, and terminates in two unequal spines ; the small 3-jointed branch is about as long as the first segment of the long branch, the basal joint being longer than the other two together. Abdomen 4-jointed ; joints subequal, fully one- fifth the length of the cephalothorax. Caudal stylets short, not divergent, bearing at the extremity four moderately long plumose hairs, the inner being shorter, and the next one considerably longer than the others ; the arrangement of the tail-setse in this species resembles Undina more than Scolecitlirix. Mahitat. Station 2, 50 fathoms tow-netting, January 1st (night collection). Station 9, 50 fathoms tow-netting, January 10th (day collection). Lat. 3° 58' N., long. 3° 42' W., 25 fathoms tow-netting, January 13th (day collection). Lat. 3° 55' 3" N., long. 4° 7' 3" E.^ 20 fathoms tow-netting, January 20th (day collection). Lat. 0° 21' 1" N., long. 7° 33' E., 20 fathoms tow-netting, January 29th (day collection). Scolecitlirix ctenojms was comparatively a rare species in the ' Buccaneer ' collection, having been observed in only a few of the tow-nettings. The most marked characteristic uf this Scolecitlirix is the extremely long branch of the fifth foot, having the last segment curved, and with the margin densely setiferous. SCOLEClTHrvIX TENUIPES*, n. sp. (PI. V. figs. 10-19.) Male. Length, exclusive of tail-seta?, 1-4 mm. Anterior antennse reaching to beyond * From the Iod"- slender fifth loot. FEOM THE GULF OF GUINEA. 49 the extremity of the abdomen, the left 21-, the right 20-jointed. The following are the proportional lengths of the joints, nearly, of the left antenna : — 5.4.3.3.3.3.3.13.4. 4.5. 5. 5. 6. 5. 5.5. G.5. 5. 3 12 3 4 5 0 7 ^S 9 10 11 12 13 14 15 16 17 18 19 20 2l' The sixteenth joint of the right antenna consists of two coalescent joints, but otherwise both right and left antennae are similar. The posterior antennae, mouth-organs, and first pair of swimmiug-feet are somewhat similar to those of Scoleclthrix DancB. The outer branch of the third pair has a distorted terminal spine, as in Scolecithrix ctenojms. The segments of all the first four pairs of swimming-feet are armed with curved, transverse rows of short, stout spinules. The fifth pair of feet consists of one very long, slender branch, and an extremely short, almost obsolete, 3-jointed one. The elongate branch has the basal joint somewhat stout and sliort, the second long, fully twice the length of the third; the fourth long and slender, longer than the second; the last joint is extremely small, with a spiniform extremity. Abdomen, caudal stylets, and tail-setae as in Scolecithrix ctenopus, which appears to be closely allied to the species now described. The fifth pair of feet are, however, decidedly different from those of Scolecithrix ctenopus, being much more slender and without the fringe of hairs. The terminal worm-like sense-organs of the anterior foot-jaws are stouter than those of Scolecithrix ctenopus, though that species is the larger of the two. Sahitat. Station 2, 50 fathoms tow-netting, January 1st (night collection). Station 9, 50 fathoms tow-netting, January 10th (day collectionj. Lat. V 55' 5" N., long. 5° 55' 5". E., 30 and 3G0 fathoms tow-nettings, January 22nd (day collection). Scolecithrix temiipes was not obtained from any surface gatliering, and was of rare occurrence in the few tow-nettings in which it was observed. Scolecithrix Dan.e (Lubbock). 1856. Undina Dana, Lubbock, Trans. Entom. Soc. vol. iv. p. 15, pi. ix. figs. 6-9. 1883. Scolecithrix Dance, Brady, Report ' Chall.' Copep. p. 57, pi. xvii. figs. 1-12. Habitat. Station 2, surface tow-netting, January 1st (night collection). Station 9, 25 fathoms tow-netting, January 10th (day collection). Station 11, 10 fathoms tow-netting, January 19th (day collection). Stations 21 and 22, surface tow-nettings, February 4th (day collection). Lat. 5° 55' 1" S., long. 11° 30' 7" E., surface tow-netting, February 18th (night collection). Scolecithrix Dance w^as observed in 57 tow-nettings, 20 of which were surface gatherings, and tiie others undei'-surface ; 10 of the surface and 24 of the under-surface were day collections, wdiile 10 of the surface and 13 of the under-surface gatherings were collected during the night, as shown by the formula ; — r 10 day collections. f 20 surface 1 m ,,;'i + ^•^-^. rr, ,,. >- I <- 10 night ditto. Tow-nettings o / < ° 1 37 under-surface | ^"^ '^^^ '^^^tto. 1 13 night ditto. SECOND SERIES. — ZOOLOGY, VOL. VI. 7 50 MR. T. SCOTT ON ENTOMOSTEACA The imder-siirface tow-nettings ranged from 5 to 260 fathoms. This species was more or less common in nearly all the tow-nettings in which it was observed. Scoj-ECiTHKix MINOR, Brady. 1883. Scnlecithrix mirwr, Brady, op. cit. p. 58, pi. xvi. figs. 15-16; pi. xviii. figs. 1-5. Hahitat. Station 3, surface tow-netting, January 2nd (day collection). Lat. 3° 5.5' 3" N., long. 4° 11' 8" E., 50 fathoms tow-netting, January 20th (day collectiou). Station 14, 10 fathoms, January 21st (night collection). Lat. 0° 21' 1" N., long. 7° 33' E., 20 fathoms, January 29th (day collection). Station 23, 235 fathoms, Eebruary 5th (day tow-netting). Station 24 (off the mouth of the Congo, colour of the water brownish-olive green to amber-brown), surface, Eebruary 6th (day collectiou). This Scolecithrixv{di?>a. somewhat rare species in the 'Buccaneer' tow-nettings; males especially were very scarce, and were observed only in a 30-fathoms tow-netting from lat. 1° 55' 5" N., long. 5° 55' 5" E. The ultimate joint of the longer branch of the male fifth foot and the appendage of the same branch were not so long as shown in the figure in the ' Challenger ' Beport, but otiierwise the ' Buccaneer ' specimens agreed with the description and drawings of Sooleciflirix minor (loc. cit.). I have examined many specimens, mature and immature, of Scoleciihrix Dance, and have certainly not found the fifth pair of feet in any of them to agree in structure with those of Scoleciihrix minor ; hence I feel satisfied that the two are quite distinct from each other. SCOLECITHRIX LONGICORNIS, n. sp. (PI. V. figS. 20-28.) Female. Length, not including tail-sette, 1-54 mm. The first body-segment is more than twice the entire length of the other three ; the forehead is rounded. Anterior antenme slender, reaching to the extremity of the abdomen, 23-jointed, and furnished with a number of very small setae (with the exception of the last joints, which bear longer setas) (fig. 21) ; the proportional lengths of the joints nearly as in the formula : — G. 4. 3. 3. 3. 3.. 3. 7. 2. 3. 4. 4.. 5 .6.5. 6. 0.6. 6. 6. 6. 5. 4 i 2 3 4 5 () 7 S U H) U ll' 13 14 15 IG 17 18 1!) 20 21 -I'l 23* The anterior foot-jaws terminate in four lobes with several plumose set?e at their extremity, while one lobe forms the base of a fascicle of slender sensory filaments ; a single filament also springs from the end of the lowest of the four setiferous lobes. Posterior foot-jaws small, the first two joints long, the third very short, the fourth equal to the entire length of the last three. Other mouth-organs similar to Scolecitlirix Dance. The first four pairs of swimming-feet similar to those of Scoleciihrix securifrons. Eifth pair small, 3-jointed, the middle joint rather longer than either of the other two, and bearing several small spiniform setae at its exterior distal angle ; the extremity of the last joint is produced forward into a triangular sharji-pointed process, wiiile an elongate spine, serrate on the outer margin, springs from the inner distal angle (fig. 27). Abdomen short, stout, composed of four segments, the first segment large, the other three very FEOM THE GULF OF GUINEA. 51 short. Caudal stylets short, the length and hreadth equal ; each stylet bears four long plamose terminal seta;, and one small seta on. the inner distal angle. Habitat. Lat. 1° 55' 5" N., long. 5° 55' 5" E., 3G0 fathoms (day collection). Station 23, 135 fathoms, February 5th (day collection). This Scolecithrix was obtained in only two tow-nettiags from comparatively deep -water. ScoLECiTHRix Bradyi, Gicsbreclit. (PL V. figs. 29-39.) 1892. Scolecithrix Bradyi, Giesbreclit, op. cit. p. 283, pis. 4, 13, 37. Length about 1-8 mm. In form like that of Scolecithrix Dance. Anterior antennis in the male as long as the cephalothorax, 19-jointed; in the female 23-jointcd and about one-fourth longer than those of the male. The proportional lengths of the joints are nearly as in the annexed formula : — Male. 4. 4. 2. 2. 2. 2. 2. 12. 3. 4. 5. 5. 5. 5. 4. 4. 5. 6. 7. 12345 B 78 ^DIO 11 12 13 14 15 16 17 18 19 20 21 22 23. Female. 5. 5. 3. 3. 3. 3. 3. 7^. 3. 4. 5. 5.5.6.6.6.6.5.5.5.6.5.3." The basal joints bear a number of setse, but the others are very spai-ingly setiferous ; posterior antenme and mouth-organs as in Scolecithrix Bance, but the larger branch of the mandible-palp bears a number of very long slender setie. The first four pairs of swimming-feet are similar to those of Scolecithrix securifrons ; the terminal spines of the outer branches are finely but somewhat ixnequally serrate on the outer margin and ciliated on the inner. Eifth pair wanting in the female, 1-branched in the male ; basal joints dilated ; the third joint of the (?) right foot elongate, with a short digit-like process on the inner margin near the distal end, the last joint divided to near the base into two subequal segments, the inner of which is curved upward so as to form a hook-like appendage. The (?) left foot 5-jointed and longer than the other; the second joint is the longest, being nearly as long as all the following three together, and bearing at its inner distal angle an appendage which is fully as long as the third joint. Abdomen and caudal stylets in both sexes as in Scolecithrix Dance. Scolecithrix Bradyi resembles Scolecithrix Dance very nearly in its general form, but is much smaller ; it differs in possessing extremely long hairs on the larger branch of the mandible-palp, and especially in the form of the fifth pair of feet. Suhitat. Station 2, 25 fathoms tow^-netting, January 1st (night collection). Station 9, 50 fathoms tow-netting, January 10th (day collection). Olf Sao Thome Island (lat. 0° 34' N., long. G° 30' 4" E.), 20 fathoms tow-netting, January 23rd (day collection). Station 23, 135 fathoms tow-netting, Eebruary 5th (day collection). Scolecithrix affiuis was obtained in thirteen of the tow-nettings, one only of which was a surface (night) gathering, the other twelve being under-surface, the depth of which ranged from 5 to 360 fathoms, and of which three were collected during the day and nine during the night, as in the formula : — f 0 day collection. r 1 surface { -. • i . tv-v- m i.^- TO (_ 1 night ditto. Tow-nettmgs 13< ^ ° \\-2 under-surface/ 3 day collections. 1 9 night ditto. 7* 52 MR. T. SCOTT ON ENTOMOSTEACA ScoLECiTHRix LATIPES, n. sp. (PI. III. figs. 21-23 ; PI. V. figs. 40-43.) Temale. Length 8'2 mm. (l-8th of an inch). Body stout. Abdomen short, 4-jointed Porehead with a median keel extending round the front to the bifid rostrum. Anterior antennte rather longer than the thorax, 23jointed, sparingly setiferous (fig. 58). The proportional lengths of the joints are as shown in the formula : — 35 . 5 . 5 . 5 . 5 . 5 ■ 11 ■ 5 . 5 . (i . 8 . 8 ■ 8 . 8 ■ 9 ■ 9 ■ 6 . 8 . 8 ■ (j . 9 . 10 . 7 T 2~irT~5^6 7 8 9 10 11 12 13 14 15 10 17 18 19 20 21 22 23' The posterior antennae, mouth-organs, and swimming-feet are somewhat as in Scole- cithrix I)ancp, but the anterior foot-jaws are strongly gibbous on the underside (PL V. fig. 42). The fifth pair of feet are simple, considerably dilated, especially towards the end, and are each furnished with three spines on the broadly-rounded apes ; the inner ^^voq, which is longer than the others, is finely serrate on the outer margin, the others are plain (PL III. fig. 22). Caudal stylets short, shghtly divergent, and furnished with four long, plumose, terminal setse. This form, of which only one or two specimens (females) were obtained, occurred in a gathering from 85 fathoms, collected February 5th at Station 23 (lat. 4° 26' T S., long. 10° V 8" E.). Scolecithrix latipes was readily distinguished from the other species of Scolecithrix by the pecuHar form of the fifth pair of feet, which are broad and leaf-like. Scolecithrix major, n. sp. (PL III. figs. 24-26 ; PL V. figs. 44, 45.) Female. Length 3 mm. (l-8th of an inch). Body elongate. The anterior foot-jaws are stout and the marginal lobes are furnished with long, spiniform, plumose, terminal setae ; all the sensory filaments are large with the exception of two, which are smaller and provided witli elongate acutely -pointed heads. The terminal spines of the swimming-feet, especially those of the third and fourth pairs, are coarsely toothed on the outer margin ; there are sixteen or seventeen large teeth along the margin. Fifth pair small, simple, 2-jointed ; the last joint is about three times the length of the other, and armed with one moderately long terminal and one small subtermiual spine, while a long spiniform seta springs from near the middle of the inner margin. Abdomen long, composed of four segments, the first three nearly equal, the last much shorter. Caudal stylets short, about as long as the last abdominal segment ; apical sette four, plumose. Habitat. Lat. 1° 55' 5" N., long. 5° 55' 5" E., 460 fathoms (day collection, January 22nd). The form of the animal, the armature of the anterior foot-jaws, and the coarsely-toothed terminal spines of the swimming-feet are characters which distinguish this from other species of Scolecithrix. A considerable portion of the anterior antennte was wanting in the only specimen obtained. Scolecithrix tumida, n. sp.* (PL III. figs. 33-38.) ? Scolecithrix ubyssalis, Giesbreclit, op. cit. p. 284, pL 13. figs. 15, 40, pi. 37. fig. 7. Female. Length 2-4 mm. Body somewhat robust ; forehead obtuse, with a small * This is probably the Scola-ithi-iv abi/ssalis of Giesbrechfc ; but, as there appear to be some difi'erences between his FEOM THE GULF OF GUINEA. 53 rostrum ; jiostero-lateral angles of last thoracic segment rounded. Anterior antennre long, reaching to near the extremity of the abdomen, 21 -jointed and sparingly setiferous. The annexed formula shows the proportional lengths of the joints : — 12 . 3 ■ 3 . 3 . ;i ■ 3 . 8 . 3 ■ 3 ■ 4 . 6 ■ 0 ■ 7 ■ 7.8.7.7.7.6.8.11 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1(5 17^18~i9~2(rTl' Anterior foot-jaws stout ; four of the marginal lobes are each armed with a long setiferous spine and two sctce ; a number of slender sensory filaments spring from the end of the anterior foot-jaws as in other species of Scolccithrix. The terminal spines of the swimming-feet are finely toothed on the outer margin ; the arrangement of the marginal teeth of the terminal spines of the third and fourth j)airs differs from those of the second, as shown in figure 36. The fifth pair are small, somewhat dilated, and 1-jointed, armed with one terminal spine, a stout and prominent spine on the inner margin, and a small tooth on the outer margin (fig. 37). Abdomen short, stout, the last segment small. Caudal stylets short, the breadth about equal to the length, and furnished with one subterminal and three apical sette. Eabitat. Lat. 1° 55' 5" N., long. 5° 55' 5" E., 460 fathoms (January 22nd, day collection). Station 23, 85, and 235 fathoms (February 5th, day collection). Scolecithrix tumida is a rare species in the ' Buccaneer ' collections ; its robust form, the spinous armature of the anterior foot-jaws, and the dilated fifth pair of feet are characters that readily distinguish it from other species of Scolecithrix. Scolecithrix dubia, Giesbrecht. (PI. III. figs. 27-32 ) 1892. Scolecithrix dubia, Giesbrecht, oj). cit. p. 281, pi. 13. fig. 29 a. 1892. Scolecithrix simulans, Scott (!MS. uame). ? Male. Length 1-6 mm. Body robust; abdomen of moderate length, 3-jointed, the middle segment rather shorter than the first or last. Anterior antennae reaching to about the end of the second abdominal segment, sparingly setiferous, composed of twenty joints, the eighth equal to the entire length of the preceding four, the last two elongate, slender. The formula shows the proportional lengths of the diflerent joints : — 5. 5. 3.3. 3.3. 3. 12. 3. 5. 6. 7.7. 7.7.5 .5.4.8.0 12 3 4 5 6 7 8 S) 10 11 12 13 14 15 10 17 18 19 20' The articulation between the sixteenth and seventeenth joints of the right antenna is imperfect and somewhat indistinct. The posterior antennae, mouth-ap^jendages, and first four pairs of swimming-feet nearly as in Scolecithrix Dcmce, except that the marginal lobes, especially the one nearest the apex, of the anterior foot-jaws bear elongate curved spines with ciliate inner margins ; the apex, as in Scolecithrix Dance, bears a number of hair-like filaments (fig. 29). The terminal spines of the swimming-feet are finely serrate on the outer and ciliate on the inner margins. The fifth pair are unequal; the (?) left consists of three joints ; the basal part of the elongate middle joint is considerably swollen and bears a (?) spiniform appendage on its inner aspect ; the inner angle at the distal end description and figures and the description and figures given in this Eeport, I leave the ' Buccaneer ' species as originally described. 54 ME. T. SCOTT ON ENTOMOSTEACA forms a produced lobe-like process ; the last joint small, curved imvard, and bearing a minute bent terminal spine. The (?) right foot is longer than the other and 5-jointed ; the first joint is about twice the length of the first joint of the (?) left foot, but the first and second joints of the (?) right are together scarcely equal to the length of the same joints of the other foot ; an elongate appendage — ? as long as the third joint — springs from the end of the second joint ; the third and fourth joints, which are subequal in length, are more slender than the preceding joint, and are together nearly equal in length to the first ; the fifth, which is scarcely so long as the fourth and appears to be connected with it by a hinged articulation, is ciliate on the inner edge. Habitat. Lat. 4° 26' 7" S., long. 10° 1' 8" E., in a tow-net gathering from 235 fathoms collected between 11 a.m. and 3.30 p.m. February 6th. This Scolecithrix somewhat resembles Amallophora in the form of the feet of the fifth pair, but differs in the number and proportional length of the joints. It also differs from any other Scolecithrix described in tliis Report in the proportional length of the joints of the anterior antenna;, the form of the anterior foot-jaws, and the fifth pair of feet. Subgenus Amallophora *. (Subgenus of Scolecithrix, Brady.) Anterior antennsB 20- to 23-joiuted. Mouth-organs and swimming-feet nearly as in Scolecithrix, except that the anterior foot-jaws are furnished with one or more appendages, each consisting of a bundle of filaments resembling a sheaf of corn in miniature. Fifth pair of feet in the male dissimilar, 1- or 2-branched, prehensile ; in the female siuiple, 1-branclied. Amallophora tvpica, n. sp. (PL III. figs. 39-lG ; PI. VI. figs. 1-1.) Length 2"7 mm. (about l-9th of an iuch). .Body elongate, moderately stout ; forehead rounded. Anterior antennai rather longer than the body, 20-jointed, and sparingly setiferous. The formula shows approximately the proportional lengths of the joints : — 15 . 18 . 10 . 10 . 10 ■ 10 ■ 10 . 17 . C4 . 21 . 25 . 2G . 26 . 22 . 14 . 15 . 14 . 16 . 14 . 10 1 2 3 4 5 6 7 8 y 10 11 12 13 14 15 16 17 18 19 20* The first seven joints bear short club-shaped appendages. Primary branch of the posterior antenna? short, secondaiy branch moderately long, the intermediate three very short (fig. 41). Mandible small, with a large 2-branched palp, one of the branches 2-, the other 4-jointed (fig. 42). Anterior foot-jaws stout, short, 4-jointed, first joint long, the second provided with an appendage bearing a large rounded cluster of curled filaments, and somcAvhat resembling a sheaf of corn in miniature ; third and fourth joints small and armed with a large spiniform and several small plumose setie (fig. 44). Posterior foot-jaws slender and elongate, 6-jointed, the first, second, and fourth joints long, the others very short and bearing a few seta;. The first four pairs of swimming-feet as in Scolecithrix ; the terminal spines are strongly serrate on the outer edge, those of the third * "A/i(u\Aa, a bundle or sheaf, aud ^epeu-, to carry. FKOM THE GULF OF GUINEA. 55 pair considerably narrowed at the base. The fifth pair is simple, consisting^ of one short 3-jointcd branch, which terminates in a small spine, and one very long" and slender branch, composed of four nearly equal parts, and bearing a ciliate digitiform process and a number of short sette at the apex. Abdomen short, tlie first segment rather narrower than tlie next ; the last is very small. The caudal stylets are also very short and somewhat divergent (PI. IV. fig. 4). Habitat. Lat. 1° 55' 5" N., long. 5^ 55' 5'' E., in a tow-net gathering from 35 fiithoms, collected January 22nd. Only one specimen of this curious form Avas obtained. Amallophora magna, n. sp. (PI. IV. figs. 5-9.) Female. Length about 4"5 mm. (2-lltlis of an inch). Body robust, attenuated towards the front, tlic first segment equal to the entire length of the other body-segments and abdomen; head produced into a distinct though small median keel, which passes round over the forehead (fig. 31). The postero-lateral angles of the last thoracic segment are produced ventrally into a small tooth. Anterior foot-jaws small; four of the marginal lobes are furnished with long terminal plumose setae, while the other forms the l)asc of a long setose spine; several small sensory filaments, some of which have rounded licads, spring from the extremity of the foot-jaw, as shown in fig. 0. The other mouth-organs and swimming-feet are similar to those in Scolec'dhrLv Daiicv, except that the large terminal spines of the swimming-feet are strongly toothed on the outer margin. Tlie fifth pair are very small, simple, 2-jointed; the second joint is nearly twice the length of the other and provided with one terminal and two submarginal setoe ; the terminal and one of the submarginal sette are long and slender, the other is very short (fig. 9). Abdomen short. Kahltat. Off Sao Thome Island, 20 fathoms, January 23rd (day collection). One specimen only of this curious form was obtained ; it wanted a considerable portion of the anterior antennae and part of the abdomen, but, though thus mutilated, the peculiar structure of the anterior foot-jaws and the large, strongly-toothed, terminal spines of the swimming-feet, together with the large size of the animal, readily distinguish this from allied species. No males were observed. Amallophoea dttbia, n. sp. (PI. IV. figs. 10-18.) Mule. Length 2-5 mm. (1-lOth of an inch). In this species the first cephalothoracic segment is nearly equal to the entire length of the other three body-segments and the abdomen. Anterior antennse about as long as the cephalothorax ; the right antenna is 18-, the left 23-jointed ; in the right antenna, which is indistinctly geniculate at the proximal half (fig. 11), the seventh joint is composed of five and the fifteenth, of two coalesced joints; the first thirteen joints of the left antenna and the corresponding joints of the right have a row of elongate setae along the upper margin, each of which is fvu'nished with a membrane-like unilateral expansion or fringe as shown in the figure, but the remaining portion of the antenna? is only sparingly setiferous. The annexed formula shows the proportional lengths of the right and left antennce : — 56 MR. T. SCOTT ON EXTOMOSTRACA Eight antenna. 12. 4 4 .4 4 .4 18 . 5 . 5 . 7 . 12 . 12 . 11 . 10 . 12 . 5 . 8 . 9. 1 2 3 4 5 6 7 » 9 10 11 12 13 14 15 16 17 18. Lett antenna. 1-J . 4 4 4 4 4 4.4.4.4.4.5.5 7 . 13 . 13 . 13 . 12 . <; . (i . 5 . 10 10. 1 2 3 4 5 6 7 8 U 10 11 12 l::! 14 15 1() 17 IS 19 20 21 •*•> 23. The mouth-organs are as in Scolccith^'lx, except that the anterior foot-jaws are each provided with two jieculiar appendages, consisting of a moderately stout filament bearing an oblong conical head, which appears to be composed of dense fibre-like tissue (fig. 13). The posterior foot-jaws are furnished at the extremity with a few hair-like papilliferous filaments (fig. 14). The swimming-feet are as in Scolecithrix, but the first four pairs difi"er in the form and amount of their armature (figs. 15, 16). The fifth pair has the second joint of the left foot elongate ; the basal part of the joint is greatly dilated, and is furnislied interiorly with a spiniform appendage which terminates in a small apical seta ; the third and fourth joints are small and slender ; both branches of the right foot are 2-jointed and furnished with small digitiform terminal processes (fig. 17). The abdomen is composed of four segments, the first l)eiug rather shorter than the others. Caudal stylets short, each bearing four moderately long, plumose, terminal hairs (fig. 18). Habitat. Lat. 1° 55' 5" N., long. 5° 55' 5' E. In two gatherings, one from 360 fathoms and one from 160 fathoms. Collected during the middle of the day, January 22nd. Variety similis. (PL IV. figs. ]9-23.) This is a form which occurred along with the other in the gathering from 460 fathoms, and which, though closely resembling it, yet diff'ers in a few points. It resembles AmaUoj^hora dnbia, es^^ecially in the form of the fifth pair of feet, but differs considerably in the proportional length of the joints of the anterior antenute and of the segments of the abdomen, as will be observed by comparing the figures of the variety with those of the species. Amallophoka eobusta, n. sp. (PL IV. figs. 24-29.) Female. Length 3 mm. (l-8th of an inch). The body is robust, with a rounded forehead and a small rostrum. The anterior foot-jaws are jorovided with a number of terminal filaments, the majority of which are comparatively short and possess ovate conical heads, while three of them are stout and moderately long and resemble those in Scolecithrix (fig. 25). Posterior foot-jaws as in Scolecithrix, except that the first joint in each is furnished with a short and stout filament having an ovate pointed head like the smaller filaments of the anterior foot-jaws. The swimming-feet are similar to those of Amallo- fhora magna, but the terminal spines are long, and finely seri'ate on the outer edge, and plain on the inner edge. The fifth feet are small, simple, and 2-jointed; a large setose spine springs from the inner margin, and a small spiniform seta from the outer margin, of the last joint ; ^\hile a plain spine, smaller than that on the inner margin, springs from the inner part of the rounded ai^ex, as shown in. the figure (fig. 28). Abdomen comj^ara- tively small, 4-jointed, the segments subequal. Caudal stylets about half the length of the last abdominal segment, and furnished with four apical plumose setae. FEOM THE GULF OF GUINEA. 57 mthitat. Station 23 (Lat. 4° 26' 7" S., long. 10° 1' 8" E.), in a gathering from 85 fathoms. Collected about midday, Eebruaiy 5th. One or two specimens only of this species were obtained. The armature of the anterior and posterior foot-jaws, the long and finely serrate terminal spines of the swimming-feet, and the form and armatiu-e of the fifth pair are characters by which this may be dis- tinguished from other allied species. Genus Euch^ta, Philippi. Eucliata, Philippi, Arcliiv f. Natiirgcsch. 1843; Dana, Proc. Amcr. Acad. Sci. 1849; Claus, Die fieilebcndeu Copepodeu, 1863 ; Brady, Report Cliall. Copep. 1883. Edch^ta maeina (Prestandrea, 1833). 1843. Euclueta Prestandrea, Philippi, Arehiv. f. Naturgesch. Taf. iv. fig. 5. 18G3. EuchcEta Prestundrece, Claus, Die freilebeudeii Copepodeu, p. 183, pi. v. fig. 12 a, pi. ix. figs. Q, 7, 9, 12, pi. XXX. figs. 8-17. 1883. Euclueta Prestandreie, Brady, Report Chall. Copep. p. 60, pi. xvdii. figs. 7-15, aud pi. xix. 1892. Euclueta marina, Giesbrecht, Fauna und Flora des Golfcs von Neapel (Copepoden), p. 262, pis. 1, 15, 16, 37. Habitat. Stations 2, 3, 9, 11, 14, 21, 24, aud others; also Lagoon, Sao Thome Island, surface tow-nettings. Euchceta, inarina was one of the commoner species observed in the collection. It occurred in lOG tow-nettings, 47 of which were surface-gatherings and 59 uuder-surface, ranging from 2 to 460 fathoms. 16 of the surface and 41 of the u.nder-surface tow-nettings Avere collected during the day, and 31 of the surface and 18 of the uuder-surface during the night, as represented in the formula : — J 16 day collections. ... . n. r ^^ ''''"^''''^ ^ 31 night ditto. Tow-nettmgsl06<^ . ^^ " ,.^^ 1 59 under-surface 1 ^^ '^^^ '^^"O" 1 18 night ditto. A greater number of Euchceta marina carried ova than any other species of Calanidse in the ' Buccaneer ' collection. The clusters of ova somewhat resembled miniature bunches of grapes. ErcH^TA PULCHRA (Lubbock). 1856. Undina pulcliru, Lubbock, Trans. Entom. Soc. iv. p. 14, pi. iv. figs. 5-8, pi. vii. fig. 6. 1883. Euclueta pulchra, Brady, Report Chall. Copep. p. 63, pi. xiv. figs. 6-9, pi. xx. figs. 14-19. mihitat. Lat. 7° 33' N., long. 15° 18' W., 25 fathoms tow-netting, January 2nd (night collection). Lat. 2° 34' 9" N., long. 5° 22' 2" E., 20 fathoms, January 21st (night col- lection). Lat. 1° 55' 5" N., long. 5° 55' 5" E., 35 fathoms, January 22nd (day collection). Lat. 0° 25' 1" N., long. 6° 36' 6''E., 10 fathoms, January 24th (night collection). These are the only tow-nettings in which this Euchceta was observed, and a few specimens only were obtained . SECOND SERIES. — ZOOLOGY, VOL. VI. 8 58 ME. T. SCOTT ON ENTOMOSTEACA EucHiETA ATJSTRALis, Brady, (PI. VI. fig. 23.) 1883. Euchceta australis, Brady, Report Chall. Copep. p. 65, pi. xxi. figs. 5-11. A single specimen of this species (a male) was obtained in a tow-net gatliering from 50 fatlioms at Station 2 (lat. 7° 54' N., long. 17° 25' W.). Collected between 7.20 and 8.20 p.m., January 1st. I have nothing to add to the description of this apparently rare species contained in the Report on the Copepoda of the ' Challenger ' Expedition, The species, after being dissected, was easily recognized by the description and figures of it in that Report. EucH^TA GiCAS, Brady. 1883. Euchata gigas, Brady, loc. cit. p. 65, pi. xxii. figs. 1-5. This Euchceta was obtained in a tow-net gathering from a depth of 35 fathoms in lat. 1° 55' 5" N., long. 5° 55' 5" E. Collected during the day, January 22nd. Two or at most three specimens (females) were obtained. EucH^TA BARBATA, Brady. (PI. VI. fig. 17.) 1883. Euchceta barbata, Brady, loc. cit. p. 66, pi. xxii. figs. 6-12. This 'Eucliceta was obtained in three different tow-net gatherings, in one from 50 fathoms at Station 2, January 1st, in one from 360 fathoms in lat. 1° 55" 5' N,, long. 5° 55' 5" E., January 22 nd, and in one from 30 fathoms, at Station 23, Eebruary 4-th. This remarkable species is readily distinguished from other EuclicetcB by the tufts of setae on the last abdominal segment, by the first abdominal segment being greatly dilated ventrally, and by the tufts of seta3 on the posterior angles of the last thoracic segment. Very few specimens (females) were obtained. ErCHiETA (?) Hessei, Brady, var. similis, nov. var. (PL VI. figs. 24 & 25.) 1883. Euchmta Hessei, Brady, loc. cit. p. 63, pi. xx. figs. 1-13, pi. xxiii. figs. 11-14. Male. Length 2"2 mm. (l-12th of an inch). Body elongate, rounded in front; the postero-lateral angles of the last thoracic segment are produced in aculeate spines, as shown in fig. 1. Anterior antennae as long as the thorax, 21-jointed, geniculate at the twelfth joint ; the eighth and twelfth joints are composed of two or three coalesced joints and are indistinctly articulated ; the basal joints are furnished with leaf -like appen- dages, and a club-shaped filament springs from the end of the last joint. The annexed formula shows the proportional lengths of the joints : — 10. 3. 3. 3. 3. 3. 3. 8. 3. 3. 4. 4. 5.6. 6. 6. 9. 14. 8. 8. 8 1 2 3 4 5 G 7 8 y 10 11 12 13 14 15 16 17 IS 19 20 21 Posterior antennae and mouth-organs similar to those of Euchceta marina, but the anterior foot-jaws, though small, are somewhat stout, as shown in fig. 4. Swimming- feet also as in that species, except that tlie terminal spines of the swimming-feet are more coarsely serrate — especially those of the third and fourth pairs, the serrations of which number about eighteen ; the secondary spines of the second pair are longer than TEOM THE GULF OF GUITs'EA. 59 in the other swimming-feet. The fiftli pair (fig. 25) closely resemble those of Euchceta Sessei as figured in the ' Challenger ' Copepocla. Abdomen composed of four nearly equal segments. Caudal stylets very short, furnished with four long plumose hairs. Hahitcd. Lat. 1° 55' 5" N., long. 5° 55' 5" E., 460 fathoms (day collection, January 22nd). This comes very near Euchceta Sessei* and is possibly a form of that species. It differs in the following points : — It wants the prominent rostrum of Euchceta Hessei ; the posterior margin of the last thoracic segment bears on each side a small but distinct aculeate spine; it possesses small but stout anterior foot-jaws; the inner edge of the terminal spines of the swimming-feet is densely cilia te. The right foot of the fifth pair has no secondary appendage and terminates in a spiniform process ; the left foot has a very short inner appendage, and the last joint, which is elongate, is geniculate near the middle. No females were observed. Etjch.^ta hebes, Giesbrecht. (PI. VI. figs. 18 & 19.) 1892. Euchceta hebes, Giesbrecht, op. cit. p. .263, pis. 15, 16, 37. Male. Length 2"7 mm. (l-9th of an inch). Body elongate, rostrum small. Anterior antennae not longer than the thorax, 22-jointed ; the second joint bears a number of small club-shaped appendages ; the upper margin of the eighth joint is produced near the distal end into a small digitiforni setiferous lobe ; the proportional lengths of the joints is shown in the annexed formula : — G. 5. 3. 3. 3. 4. 4. 9. 4. 4. 6. 6. 6. 7. 7. 8. 9. 8. 8. 9. 8. 11 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 IS 19 20 21 22 Posterior antennjB robust, the primary branch considerably shorter than the secondary. Mouth-organs as in Euchceta marina, except that the posterior foot-jaws are com- paratively short and stout. Swimming-feet nearly as in Euchceta marina ; the fifth pair are unequal in length ; the left is 2-branched, the outer branch 3-jointed, the last joint being long and slender, with a bluntly rounded extremity, the inner branch is 1-joiuted and as long as the first two joints of the outer branch ; the right foot, which has a small rudimentary inner branch, is shorter than the other and terminates in three processes ; one of these processes is stout, curved, and spiniform ; the second is oblong-ovate, somewhat truncate at the apex, and bears a dense fringe of cilia on the distal end of the inner margin ; tlie third is a strong, somewhat hook-like appendage, serrate on the inner edge. The whole forms a complicate apparatus with which the left foot probably interlocks. Abdomen elongate, of four nearly equal segments, the posterior margins of which are serrate. Caudal stylets very short, nearly obsolete, and furnished with four plumose setae — the third from the outside being considerably longer than the others. Mahitat. Station 2, 50 fathoms (night collection, January 1st). Station 9, 50 fathoms (day collection, January 10th). * This reference is to the description aud drawings of Eachnia J/csscl in the 'Challenger" Copepoda, as no Eucha;ta agreeing -with these was obtained in the ' Buccaneer ' collections, 8* 60 ME. T. SCOTT ON ENTOMOSTRACA This species is closely allied to Euchceta marina, but differs in several important points and especially in tlie character of the fifth feet ; it also wants the prominent bifid rostrum of that species. No females were observed. Etjch^ta hebes, var. valida. (PI. VI. figs. 20-22.) A form, which may be only a variety of Euchceta hebes, occurred along with that species in a tow-net gathering from 50 fathoms at Station 2 (lat. 7° 54' N., long. 17° 25' W.). But while resembling Euchceta hebes in general form and in the form of the fifth feet, it differs in some of its structural details as well as by its much greater size. The following is a description of some of its more obvious differences : — Length (male) 5*7 mm., of which the body forms two-thirds and the abdomen one- third. Anterior antennte reaching somewhat beyond the last thoracic segment, 22- jointed, sparingly setiferous ; the eighth joint, which is longer than the preceding two together, and the seventeenth, eighteenth, and last are subequal, and are the longest joints of the antenna?. The proportional lengths of the joints are nearly as shown in the formtda : — 12 . 12 . 5 ■ li ■ 7 . 8 . 9 ■ 19 ■ 6 ■ 8 ■ 11 ■ 10 . 13 ■ 14 ■ 15 ■ 10 . 19 ■ 19 ■ 16 ■ 16 ■ 15 ■ 19 i 2 3 4 5 6 7 S 9 lU 11 12 13 14 15 16 17 18 19 20 2,1 22" Between each of the large marginal teeth of the proximal half of the terminal spines of the second, third, and fourth swimming-feet there is a very small tooth ; it can only be satisfactorily distinguished by using a moderately high magnification (fig. 21). The second joint of the (?) right foot of the fifth pair is moderately short and considerably swollen, and bears interiorly at its distal end an appendage, the lengtli of which is rather greater than the elongate third joint ; the fourth joint is very slender and as long as the third, and terminates in a blunt-pointed extremity. The (?) left foot is 4-jointed, the first joint is short, the second and third elongate ; the last, which is comparatively short, ends in a complex trifid apparatus, somewhat similar to that of Euchceta hebes (fig. 22). Abdomen slender, the last segment about two-thirds the length of the preceding. Stylets short, thek breadth scarcely equal to the length ; the long seta — the third seta from the outside — of each is at least equal in length to the abdomen. Genus Candace, Dana. Candacia, Dana, Amer. Journ. Sci. 1846. Ifionyx, Kvoyer, Nat. Tidsskr. 1849. Candace, Dana, U. S. Expl. Exped. 1853. Candace pachtdactyla, Dana. 1852. Candace pachyihtctyla, Dana, U. S. Expl. Exped. p. 1113, pi. Ixxviii. figs. 2a-b. 1883. Candace pachydactyla, Brady, Report Cliall. Exped. p. 68, pi. xxxi. figs. 2-9. Habitat. Station 2, 5 fathoms tow-netting, January 1st (night collection). Lat. 4° 21' 8'' N., long. 1° 57' W., surface tow-netting, January 14th (day collection). Station 24, 10 fathoms, January 21st (night collection). Lagoon, Sao Thome Island, surface, FEOM THE GULF OF GUINEA. 61 January 27tli (clay collection). Station 23, surface, 10, 20, 85, and 185 fathoms tow- nettings, February 5th (clay collection). Lat. S" 36' 8" S., long. 12° 57' E., surface, February 9th (clay collection). This Ccmdace was obtained from 57 tow-nettings, 24 of which were surface and 33 under-surface gatherings ; 37 of the tow-nettings (16 surface and 21 under-surface) were collected during the day, and 20 (8 surface and 12 under-surface) were collected during the night, as shown in the formula : — 16 day collection. 8 nio'ht ditto. r24s surface Tow-nettino;s 57< .^_ . ..,, 33 under-surface / ^^ ^^ ^"*^°- night ditto. ■■»'■ { The under-surface tow-nettings ranged in depth from 2 to 260 fathoms. Ccmdace pachyclactyla, as noted above, occurred in twice as many day surface as in night surface- gatherings ; its distribution in this respect is thus more or less the reverse of that of most of the species described in this Report. Candace pectinata, Brady. 1878. Candace pectinata, Brady, Monog. Brit. Copep. i. p. 49, pi. viii. figs. 14, 15 ; pi. s. figs. 1-12. 1883. Candace pectinata, Brady, Report Chall. Copep. p. 67, pi. xxx. figs. 1-13. Habited. Lat. 1° 55' 5" N., long. 5° 55' 5" E., 35 fathoms, January 22nd (day collec- tion). Station 23, surface tow-netting, February 5th (day collection). This Candace was of rare occurrence in the ' Buccaneer ' collections. Candace intermedia, n. sp. (PI. IV. figs. 30-37.) ? Candace curta, Dana (1852), Crust. U. S. Espl. Expedition, Length, exclusive of tail-seta?, 2'46 mm. In form somewhat like Candace pectinata, Brady, but the posterior margin of the first thoracic segment is produced in the median dorsal line so as to form a distinct hump, which is usually of a chocolate- brown colour, while the surrounding integument is white or nearly so (fig. 56). The last thoracic segment (figs. 62, 63) is furnished on each side with four small hairs, the posterior one being the longest. The 16th, 17th, and 18th joints of the right male antennae are toothed in a manner somewhat similar to that of Candace pectinata, but the teeth on the 18th joint (the joint on the distal side of the hinge) do not form a distinct beard-like fringe as in that species. The proportional lengths of the joints, especially of the right male antenna, differ from those of C. pectinata and are very nearly as in the annexed formula : — Male antenna}. 10 . 10 . 3 . 5 . 6 . 3 . 3 . 3 . 3 . 3 . 4 . 6 . 6 . 7 . 8 . (J . 10 . 10 . 10 . 6 . 5 . 6 . 8. 1 2 3 4 5 6 7 8 9 10 11 12 X3 14 15 16 17 18 19 20 21 22 23. Female antennas. 10 . 10 . 3 . 4 . 5 . 3 . 3 . 3 . 3 . 3 . 5 . 5 . .5 . 7 . 7 . 9 . S . 9 . 7 . 5 . 4 . .5 . 6. The 17th joint in the male is usually dark-coloured. The mouth-organs and swimming- feet, except the fifth pair, resemble those of Candace pectinata. The fifth feet in the female are somewhat like those of Candace pachydactyla, but the terminal spines only 62 ME, T. SCOTT ON ENTOMOSTEACA are dark-coloured ; the fiftli feet in the male are intermediate in form (fig. 35) between Candace pectinata and Candace pachydactyla. The abdomen in the female has the first segment stout and rounded — not "produced at each side into a triangular prominence," as in Candace pectinafa. The first segment in the male, however, is produced on the right side similar to that species. The posterior margin of all the abdominal segments is finely and distinctly serrate. Between the second and third setse of the caudal stylets (counting from the outside) there is a short stout spine, which was quite conspicuous in some of the specimens. This species is intermediate between Candace pectinata and Candace pachydactyla, but is readily distinguished from both by the characteristic dark-coloured dorsal hump described above. Habitat. Station 2, 5 fathoms, January 1st (night collection). Station 9, 50 fathoms (day collection). Lat. 1" 55' 5" N., long. 5° 55' 5" E., 36 fathoms, January 22nd (day coUectionj. Station 23, surface and 10 fathoms, February 5th (day collection). Lat. 7° 5Ji' 6" S., long. 12° 14' 7" E., surface, February 9th (day collection). This species occurred in 16 tow-nettings, 9 of which were surface and 7 under-surface gatherings ; the under- surface tow-nettings were from 5 to 50 fathoms. The proportion of day to night eatherings in which it was observed is shown in the annexed formula : — f 2 day collections. 17 r 9 surface I 7 night ditto. Tow-nettmgs 16 <^ r a ^ ^•>.l. 17 under-surfaceJ^' day ditto. I 3 night ditto. Candace intermedia, though restricted in its distribution, was nevertheless of frequent occurrence in some of the gatherings in which it was observed. Candace varicans, Giesbrecht. (PL IV. figs. 38, 39 ; PI. VII. figs. 7-10.) 1892. Candace varicans, Giesbrecht, Faima und Flora des Golfes von Neapel (Copepoden), p. 439, pi. 22. figs. 22, 23. Candace tenuiremus, Scott (MS. name). Length, exclusive of tail-setce, 2"3 mm. Anterior antennse long and slender, reaching to the extremity of the abdomen, 21-jointed in the female, the right antenna in the male 23-jointed ; the proportional lengths of the joints as in the annexed formula: — Male right antenna. 10 . 10 . 5 . 4 . 0 . 7 . 3 . 4 . 3 . 3 . 4 . 4 . 8 . 7 ■ 8 . 8 . 6 . 13 . 11 . 13 . 7 ■ 6 . 8. 1 2 3 4 5 0 7 8 9 10 11 12 13 14 1-5 16 17 18 19 20 21 22 23 24. Female antenna . . . 12 . 10 . 4 . 4 . 0 . 8 . 4 . 3 . 4 . 4 . 4 . 7 . 7 . 8 . 9 . 10 . 11 . 12 . 13 . 12 . 7 . 5 . 7 . 10. The 18th joint of the right male antenna (the joint on the proximal side of the hinge) is distinctly pectinate ; the 17th joint, which is about half the length of the 18th, is finely toothed, and the 19th has a fringe of small fine setse on the upper margin ; several of the basal joints bear strong marginal spines, and the 20th joint is as long as the following two joints together. The female antemiEe resemble those of Candace truncata. The mouth-organs and first four pairs of swimming-feet resemble those of other species of Candace. The 5th pair in the female 3-jointed, the last joint long, with three long, stout. FKOM THE GULF OF GriNEA. 63 terminal setose spines, and a small spine on tlie exterior margin below the middle of tlie segment ; the 2nd joint has a stout seta on the exterior distal angle. The 5tli pair in the male are somewhat similar to those of Candace pectiuata and Candace pachydactyla; the left foot is 4-jointed, the penultimate bcmg longer than the others, and furnished with a fringe of hairs on the lower exterior margin and a small spine near the interior distal angle; the outer margin of the last joint has a fi'inge of hairs on the upper half and four spines (2 short, 1 long, and 1 intermediate) near the margin of the lower half. There is a small tuft of hairs and a spine on the inner aspect of the same foot ; the right foot termmates in a stout prehensile hand like Candace pect'mata. The posterior thoracic segment has the lateral angles produced into stout prominent spines, which in the male reach to near the end of the first abdominal segment. The abdomen in the male 5-, in the female 3-jointed; the first segment of the female abdomen is about as long as the other two together, stout and rounded, but not produced into angular processes as in Candace pect'mata. It resembles Candace trimcata in this respect, but the middle segment is much shorter than in that species. The abdomen of the female in the ' Buccaneer ' specimens is dark-coloured — almost black, but only the stylets of the male abdomen are dark-coloured. The tail-setse are also dark-coloured and densely plumose. This species is intermediate between Candace pachydactyla and Candace triincata ; its chief distinctive characters seem to be the form of the anterior male antenna and of the male and female fifth feet. Hahltat. Lat. 1°55' 5" S., long. 5° 55' 5" E. It was obtained in two tow-nettings from this locality, one from 35 fathoms and one from 460 fathoms. The peculiar arrange- ment of the colour, together with its decided character, make the species, especially the females, quite conspicuous among their confreres. Candace truncata, Dana. 1852. Candace truncata, Daua, Crust. U. S. Exj^lor. Exped. p. 1118, pi. Ixxviii. figs. 8 a-d. 1863. 1 Candace fizA^ji/iosa, Claus, Die freilebendeu Copep. p. 191, pi. xxvii. figs. 9-16; pi. xxxiii. fig. 5. 1883. Candace trimcata, Brady, Report ' Challenger ' Copep. p. 69, pi. xxviii. figs. 12-15 ; pi. xxix. figs. 1-14. Habited. Station 2, 25 fathoms tow-netting, January 1st (night collection). Lat. 1° 55' 5" N., long. 5° 55' 5" E., 20 and 30 fathoms tow-netting, January 22nd (day collections). Off Sao Thome Island, lat. 0° 38' 6" N., long. 6° 25' 8" E., 20 fathoms tow-netting, January 23rd (day collection). Station 23, surface tow-netting, February 5th (day collection). Candace truncata was a somewhat rare species in the ' Buccaneer ' collection, the tow-nettings described above being the only ones in which it was observed. It never- theless appears to have a wide distribution. 64) MR. T. SCOTT OX ENTOMOSTEACA Genus Mormonilla, Giesbrecht (1891). Corynuropis, Scott (MS. 1892). Resembles Corynura, Brady, in general appearance but differs in the following details : — 1st. The body becomes gradually narrower posteriorly, so that the thorax and abdomen are not clearly defined the one from the other. 2nd. The secondary branch of the posterior antennae is multiarticulate. 3rd. The maxillae are provided with a well-developed bilobed palp. 4th. The anterior foot-jaws are large and resemble those of Hemicalanus longicornis, Claus. 5th. The posterior foot-jaws, which are fui'nished with a number of marginal setse, are 2-jointed, the apical joint being comparatively short (fig. 17). They resemble neither Acartia nor Corynura. 6th. The outer branches of the first four pairs of swimming-feet are 2-, and the inner branches 1-jointed, except the first and second pairs, which appear to have the inner branches very indistinctly 2-joiuted. 7th. In the female the fifth pair of feet is absent or obsolete. Male unknown. These differences, especially the 3rd, 5th, and 7th, are too important to allow of the ' Buccaneer ' specimens being ascribed to Corynura, even though the general resem- blance is very striking. MoBMONiLLA PHASMA, Giesbrecht. (PI. VII. figs. 11-21.) 1892. Mormonilla phasma, Giesbrecht, Fauna uiid Flora des Golfes von Neapel (Copepoden), p. 536, pi. 43. figs. 28-32, 3-1-41. 1892. Corynuropis tenuicaudatus, Scott (MS. name). Female. Length 1-7 mm. Body elongate-pyriform, composed of five segments, the first equal to the combined length of the other body-segments and abdomen; forehead narrowly rounded. Anterior antennae slender, 5 -jointed, and bearing a number of long plain setEe, especially at the extremity, where there are six or seven of considerable length ; the second and fourth joints are subequal and fully twice the length of the third joint, as shown by the annexed formula : — Anterior antenna;. 14 . 20 . 0 . 23 . 14 I 2 3 4 W The basal joint of the posterior antennae short ; the primary branch moderately stout, 2-jomted ; the end joint about three-fourths the length of the first ; the integument of both partly covered with fine cilia. Secondary branch rather longer than the first joint of the primary branch, 8-jointed; all the joints small except the first, which is nearly equal to the entire length of the next three ; the last joint of the principal branch and all the joints of the secondary one are furnished with very long plumose setse (fig. 13). Mandibles with a broad dentate biting part ; the principal branch of the palp is furnished with long aculeate sette, and the small secondary branch with plumose setae (fig. 14). FEOM THE GULF OF GUINEA. 65 The maxillte are well developed and provided witb a stout bilobed palp — one lobe bearing long plumose, the other aculeate setae (tig. 15). Anterior foot-jaws large, 5-jointed, the first joint about twice the lengtli of the remaining portion, the three apical joints very sliort ; the third and fourth joints bear each one, and the last thi-ee, moderately long aculeate setae ; the anterior foot-jaws are also provided with four marginal setiferous lobes — three on the first joint and one on the proximal end of the second. Posterior foot-jaws smaller, 2-jointed, and bearing several stout marginal and terminal setae ; the last joint is comparatively short (fig. 17). The last joint of the outer branches of the first four pairs of swimming-feet are each provided with a long slender terminal spine, very finely serrate on the outer and ciliate on the inner edge, and also with several long plumose seta; ; the inner branches, which are shorter than the outer, bear two long terminal setse, and a sub terminal one. In the first pair, which differ from the others, the exterior margin of the outer branch is armed with three stout spines and a subterminal spiniform seta, while the interior margin of the inner branch bears three processes resembling somewhat the dilated bases of rudimentary hairs. The inner margin of the second basal joint is also armed with several short spines (fig. IS). Abdomen slender, 3-jointed, the middle segment scarcely half the length of either the first or third. Caudal stylets very slender, once and a half the length of the abdomen, bearing each four long terminal setae, and a small subterminal seta exteriorly, while a moderately long seta springs from the outer margin and near the base of each stylet, as shown in figure 21. Rabitat. Lat. 1° 65' 5" N., long. 5° 55' 5" E., 360 fathoms, tow-net gathering. Collected during the day, January 22nd. Temperatuj-e of the water about 43° F. Lat. 4° 24' 7" S., long. 10 1' 8" E., in tow-net gatherings from 235 fathoms and 185 fathoms. Collected between 11 a.m. and 3.30 p.m., February 5th. Temperature of the water at 200 fathoms 55° E. A considerable number of specimens were obtained in the first of the three ffatherinajs. No males were observed. This species has a close general resemblance to Corymira gracilis, Brady, and I was at first incHued to ascribe it to that genus, but a further study of the structure of the animal showed that there were differences between it and Qorijnura so important as to make its position in that genus untenable (see remarks to description of genus, p. 61). Genus Acartia, Dana. Acartia, Dana, Amer. Journ. Sci. 1846 ; Brady, Report ' Chall/ Coi^ep. 1883. Dias, Lilljcborg, Crust, ex. ord. trib. 1853 ; Glaus, Die freilebend. Copep. 1863 j Boeck, Oversigt Norg. Copep. 1864 ; Brady, Monogr. Brit. Copep. 1878. Acartia laxa, Dana. 1852. Acartia laxa, Dana, Crust. U.S. Expl. Exped. p. 1123, pi. Ixxix. figs. 5 a-c. 1883. Acartia laxa, Brady, Report ' Chall.' Copep. p. 73, pi. xxxii. figs. 1-11. Habited. Station 2, 25 fathoms, tow-netting, January 1st (night collection). Station 9, 50 fathoms, January 10th (day collection). Ofl' Sao Thome Island (lat. 0° 38' 6" N., SECOND SERIES. — ZOOLOGY, VOL. VI. 9 66 ME. T. SCOTT ON ENTOMOSTEACA long. 6° 25' 8" E.), 20 fathoms, January 23rd (day collection). Station 22, 20 fathoms, February 4th (day collection). Lat. 5° 55' 1" S., long. 11° 30' 7" E., surface, Eebruary 18th (night collection), &c. Acartia laxa was observed in 38 tow-nettings, 11 of which were surface and 27 under- surface gatherings. The under-surface tow-nettings ranged in depth from 5 to 235 fathoms. Eour of the surface and 19 of the under-surface gatherings were collected during the day, while 7 surface and 8 u.nder- surface gatherings were collected during the night, as shown in the formula : — f 4 day collections. 11 surface \ ^ -^^^ ^^^^0. Tow-ncttin2:s- 38 ^ , "^ . 27 under-surface \ ^^ "^^^ ^^^"0. J- 8 night ditto. Acartia laxa was of frequent occurrence in nearly all of the tow-nettings in which it was observed. AcAiiTiA DENTICORNIS, Brady. 1883. Acartia denticornis, Brady, op. cit. j). 73, pi. xsxi. fig. 1, pi. xxxii. figs. 12-17. Habitat. Lagoon, Sao Thome Island, surface tow-netting, January 27th (night col- lection). Libreville, Gaboon River, surface, January 28th (day collection). Lat. 4° 40' S., long. 10° 25' 2" E., surface, Eebruary 5th (night collection). Bananah Creek, Congo Ptiver, surface, Eebruary 7th (day collection). Loanda Harbour, surface, Eebruary 13tli (day collection). The distribution of Acat'tia denticornis within the area dealt with in this Report appears to have been more restricted than Acartia laxa ; it was also more confined to inshore and surface gatherings than was that species. It is interesting to note that this apparent preference of A. denticornis for localities more or less inshore is borne out to some extent by the ' Challenger ' records, where the following statement occurs (loc. cit. p. 74) : — " Abundant in Hilo Harbour, Sandwich Islands (August 1875) ; one or two specimens noted in a gathering from the Philippine Islands and (?) in the Atlantic, north of Tristan d'Acunha." Acartia denticornis was obtained in 14 of the ' Buccaneer ' tow-nettings — all of them surface gatherings. Eight of the tow-nettings were day and 6 were night collections. The specific gravity of the water in which it occurred varied from 1*0255 to 1-0087. ACABTIA PLUMOSA, u. sp. (PI. VII. figs. 22-32.) Length 1'2 mm. Body elongate-ovate, somewhat rounded in front; the rounded postero- lateral angles of the last thoracic segment bear a number of small spines. Anterior antennae about as long as the cephalothorax, those of the female 20-jointed and furnished witli numerous plumose setae ; the annexed formula shows the proportional lengths of the joints ; — 18 ■ 11 . lU ■ U . 12 . 8 . 8 ■ 5 . 13 . 11 . 15 ■ 15 . 1.5 ■ ]2 . 14 ■ 15 ■ 10 ■ 18 ■ 10 ■ 8 1 2 3 4 5 6 7 8 y 10 11 12 13 14 15 It) 17 18 19 2o' FROM THE GULF OF GUINEA. 67 The male right antenna is 17-joiute(l ; the 11th, 12th, and 13th appear to be each composed of two coalesced joints, indistinctly hinged between the 12th and 13th joints, both of which are ciliate on the upper margin. On the proximal side of the hinge there is one and on the distal side three short stout spines, as shown in fig. 8. Posterior antennae and mouth-organs as in Faracartia spinicaiidata. The length of the joints of the inner branches of the first pair of swimming-feet is about equal, while the first joint of the outer branch is mvich stouter and once and a half the length of the next. The inner branch of the fourth pair is slender, the first joint of which reaches nearly to the middle of the second joint of the outer branch; the last joint of the outer branch is much smaller than either of the other two joints ; the terminal spines are long and slender (fig. 27). The fifth pair in the female are each furnished with two long setae, one of which is submarginal and plumose and one apical ; the basal part of the plain apical seta is considerably dilated and gibbous (figs. 29, 30). The right fifth foot in the male is much longer than the other, and the penultimate joint, which is shorter than either the preceding or following joints, is produced interiorly into an elongate protuberance ; the last joint of the left foot is armed with a large spine on its inner aspect ; each foot termi- nates in a short stout spine, and the first joint of both is furnished with a long plum se seta on the outer margin (fig. 30). In the abdomen of the female the first segment is about once and a half the length of the next and fully twice the length of the last segment ; the first and second segments are sparingly dentate on the posterior margin (tig. 31). Caudal stylets longer than the last, and nearly as long as the penultimate, abdominal segment ; caudal setae as in Acartia Clausi. The first segment in the male abdomen is considerably narrower than those that follow. The caudal stylets are about three-fourths the length of those of the female and not longer than the last abdominal segment, and furnished with setae as in the female (fig. 32). Habitat. Bananah Creek, Congo River, in a surface gathering collected at noon, Eebi'uary 7th; the specific gravity of the water when the gathering was made was 1"00870 ; and in Loanda Harbour, in two surface gatherings collected in the seaward part of the Harbour during the afternoon of the loth February. The surface temperature of the water was about 79° P. Acartia plumosa somewhat resembles Acartia discandata (Giesb.), especially in the male right anterior antennae and fifth pair of feet, which are quite prominent in adult specimens. Acartia Clausi, Giesbrecht. (PL VII. figs. 33-40.) 1889. Acartia Clausi, Giesbreclit, Rendicouti R. Accad. d. Liucei, vol. v. fasc. 11. 1892. Acartia gahoonensis, Scott (MS. name). Length fully 1 mm. Viewed doi'sally the body is oblong-ovate, the forehead is broadly triangular, almost truncate, with the lateral angles somewhat produced ; the last thoracic segment has the postero-lateral angles rounded. Anterior antennae nearly as long as the thorax, those of the female, which are 21-jointed, are sparingly setiferous, except towards the extremity, where the last five joints bear moderately long plumose setae ; a plumose seta 9* 68 ME. T. SCOTT ON ENTOMOSTRACA also springs from the 8th and 12th joints, counting from the end. The proportional lengths of the joints are nearly as shown in the formula: — 34 ■ 8 . 10 . G ■ 11 . 16 . 14 . 15 . 15 . 13 ■ 11 . 16 . 15 ■ 18 . 15 ■ 15 . 17 . 9 ■ 16 ■ 10 . 6 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21' The jointing of the proximal half of the antennae was somewhat indistinct and required a high power of the microscope and careful focussing to make out the articulations. The right anterior antenna of the male is 15-jointed, and hinged between the 11th and 12th joints; both of these joints are fringed with small teeth on the upper margin, while a moderately stout spine springs from the jiroximal end of the 12th joint (fig. 35) ; the male antennoe are sliorter than those of the female, and are provided with a greater number of plumose setse. The posterior antennae and mouth-organs resemble those of Paracartia spiiiicaudata. The first four pairs of swimming-feet also resemble those of that species. The fifth pair in the female have the apex subtriangular and are each furnished interiorly with an elongate stout spine, serrate on the inner margin of the distal half and exteriorly with a long plumose seta (fig. 31). In the male the fifth pair are com- paratively short and stout, as in Acartia denticornis, Brady ; the proximal joint of each is furnished on the exterior margin with a long plumose seta (fig. 38). Abdomen in the female short, stout, and composed of three segments ; the first is longer than both the other two together, the second is about equal in length to the third ; the posterior margin of the first and second joints is fringed with small teeth. The caudal stylets are some- what longer than the last abdominal segment, and are each provided with six plumose setfB arranged as follows : — one, strongly curved, near the middle of the exterior margin ; one subterminal ; three terminal, tlie middle one being much longer than any of the others ; and one (small) on the lower half and near the inner margin of the stylet. The abdomen in the male is composed of five segments ; the first is rather narrower than the next, and the penultimate one is very short. The stylets are shorter than those of the female, but the number and arrangement of the plumose sette are similar (fig. 34). Habitat. Lil^reville, Gaboon River, in a surface gathering collected at midday, January 28th. The surface temperature of the water was 83°'l P., and the specific gravity 1'02301. This Acartia resembles Acartia denticornis, Brady, in several of its characters, but differs in some important points, especially in the armature and proportional length of the joints of the male right anterior antenna and in the form of the male and female fifth feet and abdomen. Subgenus Paracartia, n. subgen. Near Acartia, Dana, but differing very markedly in the form of the fifth pair of feet, wliich in the female are each armed with a stout curved spine ; in the male the fifth pair are large and unsymmetrical, that of the left side being about half the length of the right ; the male right antenna has also the joints of the proximal half somewhat tumid, as in Pontella. FEOM THE GULF OF GULS'EA. 69 PaRACARTIA SPINICAUDATA, 11. sp. (PL VIII. figs. 1-11.) Female. Length 1-25 mm. Ceplialotborax elongate, rather tumid, rounded in front, the postero-lateral angles of the last thoracic segment acute. Anterior antenna as long as the cephalothorax, 20-jointed, and hearing a number of long plumose setaj distrilnited as follows— one on each of the 2nd, 3ixl, 1th, 8th, 9th, 10th, 13th, 15th, IGth, and 18th joints, two (one smaller than the other) on the 19th, and five on the last joint. The 7th joint is about as long as all the preceding three together ; the 12th and last joints are shorter than the others. The proportional lengths of the joints are nearly as in the annexed formula : — 30 . 16 ■ 9 . 13 . 11 . 9 . 30 ■ 15 . 10 . 15 . 15 . 12 . 6 . 14 ■ 12 . 16 . 13 ■ 15 ■ U ■ 7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20" Posterior antennae, mouth-organs, and first four pairs of swimming-feet as in Acartia luxa, except that the last joint of the outer branch of the first swimming-feet has the lower exterior surface setose. Pifth pair of feet small, 1-branched, the basal part short and tumid and furnished Avith a stout curved spine, the distal half of which is strongly toothed on both margins ; exteriorly and close to the spine and about a third of its length is a small plain seta ; the right and left branches are alike. Abdomen short, 3-jointed ; tlie first segment is somewhat triangular in form and has the distal end fully twice the breadth of tlie next segment ; it is also longer than both the second and last segments together. Caudal stylets short and broad, rather longer than the last abdominal segment, each stylet armed with a prominent and strong terminal spine and two setae, one on each side of the spine ; there are also two setse on the exterior margin of the stylets, and a third, Avith a distinct basal part, a little above the inner of the two terminal setae. The terminal spines, which are about double the length of the stylets, and all the setae, except the one last described, are plumose. Rubltat. Eananah Creek, Congo Eiver, in one surface tow-nettiug collected at noon and in another collected at 4.30 p.m. February 7th, 1886. Several specimens, all females, were obtained in these two tow-nettings. The more obvious characters which serve to distinguish this species are the fifth feet and the peculiar form of the abdomen. Pakacautia dubia, n. sp. (PL VII. tigs. 41, 42 ; PL VIII. figs. 12-15.) Male. Length about 1-2 mm. Body elongate, broadly subtriangular in front, and rounded posteriorly, composed of five segments ; head indistinctly separated from the thorax. Anterior antennae about as long as the body, that of the left side provided with a number of moderately long setae, 20-jointed, the proportional lengths of the joints being nearly as shown in the formula : — 16 ■ 14 ■ 6 ■ 5 ■ 5 . 8 . 10 . 10 . 12 . 11 ■ 9 ■ 20 ■ 20 . 15 . 12 . 16 . 11 . 18 . 10 . 8 ~1 2" 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18^ 19 20" The proximal half of the right antenna, which bears several long plumose hairs, has the lower portion somewhat dilated ; there is a hinged articulation between the fifth 70 ME. T. SCOTT ON ENTOMOSTEACA and sixth joints, counting from the end. The sixth joint, which is nearly as long as the remaining' portion of the antenna, has a rounded excavation on the upper edge and near the proximal end; the lower side of the excavation is produced into a stout tooth-like lobe ; the fifth joint, still counting from the end of the antenna, is about half the length of tlie preceding, and bears a styloid process on its upper margin and a long plumose seta at the upper distal angle ; the ultimate and penultimate joints are also furnished Avith a number of long plumose setae (PI. VII. fig. 42). The posterior antennae and mouth-organs as in Paracartia spinicaudata. The first four pairs of swimming-feet similar to those of Acartia. The fifth pair is largely develojied, that of the right side large, 4-jointed, the first and second joints stout, the other two slender, elongate; the fourth joint appears as if it were articulated to the side of the third. There is a stout digitiform process on the inner side of the upper half of the second joint, and near the middle of the third joint the outer margin is produced into a bluntly triangular lobe ; the last joint bears an apical appendage, the basal part of which is tumid, the extremity slender and setiform. The right foot has an inner rudimentary second branch composed of one joint about equal in length to the first joint of the outer branch. The left foot, which is stout, scarcely reaches to the middle of the second joint of the principal branch of the right foot, and appears to be 3-jointed ; the second joint is furnished with a membraneous, curved (?) sexual process, as shown in figure 9. Abdomen composed of five segments, the first short, of greater width than the next, the outline of the sides rounded (PL VIII. fig. 15) ; the second and third joints are long, while the combined length of the fourth and fifth is scarcely equal to the third. The stylets are somewhat longer than the last abdominal segment, and have the third apical seta, counting from the outside, considerably longer than any of the others. Habitat. Loan da Harbour, in material collected with surface tow-net, on the afternoon of Pebruary 15th. Several specimens, males only, were obtained. As females only of Paracartia spinicaudata, and males only of P. dubia, were obtained in the tow-net gathering from Loanda Harbour, it is just possible that they may both belong to the same species, but the difference between the two is so considerable and so marked that it seems better, for the present at least, to describe them under separate names. A species described and figured by I. C. Thompson in the ' Proceedings of the Liverpool Biological Society,' vol. ii. p. Ill (1888), as Acartia verrucosa, resembles somewhat the Paracartia spinicaudata of this Report ; but the difference in the form of the fifth feet and in other important details is great enough to render them at least specifically distinct. Genus iEiiDius, Brady. Aitidtus, Brady, Report ou the Copepoda of the ' Challenger' Expedition, 1883. J^TiDius AiiMATUS, Brady. 1883. ALitdhis armatus, Brady, Report ' Chall.-" Copep. p. 7G, pi. x. figs. 5-16. Habitat. Station 2, 5 fathoms tow-netting, January 1st (night collection). Lat. 3° 58' FEOM THE GTJLF OF GUINEA. 71 N., long. 3° 42' W., 50 fathoms, January 13tli (day collection). Lat. 3° 55' 3" N., long. 4° 7' 3" E., 30 fathoms, January 20th (day collection). Off Sao Thome Island (lat. 0" 34" N., long. 6'' 31' 6" E.), 20 fatlioms, January 23rd (day collection). Station 3, 135 fathoms, Fehruary 5th (day collection). JEtidius armatus occurred in 19 toAV-nettings, all of which -were under-surface col- lections and ranged in depth from 5 to 460 fathoms ; 2 of the tow-nettings were collected during the night, the other 17 were day collections. With one exception, all the tow-nettings were from 20 fathoms or more, and eleven of them from 50 fathoms and over. The difference between the bathymetrical distribution of this species and of Acartia denticornis is very marked, the Acartia having been observed only in surface gatherings. The distribution of ^tidius was nearly coextensive with the area examined, aud in some of the tow-nettings it was of comparatively frequent occurrence. The strong curved rostrum, and the sj)inous and strongly produced lateral angles of the last thoracic segment, are so conspicuoiis as to make the species readily distinguished from other Copepoda. It was obtained at five of the ' Challenger ' stations, one of which (Station 348, lat. 3 10' N., long. 14 51' W.) was in the vicinity of the area traversed by the ' Buccaneer.' iETiDius ARMiGER (Gicsbrecht). (PI. VIII. figs. 16-27.) 1892. Gaetanm armiger, Giesbrecht, Fauna und Flora des Golfes von Neapel (Copepoden), p. 224, pi. xiv. figs. 19, 20, 22, 26, 28, pi. xxxvi. figs. 2, 6. Female. Length, exclusive of tail-setae, 2*6 mm. (about 1-lOtli of an inch). The male is rather smaller than the female. Body robust, composed of four segments, the first segment more than twice the entire length of the other three, rounded anterioi-ly and furnished with a prominent sharp-pointed rostriim. The postero-lateral angles of the last thoracic segment are produced backward into spiniform processes as long as the first abdominal segment. Anterior antennae reaching to the extremity of the abdomen, alike in both sexes, and composed of 24 joints, which are sparingly setiferous ; the prof brtional lengths of the joints nearly as in the formula : — !) ■ (i ■ 3 ■ 3 ■ 3 ■ 3 ■ 4 ■ 0 ■ .3 ■ .3 . 4 ■ 6 ■ .5 ■ 6 . 7 ■ 7 ■ T ■ t) ■ 8 ■ 7 . 8 ■ 8 . 7 . 3 1 1' 3 4 5 (i 7 8 'J 10 11 12 13 14 1-5 16 17 18 19 20 21 22 23 24' The basal joint of the posterior antennte wants the three setae shown in Brady's figure of u'Etidiiis armatus ; the first joint of the secondary branch is small, the second larger, the third, fourth, and fifth small and bearing each a long plumose seta ; the sixth joint is fully one third the length of the whole branch, and furnished with one plain and three long plumose terminal setae. Mandibles and maxillae as in ^E. armatus ; one of the two, small intermediate digits of the maxilla-palp terminates in a spiniform plumose seta. Foot-jaws also similar to those of ^TJtidius armatus, except that the two outer marginal lobes of the anterior foot-jaw terminate each in a stout elongate spine, ciliate on the inner edge ; and the inner distal angle of the basal joint of the second foot-jaw forms a blunt, rounded process, the end of wliich is ciliate and bears a few setae (fig. 22). The 72 MR. T. SCOTT ON ENTOMOSTRACA lirst four pairs of swimming-feet resemble those of ^tidius armatus, except that the second joint of the inner branch of the second pair is shorter than the other. Fifth pair in the male small, each composed of a basal joint and two 1-jointed branches ; the outer branch is comparatively large and bears two small unequal teeth at the extremity ; the inner branch is small and rudimentary, with a rounded end. Abdomen in both sexes composed of five (?) segments, the last segment very small, the other segments in the male al)domen subequal ; in that of the female the first segment is large and tumid, the second smaller, while the third and fourth are about equal and smaller than the second. Caudal stylets short and broad, and furnished with four long and two very small terminal plumose setse. HaUtat. Lat. 1° 55' 5" N., long. h° 55' 5" E., 360 and 460 fathoms, January 22nd (day collection). Station 23, 135 fathoms, February 5th (day collection), ^tkl'ms armiger, of which only two or three specimens have been obtained, is quite distinct from ^. armatus, being readily distinguished by the difference in the form of the male fifth feet, and by the peculiar spiny armature of the forehead and last thoracic segment. Genus Clausocalanus, Giesbrecht, 1888. Drepanopus, Brady (in part). Clausocalanus fukcatus (Brady). 1883. Drepanopus furcatus, Brady, Report of the ' Challenger ' Copepoda, p. 77, pi. iv. figs. 1 & .2 ; pi. xxiv. figs. 12-15. 1892. Clausocalanus furcatus, Giesbrecht, Fauna und Flora des Golfes von Neapel (Copepodeu) , p. 194, pi. xxxvi. figs. 32, 33, 35. Hahltat. Station 2, 25 fathoms (night collection), January 1st. Lat. 3° 58' N., long. 3° 42' W., 25 fathoms (day collection), January 13th. Off Sao Thome Island (lat. O'^ 34' N., long. 6" 30' 4" E.), 10 fathoms, January 23rd (day collection). Station 23, 10 fathoms, February 5th (day collection). Lat. 6° 39' 5" S., long. 11° 24' 7" E.. surface, February 8th (night collection), &c. This species occurred in 20 tow-nettings, 3 of which were surface and 17 under-surface gatherings. The under-surface gatherings were from various depths ranging from 2^ to 50 fathoms. The 3 surface tow-nettings were night collections ; 11 of the under- surface were day and 0 were night collections, as shown by the formula : — rno day collections. ..• onf ^'^'"^^^^ I 3 night ditto. Tow-nettmgs 20< ^„ , "^ ,., 1 17 under-surface Pl ^^^y ^1^*^. L 6 nisht ditto. Clausocalanus latipes, n. sp. (Provisional name.) (PL VIII. figs. 28-37.) Female. Anterior antennse long and slender, provided with a very few short setae and FEOM THE GITLF OF GUINEA. 73 composed of 23 joints, the proportional lengths of the joints being nearly as shown in the formula : — 3.5.2.2.2.2.2.4.2.2.3.3.4.4.4.4.4.4.4.4.4.5.6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 iTTS 19 20 21 22 23' The posterior antennae nearly as in Drepaiwjms pectinalas. Mandibles well developed, strongly dentiferous on the biting-edge, and furnished with a large two-branched palp one branch being 2-, the other '1-jointed (fig. 29). Anterior foot-jaws 4-jointed, the last two very small; marginal lobes six, tive of tliem large, each with two (or three) plumose terminal setae; the other small, forming the base of a single plain seta; three plain sette spring from the last joint of this foot-jaw. The posterior foot-jaws are 7-jointed ; the first and second joints are large, subequal, and longer than the entire length of the next three ; the third to the last joints are small and furnished with a few plumose hairs (fig. 31). First pair of swimming-feet similar to those of Drepanopus pect'matits, but there are longer spines on the outer distal angles of the first two joints of the outer branch, and the inner distal angle of the second basal joint tei'minates in a short spine instead of a plumose hair. The three following pairs are also similar to Drepanopvs pectinatus, except that the distal margin of the second basal joint is strongly denticulated in the second pair, and in the third 2iair is furnished with a few large spiuiform teeth ; the tei'minal spines of the outer branches are long and broad, and finely serrate on the outer margin. The fifth pair are robust, simple, and composed of two 2-jointed branches of unequal length ; in the short branch the last joint is much smaller than the other and terminates in three conical tooth-like prolongations ; in the other branch, which is at least twice the length of the short one, the last joint is rather longer than the first, and bears a small spine near the middle of the outer margin and three spiniform teeth at the extremity (fig. 35). The abdomen is composed of four segments, the first longer tlian the others, the next two subequal, the last small. Caudal stylets about as long as the last abdominal segment and bearing four plumose terminal hairs. Habitat. Lat. 1° 55' 5" N., long. 5° 55' 5" E., 35 fathoms. One specimen only of this species has been obtained ; it appears to be a female. While agreeing with Drepanopxis in its more important details of structure, Clausocalanus latipos differs from both the species described in the Report on the ' Challenger ' Copepoda, especially in the number and proportional length of the joints of the anterior antennae autl in the form of the fifth feet. It agrees in some respects with Clausocalanus furcatus, Brady, but in that species, the inner branches of the second pair of swimming- feet are 1-jointed, the fifth pair and the anterior antennae also differ cousideraljly, so that for the present it seems better to consider the species as distinct. Clausocalanus aecuicornis (Dana). (PI. VIII. figs. 38-47.) 1849. Calanus arcnicornis, Dana, Amer. Journ. Sc. vol. viii. 1892. ClauavcaJa litis arcuicornis, Giesbrecht, op. cit. p. 193, pis. ], 2, 10, 3G. Length, not including tail-setae, 1-3 mm. Body elongate, composed of five segments, SECOKD SEIUES. — ZOOLOGY, VOL. VI. 10 74 ME. T. SCOTT ON ENTOMOSTEACA the first nearly tAvice t)ie entire length of the other four. Porehead rovinded, produced into a sniall, sharp-pointed rostrum. Anterior antennre slender, as long as the cephalo- thorax, 20-jointed, and sparingly setiferous, the proportional lengths of the joints as in the formula : — 34 . 4. 4. 4. 4. 3.3. 4.4.4. 4. 10 . 16 . 10 . 12 . 12 . 18 . 15 . 18 . 22 "T 2 3 4 5 0 7 « 0 10 11 12 13 14 1-5 16 17 18 19 20' The first joint is stout and long, and the second considerahly broader than those immediately following. The primary branch of the posterior anteunfe is short and 2-jointed ; the secondary branch is fully twice the length of the other, and composed of six joints ; the second joint is long and about equal to the entire length of the next four ; the third, fourth, and fifth joints are very small (fig. 39). Mandible-palp small, one branch is 4-, the other 2-jointcd (fig. 40). Maxillte nearly as in Brepanoiyus j^ectiiuctiis. Anterior foot-jaw very small, with four (or five) marginal setiferous lobes. Posterior foot-jaw small, 7-jointed, and bearing a few spinous setoe ; the first and second joints are elongate, the third short, the fourth about twice the length of the third, the fifth about equal to the third and as long as the next two together (fig. 44). The first four pairs of swimming-feet resemble those of Drepanopus pectinatns, except that the first two joints of the outer branch of the first pair have no spines on the exterior distal angles. The fifth pair are simple and consist of one very short 2-jointed In'anch, and one which is long and 4-jointed ; the last joint of the short branch is very small and terminates in three small spines ; the extremity of the long branch terminates on one side in a digitiform lobe, which is opposed by a finger-like process, articulated to the l)asal part of the lobe ; both are fringed wdth fine cilia (fig. 45). Abdomen 5-jointed, the last segment very small. Caudal stylets short, length about equal to the breadth, each furnished with four plumose terminal seta?. Habitat. Station 2, 50 fathoms, January 1st (night collection). Station 9, 50 fathoms, January 10th (day collection). Lat. 3^ 58' N., long. 3° 42' W., 25 and 50 fathoms, January 13th (day collection). Off Accra, 3 fathoms, January 16th (night collection). Lat. 1° 55' 5" N., long. 5° 55' 5" E., 3C0 fathoms, January 22nd (day collection). Off Sao Thome Island, 20 fathoms, January 23rd (day collection). Males only of this species were obtained. Genus Phylloptjs, Brady. Phyllopus, Bi-ady, Report on the Copep. of tlie Chall. Exp. 1883. Phylloptjs bidentatus, Brady. (PL \1. figs. 26-28.) 1883. P/tyllopus bkkntatus, Brady, Report Cluill. Copep. p. 78, pi. v. figs. 7-14. Habitat. Station 2, 5 fathoms, January 1st (night collection). Lat. 1° 55' 5" N., long. 6° 55' 5" E., 360 fathoms, January 22ud (day collection). Temperature of water at 360 fathoms about 43' E. Three specimens only of this curious form were obtained, and they were all more or FEOM THE GULF OF GUINEA. 75 less damaged ; two of them were carefully dissected, from tliese dissections figures have been prejiared of a few of the more important details, not represented in the ' Challenger ' Report. I have also been enabled to add tlie following description : — Secondary branch of the anterior antennfe nearly twice the length of the primary branch, 8-jointed, the last nearly as long as the preceding six joints, and furnished with four terminal hairs. Both branches of the first four pairs of swimming-feet 3-jointed, the middle joint of the outer branch of the first pair shortest, bearing a comparatively long, slightly curved, setiferous spine on the exterior distal angle ; the last joint has two shorter and more slender spines on its outer margin, and a long slender terminal spine, both branches furnished with numerous, long, plumose setse. In the second, tiiird, and fourth pairs the inner are much shorter than the outer branches ; the three joints of the outer branches are each armed with a stout dagger-like spine at tlie outer distal angles ; the last joint has two similar additional spines inserted in excavations of the outer margin, and a broad falciform terminal spine, finely serrate on the outer margin ; both branches are well furnished with plumose seta3. The fifth pair in the female resemble the figured example in the ' Challenger ' Report, but theii* form seems to vary somewhat in different specimens, both as regards the serration of the last joint, and also the comparative length and breadth of the joints. Abdomen in the female 4-jointed, first joint much larger than the others and dilated. Caudal stylets short, not divergent, each with five long, plumose terminal sette, the second from the inside longer than the others. The mouth is a short tube ; the front part projects outward and backward so as to form an oblique opening. The edge of the upper part of the tube has a dense fringe of hairs, which can be readily observed if tlie specimen be in a favourable position. Judging from a careful examination of the ' Buccaneer ' specimens, I am inclined to think that the figures in the ' Challenger ' R-eport represent a female instead of a male. Genus Temora, Baird. Temora, Baird, Brit. Entomostraca, 1850. Diaptoinus, Lubbock, Trans. Eutoin. Soc. 1856. Temora stylifeka (Dana). 1849. Calanus stylifer, Dana, Amer. Joiu"n. Sci. vol. viii. 185G. D'utptomus dubius, Lubbock, Trans. Entom. Soc. vol. iv. n. s. p. 21, pi. ii. figs. 1-7. 1883. Temora dubia, Brady, Report Cliall. Copep. p. 79, pi. xxv. figs. 1-17. Kahitat. Station 2, surface and 25 fathoms, January 1st (night collections). Station 9, 25 fathoms, January 10th (day collection). Station 11, 10 fathoms, January 19th (day collection). Lat. 1° 55' 5" N., long. 5° 55' 5" E., 360 fathoms, January 22nd (day collection). Lagoon, Sao Thome Island, surface, January 27th (one day and one night collection). Libreville, Gaboon River, surface, January 28th (day collection). Station 23, 10, 20, 135, and 185 fathoms, Pebruary 5th (day collections). Bananah 10* 76 MR. T. SCOTT ON ENTOMOSTEACA Creek, Congo Pviver, surface, February 7th (two day collections). Lat. S'' 55' 1" S., long. 11° 30' 7" E., February 18th (night collection). Temora stylifera was observed in 105 tow-nettings, 61 of them surface and 4-1 under- surface gatherings : of the surface gatherings 25 were collected during the day and 36 during the night ; of the under-surface gatherings, which ranged in depth from 2 to 360 fathoms, 37 were collected during the day and 7 during the night, as shown by the annexed formula : — r 25 day collections. ... . n- r^^ '"'^''''^ 1 36 night ditto. Tow-nettmgs 10o{ r^n a v,, 1 44 under-surface (37 day ditto. 1. 7 night ditto. This was one of the more common and generally distributed species in the ' Buccaneer ' collection ; it also appears to be one of the most common of the extra-European Copepoda. Temora longicornis (Muller). (PI. VII. fig. 47.) 1785 ?. Cyclops longicornis, Muller, Eiitom. p. 115, t. xix. figs. 7-9. 1850. Temora finmarchica, Baird, Brit. Eiitom. p. 228, pi. xxviii. figs. 1 a-g. 1849?. Calanus turbinatus, Dana, Amer. Journ. Sc. vol. viii. 1857. I>iaptomus longicaudatus, Lubbock, Aun. & Mag. Nat. Hist. ser. 2, vol. xx. pi. x. figs. 11, 12; pi. xi. figs. 12, 13. 1878. Temora longicornis, Brady, Monogr. Brit. Copep. vol. i. p. 54, pi. iii. figs. 10-19. Bahitat. Lat. 7° 33' N., long. 15° IS' W., surface, midnight, January 2nd. Station 9, 50 fathoms, January 10th (day collection). Off Accra, 3 fathoms, January 15th (night collection). Same locality, January 16th, surface, night collection, and 3 fathoms, day collection. Lat. 1° 55' 5" N., long. 5° 55' 5" E., 35 and 460 fathoms, January 22nd (day collections). Libreville, Gaboon lliver, surface, January 28th (day collection). Bananah Creek, Congo River, surface, February 6th (day collection). Loanda Harbour, surface, February 13th (day collection), and again on the 15th in the seaward part of the Harbour, also surface (day collection). Lat. 5° 40' 8" S., long. 11° 33' 4" E., surface, February 19th, &c. (day collection). This Temora was observed in 57 tow-nettings, 40 of which were surface and 17 under- surface gatherings ; 16 of the surface gatherings and 12 of the under-surface were day collections, while 24 surface and 5 under-surface were night collections, as shown by the formula : — r 16 day collections. ,,. ^ rlOs^ii-foce 1 24 night ditto. Tow-nettmgs 57 < ^ , ,. b7 under-surface (12 day ditto. I 5 night ditto. The under-surface tow-nettings were from depths ranging from 3 to 50 fathoms, and one from 135 and another from 460 fathoms. Temora longicornis was not only generally distributed throughout the area examined, FEOM THE GULP OF GUINEA. 77 but was a moderately common sjiecics in some of the tow-nettings in which it occui-red. This species is readily distinguished from either Temora slylifera (Dana) or Temora armata, Claus, by having the last thoracic segment in both sexes rounded at the postero-lateral angles. The first pair of swimming-feet have the inner branches more or less distinctly 2-jointed. The male fifth pair (fig. 1-7) differ somewhat from the same pair of feet in British specimens, but otherwise the ' Buccaneer ' specimens agree with those of the British seas. Genus Centropages, Kroyer. Centropaijes, Kroyer, Nat. Tidskr. 1849 ; Boeck, Oversigt Norges Copep. 18G4 ; Brady, Monogr. Brit. Copep. 1878. Caiopia, Dana, Proc. Amer. Acad. Sci. 1819. Calano/iid, id. (in part) Crust. U.S. Expl. Exped. IS.oS. Ichthyophorba, Lilljeborg, De Crust, ex. ord. trib. 1853; Claus, Die freilcbendcn Copepoden, 1803. Centropages epvAchiatus (Dana). 1852. Calanopia brachiutu, Daua, Crust. U.S. Expl. Exped. p. 1133, pi. Ixxix. figs. 7 a,h. 1883. Centropages brachiatiis, Brady, Report Cliall. Copep. p. 82, pi. xxvi. figs. 1-7. KaUtat. Lat. 7° 33' N., long. 15° 18' W., surface, January 2nd (midnight collection). Lat. 5° 10' N., long. 2," 5C' 2" AY., surface (close inshore), January 12th (night collection). Station 21, surface, February 4th (day collection). Station 23, 20 fathoms, February 5th (day collection). Bananah Creek, Congo Ptiver, surface, February 7th (two day collec- tions). Loauda Harbour, surface, February 13th (day collection). Centropucjes brachiatus was observed in 37 tow-nettings, comprising 28 surface and 9 under-surface gatherings. The under-surface tow-nettings included two at 3 fathoms, two at 10 fathoms, one at 20 fathoms, two at 25 fathoms, and two at 50 fathoms. 14 of the surface and G of the under-surface gatherings were day collections, while 14 surface and 3 under-surface were night collections, as shown by the formula : — r 14 dav collections. ..• ^.r-8«"^"^^«^ 1 14 night ditto. Tow-nettmgs 3/< "l ^. ^ '^ ^.^^ l 9 under-surface I & clay ditto. I 3 night ditto. This, thotigh occurring in a considerable number of tow-ncttings, was by no means a common species. The size of the ' Buccaneer ' specimens agreed with those of the 'Challenger' collections, viz. 8-lOOths of an inch=about 2 mm. (not 4-4 mm. as stated in the ' Challenger ' Report). Centropages fifrcatus (Dana). 1852. Catopid furcata, Dana, Crust. U.S. Expl. Exped. p. J 173, pi. Ixxix. figs. 1 a-d. 1883. Centropages fur catus, Brady, Report Cliall. Copep. p. 83, pi. xxviii. figs. 1-11. Bubltat. Lat. 7° 33' N., long. 15° 18' W., surface, January 2nd (midnight collection). Lat. 5° 10' X., long. 3° 56' 2" AV., surface (close inshore), January 12th (night collection). 78 ME. T. SCOTT ON ENTOMOSTEACA Lat. 1° 55' 5" N., long. 6° 56' 5" E., 10 and 30 fathoms, January 22ncl (day collections). Libreville, Gaboon River, surface, January 28th (two day collections). Lat. 5° 5G' 5" S., long. 11° 17' 2" E., surface, Eebruary 8tli (night collection). Loanda Harbour (seaward), surface, Eebruary 1-Jth, &c. (day collection). This Centropages was observed in 49 tow-nettings, 33 of whicli were surface and 16 under-surfaee gatherings ; 11 of the surface and 11 of the under-surface tow-nettings were day collections, and 22 surface and 5 under-surface were night collections, as shown by the annexed formula : — 11 day collections. I 122 T H- ,^ r^^ ^^^^'^^^^ 1 22 night ditto, low-nettings 19 < «. & Lie under-surface | ^^ ^^y ditto. (. 5 night ditto. The under-surface tow-nettings were from depths ranging from 3 to 50 fathoms. This species can be readily distiuguished, even in the immature stages, by the characteristic ai'mature of the last thoracic segment. Centropages violacetjs (Claus). 1863. Ichthi/ophorba violacea, Claus, Die freilebenden Copep. p. 199, pi. xxxi. figs. 13, 14. 1883. Centropages violaceus, Brady, Report Cliall. Copep. p. 83, pi. xxvii. figs. 1-14. Habitat. Station 2, 50 fathoms, January 1st (night collection). Station 9, 25 fathoms, January 10th (day collection). Off Sao Thome Island (lat. 0° 32' 7" N., long. 6° 31' 6" E.), 10 fathoms, January 23rd (day collection). Lat. 1^ 47' 7" S., long. 8° 21' 3" E., surface, Eebruary 4tli, &c. (night collection). Centropages violaceus was obtained in 11 tow-nettings, one of which was a surface (night) gathei'ing, and the other 10 under-surface gatherings ; G of the under-surface gatherings were day, and 4 were night collections, as shown by the formula : — r 0 day collection. r 1 surface 1 i uight ditto. Tow-nettmgsll<^ r ^ n n r 1 10 under-surface/^ 'W collections. I 4 night ditto. Eour of the under-surface gatherings were from 10 fathoms, two from 15 fathoms, one from 20 fathoms, two from 25 fathoms, and one from 50 fathoms. This Centropages was much rarer in the ' Buccaneer ' collections than the other two species recorded in the ' Challenger ' collection. On the other hand, it was the more common of the three species of Centropages observed by Dr. Brady. Centropages violaceus differs from the other two species in having the postero-lateral angles of the last thoracic segment rounded oflP instead of being produced into spinous processes. No indication of colour could be detected in the ' Buccaneer ' sijecimens. Tliis was probably due to their long immersion in spirit, which had extracted the colour characteristic of the species. FROM THE GULF OF GUINEA. 79 Genus Temokopia, n. gen. (Provisional name.) Anterior antennae ? 22- or ? 23-jointed ; the right antenna of the male 19-joiuted, hinged between the 15th and 16th joints. Posterior antenn!3e and mouth-organs as in Calanus. Inner branch of the first pair of swimming-feet 2-jointed, of the second, third, and fourth pairs 3-jointed. Pifth pair in the female simple, alike on both sides, and each composed of a single 3-jointed branch ; in the male the fifth pair, which are prehensile, and each composed of a single branch, are large and conspicuous. The female abdomen consists of four and the male of live segments ; the first segment in the female is considerably dilated. Temoropia mayumbaensis, n. sp. (PL VIII. figs. 18, 49 ; PL IX. figs. 1-12.) Length '93 mm. Body elongate-ovate, composed of five segments ; the first segment, which is about as long as the combined length of the next three, is indistinctly articu- lated at the upper half. Porehead broadly triangular. Anterior antennae of the female ? 22- or ? 23-jointed.* The right anterior antenna of the male scarcely reaches to the end of the thorax, is sparingly setiferous, and 19-jointed, constricted between the 11th and 12th, and hinged between the 15th and 16th joints ; the proportional length.s of the joints as in the formula : — Male : 30 . 10 . 8 . 8 . 9 . 6 . 7 ■ 8 . fl . 9 . 14 . 27 . 11 . 12 . 27 . 28 . 17 . 15 . 22 Eight anterior antenna. ^ 2 3 4 5 0 7 8 9 10 11 11' 13 14 15 10 17 18 19 ' Posterior antennae and mouth-organs as in Calanus. The inner branches 6f the first pair of swimming- feet are 2-joiuted ; the inner branches of the second, third, and fourth pairs 3-jointed ; the first joint is short, while the last is equal to the combined length of the preceding two joints. Pifth pair of feet in the female simple, each composed of a single 8-joiuted branch, one branch being rather longer than tlie other ; the first joint in both is somewhat dilated ; the inner distal angle of the second joint is furnished with a spiniforra seta nearly as long as the last joint ; the last joint has a conical and pointed extremity with a small tooth-like process on the inner margin. The fifth pair in the male is large and conspicuous ; tlie right foot is composed of two moderately large joints, which decrease in breadth towards the extremity, and terminates in a long slender curved spine. The left foot, which consists of three broad joints, has an excavation at the apex in Avhich the terminal sjjine of the foot probably interlocks, wliUe a long curved spine springs from the end of the first joint (PL IX. fig. 9). The abdomen in the female consists of four, in the male of five, segments; the first segment in the female is considerably swollen, and is produced ventrally and posteriorly into a large rounded process (PL IX. fig. 10). Caudal stylets short, each furnished with three stout plumose terminal seta3, and a small seta on the inner margin. Habitat. Lat. 1° 55' 5" N., long. 6° 55' 5" E., 35 and 360 fathoms (day collections). Station 23 (lat. 1° 26' 7" S., long. 10° 1' 8" E.), 235 fathoms (day collection). * The basal portions only of the anterior antenn;e of all the females, and of tho left antenna of all the males, remain iutact ; tboy were broken off, mostly, at the end of the eighth joint; but, judging from the number of joints in the male right antenna, the female antenme probably consist of twenty-two or twenty-three joints. 80 MR. T. SCOTT ON ENTOMOSTRACA About twenty specimens of this species were obtained in tow-nettings from the localities described ; tlie specimens were all more or less imperfect, especially tbe anterior antennae and swimming-feet. The specific name has reference to Mayuraba, a place on the coast near Station 23, one of the two localities where the species was obtained. Genus Mectnoceba, I. C. Thompson (1888). 1888. Mecynocera, I. C. Thompson, Jouru. Liun. Soc. (Zoology) vol. xx. p. 146. Mectnocera clatjsii, I. C. Thompson. (PI. I. figs. 27-3i ; PI. II. 7-10.) 1888. Mecynocera clausii, I. C. Thompson, Jouni. Linn. Soc. (Zoology) vol. xx. p. 140, pi. xi. figs. 1-4. Length fully 1 mm. Female somewhat longer than the male. Body elongate, slender. Cephalothorax composed of six segments ; viewed dorsally the first is almost cylindrical ; forehead somewhat angularly rounded ; the postero-lateral angles of the last segment are rounded. Anterior antennae fully twice the length of the animal, slender, 2i-jointcd ; the Kith to the 20th joints are considerably longer than any of the others ; several of the middle joints of both antennce in male and female are provided with longitudinal rows of small spiniform teeth ; two, or even three, rows were observed on some of the joints, on others only one row ; the antenna; are sparingly setiferous (PI. I. fig. 31). The annexed formula shows the proportional lengths of the joints : — 7 . 14 . 7 . 7 . 7 . 7 . 7 . 12 . 12 . 10 . 12 . 13 . 14 . 17 . 18 . 22 . 24 . 29 . 26 . 24 . 18 . 12 . 8 .14 1 2 3 4 .5 6 7 S 9 10 11 12 13 14 15~10 17 18 19 20 21 22 23 24" The basal joint of the posterior antennoe stout, primary branch 2-jointed (exclusive of the basal joint), the first being nearly a third longer than the other; secondary branch 7-jointed ; the second joint is longer than the first, and nearly equal to the entire length of the next four ; the tliird to the last joints very short (PI. I. fig. 30). Mandible-palp well developed, 2-branched, basal part stout, distally narrowed and jiroduced to form the base of the 1-jointed branch ; the second branch, which occupies a submarginal position, is ^-jointed (PL II. fig. 7). Poot-jaws and swimming-feet nearly as in RJdncalanus, except that the inner branches of the first swimming-feet are 1-joiuted, the inner branches of the second, third, and fourth pairs are 3-jointed ; the exterior distal angles of the joints of the outer branches are armed with short stout spines which are curved inwardly ; the last joint of the outer branches of the fourth paix has a similar spine on the exterior margin (PL I. fig. 33) ; the outer branches of all the first four pairs possess long delicate terminal spines. Tlie fifth ])My are 1-branched, alike on both sides and in both sexes ; basal portion 2-jointed, not much stouter than the terminal portion, which is 3-jointed. There is, so far as could be observed, no terminal spine. Caudal stylets somewhat divergent, and about two thirds the length of the last abdominal segment ; caudal setae four, long, plumose. Habitat. Station 2, 25 fathoms, collected January 1st. Lat. 6" 31' N., long. 12' 39' W., surface, collected January Gth. Lat. 1. 31' G" N., long. & H 4" W., 50 fathoms, collected FEOM THE GrLF OP GUINEA. 81 January lltli. Oflf Sfio Thome Island (lat. 0° 34' N., long. & 30' i" E.), 20 fathoms, collected January 23rd. Lat. 4 26' 7" S., long. 10 1' 8" E., 235 fathoms, coUcctcd February 5th, etc. Meci/nocera Clausii Avas observed in 16 of the tow-net collections, 1 only being a surface gathering; the deepest under-surface gathering in which it was observed was 235 fathoms. 1 day collection. r 1 ciay coueciic 1 surface | 0 night ditto. Tow-nettings 16s. ^ -, ^ . ,, ,. 1 15 under-surface/ ^^ '% collections. I 3 night ditto. The ' Buccaneer ' specimens of this species differed from Ilecynocera Clausii, I. C. Thompson, as described and figured in the ' Transactions ' of the Linneau Society, vol. xs. p. 150, pi. xi. tigs. 1-1. Ilecynocera Clavs'd is there described as wanting a fifth pair of feet, whereas the ' Buccaneer ' specimens possess a fifth pair large enough to be easily observed without requiring to dissect the animal to see them. Genus Phaenna, Glaus. Phaenna, Claus, Die freilebenden CopejDodeu, 18(53. Phaenna spinifeea, Glaus. (PL VI. fig. 35 ; PI. VII. figs. 1, 2.) 1863. Phaenna spinifera, Clans, Die freilebenden Copepodeu, p. 189, pi. xxxi. tigs. 1-7. Length 2'25 mm. Body globose (breadth about 1"1 mm.), composed of five segments, the first rather longer than the next two together. Anterior antennae as long as the cephalothorax, 2i-jointed. The proportional lengths of the joints are very nearly as shown in the formula : — 10 .4. 3. 4. 4.4. 4. ■> .4.4. 4. 6.7.9. 9. 9. 10. 10 .8.9.7.8.9.4 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24' Sparingly setiferous ; the basal joint in the female bears on its upper margin a single plumose seta*. The ends of the third, last, and of the basal joints bear each a plumose hair on the underside. In the male the basal joint wants the plumose seta. The posterior antennae have the primary branch much shorter than the secondary ; the secondary branch 5-jointed ; the first and last joints are large, the three intermediate ones very small, both branches furnished with long plumose hairs. Mandibles elongate, bearing numerous small teeth at the distal ends ; mandible-palp stout, 2-branched, both branches furnished with plumose hairs, the basal part with three short hairs on its inner aspect. Maxillre large, foliaceous. Anterior foot-jaw.s short, truncate; joints crowded, not clearly defined, setiferous, the apical part bearing one long, faintly serrate, spinif orm, curved appendage ; and a number of peculiar, cylindrical processes (sense- * " Das basale Glied triigt im weiblicheu Gescliiecbte eine befiederte Borste," Claus, loc. cil. p. 189. SECOND SERIES. — ZOOLOGY, VOL. VI. 11 82 MR. T. SCOTT ON ENTOMOSTRACA organs ?), densely ciliated at the extremity ; posterior foot-jaw in the female slender, (j-jointed, the last two joints very small. Three long setaj, plumose along the upper edge, spring from the terminal joints ; the basal joints are sparingly setiferous ; the posterior foot-jaw is stouter in the male, and the terminal joints bear a much larger number of setae. First pair of swimming-feet 2-branclied, the outer 3-jointed, the inner 2-jointed ; both branches with numerous stout plumose setge, the terminal spine of the outer branch slender, and faintly serrate on the outer margin. The inner branch of the second pair 2-jointed, of the third and fourth pairs 3-jointed and armed on the side with fascicles of short, stout, and sharp-pointed spines ; the outer branches foliaceous and bearing several strong spines on the exterior margin, one at the base of the first and second joints, and three on the last joint ; the terminal spines of the outer branches of the second, third, and fourth pairs broad, falciform, the outer margin faintly serrate. The fifth pair wanting in the female, in the male simple, 1-branched, 5(?)-jointed, the left branch longer and stouter than the right, with the last joint small and fringed with hairs ; the right branch terminates in a slender spine. Abdomen in the male 5-, in the female 4-jointed, the last joint the smallest. Caudal stylets short, divergent, and furnished with several plumose seta3, the second seta fi'om the inside being much longer than the others. Habitat. Station 9, 25 and 50 fathoms, January 10th (day collections). Lat. 1 55' 5" N., long. 5" 55' 5" E., 35, GO, and 360 fathoms, January 22nd (day collections). Station 23, surface, 20 and 85 fathoms, February 5th (day collections). These were the only gatherings in which Fhaenna spinifera was obtained. The ciliated processes of the anterior foot-jaws resemble somewhat the worm-like sense-organs of the same appendages in Scolecithrix, but instead of being produced so as to form lengthened hair- or " worm-"like processes, as in that genus, they are cylindrical and truncate, and furnished with a terminal fascicle of delicate cilia. Subfamily Pontellin.T3, Dana. Genus Labidocera, Lubbock, 1853. PonteUa, Dana, (in imrt), Amcr. Joum. Sci. 184-6; Claus, Die freilebeuden Copep. 1803; Brady, Monogr. Brit. Copep. 1878 ; id. Report Chall. Copep. 1883. Labidocera, Lubbock, Ann. & Mag. Nat. Hist. ser. 2, vol. xi. (1853). Labidocera detrtjncata (Dana), var. intermedia. (PL VI. figs. 36-38 ; PI. VII. figs. 3, 4.) Length 3 mm. Ccphalothorax elongate-ovate, the postero-lateral angles of the last thoracic segment produced, acute. Anterior antennge in the female 23-jointed, the upper margin of the first eight or nine joints furnished with moderately short, plumose seta3, and the lower margin with a fringe of delicate hairs extending to the 12th joint. Right anterior antennse of the male 17-jointed, hinged between the 13th and 11th FEOM THE GULF OF GUINEA. 83 joints, the upper margins of these joints minutely denticulate (a j-inch objective is required to see the denticulation distinctly). The 12th joint is not denticulate. Mandible strongly toothed; the distal end is covered exteriorly with numerous short spinous setae arranged in oblique rows ; the two inner teeth of the mandible are large and wide apart. The posterior foot-jaws are somewhat similar to those of Labklocera acuta, Dana. The third segment of the right fifth foot of the male has the base produced into a long stout spine, and at the distal end is furnished with a long curved and slender appendage, bearing two short claw-like processes at its extremity. The left foot is 3-jointed ; the second joint is shorter than the first, the third is about equal in length to the second and somewhat triangular in shape ; the apex terminates in three teeth, the middle one being the longest. The fifth pair in the female are inter- mediate between Labidocera detruncata and Labidocera acutifrons, Dana. Abdomen in the male 4-jointed, in the female 3-jointed ; the middle segment in the female large and tumid, the last segment of the male abdomen smaller than the other three, which are subequal in length. The form here described differs from Labidocera, detruncata, as described and figured in the ' Challenger ' Report, in the following particulars : — the right anterior male antenna differs in the proportional length of the joints and in the absence of the prominent denticulations on the 12th, 13th, and 11th joints, but especially on the 12th, and also in the postero-lateral angles of the last thoracic segment being acutely and strongly produced so as to resemble, in this respect, Labklocera acutifrovs. The fifth pair of feet in the male of the variety here described resemble Dana's figure very closely, much more so than that of the specimen figured in the Report on the ' Challenger ' Copepoda. Habitat. Lat. 5° 58' N., long. 14' 20' W., surface, January 6th (one day and one night collection). Off Sao Thome Island (lat. 0 32' 7" N., long. 6 31' 6" E.), 10 fathoms, January 23rd (day collection). Lagoon, Sao Thome Island, surface, January 27th and 28th (one day and one night collection). Lat. 1 30' 3" S., long. 8 8' 6" E., surface, February 3rd (night collection). Lat. 4° 55' 9" S., long. 10 47' 3" E., surface, Feb- ruary 5th (night collection). Lat. 5 50' 5" S., long. 11' 17' 2" E., surface, February 8th (night collection). Lat. G 39' 5" S., long. 11 24' 7" E., surface, February 8th (night collection). This was comparatively a rare species in the ' Buccaneer ' collection. The above is a full list of the localities where it was obtained. /_ Labidoceka Dakwinii (Lubbock). (PI. VI. figs. 39-42 ; PL VII. figs. 5, 6.) 1853. Labidocera Danvinii, Lubbock, Ami. & Mag. Nat. Hist. ser. 2, vol. ii. p. 29, pi. i. figs. 1-11. 1892?. Labklucera Lubbockii, Giesbrecht, Pelag. Copep. Golfes von Neapel, p. 459, pis. 23, 25, 41. Length, male 2" 2 ram., female 2-4 mm. The forehead is broadly rounded, and docs not possess any angular median projection. The last thoracic segment has the lateral angles considerably produced, and in the male more so on the right side than the left, but the 11* 84 ME. T. SCOTT ON ENTOMOSTRACA same on both sides in the female. Anterior antennae 21<-jointed; the two basal joints are moderately stout and large, several of the succeeding joints are very short, while from the 16th to the end all the joints, but especially the 18th and 19th, are elongate and slender. The approximate proportional lengths of the joints are shown in the formula : — 7.10.1.1.1.1.2.2.3.3.3.4..5.5.6.9.9.10.11.8.7.7.6.6 T 2 3 -4 5 6 7 « y 10 11 12 13 1-1 15 16 17 18 liJ 20 21 i'l> 23 24' The middle joints of the right male antenna are slightly swollen ; the 3rd joint has a number of indistinct articulations ; the 9th and 10th joints, between which is a dis- tinctly hinged articulation, are furnished with marginal appendages that are toothed along the upper edge ; the free portion of the appendage of the 9th joint extends hack- ward the whole length of the preceding joint, while that of the 10th joint projects only a little forward beyond the joint to which it belongs ; the 7th joint is about twice the length of the preceding one, and equal to the next ; the 9tli is a little shorter than the 8th, and about half the length of the 10th ; the 11th is about two thirds the length of the 10th, and equal to the next two together. The marginal teeth on the appendage of the 9th joint spring from the distal end of a quadrangular base ; the basal parts of the teeth are closely applied to each other, end to end, as shown in the enlarged drawing ; the marginal teeth on the appendage of the lOtli joint are somewhat conical in shape, and are slightly curved forward. The apical portion of the posterior foot-jaw is 4-jointed (PI. VI. fig. 39). The first joint of the right tif th foot of the male (fig. il) has a broad triangular outline, and part of the outer angle is, as it were, cut off to form an attachment for the next joint; the last joint is considerably swollen, so that the inner marffin forms an elevated arch ; a stout curved and snoon-like claw is articulated to the exterior portion of the joint, and the claw is opposed by a produced basal process so as to form a prehensile organ closely resembling the beak of a bird, and giving to the whole joint somewhat the appearance of an enlarged " bird's-liead process " observed in species of Polyzoa. The last joint of the left foot has a bifid apex and a small blunt- pointed tooth on its outer margin ; part of its inner surface is covered with fine cilia, while the inner angle of the second joint is produced in the form of a ringed (? sexual) process. Fifth pair in the female simple, the basal joints stout, with a small seta on the proximal half ; outer branches elongate, attenuated towards the pointed apex, and furnished exteriorly with a comparatively large subapical spine, and with a minute spine on the interior edge. The inner branches are small, curved, stoutly spiniform, and not half the length of the outer In-anch. The abdomen in the male is composed of four, in the female of two segments, as shown in PL VI. fig. 12 and PI. VII. fig. 5. In the female the caudal stylets are unequal in length ; the fourth caudal seta, counting from the outside, in both male and female, but especially the former, is considerably long er than the others (fig. 42). In all the female specimens obtained an apparently structureless membrane of an irregular outline covered the greater portion of the abdome n, and extended beyond the stylets to about halfway over the caudal setae, as shown in tig. 42. HahiUd. Libreville, Gaboon Uiver, in surface tow-net material collected after midday, January 28th. FEOM THE GULF OF GUINEA. 85 Tliough the Labldocera now described differs in one or two points from Sir John Lubbock's ir- » L28 under-surface (21 f^ay ditto. 1 7 night ditto. This species was abundant in the ' Buccaneer ' collection, l)oth sexes being frequent. Its distribution was co-extensive with the area examined. Family CYCLOPID.E. Genus Oithona, Baird. Oithona, Baird, Zoologist, 1843. OiTHONA Challengerii, Brady. 1883. Oithona ChaUengerii, Brady, Ecport Cliall. Copep. p. 97, pi. xl. figs. 1-10. Huhitut. Station 2, 5 ftithoms, January 1st (night collection). Station 9, 50 fathoms, January 10th (day collection). Station 18, surface, February 3rd (day collection). Station 23, surface, February 5th (day collection). Lat. 5" 53' S., long. 11' 31' 1" E., surface, February 18th (night collection), &c. 0. ChallemjerU seemed to be distributed all over the area examined ; in some tow- nettings it was rather rare, but in others frequent. Considerable care was necessary in diagnosing the species, owing to the close resemblance between it and others of the same genus, and to their being so long immersed in spirit, which rendered it very di£Bcult to make out the number of joints in the antennae. Oithona plumipera, Dana. 1852. Oithona plumiftru, Dana, Crust. U.S. Expl. Expcd. p. 1100, pi. 76. Ilaliitat. Lat. 4 31' 6" K., long. 6 4'4" W., 25 fathoms, January lltli (day collection), lat. 3' 58' N., long. 3 42' W., 50 fathoms, January 13th (day collection). Lat. 2 22' 2" S., long. T 45' E., 20 fathoms, February 3rd (day collection). Station 21, surface, February SECOND SERIES. — ZOOLOGY, VOL. VI. 12 90 ME. T. SCOTT ON ENTOMOSTEACA 4tli (day collection). Station 22, 20 fathoms, February 4tli (day collection). Station 24, surface, February 6th (day collection). Lat. 7 ' 38' S., long. 12' 3' 3" E., surface, February 9th (night collection). This Oilhona has long densely plumose setjB of a persistent purplish colour, which are sufllciently conspicuous to enable the species to he readily distinguished. Oithona plumifera, though frequent in the tow-nettings in which it was observed, appeared to be somewhat rare generally, as the seven collections noticed above were the only ones in which it was obtained. Oithona minuta, n. sp. (PL IX. figs. 14-25.) Length, female "64 mm., male -5 mm. Body moderately stout, ovate. Anterior antennee not reaching to the end of the thorax : in the female composed of nine distinct joints; the basal joint, which forms about a third part of the whole length of the antenna, is indistinctly divided into seven unequal portions by very faint lines that do not appear to be true joints. If these indistinct articulations be included the female antennfB will consist of fifteen joints, the proportional lengths of which are nearly as shown in the formula : — (32 . 4 . 4 . 13 . 4 . 4 . 4) . 14 ■ 24 . 34 ■ 10 ■ 16 . 6 . 12 . 11 (1 .2.3. 4 .5.0.7). 8 . 0 . 10 . 11 . 12 . 13 . 14Tl5" The figures in parentheses refer to the indistinct pseudo-articulations observed in the elongate basal joint. Male antennae 11-jointcd, hinged between the ninth and tenth joints (fig. 16). Posterior antennse nearly as in Oithona spinlrostrls, Glaus (fig. 17) The principal branch of the mandible-palp is armed with two stout, curved, claw-like apical appendages bearing minute marginal spines ; the accessory branch is 4-jointed and furnished with several long plumose setoe (fig. 19). The biting part has on one side a short, stout, submarginal tooth, and on the other side a spiniform seta at the apical angle fully twice the length of the apical teeth (fig. 18). Anterior and posterior foot-jaws nearly as in Oithona Challengerli or Oithona sjmiirostris, as are also the swimming-feet. The feet of the fifth pair in the female are bisetose, with moderately long plumose setse ; those of the male very minute, with two very small setae. Abdomen of the female 4-, of the male 5-jointed ; stylets as long as the last abdominal segment ; the last abdominal segment and stylets in the male are a third shorter than in the female, the tail-seta? in the male arc also much shorter than in the female (figs. 24, 25). This minute but distinct Oithona was obtained in a tow-net gathering collected at Bananah Creek, Congo River, February 7th ; the sp. gr. of the water was only 1-00870. In two tow-net gatherings from the seaward portion of Loanda Harbour, February 15th, surface-temperature of the water at noon 79"-2 F. : the Loanda Harbour tow-net gatherings were collected during the afternoon. Oithona minuta was moderately common in these last two gatherings, and many of the females carried ovisacs. FEOM THE GULF OF GUINEA. 91 OiTHONA SETiGERA, Dana. 1852. Oiihona setigera, Dana, Crust. U.S. Expl. Exped. p. 1101, pi. ~G. Ilabitat. In tow-net gatherings from 50 fathoms, lat. 3 58' N., long. 3 42' W. (temperature 61°' 15 P., sp. gr. 1-02531), collected between 8 a.m. and 1 p.m., January 13th ; and from 3G0 fathoms, lat. 1 55' 5" N., long. 5° 55' 5" E. (temperature about 43"^ P.), collected January 22nd. Oiihona setigera was also obtained in a few other gatherings, but was much less frequent than Oithona Challengerii. Subfamily Longipediinjj;, Boeck. Genus LoNGiPEDiA, Claus (1863). LONGIPEDIA MINOR, T. & A. Scott. (PI. XII. flgS. 10-13.) 1882. Longipedia coronata, Giesbrccht, Die freileb. Copepodeu dcr Kieler Folircle, p. 99, pis. i., iv., xii. 1893. Longipedia coronuta, var. vii/ior, T. & A. Scot, Anu. Scott. Nat. Hist. vol. ii. pt. 2, p. 93. 1893. Longipedia coronata, var. in'inor, T. Scott, xi. Aim. Rept. Fishery Board for Scotland, pt. iii. p. 200, pi. ii. figs. 1 1-20. Habitat. Lat. 1 55' 5" N., long. 5 55' 5" E., 460 fathoms, tow-net gathering, collected January 22nd. Luanda Harbour, in three surface tow-net collections, Pebruary 15th. Pour or five specimens in all were obtained ; they differed considerably from Longijjedia coronata as described by Drs. Claus and Brady. Genus Microsetella, Brady & P^obertson (1873). Microsetella, Brady & Eobertson, Ann. & Mag. Nat. Hist. scr. 4, vol. xii. p. 130 (1873). Ectinosoma, Brady (in part), Mon. Brit. Copepoda, vol. ii. p. 13; id. Report on tlie ' Cliallenger ' Copepoda, p. 100 (1883). Microsetella atlantica, Brady & Robertson. 1873. Microsetella atlantica, Brady & Robertson, Ann. & Mag. Nat. Hist. ser. 4, vol. xii. p. 130, pi. ix. tigs. 11-lG. 1880. Ectinosoma atlanticum, Brady, Mon. Brit. Copep. viii. p. 13, pi. xxxviii. figs. 11-19. 1883. Ectinosoma atlunticum, id. Report Cliall. Copep. p. 100, pi. iv. figs. 10-14. Habitat. Lat. T 33' N., long. 15' 18' W., surface, January 2nd (night collection). Lat. 3° 58' N., long. 3 42' W., 50 fathoms, January 13th (day collection). Lat. 1 55' 5" N., long. 5° 55' 5" E., 460 fathoms, January 22nd (day collection). Lat. 6' 47' 5" S., long. 11' 30' 6" E., surface, Pebruary 8th (night collection), &c. Microsetella atlantica was observed in 40 tow-nettings, 19 of which were surface and 21 undcr-surface gatherings; 4 of the surface and 15 of the under-surface gatherings were day collections, Avhile 15 of the surface and 6 under-surface were night collections, as shown by the annexed formula : — r 4 day collections. {10 surface { ik • i j. i-j-i 1 15 night ditto. 21 under-surface 1 15 day ditto t 6 night ditto. 12* 92 ME. T. SCOTT ON ENTOMOSTEACA The under-surfoce tow-nettings included eighteen gatherings from 2i to 50 fathoms, and one at 185, 235, and 460 fathoms. This species appeared to be distributed all over the area examined, and was comparatively frequent m some of the gatherings ; females with ovisacs were not uncommon. Canthocamptus rosens, Dana, probably belongs to this species. Dana's description (so far as it goes) and figure agree with Microsetella atlantica, but the descrij)tion is too meao-re to admit of a satisfactory comparison. There is a difference between the two as reo-ards size and colour, but such differences are not of much value unless allied with structural differences. Genus Ectinosoma, Boeck. Ectinosoma, Boeck, Oversigt Norges Copepodei-, ISQi. Ectinosoma, Brady (in part), Mon. Brit. Copep. vol. ii. p. 10. Ectinosoma Chrystalii, n. sp. (Pi. IX. figs. 26-35.) Length 1 mm. Body robust ; anterior antennse short, stout, furnished with numerous long setfe; 6-jointed, the third joint is somewhat longer than either the preceding or following ; the last is smaller than the others and about two-thirds the length of the penultimate joint, truncate at the apex, and furnished with three long apical sctse. The long middle joint of the posterior foot-jaw is setose on the ujiper edge, and a long plumose seta that extends beyond the apex of the foot-jaw springs from the upper distal angle of the first joint ; last joint short, provided with three seta3 (fig. 34). The second basal joints of the first pair of swimming-feet are furnished interiorly with a setose spine that extends nearly to the middle of the second joint of the inuer branches ; the outer branches, which are comparatively short, reach only to the end of the second joint of the inner branches, and the spines on the exterior edge are elongate and sharp-pointed, other- wise the first pair closely resemble those of Ectinosoma spinipes. The second basal joint of the fourth pair is somewhat produced and armed exteriorly with an elongate setose spine ; the branches of tlie fourth pair are nearly of equal length, and armed similar to the first pair, except that the exterior marginal spines of the outer branches are not elongate nor setose. Eifth pair nearly as in Ectinosoma melaniceps, Boeck. Caudal stylets about equal in length to the last abdominal segment; the inner of the two principal caudal sctoe considerably longer than the other. Sahitat. Station 3 (lat. T 1' 1" N., long. 15' 54' W.), 25 fathoms, collected between 9 A.M. and 5.30 p.m., January 2ud. Several specimens, all females, were obtained in this gathering. The species is named after Professor Chrystal, who designed a tow^-net used in collecting some of the material from which the Copepoda described in this Report were obtained. Genus Bradya, Boeck, 1872. Bradya, Boeck, Nye Stegter og Arter af Saltvands-Copepoder, 1872. Bradya brevicornis, sp. n. (PI. IX. figs. 36-43.) Length 88 mm. Somewhat similar in form to Bradya typica, Boeck. Anterior FEOM THE GULF OF GUI^'EA. 93 antennce short, stout, upper edge fringed witli long sctEe, 7-jointed, the second joint shorter than, and having the upper distal angle produced so as to extend considerably over, the next joint; the fourth joint is much shorter than either the preceding or following joints ; the last joint is very small and hears two long terminal setae. In the 2-jointed secondary branches of the posterior antennse the distal joint is about twice the length of the proximal one (fig. 38). The anterior foot-jaws are short and stout. The small terminal joint of the posterior foot-jaws boars two long, stout, blunt-pointed spuaes, ciliate on both edges, and a long, slender seta ; a long, plain seta springs from the end of the first joint (fig. 10). The first four pairs of swimming-feet are nearly as in Bradya typica ; the fifth pair are longer than broad, the apex of the second joint is obliquely truncate and furnished with two setae, while the inner distal angle terminates in a stout conical spine. Caudal stylets about once and a half the length of the last abdominal segment. The imicr of the two principal tail-sette is about twice the length of the other ; a small spiniform seta sjjrings from the outer margin and near the distal end of each stylet. Habitat. In a surface tow-net gathering from a lagoon, Sao Thome Island, collected January 21st. Subfamily T a c H i d 1 1 n .e, Boeck. Genus Euterpe, Claus. 'Euterpe, Clausj Die freilebenden Copepoden, 1803 ; Brady, Monog. Bi'it. Copep. 1880. Euterpe gracilis, Claus, var. armata, n. var. (PL XII. figs. 11-23.) Length '9 mm. Body as in Euterpe gracilis, but with the rostrum more pyramidal, slightly curved. Anterior antennse 7-jointed, shorter than the first body-segment. The proportional lengths of the joints as in the formula : — 5. 10. 8. 9. 6. 5. 9 1 2 3 4 5 6 7' The fourth joint bears one and the last joint two slender sensory hairs at their distal end. The last three joints also bear a number of long plain sette. Posterior antennne 4-jointed, the first two short, the third and fourth longer, subequal ; a small 1-joiuted secondary branch springs from near the end of the second joint. The mouth-organs and s-wimming-f eet are similar to those of JEtiterpe gracilis, but with the following differences : — The second joint of the inner branches of the first pair of swimming-feet bears a mode- rately long and stout setiferous terminal spine, which is curved outwards ; near the middle of the same joint is a curved transverse row of seta) extending from the outer margin to fully halfway across the joint. The extremity of the outer branches of the second pair is furnished with a long spine, finely serrate on the outer edge, a shorter setiferous spine, a long slender plumose seta, and several small setose spines ; the inner branches also bear a row of small spines at their extremities in addition to the jjluuiose hairs. The inner branches of the third and fourth pairs are each armed with a long, stout, strongly seti- 94 MR. T. SCOTT OiS' ENTOMOSTEACA ferous, and straiglit terminal spine, iu addition to several smaller spines and a slender plumose seta. The extremity of the outer branches bears a long curved spine, serrate on the outer edge, two smaller dagger-like spines, and a plumose hair ; these smaller spines and the spines at the outer distal angles of the first and second joints are strongly serrate on both margins. A row of spinous setae extends obliquely across the lower middle portion of the last joint of the inner branches of the fourth pair as well as round the extremity of the joint. The fifth pair as in Euterjie gracilis, but with only one short and three long dagger-like terminal spines. A moderately long seta springs from the external margin and near the base of each branch, and a row of small spines extends obliquely from the marginal seta to fully halfway across the segment ; moreover, the extremity and inner margin of each branch are fringed wdth short spinous setee. Ovisac single, large, containing numerous ova. Habitat. Station 9, 50 fathoms, January 10th (day collection). Off Accra, svirface, 1 day and 1 night collection ; 3 fathoms, 1 day and 1 night collection, January 16tb. Lagoon, Sao Thome Island, surface, January 27th (night collection). Station 23, 235 fathoms, Eebruary 5th (day collection). Loanda Harbour, surface, February 15th (day collection). This species was obtained in 29 tow-nettings, 10 of which were surface and 13 under- surface gatherings ; 4 of the surface gatherings were collected during the day and 12 during the night, while 10 of the u nder-surface were collected during the day and 3 during the night, as shown by the annexed formula : — r 4 day collections, r 16 surface 1 12 night ditto. Tow-nettings 29 < r -ir^ -i ^•^.i. 1 13 under-surface J ^^ ^'^^ ^^<^^«- I 3 night ditto. The under-surface gatherings were from depths ranging from 2i to 235 fathoms. The form here described, though agreeing generally with Miter;pe gracilis, differs in several important points, as, for instance, in the proportional length of the joints of the anterior antennae, in the inner branches of the third and fourth pairs of swimming-feet being furnished with prominent, strongly setiferous, terminal spines, and in the fifth pair j)ossessing four instead of five terminal spines. These difi'erenccs, which are suflQciently characteristic to allow of the variety being readily distinguished, may ultimately be considered of specific value ; meanwhile, however, I prefer to consider the ' Buccaneer ' specimens as constituting a variety of Eutei^e gracilis. Subfamily AmymoniN-E, Boeck. Genus Amymone, Glaus. Anu/monc, Die frcilebeudeu Copepocleu, 1863; Brady, Monog. Brit. Coj^ep. 1880. Amymone Andrewi, u. sp. (PL XI. figs. 44-47 ; PI. X. fig. 1.) Length "55 mm. Cephalothorax somewhat similar in form to Ariiymone sphcBrica, Claus, except that the last thoracic segment is more produced and does not bear any spine-like FEOM THE GULF OF GUINEA. 95 processes. Anterior anteunfe not longer than the first thoracic segment, 8-jointed, the proportional lengths as follows : — 24 . 24 ■ 18 . 13 . 6 . 5 . 3 . 8 1 2 3 4567 8' The fourth joint bears a long sensory hair at its distal end, and two similar but rather small hairs spring from the extremity of the last joint. Posterior antennjB slender, 3-jointed, the second and third joints subequal, the last terminating in one long and one short, stout, claw-like seta ; the first joint bears at its distal end a small 1-jolnted secondary branch possessing four apical setaj. The terminal joint of the first foot-jaws is slender, and furnished with several long plumose hairs and at the extremity with three stout spini- form setse. A stout sctiferous process springs from the end of the second last joint and reaches to the end of the spiniform sette just described. Second foot-jaws 2-jointed, long, and powerful. The hands possess strong curved terminal claws, bearing below the middle portion one long and one short spinous seta. The Ijasal part of the hands is produced out- ward into a stout, curved, spiniform process ; the hollow formed by this spiniform process bears a peculiar dilated appendage, furnished with several small spine-like tubercles on its outer surface. The inner margin of the hand is doubly and finely serrate. The integument is closely beset with minute tubercles, much more prominent and distinct than those of A. sphcerica. Habitat. Lagoon, Sao Thome Island, surface, January 27th (night collection). Specific gravity of the water 1"0237 to 1'0255. One specimen only of this curious species was obtained : I was able to prepare the foregoing diescription without dissecting it. The posterior foot-jaws in this species form powerfal gL'asping-organs. Thej)roduced base of the hand acting as a sort of thumb and the terminal claw as a finger, with the dilated appendage in the hollow at the base of the hand acting as an interlocking arrangement, form together an elaborate and efficient instrument for grasping purposes, such as I have not observed in any other described species. This curious and interesting genus is represented in various and widely distant localities. It has been observed in various parts of the North Sea, as at Heligoland, Christiania, and several places on the English and Scotch coasts ; at Messina, Naples, and other localities on the Mediterranean coast ( Ckms) ; in the Gulf of Mexico (Herrick) ; and on the "West Coast of Africa, as now recorded. The species is named after my son Andrew Scott, who has assisted me so well with the preparation of this Eeport, and who discovered the only specimen of this genus obtained in the ' Buccaneer ' tow-nettinsrs. r>- Subfamily Stenheliin.e, Brady (1880). Genus Stenhblia, Bocck (1864). Stenhelia, Boeck, Oversigt Norges Copepoder, 1864. Stenhelia accraensis, n. sp. (PI. X. figs. 2-12.) Length -85 mm. Body moderately robust ; first cephalothoracic segment considerably 96 ME. T. SCOTT ON ENTOMOSTEACA lono-er than the entire lenijth of the other four ; rostrum prominent. Anterior antennae short and stout, 9-jointed ; the upper distal angle of the fourth joint is produced forward over the next, while the terminal joint is ahout as long as the total length of the pre- ceding four ; the relative lengths of the joints are nearly as shown in the formula : — 10. 8.5. 3. 2.3. 2.2. 9 1 2345678 9' Mandibles and maxillae nearly as in Stenlielia hispida. Foot-jaws nearly as in Stenlielia ima. The swimming-feet are also nearly as in the last-named species, except that the proportional lengths of the joints are somewhat ditfercnt; the first joint of the inner branches of the first pair is not longer than the outer branches and not much longer than the combined length of the second and third joints. The inner branches of the fourth pair are somewhat longer than the outer branches. The fifth pair closely resemble those of Stenlielia ima (fig. 11). Caudal stylets somewhat widely apart, about equal in length to the last abdominal segment, and furnished with four apical seta3 (fig. 12). Habitat. Accra, in a shore gathering, collected January 16th, Subfamily CANTHOCAMPTiNyE, Brady (1880) . Monograph of the British Copepoda, vol. ii. p. 47. Genus Laophonte, Philippi (1810). Laophonte, Philippi, Archiv fiir Naturgeschichte, 1840. Cleta, Claus, Die freilebendeu Copepoden, 1863. Asellopsis, B. & R., Ann. & Mag. Nat. Hist. vol. xii. 1873. Laophonte serrata (Claus). (PI. XII. figs. 21-28.) 1863. Glefa serrata, Claus, loc. cit. p. 123, t. xv. figs. 13-20. 1880. Laophonte serrata, Brady, op. cit. vol. ii. p. 71, pi. Ixxii. figs. 1-14. RaUtat. Accra, in a shore gathering, collected January 16th. This, though ajoparently widely distributed, is nevertheless a rare species. It has been obtained in a few British localities, but always sparingly. The strong conical tooth -like process on the second joint of the anterior antennae and the serrated margin of the third joint (fig. 25) are well-marked characters of the species. Laophonte longipes, n. sp. (PI. X. figs. 13-23.) Length '6 mm. Body elongate ; anterior antennae 7-jointed ; the first thi'ee joints are together about equal to twice the entire length of the other four, and the last is about equal to the combined length of the two preceding joints. The relative lengths of the joints are nearly as follows : — 6.7.7.2.2.2.4 12 3 4 5 6 7' FROM THE GULF OF GUTXEA. 97 The upper distal portion of the fourth joint is produced and forms the base of a sensory filament and one or two setae. The secondary branch of the posterior antennae is very short and provided with four setae — three terminal and one subterminal. Mouth-organs nearly as in Laophonte similis, Claus. The outer branches of the first pair of swimming- feet 2-joiuted, not reaching to the middle of the inner branches ; the first joint is about two-thirds the length of the second. The inner branches of the foui'th pair, which reach nearly to the end of the second joint of the outer branches, have the first joint fully half as long as the second, but the first and second joints of the outer branches are about equal in length. Fifth pair nearly as in Laophonte curticauda. Caudal stylets somewhat divergent ; length about tln-ee times the breadth ; principal tail-setae elongate, two-thirds the length of the animal. Mahitat. In a shore gathering from Sao Thome Island, collected January 25th at low water ; and in a tow-net gathering from 20 fatlioms off Stlo Thome, collected January 23rd. Laophonte rxoM^aEA, n. sp. (PI. X. figs. 21-30.) Length 'fG mm. (l-oith of an inch). Body elongate, slender. Anterior antennae 7-jointed, nearly as in Laophonte hrecicornis ; tlie annexed formula shows the pro- portional lengths of the joints : — G. 7. 7. 2. 2. 3. 4 12 3 4 5 6 7' The posterior antennae and mouth-organs are also nearly as in Laophonte brevicornis, except that the posterior foot-ja^ys have the second joint finely ciliate on the inner edo-e and furnished with a small seta near the middle of the exterior edge. Inner branches of first swimming-feet small, 2-jointed ; inner branches of fourth pair very short, scarcely longer than the first joint of the outer branches, 2-jointed ; the first joint is very small, and the apex of the second is provided with one stout terminal and two subterminal setae. The outer branches are armed with a stout apical spine (fig. 28). Eeet of the fifth pair nearly as in Laopjhoute curticauda, Eoeck ; outer margin and surface of basal joints ciliate. Caudal stylets somewhat divergent ; their breadth is nearly equal to half the length, and each is provided with two stout apical setae, the inner one being nearly double the length of the other. Hahitat. Shore, Sao Thome Island, in the same gathering as the last. Laophonte brevicornis, n. sp. (PI. X figs. 31-37.) Length -58 mm. Body slender. Anterior antenna^. G-jointed, the fourth and fifth joints very short; the upper portion of the fourth is produced so as to extend to near the extremity of the following joint and form the base of a moderately stout sensory filament. The relative lengths of the joints are nearly as shown in the annexed formula : — 10 . 7 . 7 . 2 . 2 . 8 1 2 3 4 .5 «" Second joint of posterior foot-jaws with a row of very fine cilia on the upper margin; SECOND SEKIES.^ZOOLOGY, VOL. VI. 13 98 ME. T. SCOTT ON ENTOMOSTEACA both the two joints and the terminal claws appear to be otherwise destitute of spines or setas. Outer branches of first pair of swimming-feet 2-jointed, fully half the length of the first joint of the inner branches, the joints subequal ; the length of the first joint of the inner branch is equal to nearly four times its breadth ; the terminal claw is stout, and fully two-tliirds the length of the first joint and nearly twice and a half the length of the second (fig. 34). The inner branches of the fourth pair, which are scarcely equal in length to the first joint of the outer branches, are composed of two nearly equal joints — the first being the smaller of the two and possessing a moderately long seta on its inner edge; the last joint is furnished with two coarsely plumose terminal setae and a similar seta on the inner and outer margin ; the joints of the 3-jointed outer branches are subequal in length, but the middle one is the shortest of the three (fig. 35). The second joint of the fifth pair, which is considera1)ly smaller than the basal joint, is broader at the distal than the proximal end, and furnished with six setae round the exteriorly oblique apex ; the basal joint is somewhat truncate at the apex and provided with three plain apical setse and two coarsely plumose setae on the lower portion of the inner margin (fig. 36). Caudal stylets about equal in length to the last abdominal segment and comparatively wide apart. Each stylet is furnished with one long and stout and a few small setae ; the length of the principal seta is equal to about once and a half the combined length of the stylet and last abdominal segment, and has the extremity curved outwards (fig. 34). JIahilat. In a shore gatliering at Accra, collected January IGth. Genus Cletodes, Brady (1872). Cktodes, Brady, Nat. Hist. Traus. Northumb. & Durham, 1872. Lilljeborffia, Clans, Die Copeijodcii-Fauna von Nizza, 1866. Orthopsi/lliis, Brady & Robertson, Ann. & Mag. Nat. Ilist. vol. xii. 1873. Cletodes linearis (Glaus). (PL XII. figs. 29-32.) 1866. Lilljeborffia linearis, Claus, Die Copepoden-Fauna von Nizza, p. 22, t. ii. figs. 1-8. 1873. Orthopsijlhs linearis, B. & R., Ann. & Mag. Nat. Hist. vol. xii. p. 138. 1880. Cletodes linearis, Brady, Brit. Copep. vol. ii. p. 95, pi. Ixsx. figs. 1-14. Habitat. Accra, in a shore gathering, collected January IGth. Loanda Harbour, in a surface tow-net gathering, collected February 13th. This species, though numerically scarce, appears to have an extensive distribution. In 'British Co]:)epoda' Professor Brady records it from Scilly Islands, also from Newry and Roundstone, Ireland, and Glaus has recorded it from Nice. Subfamily HARPACTiciNyE, Boeck (in part). Oversigt Norges Copepoder, 1864. Genus Dacttlopus, Glaus (18G3). Dactylopus, Clans, Die t'reilebenden Copepodeu, 1863. Dactylopus, Brady, British Copepoda, 1880. niOM THE GULF OF GUINEA. 99 Dactylopus latipes, n. sp. (PL X. figs. 38-43.) Length 1-25 mm. (l-20th of an inch). Body moderately robust. Fii'st segment of the cephalothorax once and a half the entire length of the other fom* segments; rostrum sliglitly curved, stout, of moderate length. Anterior autennte short, stout, 9-jointed ; first joint large, the fourth provided with a long sensory filament ; the proportional lengths of the joints nearly as in the formula : — ^5 . 8 . 7 . e . ^ . A . 2 . l . S 1 2 3 4 o tj 7 S i)' Second foot-jaws short and stout ; a plumose seta springs from near the inner distal angle of the first joint ; the inner margin of the second joint is ciliate, and a small seta springs from the side and near the middle of the same joint (fig. 10) ; the terminal claw is provided Avith a slender seta near the base. Pirst pair of swimming-feet nearly as in Dactylopus tishoides, Clans. The fifth pair consists of large foliaceous plates jmrtly overlapping each other and forming, apparently, a kind of ovigerous pouch for the pro- tection of the ova (fig. 42 ; see also fig. 38). Abdominal segments fringed with small teeth ; their general surface is also more or less hispid. Caudal stylets about equal in length to the last abdominal segment and rather longer than broad. The inner of the two principal tail-setai is equal to the entire length of the abdomen and stylets. Hahitut. Accra, in a shore gatliering with Dacfijloims prophiquus, Lauphonte serrata, Stenhella, &c., collected January 16th. Dactylopus propinqui's, n. sp. (PI. X. figs. 44-52; PL XI. figs. 1-3.) Female. Length '5 mm. (l-50tli of an inch). Body moderately stout. Anterior antennae short and stout, 6-jointed ; the upper portion is produced and forms the base of a long sensory filament. The annexed formula shows the proportional lengths of the joints : — 8 . 5 . 8 . 2 . 4 . r, 12 3 4 5 0 Posterior antennae nearly as in Dactylopus tishoides, Claus (PL X. fig. 47). The first joint of the posterior foot-jaws bears two small spinous seta; on the inner margin and another at the inner distal angle ; a row of small spinous setae extends diagonally from near the outer edge at the proximal end to the upj)er edge near the distal end of the second joint ; the terminal claw is stout and provided wdth a small seta on its inner aspect. The outer branches of the first swimming-feet consist of three nearly equal joints — the middle one being somewhat shorter than the first or third, the last two joints of the inner branches very short and armed with one stout terminal claAV and a long seta ; the exterior margin of both the last two joints bears several small spiuiform teeth (fig. 49). The inner branches of the second, third, and fourth pairs are somewhat shorter than those of Dactylopus Stromii (Baird), but otherwise they resemble very closely the same swimming- feet of that species. The second joint in the fifth pair, which does not extend much beyond the apex of the basal joint, is subquadrangular in outline and furnished with five 13* 100 Mil. T. SCOTT OX ENTOMOSTRACA long sette on its outer nearly straight marg-in, and another on the inner lateral margin; the hroadly triangular portion oi' the basal joint hears one apical and two suhapical stout plain seta?, and two slender setse spring from the anterior margin (fig. 50). Caudal stylets very short, fringed with long slender serrse ; the longer of the tAvo principal terminal setae is fully twice the length of the abdomen. Ovisacs two. Habitat. Accra, in a shore gathering collected January 16th. Off Sao Thome Island, in a tow-net gathering from 20 fathoms, collected January 23rd, and in a tow-net gathering from a lagoon by the shore of Sao Thome Island, collected January 23rd. A form, which is probably the male of the Dactylopus now described, occurs in the same gatherings with it. The only important difference is in the anterior antennae, which are somewhat longer and 8-joiuted ; they are hinged between the fifth and sixth joints. But though the anterior auteuuse of the male usuallj^ consist of the same number of joints as in the female, and frequently of a fewer number, it occasionally happens that they are composed of more joints — as, for instance, in I/i/ojysi/Ilns coriaceus (Brady and Bobertson *) and Ilyopsi/llns ajjiiiis, described in this Report, in both of which the male antennai consist of a greater number of joints than those of the female. The first swimming-feet of the male of Dactylopus projjinquus are similar to those of the female already described ; the second pair resemble those of the male of Dactylopus Stroma (Baird). The first abdominal segment is provided with a pair of trispinose appendages as shown in PL XL fig. 3 (see also PI. X. fig. 41). Genus Thalestris, Claus. Thalestris, Claus, Die freilebenden Copepodeu, p. 128 (1863). Thalestris forpicula, Claus. (PI. XII. figs. 33-11.) 1863. Tlialeslris forjicula, Claus, Die freilebenden Copepoden, p. 131, pi. xvii. figs. 7-11. Habitat. In a shore gathering from Accra, collected January 16th. The length ("5 mm.) of the ' Buccaneer ' specimen is less than that stated by Claus, which is 'S mm. The anterior antennae are 8-jointed ; the relative lengths of the joints being nearly as shown by the annexed formula : — 9.8.6.5.4.4.3.4 12 3 4 5 6 7 8' The secondary branch of postei'ior antennae 2-joiuted. First pair of swimming-feet elongate, the inner branches considerably longer than the outer ; terminal claws short and stout. Inner branches of the second, third, and fourth pairs shorter than the outer branches : in the fourth pair the inner branches reach only to about the end of the second joint of the outer branches, while the outer branches are long and slender, Avith a long slender terminal sjiine, ciliate on the outer edge (fig. 39). Second joint of the fifth pair * Brit. Copep. vol. ii. pi. Ixxxii. fig. 4. FROM THE GULF OF GUINEA. 10] elongate, larg-cr tlian the basal joint and furnished with six plain setae — two apical, two suhapical, and two on tlui lower half of the outer margin (fig. 10). Caudal stylets very short ; the basal part of the principal caudal setae is distinctly g-il)bous, as shown in fig. 41. Clans also, op. cit., describes and figures this character of the tail-setae. He obtained Thalestris fovficula at Messina. Genus Ilyopsyllus, Brady & Eobertson. IlyopsyUus, Brudy & llobcrtsou. Aim. & Mag. Nat. Hist. s. 4, vol. xii. p. 132 (1873). Ilyopsyllus affinis, n. sp. (PI. XI. figs. 4-17.) Length "5 mm. Body tumid, .similar in form to Ilijopsyllus coriaceus, B. & E,. ; rostrum broadly triangular, furcate at the apex. Anterior antenna? S-jointed in the female, 8-jointed in the male ; the produced upper distal portion of the dilated liasal joint is more or less hispid and furnished with several spiniform seta? ; a curved fold fringed with long stout serrse occurs near the distal end of the base, and extends from the upper margin downwards about two-thirds the breadth of the joint. In the female the three apical joints are of nearly equal length. The proportional lengths of the joints are nearly as shown in the formula : — Female : 20 . 10 . 8 . 7 . 8 1 2 3 4 5 6 7 8 llalc : 8 . 20 . 5 . t) . 7 . lU . 0 . .5 The third and fourth joints in the male are each provided with a long " olfactory " appendage, as are also the female antennae, and these olfactory filaments appear to have a small joint near the proximal end, as shown by the figs. 4 and 5 ; posterior antennte and mandibles nearly as in Ilyopsijllus coriaceus. Eig. 10 represents what appear to be the maxillae and oral aperture. Figs. 11 and 12 represent what appear to be the anterior and posterior foot-jaws as observed in the dissections of the animal. The first four pairs of swimming-feet resemble those of Ilyopsyllus coriaceus, except that the middle joint of the outer branches of the first pair is somewhat longer than either the first or third joints. Fifth pair small, simple, obliquely truncate at the apex, with the lateral angles somcAvhat produced and bearing each a smtill spiniform seta, and a similar seta springs from the distal half of the outer margin ; a transverse curved row of small spines extends nearly across the basal part of each foot (lig. 15). Abdominal segments fringed with stout cilia. Caudal stylets short, breadth about equal to the length, each furnished with two very short set;© and a long one, which is slightly spathulate at the base. Habitat. In a shore lagoon at Sao Thome Island, among species of Conferva. 102 ME. T. SCOTT ON ENTOMOSTEACA Genus Harpacticus, Milne-Edwards (1838). Harpacticus chelifer, ?var. (PI. XII. figs. 42-46.) 1776. Cyclops chelifer, Miiller, Zool. Dan. Prodr. 2413 ; Entomostraca, p. Hi, t. xix. figs. 1-3. 1850. Arpacticus, Baird, Brit. Entom. p. 212, t. xxix. figs. 2, 3, 3 a-g. 1863. Harpacticus, Clans, Die freilebendeu Copcpoden, p. 135, t. xix. figs. 12-19. 1880. Harpacticus, Brady, Brit. Copep. vol. ii. p. 146, pi. Ixv. figs. 1-15, pi. Ixiv. figs. 10, 11. A form of Harjiacticus closely resembling Harpacticus chelifer was obtained in a shore gathering collected at Accra, January 16th, and in a tow-net gathering from 185 fathoms at Station 23, collected February 5th. The chief point of difference seems to be the absence of the curved spines or " claws " on the inner distal margin of the last joint of the posterior foot-jaws ; the inner margin of these foot-jaws is also not concave as in S. chelifer, but in all other respects the ' Buccaneer ' specimens closely resemble that species. Genus Miracia, Dana. Miracia, Dana, Proceed. Amer. Acad. Sci. 1849. Miracia efferata, Dana. Habitat. Station 2, 50 fathoms, January 1st (night collection). Station 9, surface, 25 and 50 fathoms, Jahuary 10th (day collections). Station 14, 10 fatlioms, January 21st (night collection). Lat. 1° 55' 5" N., long. 5° 55' 5" E., 10 to 360 fathoms, January 22ud (day collections). Lat. G" 3' 3" S., long. 11° 7' 5" E., surface, Eebruary 8th (day collection). This Miracia was observed in 49 tow-nettings, 18 of which were surface and 31 under- surface gatherings. The uuder-surface gatherings were from 3 to 360 fathoms, 8 of the surface and 21 of the under-surface tow-nettings were day collections, while 10 surface and 10 under-surface were night collections, as shown by the formula : — f 8 day collections. rl8 surface \ ^i^ • w ivi m i.i.- ,n) ^10 nm'ht ditto. Tow-nettings 49 < ^ tsi under-surface ( 21 day ditto. 1 10 night ditto. It was of frequent occurrence in several of the gatherings, and many of the specimens carried ovisacs. MlKACIA MINOR, u. sp. (PL XI. figs. 18-30.) Length -93 mm. General form as of Miracia efferata, but not half the size. Anterior antennce 8-jointed, slender in the female ; the proportional lengths of the joints are as follows : — IS . 15 . 13 . lit . 14 . 20 . 11 . 15 FEOM THE GULF OF GUINEA. 103 The joints bear from, one to four setae each, except the last, which has one on the upper and four on the lower side ; it has also three terminal sette. The seta wliich springs from the upper distal angle of the third joint is longer than those on the other joints except the last, and a long sensory filament springs from the upper distal angle of the fourth joint. In the male antennae the first three joints are short, the third being shorter than either of the other two ; the fourtli is dilated and longer than the preceding three together ; the fittli is short ; the sixth long and slender ; the seventh is very small ; the eishtli a little longer than the seventh and furnished with four terminal seta} ; the male antenna} hinged between the fifth and sixth joints. The following are the proportional lengths of the joints : — 10 . 9 . 4 . 24 . 9 . 11 . 2 . 5 1234 5 678 Posterior antenna} 4-jointed — the last joint as long as the preceding two together, and ciliated along one of its margins. A small 1-jointed secondary appendage, furnished with two stout terminal setaj and a few marginal cilia, springs from the end of the second joint. Mouth-organs as in Mlracia efferata, except that the posterior foot-jaws are 3-jointcd and nearly alike in both sexes, but that of the male has a longer terminal claw ; in neither, however, is the terminal claw so short as in Miracia efferata. The first pair of swimming-feet has the inner branches scarcely so long as the outer ones ; the second joint of the outer branches is furnished with a moderately long plumose hair on the inner distal angle ; the inner margin is fringed with short stoixt settc, as are also the ends of the first and second joints. The second pair in the female resembles the third and fourth pairs, but are rather smaller. The inner branches of the second jiair in the male are 2-jointed ; the last joint bears one short terminal spine, and one on the lower half of the outer margin ; on the inner margin are two long plumose hairs. The third and fourth pairs are similar in both sexes ; the inner branches being shorter than the outer ; all the joints of botli branches are fringed with hairs on the external margin ; the inner distal angle of the last joint bears a long, slender, non-plumose hair (or spine). The fifth feet small, foliaceous, 2-jointed ; the proximal joint in the male is armed with two spinous setae ; the distal bears one long setiferous spine and two short spines, also a small hair on the inner aspect, as shown in the figure. In the female the proximal joint is armed with one long setiferous spine and four small spinous setjie (one of which is very minute) ; the distal joint is somewhat cylindrical in form, and is furnished with several setiferous spines at the extremity. Abdomen in the male 5-, in the female i-jointed — the first two joints being coaleseent in the female. The posterior margin of the last three segments, in both sexes, fringed with small spinous seta}. Caudal stylets rather longer than the last abdominal segment, each furnished with one moderately long setiferous and two shorter spines, besides several spinous setae on the outer aspect near the middle of the stylet. At the extremity are one long and stout and one short setiferous spine and a number of spinous setee ; the long terminal setiferous spine is fully half as Ion"- again as the stylet. 104 MR. T. SCOTT ON ENTOMOSTRACA Hahitat. Station 23, 235 fathoms, February 5th (day collection). Several speciniens, a few carrying ovisacs, vv'ere ohtainecl in this gathering, which was the only one in which Miracla minor was observed. It differs from both Dana's species, especially in the number and proportional lengths of the joints of the anterior antennae. Genus Machairopus, Brady. Machairopus, Erady, Report on the ' Challenger' Coj^epoda, 1883. Machairopus idyoides, Brady. 1883. Machairopus idyoides, Brady, Report ■ Cliallenger ' Copep. p. 101, pi. xli. figs. 1-12. Habitat. The shore of Sao Thome Island, January 31st (day collection). This collection, which contained a very small quantity of weed and sand, yielded a number of Sarpacticidm, including two specimens of the Machairopus. The ' Challeuger ' specimens (" two or three only were found ") were from Betsy Cove, Kergueien Island. The full and carefully figured details which accompany the description of this species make its identification comparatively easy and certain. Genus JEgisthus, Giesbrecht, 1891. JEffisthus, Giesbrecht, Fauna und Flora des Golfes von Neapel (Pelagisehe Copepoden), p. 573 (1892). Thaumatopsytlus * , Scott, MS. name, 1892. Body slender, elongate, and with a more or less sharp-pointed rostrum. Anterior antennfe slender, in the female about equal in length to the first body - segment, 6-jointed ; in the male the anterior anteunjB are longer, and consist of a greater number of joints. Posterior antennae somewhat similar to those of Iliracia, 3-jointed, and with a small 1-jointed secondary branch. Mandibles well develojjed, the broad biting apex irregularly toothed ; mandible-palp (?) absent or very rudimentary. Posterior foot-jaws 5-jointed, the three apical joints very small; a long, stout, curved spine springs from the inner distal angle of the second joint ;. in the male the posterior foot-jaws are smaller than those of the female. Both branches of the first four pairs of swimming-feet 3-jointed and of nearly equal length ; in the first pair in the female the articulation between the second and third joints is imperfect and indistinct. Fifth pair simple, 1-brauched, 1- (or indistinctly 2-) jointed in the female; distinctly 2-jointed in the male. The tail-seta3 of the species for which the genus is instituted are extremely long, and may or may not form a generic character. {Note. — ^Tliis description was written before I saw Giesbrecht's worlc.) jEgisthus longirostris, n. sp. (PI. XI. figs. 31-44) Body elongate, slender, gradually tapering towards the posterior end ; forehead produced into a long pointed rostrum. Caudal stylets short, each terminating in an * Oavpariis, ■wonderful ; ;f t>XAos, a flea. FEOM THE GULF OF GUINEA. 105 extremely long, slender, jointed, setiferous sjiine, bearing a plumose seta at its extremity (fig. 31). Length, exclusive of caudal spines, 2-4 mm. ; Icngtli to the extremity of the caudal spines 12-5 mm. (J an inch). Anterior antennae (female) slender, about equal in length to the first cephalothoracic segment, 6-jointed, sparingly setiferous, penultimate joint very short. The upper distal end of the first joint is produced to form a broadly conical tooth provided with an apical seta. A long " olfactory " appendage springs from the end of the third joint. The relative lengths of the joints are nearly as follows : — 10 ■ 12 ■ 13 . 8 . 1 . 3 1 2 3 4 5 6' Anterior antennse of the male very long aud slender, fully twice the length of tliose of the female, 7-jointed, penultimate joint extremely long ; the olfactory appendage that springs from the distal half of the fourth joint and the principal apical seta are also very long. The annexed formula shows the relative lengths of the joints : — 12 . 13 . 5 . 15 . 6 . 38 ■ 12 1 2 3 4 5 6 7 ■ Both the male and female antenntB are geniculate between the first and second joints (fig. 3i). Second and third joints of the posterior antennae elongate : secondary branch very short, with two apical setae. Mandibles broad, with the truncate distal end irregularly toothed and bearing a pectinate stout seta at the outer angle (fig. 36) ; no trace of a palp was observed. The maxillae have a well-developed biting part aud a small secondary appendage bearing three apical setae. Anterior foot-jaws small ; first joint armed with two stout spines, setose on both edges, and a small spine and a seta ; the very small terminal point bears three apical setae. The last three joints of the second foot-jaws are very small and furnished with several long setae ; the inner distal portion of the elongate second joint is produced and forms the base of a long, stout, curved spine ; there is a small setiferous process on the inner margin of the proximal end (fig. 39). The posterior foot-jaws in the male are somewhat similar to those of the female, but smaller and less setiferous (fig. 40). The middle joint of the second, third, and fourth pairs of swimming-feet shorter than the first or third ; the marginal spines of the outer branches stout, dagger-shaped, and serrate on both margins ; terminal spines elongate, falcate, serrate on the outer edge, the inner edge ciliate. Fifth pair of feet simple, each foot armed with three long dagger-shaped spines on the outer margin and two at the apex : both edges of these spines are serrate except near the base : there are two plumose setae near the middle of the inner margin, and a plain seta near the base of the outer margin of each foot, as shown in fig. 48. Hahitat. In a tow-net gatliering from 360 fathoms. Lat. 1° 65' 5" N., long. 5° 55' 5" E., collected January 22nd ; and in tow-net gatherings from 185 fathoms and 235 fathoms, Station 23, collected February 5th. Several specimens of this remarkable species were obtained. They do not agree with ^gisthus aculeatus, Giesbrecht, — e. y. the fifth pan- of thoracic feet, &c. SECOND SERIES. — ZOOLOGY, VOL. VI. 14 106 ME. T. SCOTT OX ENTOMOSTEACA Genus Clytemnestra, Dana. Clytemnestra, Dana, Proc. Amer. Acad. Sci. 1849. Goniojjsyl/us, Brady, Report ' Challenger/ Copepoda, 1883. Goniopelte, Claus, Arb. Zool. Inst. Wien, 1889. Saphir, L. Car. 1890. Head and first thoracic segment coalescent. Forehead usually subrostrate. The joints of the cephalothorax much constricted in front, dilated behind so as to form jirominent lateral triangular processes. Anterior antennee 6- to 8-jointed, geniculate in the male. Posterior antennae 3(or 4 ?)-jointed ; secondary branch wanting, or very small and rudimentary. Mandible slender, apex obscurely digitiform ; the palp absent or very rudimentary. Maxillae also rudimentary. Anterior foot-jaw small, clawed at the apex. Posterior foot-jaw elongate, 2- or 3-jointed; terminal claw, in the male, long and powerful, in the female small. First pair of swimming-feet 2-branched, inner branch 3-jointed, the outer with one to three joints. The second, third, and fourth pairs nearly alike, 2-branched, both branches 3-jointcd. Feet of fifth pair 1-branched, the branches similar and 1-jointed, and the same in both sexes. Clytemnestra rostrata (Brady). (PL XII. figs. 47-57 ; PI. XIII. figs. 1-3.) 188.3. Goniopsyllus rostratus, Brady, Report on the ' Challenger ' Copepoda, p. 107, pi. xlii. figs. 9-16. 1849. Clytemnestra (?) scuteUata, Dana, Proc. Amer. Acad. Science. 1860. Clytemnestra (?) tenuis, Lubbock, Trans. Linn. Soc. vol. xxiii. p. 180, pi. xxix. figs. 6, 7. 1889. (?) Goniopelte gracilis, CLaus, ArlD. Zool. Inst. Wien, t. ix. Length about 1-25 mm. The body is usually more or less curved inwards. The fore- head is subtruncate, with middle part produced forward so as to form a prominent rostrum. Postero-lateral angles of the tirst four thoracic segments extended backward into angular jirocesses ; the last thoracic segment smaller than either the preceding one or the first al)dominal segment, its postero-lateral angles not produced. Abdomen 5-jointed in the male, 4-jointed in the female ; the first abdominal segment in the female composed of two coalescent segments, with usually a pellucid spot in the median dorsal line (PI. XII. fig. 48). Body, seen dorsally, elongate, narrow, and tapering gradually from the head backwards. Caudal stylets short, about as long as the last abdominal segment, each furnished with a few short marginal hairs, and in the male with two long plumose terminal setse. The plumose setae are wanting in the female and are replaced by two or three plain and very small hairs. Anterior antennae in both male and female 7-jointed, the proportional lengtlis of the segments being nearly as follows : — Male. 12 . 19 . 6 . 22 . 3 . 18 . 25 1 2 3 4 5 6 7 Female. 12 . 20 . KJ . 15 . 15 . 17 The anterior antennae of both male and female are sparingly setiferous. There is a hair-like filament on the upper margin and near the middle of the third joint in both sexes, while the upper distal angle of the fourth segment and the extremity of the last FEOM THE GULF OF GUmEA. 107 bear each two similar filaments or " sensory liairs," one of which on both seg-mcnts is longer and stouter than the other. In the male the third (?) and last joints are hinged, and the fifth hears a spiuiform ajipendage. The posterior antennte are of moderate length and 3-jointed (Clans says 4-jointed, and the hasal joint of some of the ' Buccaneer ' specimens has a faint line, requiring the |-inch objective to see it, crossing the basal segment near the middle, which may be a pseudo-joint ; hut there are certainly only three distinct jo'mts in all of the ' Buccaneer' specimens examined), having at the distal end of the first segment a 1-jointed rudimentary branch bearing two long terminal plumose setae. The lower margin and the distal half of the surface of the last segment of the primary branch is setose ; the upper edge of the same segment hears one, and at the extremity five setae. Mandibles small, basal part somewhat dilated, the upper part slender, with the extremity furcate or obscurely digitiform; the mandible-palp absent or very rudimentary (no palp was observed in any of the ' Buccaneer ' specimens, though they were dissected with the greatest possible care). Maxillae rudimentary, bearing two terminal spiniforni seta?, and one seta near the middle of the basal part. Anterior foot- jaws small ; the end joint with three terminal spiniform setae, the middle one being the longest. Thei-e is at the end of the basal segment a lu-oportionally large marginal process bearing thi-ee terminal spinif or tn hairs, which imparts to the anterior foot-jaws the appearance as if they were 2-branched; a long, slender, marginal hair springs from the i^roximal half of the basal joint. Posterior foot-jaws in the male large, composed of two long segments and a long, curved, terminal claw, nearly as long as the second joint, and forming a powerful prehensile organ ; the upj^er margin of the second joint is finely serrate. The jjosterior foot-jaw in the female, which is also 2-jointed (PI. XII. tig. 50), is shorter and more slender than that of the male, the terminal claw being also short and feeble, the length of the whole ajjpendage being little, if at all, longer than the first joint of the male cxppendage (Prof. Brady describes, loc. cit., the posterior foot-jaws as possessing a rudimentary third joint, but no such joint was observed in the ' Buccaneer ' specimens). First pair of swimming-feet 2-branched, inner branches 3-jointed, the last joint being the shortest ; outer branches 1-jointed, rather longer than the first joint of the iimer branches. All the joints are furnished with long plumose hairs ; a single plumose hair springs from the outer margin of the second basal joint. Second, third, and fourth pairs nearly alike, also 2-branched, both branches 3-jointed, joints subequal ; the outer branches rather shorter than the inner ones, all well furnished with long plumose setae. Fifth pair of feet 1-branched, 2-jointed, slender, the second joint twice the length of the first, bearing a long, slender, setiferous, terminal spine, and a similar one on the iimer margin near the extremity of the joint; four short spinous hairs spring at irregular intervals along the outer margin ; there is also a slender hair on the outer margin and near the distal end of the first joint. The preceding description of the five pairs of feet applies to both sexes. Ova not apparently enclosed in a sac, but forming a single cluster somewhat similar to that of Eaclueta marina. Habitat. Station 2, surface, January 1st (night tow-netting). Station 9, 50 fathoms, 14* 108 ME. T. SCOTT ON ENTOMOSTEACA January 10th (day tow-netting). Lat. 1° 55' 5" N., long. 5° 55' 5" E., 460 fathoms, January 22nd (day tow-netthig). Station 23, 10, 185, 235 fathoms, February 5th, &c. (day tow-nettings, and a surface night tow-netting). This interesting species was obtained in 81 tow-nettings, 16 of these being surface and 15 under-surface collections. One of the surface and 9 of the under-surface tow- nettings were day collections, while 15 surface and 6 under-surface were night collections, as shown in the formula : — r 1 day collection. rl6 surface | 15 uigi^t coUections. Tow-nettings 31^ . 9 day ditto. (^ lo under-surface < •' I 6 night ditto. The under-surface tow-nettings ranged from 3 to 460 fathoms. Clytemnestra rosfrata was of more or less frequent occurrence in nearly all the tow- nettings in which it w^as observed. Siiecimens carrying ova were not uncommon in some of the collections. The form here described, including its real and supposed varieties, has been the subject of a good deal of misunderstanding and controversy, due in great part to the meagreness and insufficiency of Dana's description and figures. Nevertheless, after having carefully dissected and examined a large number of specimens, I have no doubt whatever that the species under consideration belongs to Dana's Clytemnestra, and I hesitate to ascribe it to his Clytemnestra scutellata only because of the difference in number of the joints of the inner branches of the first pair of swimming-feet, which in C. scutellata, as described by Dana, are 3-jointcd, but which in the ' Buccaneer' specimens are 1-jointed; and also because of the very marked difference in the form of the dorsal aspect between the ' Buccaneer ' specimens and Dana's figure of Clytemnestra scutellata. Dana's figure represents the thoracic as decidedly broader than the abdominal part of the body, whereas the form of the ' Buccaneer ' specimens is elongate-narrow, with the breadth gradually diminishing from the head to the last abdominal segment, and in this respect they agree with Goniopsyllus rostratus, Brady, and Goniopelte gracilis, Clans. Further, the ' Buccaneer' specimens differ from GoniopsyUus rostratus, as, figured and described by Prof. Brady in the ' Challenger ' Report, in two important points : first, the posterior antennse of the ' Buccaneer ' specimens possess a rudimentary but yet distinct secondary branch bearing two plumose hairs, while in Goniopsyllus rostratus the secondary branch is wanting, being represented by a single plumose hair attached to the end of the basal joint of the primary branch ; second, the inner branches of the first pair of swimming-feet in Goniopjsyllus rostratus are described as 3-jointed, whereas in the ' Buccaneer ' si)ecimens they are only 1-joiuted, and are so in both the male and female. On the other hand, the species described and figured by Prof. Claus as Goniopelte gracilis agrees, so far as I can make out, in every essential particular with the ' Buccaneer ' specimens, so that the ' Buccaneer ' specimens appear to belong to Goniopelte gracilis, Claus, rather than to Goniopsyllus rostratus, Brady. In an interesting paper by Prof. Claus in the ' Zoologischcr Anzeiger,' No. 378 FROM THE GULF OF GUINEA. 109 (Nov. 30, 1891), he discusses somewhat fully the classification of the species now under consideration, as well as that of its allied forms, and also the various opinions expressed by different writers bearing on tlie same question. In this paper Prof. Clans shows, more or less conclusively, that Sai^phir rosti^atus, L. Car., is synonymous with Goniopsyllus rostratus, Brady, and also that Chjtemnestra Uendorffi, Poppe, is equivalent to Goniopelte gracilis, Claus. In a concluding uote, referring to the likelihood that Goniopelte may be synonymous with Goniopsyllus, he says : " But if it is desirable, — which I could not advise, taking into account the different points, — that the two forms Goniojjelte and Goniopsyllus should be made only different species of the same genus, Clytemnestra, for reasons given in my work on Copepods, would not be valid as a generic name. It must in that case be Goniopsyllus, Bi'ady." With all deference, however, to W'hat Prof. Claus has stated, I prefer meantime to restore Dana's generic name, Chjtem- nestra ; for, though his description be imperfect, there need be no uncertainty as to his figures. {Note. — The jireccding remarks on Chjtemnestra were written at the close of 1891, and long before I saw Giesbrecht's Monograph of the Neapolitan Copejjoda.) Genus Setella, Dana. Setella, Dana, Crust. U.S. Expl. Exped. 1852. Setella gracilis, Dana. 1852. Setella gracilis, Dana, Crust. U.S. Expl. Exped. p. 1198, pi. Ixxxv. figs. 3 a, g. 1883. Setella gracilis, Brady, Report Chall. Copep. p. 108, pi. 1. figs. 1-10. Habitat. — Station 2, 5 fathoms, January 1st (night collection). Station 9, 50 fathoms, January 10th (night collection). Lat. 1° 55' 5" N., long. 5° 55' 5" E., 460 fathoms, January 22nd (day collection). Station 18, surface, Pebruary 3rd (day collection). Lat. 6" 47' 5" S., long. 11" 30' 6" E., surface, February 8th (day collection), etc. Setella gracilis was obtained in 85 tow-nettings, 31 of which were surface and 51 under-surface gatherings. The under-surface gatherings were from various depths, from 2-| to 460 fathoms. 11 of the surface and 34 of the under-surface tow-nettings were collected during the day, and 23 of the surface and 17 under-surface w^ere night collec- tions, as shown by the formula : — 11 day collections. 34 surface {. ... n^ , l23 nisht ditto. Tow-nettmgs 8o ^ r o . i ' t ( 51 under-surface | 3* "'^^ ^^i^*"- 1 17 night ditto. A considerable proportion of the specimens carried ovisacs. The size of the specimens varied sufficiently to lead me to think that there were more than one species of Setella in the collection ; but careful dissection showed little, if any, structural diflPerence among the specimens, and any structural difference observed was easily accounted for by difference in maturity or sex. 110 MR. T. SCOTT ON ENTOMOSTRACA Section II. P(ECIL0ST03fA, Thorell. Family COEYCiEID^, Dana. Genus Cortc^eus, Dana. Corycmiis, Dana, Proc. Acad. Nat. Sci. Philadelpliia, 1845. Corijc ,, , =' ,.^^ 162 under-surface 1^^ ^^^^ ^^^tto. I- 18 night ditto. This was the most common species of Corycceus in the collection, both as regards its general distribution throughout the area examined and its frequency in the tow-nettings in which it occurred. Corycaus pellucidus, Dana. 1852. Cory cceus pellucidus, Dana, Crust. U.S. Expl. Exped. p. 1224, pi. Ixxxvi. fig. G. 1863. Coryceeus rostratus, Claus, Die freilebenden Copepoden, p. 157, pi. xxviii. fig. 5. 1883. Cory ccEus pellucidus, Brady, Report Chall. Copep. p. 112, pi. lii. figs. 15-19. Habitat. Station 2, 50 fathoms, January 1st (night collection). Station 9, surface, 25 and 50 fathoms, January 10th (day collections). Lagoon, Sao Thome Island, surface, January 27th (one day and one niglit collection). Station 18, surAice, February 3rd (day collection). Lat. 7° 38' S., long. 12" 3' 3" E., surface, February 9th (night collection), &c. This Coryceeus, which was a moderately common species in the collection, occurred FEOM THE GULF OF GUINEA. Ill in 81 of the tow-nettiugs, wliich comprised 42 surface aud 3i) iinder-surface gatherings. The under-surface tow-nettings ranged in depth from 2 to 360 fathoms. 15 of the surface and 30 under-surface tow-nettings were day collections, while 27 surface and 9 under-surface were night collections, as shown in the formula :— r 15 day collections, r -12 surface { 37 ^^.^ ditto. Tow-ncttmgs 81 < ^„^ 1 ■,-,, 1 39 under-surface / ^0 day ditto. (. 9 night ditto. The distrihution of Corycceus pelbicidus was co-extensive "with the area examined. The long spine-like and strongly setiferous hairs of the posterior foot-jaws form an easily recognized character of this species. CoRTC^us LIMBATUS, Brady. 1883. Conjcceus Umbatus, Brady, Report Chall. Copep. p. 114, pi. xlix. figs. 18-22. Habitat. Station 2, night collection. January 1st. Station 9, 50 fathoms, January 10th (day collection). Station 11, 10 fjxtlioms, January 19th (day collection). Lagoon, Sfio Thome Island, surface, January 27th (night collection). Lat. 7° 38' S., long. 12° 3' 3" E., surface, February 9th (night collection), &c. Corycceus Umbatus was obtained in 25 tow-nettings, 10 of which were surface and 15 under-surface gatherings. The dejith of the under-surface toAv-nettings ranged from 2| to 50 fathoms, exclusive of two, one of which was from 260 fathoms and one from 360 fathoms. 4 of the surface and 10 of the under-surface tow-nettings — including the two specially referred to — were day collections, while 6 of the surface and 5 of the under- surface were night collections, as shown by the formula : — 4 day collections. f 4 day collect: 10 surface | 6 night ditto {'I Tow-nettings 25 , ,^ , [15 under-surface f 10 ^^y^^itto. 5 night ditto. This Corycceus, though generally distributed over the area examined, was nevertheless a comparatively rare species, only a few specimens at most being observed in any one of the tow-nettings in which it occurred. CoKYC^us VENUSTUS, Dana. 1852. Corycmis venusfus, Dana, Crust. U. S. Expl. Exped. p. 1222, pi. Ixxxvi. figs. 4 a-d. 1883. Corycmis renu.stus,V,xa.Ay, Report Chall. Copep. p. 115, pi. liv. figs. 8-10. Habitat. Station 2, surface, January 1st (night collection). Station 9, surface and 25 fathoms, January 10th (day collections). Lat. 1 55' 5" N., long. 5° 55' 5" E., 30 and 460 fathoms, January 22nd (day collections). Lat. 6 23' 3" S.,long. 11° 3' 8" E., surface, February 8th (day collection). This species — one of the rarer of the CorycmidcB in the collection — was obtained in 24 tow-nettings, 13 of which were surface and 11 under-surface gatherings. The 112 ME. T. SCOTT ON ENTOMOSTEACA svxrface tow-nettings comprised 7 day and G night collections, and the under-surface 7 day and 1 night collections, as shown in the formula : — f 7 day collections. ,,. ^ J 13 surface ( 6 night ditto. Tow-nettmgs 2i< ^„ -, ,.,, Ill under-surface (^ ^% ^^^^to. 1. 4 night ditto. The under-surface tow-nettings included four at 10 fathoms, one at 15 fathoms, one at 20 fathoms, two at 25 fathoms, one at 30 fathoms, one at 60 fathoms, and one at 160 fathoms. CoRTC^us sPECiosus, Dana. 1852. Corycfeus speciostis, Dana, Crust. U.S. Expl. Exped. p. 1222, pi. lxxx\'i. figs. 4a-d. 1883. CoryccBus speciosus, Brady, Report Chall. Copep. p. 115, pi. liv. figs. 8-10. Habitat. Station 2, 5, 25, and 50 fathoms, January 1st (night collection). Station 9, surface, 25 and 50 fathoms, January 10th (day collections). Lat. 1 55' 5" N., long. 5° 55' 5" E., 10, 20, 30, 60, 260, 360, and 160 fathoms, January 22nd (day collections : the nets were fixed at intervals on a deep-sea line and exposed simultaneously from 11 A.M. to 2.23 p.m.). Station 23, surface, 10, 20, 135, 185, and 235 fathoms, February 5th (day collections : nets fixed on deep-sea line and exposed simultaneously from 11 A.M. to 3.30 p.m.). Lat. T 54' 6" S., long. 12' 11' 7" E., surface, Eebruary 9th (day collection), &c. This fine and well-marked species was observed in 86 tow-nettings, 32 of which were surface and 51 under-surface collections. The depth of the under-surface tow-nettings ranged from 2 to 460 fathoms. 17 of the surface and 39 of the imder- surface tow-nettings were day collections, while 15 surface and 15 under-surface were night collections, as shown in the annexed formula : — rl7 day collections, r 32 surface 1 15 night ditto. Tow-nettings 86 < , ..^ , ,.,, 1 54 under-surface ( "^^ '^""^ '^^^^''^ 1 15 nidit ditto. "a^ o Corycceus speciosus was one of the more common species of the Gorycceidce observed in the collection, but it was not obtained in any gathering from localities where the water was of a decidedly brackish character, as at Bananah Creek. The remarkably divergent caudal stylets made this an easily recognized species ; several specimens were obtained with ovisacs. CoRTC^us OBTUSUS, Dana. 1852. Corycieus obtusus, Dana, Crust. U.S. Expl. Expcd. p. 1211, pi. Ixxxv. fig. 6. 1857. V Corycceus angUcus, Lubbock, Ann. & Mag. Nat. Hist. vol. xx. pi. xi. figs. 14-17. 1883. Coryaeus obtusus, Brady, Report Chall. Copep. p. 116, pi. xlvi. figs. 7-9. Habitat. Station 2, 50 fathoms, January 1st (night collection). Ofi' Accra, 3 fathoms, January 16th (day collection). Lagoon, Sao Thome Island, surface, January 27th (night collection). Loanda Harbour, surface, Eebruary 13tli (day collection). FKOM THE GULF OF GUINEA. 113 Corycceus ohtusus Avas observecl in 39 tow-nettings, 23 of which were surface and IG under-surfaee gatherings ; 7 of the surface and 10 of the undor-surface tow-nettings were collected during the day, while 10 of the surface and 6 of the under-surface were night collections, as shown in the annexed formula : — j 7 day collections. f 23 surface \ -,n „^„k+ a-*.*.^ m j-i- on ) 1 1" night ditto. Tow-nettings 39 < i. & (.10 under-surface { ^^^ '^^y '^it^^- 1 0 night ditto. The under-surface tow-nettings ranged from 2i to 50 fathoms, and one at 185 fatlioms. The hook-like process at the base and on the under surface of the first abdominal segment seems to be peculiar to this species and forms one of its distinctive characters. Genus Copilia, Dana. -^ Copilia, Dana, Proc. Amer. Acad. Sci. 1849; Brady, Report on the Copepoda of the ' Challenger' Expedition, 1883. Copilia mirabilis, Dana. 1852. Copilia mirabilis, Dana, Crust. U.S. Expl. Exped. p. 1232, pi. Ixxx. figs. 14 a-g. 1856. Saphirina styUfera, Lubbock, Trans. Entom. Soc. vol. iv. p. 28, pi. iv. figs. 9, 10 ^ . 1863. ? Copilia denticulata, Claus, Die freilebcnden Copepoden, p. 161, pi. xxv. figs. 14-20. 1883. Copilia mirabilis, Brady, Report Chall. Copepoda, p. 117, pi. liii. figs. 1-11. Habitat. Station 2, surface and 50 fathoms, January 1st (night collection). Station 9, surface and 25 and 50 fathoms, January 10th (day collection). Lat. 1° 55' 5" N., lono'. 5° 55' 5" E., 10, 20, 30, 60, and 300 fathoms, January 22nd (day collection). Station 23, surface, February 5th (day collection). Copilia mirabilis was observed in 70 tow-nettings, 21. of which were surface and 46 under-surface gatherings. The under-surface gatherings ranged in depth from 2 to 300 fathoms. 12 of the surface and 33 of the under-surface tow-nettings were day collections, while 12 surface and 13 under-surface were night collections, as shown by the annexed formula : — f 12 day collections. ..• ,^(24 surface 1 12 night ditto. Tow-nettings 70 ^ r ^ -, T (.46 under-surface P3 '% ^^^^to. 1 13 night ditto. This species was of frequent occurrence in several of the tow-nettings. Copilia qladeata, Dana. 1849. Copilia quadrata, Dana, Proc. Amer. Acad. Boston, vol. ii. 1866. Sapiiirinella pellucida, Claus, Die Copepoden-Fauna von Nizza. 1892. Copilia quadrata, Giesbrecht, Fauna und Flora des Golfes von Neapel (Pelagische Copepoden), p. 658, pi. 2. fig. 3, pi. 50. figs. 1, 10, 13, 16, 22, 28, 33, 36, 41. SECOND SERIES. — ZOOLOGY, VOL. VI. 15 114i MR. T. SCOTT ON ENTOMOSTEACA Uahltat. Station 23 (lat. i^ 26' 7" S., long. 10 1' 8" E.), 30 fathoms, in a tow-net slathering collected between 11 a.m. and 3 p.m. A few specimens (male and female) were observed ; they were readily distinguished by being larger and much broader in proportion to the length than the others. ? COPILIA DENTICULATA, Claus. 1863. Copilia denticulata, Claus, Die freilebenden Copepodcn, p. 161, pi. xxv. figs. 14-20. One or two specimens ( 2 ) of a Copilia apparently belonging to this species occurred in a few of the tow-net gatherings along with Copilia mirabilis. Copilia Pultoni, n. sp. (PI. XI. figs. 15-50 ; PL XII. figs. 1-3.) Length, including caudal stylets, 5"3 mm. {\j of an inch), the length of the caudal stylets is about 1"6 mm. The first cephalothoracic segment is equal to about four-tenths of tlie entire length of the animal, including the stylets. Anterior antennae as in Copilia mirabilis, Dana, 6-jointed, the proportional lengths of the joints as in the formula : — 40 . 35^ 17^5^. 17_^ 1 2 "~3 ^ 5 W Posterior antennse and mandibles also nearly as in Copilia mirabilis, except that the third joint of the posterior antennse is scarcely two-thirds the length of the preceding joint, and tlie marginal spine of the second joint is much smaller than that on the intero- distal angle of the first joint (PI. XL figs. 47-48). The maxillfe consist each of a single broadly spatulate joint bearing three apical spines (PI. XL fig. 49). Anterior foot- jaws stout, 1-joiuted, and provided with two terminal spines and two lateral spiniform seta3 (PL XL fig, 50). Posterior foot-jaws 2-jointed and armed with a stout, nearly straight claw (PL XII. fig. 1). SAvimming-feet as in Copilia mirabilis. Fifth pair rudi- mentary, each consisting of one small joint provided with a terminal spine and two small setae. The abdomen is 4-jointed and is about equal to the combined length of the last three thoracic segments ; the postero-distal angles of the first a1)dominal segment each bear two small spiniform seta?, and the last joint is about equal to the combined length of the two preceding joints. The second last thoracic segment only is produced into a median dorsal spine. Habitat. Station 23, in a tow-net gathering from 30 fathoms, collected February 5th. Only three specimens were obtained. The comparatively short posterior abdominal segment distinguishes this species at a glance from Copilia mirabilis, Dana. It differs from Cojjilia Briicll, I. C. Thompson, by the evenly rounded outline of the first body-segment, in the proportional length of the joints of the posterior antenna;, in the second last thoracic segment being produced into a median dorsal spine, and in the presence of a fifth pair of feet, besides one or two other points shown by the drawings. In the Report on the ' Challenger ' Copepoda the abdomen of Copilia is, in the FEOM THE GULF OF GUINEA. 115 definition of the genus, stated to eonsist of five segments, and in the drawings of CopUin mirahllls the fourth pair of swimming-feet are I'eiJresented as attached to wliat is descrihed as the last thoracic segment ; if this he correct, then, shouki a fifth pair of feet he present, they would necessarily be attached to the same segment as the fourth pair, which Avould be very unusual, the fifth pair only being usually attached to tlie last segment of the thorax. In the species now described, if the abdomen be held to consist of five segments, the appendages of the first segment are not a fifth pair of feet, and the fourth pair are attached to what, in that case, is the last thoracic segment, and a separate segment, for the support of a fifth pair of feet, is entirely absent. In these circumstances I prefer to consider the abdomen as consisting of four segments and that the fourth pair of swimming-feet are appendages of the second last segment of the thorax, and further that the rudimentary appendages of the next, or last, thoracic segment are a fifth pair of feet, because such an arrangement of the parts is more in harmony witli those of closely allied genera. Genus Ltjbbockia, Clans. Lubbockia, Claus, Die freilebeiulcn CopeiJodcu, 1863 ; Brady, Report on the Copepoda of the ' Challenger' Expedition, 1883. LUBCOCKIA SQUILLIMANA, Claus. 1863. Lubbockia squiUimana, Claus, Die freilebenden Copcpodcn, p. 164, jil. xxv. figs. 1-5. 1883. Lubbockia squiUimana, Brady, Report Chall. Copep. p. 118, pi. liii. figs. 12-16, pi. liv. figs. 1-7. Hcdntat. Station 3, 100 fathoms, January 2nd (day collection). Station 9, 25 fathoms, January 10th (day collection). Lat. 1° 55' 5" N., long. 5 55' 5" E., 360 fathoms, January 22nd (day collection). Station 23, surface and at 10 fathoms, February 5th (day collection). Lat. 8° 30' 8" S., long. 12 5' 7" E., surface, February 9th (day collection), &c. Luhhockia squilUmana was observed in 39 tow-nettings, 13 of which were surface gatherings and 26 under-surface. The under-surface gatherings were from various depths from 10 to 360 fathoms ; 3 of the surface and 18 of the iinder-surface tow- iiettings Avere day collections, while 10 surface and S under-surface were night collections, as in the formula : — r 3 day collections. ..• on f ^'^ '"''^'''''' i 10 night ditto. Tow-nettmgs 39 < " I 26 under-surface j 18 day ditto. I 8 night ditto. Though generally distributed throughout the ar(^a represented in this Report, and though observed in a considerable number of gatherings, Luhhockia was of less frequent occurrence in the tow-nettings in which it was obtained than some other species with a more restricted distribution. Specimens of both sexes were collected, but females were much more common than males ; several females carrying ovisacs were taken. 15* 116 MR. T. SCOTT ON ENTOMOSTRACA Genus Onc^a, Philippi. Onceea, Philippi, Wiegmana's Arcliiv, 1843. Antaria, Dana, Proc. Amer. Acad. Sci. 1849. Onc^a obtusa (Dana). 1843. Onceea venustat, Philippi, Wiegmanu's Archiv, pi. 111. fig. 3. 1852. Antaria obtusa, Dana, Crust. U.S. Expl. Exped. p. 1230, pi. Ixxxvi. figs. 13 a-c. 1883. Onceea obtusa, Brady, Report Chall. Copep. p. 120, pi. li. figs. 1-11. Habitat. Station 2, surface, 5, 25, and 50 fathoms, January 1st (night collections). Station 9, surface, 25 and 50 fathoms, January 10th (day collections). Lat. 1° 55' 5" N., long. 5° 55' 5" E., 10, 20, 30, 260, 360, and 460 fathoms, January 22nd (day collections). Bananah Creek, Congo River, surface, February 7th (day collection). Loanda Harbour, surface, Pebruary 13th (day collection). Onccea obtusa was observed in 119 tow-nettings, 60 of wdiich were surface and 59 under-surface gatherings. The under-surface tow-nettings ranged in depth from 2 to 460 fathoms. 20 of the surface and 41 of the under-surface gatherings were day col- lections ; 34 of the surface and 18 of the under-surface gatherings were night collections, as shown by the formula : — 26 day collections. r lb clay collect! 60 surface \ 3^ ^^„^^ ^j^to Tow-nettings 119 , .-, n tm; (.59 under-surface P^^^'^y^^^^*^- (. 18 night ditto. This was one of the most common and most generally distributed species in the ' Buccaneer ' collection ; many of the specimens carried ovisacs, and though the collection had been for several years in spirit a considerable proportion of the OnccBce retained much of the vivid coloration so characteristic of the species. ONcasA GRACILIS (Dana). (PI. XIII. figs. 4-12.) 1853. Antaria gracilis, Dana, Crust. U.S. Expl. Exped. p. 1229, pi. Ixxxvi. fig. 11 a. Length I'l mm. Cephalothoras narrow, ovate. Abdomen elongate, slender ; the breadth of the first abdominal segment is somewhat less than two-thirds its length, and one-third the length of the abdomen, exclusive of the stylets ; the second segment is scarcely half the length of the first, and equal to the combined length of the next two ; the third segment is nearly twice the length of the last, while the caudal stylets are somewhat longer than the last abdominal segment (fig. 12). The anterior antenna? are similar to those of OnccBa obtusa, but are more slender ; the relative lengths of the joints are nearly as in the formula : — 4 . 4 . 13 . 2 . 1 . 3 r~2 3 4 5 6' The last joint of the posterior antennte about as long as the preceding one, but more slender and furnished with four long, stout, ajjical setae, and another seta near the base. Mouth-appendages nearly as in Onceea obtusa, except that the last joint of the posterior foot-jaw is elongate and armed with a long, powerful, nearly straight terminal claw. FEOM THE GULF OF GUINEA. 117 which is finely serrate on the inner edge (fig. 10). First swimming-feet also similar to that species, but more slender, and provided with much longer terminal spines, — the terminal spine of the outer branch is equal to about three times the length of the joint from which it springs. The terminal spines of the three pairs (both branches) are also long. The inner branch of the fourth pair is much shorter than the outer branch, and its three joints are nearly equal in length ; the terminal spine is long and setiform. Fifth pair of feet as in Onccea obtum. Habitat. Station 2, 50 fathoms, collected January 1st, between 7.20 and 8.20 P.M. Station 9, 50 fiithoms, collected January 10th, during the day. Ofi" Appi * (near Porto Novo), surface, collected January 18th (day). Lat. 3° 55' 3" N., long. 4° 7' 3" E., 30 fathoms, collected January 20th. Lat. 2° 34' 9" N., long. 5° 22' 2" E., 20 fathoms, collected January 21st. Lat. 1° 55' 5" N., long. 5° 55' 5" E., 360 fathoms, collected January 22nd. Station 23, in two gatherings at 30 and 85 fathoms, collected February 5th. All the gatherings except the first one w^ere collected during the day. Though I have included this species under Onccea, it nevertheless differs very markedly from the very common Onccea ohtusa, Dana. The last joint of the posterior antennse is elongate and slender ; the inner branch of the fourth pair of swimming-feet is considerably shorter than the outer branch, and consists of three nearly equal joints ; the al)domen is long and slender, and the last three segments are much longer, com- paratively, than in Onccea obtusa. These differences, taken together, should j^erhaps be considered of more than merely specific value, but I prefer meantime to refer the species above described to Oncceci. Note. — The species described above agrees in several points with Concea rapax, Giesbrecht (Mon. Pelag. Copep. of the Gulf of Naples), and should perhaps be ascribed to that genus. ONCiEA MEDITERRANEA (Claus). (PI. XIII. figS. 13-17.) 1863. Antaria mediterranea, Claus, Die freilebenden Copepadeu, jj. 159, pi. xxx. figs. 1-7. Length '85 mm. (l-30th of an inch). Somewhat like Onccea obtusa in general form, but with a proportionally shorter abdomen. Abdomen, including caudal stylets, equal to about two-fifths the length of the ccphalothorax ; length of first abdominal segment equal to about twice the breadth, and to fully twice the entire length, of the remaining segments ; and, togetlier with the caudal stylets, the length of the last abdominal segment is rather greater than that of the two iireceding segments added together. Caudal stylets about twice as long as broad, and nearly equal in length to the last two abdommal segments. Anterior antennse slender ; the pro2)ortional lengths of the joints are nearly as shown in the formula : — 2.3.8.2.1.2 12 3 4 5 0" * Note lij Mr. llattray. — " Appi is a flourishing village, with three French factories. It is the nearest port to the inland town of Porto Novo, and communicates with it by a lagoon. The surf at Appi is very heavy, and it is impossible to land except in a native boat built for that purpose. The boats are manned by about sixteen negroes and propelled by paddles. The beach is steep and sandy." lis ME. T. SCOTT ON EXTOIMOSTEACA Last, joint of the posterior antennEe fully three-fourths the length of the precetlinp^ joint. Mouth-organs similar to those of Oiicaa ohtusa, except that the last joint of the posterior foot-jaw is broadly ovate; the fringe of hairs on the inner margin extends backwards from the apex nearly three-fourths the length of the joint, and is bounded at the proximal end by a small spine (fig. 16). The swimming-feet are similar to those of Onccea ohtusa, but the joints, especially of the outer branches of the first pair, are jiroportionally longer, and the length of the terminal spines of both branches of all the swimming-feet is much greater than those of that species : in the iiist pair the terminal spine of the outer branches is equal to the combined length of the second and last joints ; in the fourth pair the terminal spines of both branches are equal to the entire length of the branches they spring from ; the terminal spines of the inner branches are also serrate on both branches. The fifth pair, like those of Onccea ohtusa, are very small and rudi- mentary. One or two females only of this species were obtained. Habitat. Station 9, 50 fathoms, collected January 10th. Lat. 1^ 55' 5'' N., long. 5' 55' 5" E., 300 ftithoms, collected January 22nd. This species, though closely resembling Onccea ohtusa, appears to be quite distinct from it ; the following are some points in which it differs from that species : — the last joint of the secondary branch of the posterior antennae is considerably longer ; the joints of the outer branches of the first swimming-feet are proportionally longer ; the abdomen is shorter, being only equal to about two-fifths of the length of the cephalothorax ; and the terminal spines of the swimming-feet, and especially of the fourth pair, are of much greater length than those of Onccea ohtusa. Onccea mecliterranea (Claus) seems to agree much closer with this species than with Onccea ohtusa (Dana), and I have therefore ascribed it to the species described by Dr. Claus. Genus Hersiliodes, Canu, 1888. Hersilioees LiviNGSTONi, n. sp. (PI. XIII. figs. 31-38.) Length, exclusive of tail-setse, 1-03 mm. Viewed dorsally the body is broadly ovate, and much constricted near the posterior end ; it is composed of six segments, the first being nearly equal to the entire length of the other five ; the fifth segment is short, and considerably narrower than that which precedes or follows it ; the breadth of the last segment is greatest posteriorly. Forehead rounded. Anterior antennae stout, 7- jointed, and bearing numerous setiB; the proportional lengths of the joints are nearly as shown in the formula : — 15 . 25 ■ 12 . 18 . 14 . 11 . 11 12 3 4 5 6 7 ■ Posterior antenniie stout, 4-jointed, the first joint being nearly equal to the combined length of the other three; the third joint bears two stout curved spines at the exterior distal angle, while the truncate extremity of the last joint is armed with four elongate curved sj)ines and a few setse (fig. 33). The mouth is in the form of a small conical tube, the margin of which is fringed with cilia. The mandible is armed exteriorly with a stout, somewhat curved tooth, having a doul:)le row of scrratures along FROM THE GULF OF GUINEA. 11!) its inner margin, and interiorly with tliree setiferous spines. Maxillse simple, terminating in two very short and rounded spiniferous lohes (tig. 3i). The anterior foot -jaws are furnished with a short, stout, and slightly curved terminal claw, which is provided Avith several setiferous spines at the base, while two stout setiferous sjiines spring from the end of the tirst joint ai\d close to the basal part of the claw. The posterior foot-jaws are large ; they arc furnished with several spiniform plumose setae on the inner margin, and terminate in stout, elongate, and strongly curved claws, from the base of which springs a strong and curved claw-like spine (fig. 35). Both branches of the first four pairs of swimming-feet 3-jointed ; joints short and broad. The exterior margin of the outer branches of the first pair is furnished with four spines, — one on each of the first and second, and two on the last joint. Hound the end and inner margin of the last joint there are six long plumose setae, while one long seta, also plumose, springs from the inner distal angle of the second joint. The first and second joints of the inner branches have no spine on the outer margin ; the outer distal angle of the second joint forms a tooth-like process; the last joint is furnished with a stout spine on the lower half of the exterior margin, — the margin being hollowed out to receive the base of the spine; there are also five plumose setae round the end and inner edge of the last joint. The extremities of both branches of the second, third, and fovxrth pairs are armed with one long and one short spine ; the long sj)ine of the outer branches is ciliate along the inner edge (tig. 37). The foot of the fifth pair consists of a broad foliaceous joint, rounded at the extremity, and furnished with one long terminal and three small submarginal setse (fig. 38). Abdomen composed of four segments; the first is con- siderably dilated, the first, third, and fourth are about equal in length, but the second is rather longer. Caudal stylets half as long again as the last abdominal segment, some- what divergent, and furnished AA^th two long and three short terminal set£e ; there is also a small submarginal spine about one-third the length of the stylet from the extremity (fig. 31). Habitat. Loanda Harbour ; surface tow-net gathering, collected February 15. Genus Pachysoma, Claus. Pachysoma, Claus, Die freilebenden Copepoden, 1863. Pachysoma punctatum, Glaus. (PI. XIII. figs. 18-21.) 1863. Pachysoma jMnctatiim, Claus, op. cit. p. 163, pi. xxv. figs. C-11. Length 2"5 mm. Body rotund; forehead produced into a small triangular pointed rostrum. Anterior antennae very short, stout, 7-jointed, the third and fourth joints shorter than the others ; the proportional lengths of the joints are as follows : — 30 .2.5. 9 .12. 22 . 20 . 1.5 1 2 3 4 5 6 7 ' Posterior antennae nearly as in Liohomolgiis, 1-jointed, the third joint short, the others of moderate length and subequal (fig. 20). Mandibles small, stylet-shaped, ciliate along one edge ; the maxillae consist of small 1-jointed appendages bearing two long apical 120 ME. T. SCOTT ON ENTOMOSTE.ACA setse. Anterior foot-jaws rudimentary, 1-jointed, with a moderately stout terminal claw and a small seta (fig. 23). Basal joint of posterior foot-jaws greatly dilated ; second joint stout, bearing two marginal spiniform setae and armed with a strong curved terminal claw, which is provided with a small seta near the base and on the inner aspect. Swimming-feet nearly as in Lichomolgiis, both branches 3-jointed ; the setse on their inner margins are stout and densely plumose ; the inner branches are considerably lono-er than the outer (fig. 2\). Eifth pair rudimentary and provided with one small marginal and two apical plumose setae. Abdomen short, composed of four segments ; first segment large, the next three much shorter and narrower ; in the male the postero- lateral angles of the first abdominal segment carry two plumose setse. Caudal stylets about equal in length to the first abdominal segment ; apical setse three, and one on the outer edge about one-third the length of the stylet from the proximal end. The structure of the integument is shown in fig. 18. KaUtat. Station 9, in a tow-netting from 25 fathoms. Lat. 2' 34.' 9" N., long. 5' 22' 2" E., 20 fathoms. Station 14, in two tow-net gatherings from 10 and 20 fathoms. Lat. r 55' 5" N., long. 5° 55' 5" E., 20 fathoms, and lat. 0' 21' 1" N., long. T 0' 33" E., 20 fathoms. Though observed in these six separate tow-net gatherings, very few specimens were obtained. Genus Lichomolgus, Thorell. Lichomolgus, Thorell, Om Krustaceer i Ascidier, p. 74 (1859). LiCHOMOLGTJS CONGOENSIS, n. sp. (PL XIII. figs. 39-48.) Length fully 1 mm. Cei^halothorax moderately robust. Anterior antennae fully half the length of the first cophalothoracic segment, 7-jointed, nearly as in Lichomolgus fucicolus; the relative lengtlis of the joints are shown in the formula : — 12 . 26 . 8 ■ 17 . 18 . 15 . 10 12 3 4 5 6 7' Posterior antennae 4-jointed ; first, second, and fourth joints elongate, subequal ; third joint very short and bearing two stout seta3 on the upper distal angle ; the last joint is armed with two slender curved terminal spines and two setse ; there is also a small seta on the inner margin near the apex (fig. 41). The mandible consists of a comparatively broad and apparently abruptly bent process, the truncate apex of which is furnished with a comb-like fringe of short setae ; a stout stylet-like appendage, finely crenate on the upper edge, springs from the outer distal angle, and is closely applied to the anterior edge of the ajipendage, and extends some distance beyond its fringed apex (fig. 42). The maxillae are simple 1-jointcd appendages, bearing a few apical setae (fig. 43). Eoot-jaws nearly as in Lichomolgus fucicolus, except that the posterior foot- jaw is armed with a long curved spine on the inner margin of the proximal half of the second joint (fig. 45). The four pairs of swimming-feet are also nearly as in Lichomolgus fucicolus, except that there are stout dagger-shaped spines on the exterior margin and FEOM THE QVLF OF GUINEA. 121 apex of the outer branches ; the apex of the inner branches is also provided with similar spines ; the inner branch of the fourth pair is 2-jointed (fig. 4G). Fifth pair subquad- rangular, rather longer than broad, and furnished with two stout terminal spines. Abdomen scarcely equal to half the length of the cephalothorax. Caudal stylets about as long as broad, and three-fourths the length of the last abdominal segment. The fourth tail-seta, counting from the outside, is stouter and rather longer than the others. HahitcU. Bananah Creek, Congo River, in a surface tow-net gathering, collected Eebruary 6th. Only two specimens (females) were obtained. Genus Pseudanthessius, Claus. Pseudanfhessius, Claus, Arb. Zool. Inst. Wien, 1889. PSETJDANTHESSITJS PUOPINQUITS, n. sp. (PI. XIII. figs. 49-56; PL XIV. figs. 1, 4.) Length 1'3 mm. (l-18th of an inch). Anterior antennae 7-jointed; the formula shows the proportional lengths of the joints : — 12 . 21 . 6 . 12 . 12 . 11 . 8 12 3 4 5 0 7 The short penultimate joint of the posterior antenna3 bears a long slender spine on its upper distal angle ; the last joint is provided \vdth a stout curved apical spine and five setae. Mandibles somewhat as in Lichomolgus congoensis, but the stylet-like appendage is longer and strongly dentate on the upper edge, the basal tooth being much larger than the others (PI. XIII. fig. 52). Maxillae armed with three stout terminal spines, two of which are serrate on both edges, and a small marginal seta (PI. XIII. fig. 53). Anterior foot-jaws stout, 1-jointed, and provided with four strong terminal spines, the two larger of which are furnished with several tooth-like processes. Posterior foot-jaws in the female short, 3-jointed ; the second joint carries two short, stout, marginal spines, and the last joint, which is small, carries one terminal and four lateral seta3 (PL XIII. fig. 54). In the male the posterior foot- jaws are more slender; the first and second joints are fully twice as long as broad, and the inner margin is fringed with cilia ; the last joint is very short and forms the base of a stout, elongate, curved claw, which is fur- nished with two small setae near the base. The fourth pair of swimming-feet are nearly as in Pseudanthessim Thorelli (Brady), but the margins of the 1-jointed inner branches are not ciliate ; a moderately long plumose seta springs from the proximal half of the inner edge (?and probably also from the outer edge opposite to the other) (PL XIV. fig. 3). The first three pairs of swimmiug-feet are nearly as in Lichomolgus fucicolus. The fifth pair consist each of a moderately stout joint, furnished with two apical spines. Abdomen, inclusive of stylets, nearly equal to three-foiu'ths the length of the cephalo- thorax : in the male the first segment is as long as the next two together ; in the female the first segment is rather more than half the length of the abdomen, the remaining three segments are as in the male. Caudal stylets once and a half the length of the last abdominal segment, and furnished with one seta near the middle of the outer margin and four apical setae. Habitat. Loanda Harbour, in a surface tow-net gathering, collected February 15th. Very few specimens were obtained. SECOND SERIES. — ZOOLOGY, VOL. VI. 16 122 ME. T. SCOTT ON ENTOMOSTEACA Genus Saphieina, Thompson. Saphirina, Thompson, Zoological Researches, 1829 Saphieina ovalis, Dana. 1852. Saphirina oralis, Dana. 1883. Saphinna ovalis, Brady, Report Chall. Copep. p. 123, pi. xlvii. figs. 1-12. Habitat. Station 2, January 1st (night collection). Lat. 1" 55' 5" N., long. 5^ 55' 5"E., 10 and 30 fathoms, January 22nd (day collections). Station 21, surface, February 4th (day collection). Station 2i, surface, February 6th (day collection), etc. This Saphirine was obtained in 27 tow-nettings, 10 of wliich were surface and 17 under-surface gatherings. The uuder-surface tow-nettings ranged from 2 to 50 fathoms, with the exception of one which was from 185 fathomxS. 2 of the surface and 13 of the under-surface were day collections, while 8 surface and 4 under-surface were night collec- tions, as shown in the formula : — J 2 day collections, f 10 surface. |. g night ditto. Tow-nettings 27 . -^3 ^ ^^^^^ I 17 under-surface < •' K 4 night ditto. Only one or at most very few speciniens were observed in any one of the tow-nettings, Tlie females of Safhlrlna ovalis were usually readily distinguished from other Saphirines by the numerous, circular, opaque white spots scattered somewhat symmetrically over the entire dorsal surface, and which imparted a rather elegant appearance to the specimens. (It will be understood that the ornamentation described is that of specimens which have been several years in spirit.) Note. — This appears to be the species described by Giesbrecht as Saphirina stellata and = S. ovalis of Dr. Brady's ' Challenger ' Coi)epoda, but not S. ovalis, Dana. Saphieina inj^qualis, Dana. (Not S. nlgromaculata, Claus.) 1852. Saphirina inatqualis, Dana, Crust. U.S. Expl. Exped. p. 1241, pi. Ixxxvii. fig. 7. 1860. Saphirina elegans ( ? ), Lubbock, Trans. Liuu. Soc. vol. xxiii. p. 12, pi. xxix. figs. 18, ID. 1883. Saphirina incequalis, Brady, Report Chall. Copep. p. 124, pi. xlviii. iigs. 1-5. Ilahitat. Station 9, 25 fathoms, January 10th (day collection). Station 11, 10 fathoms, January 19th (day collection). Station 14, 20 fcithoms, January 21st (night collection). Station 18, surface, February 3rd (day collection). Station 24, surface, February 6tli (day coUection). Lat. 5' 40' 8" S., long. 11 33' 4" E., surface, February 19th (day col- lection), &c. Saphirina incequalis was observed in 41 tow-nettings, 22 of which were surface and 19 under-surface gatherings ; 8 of the surface and 14 of the under-surface gatherings were day collections, Avhile 11 of the surface and 5 of the under-surface were night collections. The under-surface tow-nettings ranged from 2| to 25 fathoms, with the exception of one which was from 360 fathoms. 5 dav collections. pO surface 1 5 night ditto. FROM THE GULF OF GUINEA. 123 r 8 day collections, r 22 surface 1 11 niilit ditto. Tow-nettin£?s 41 < r^ , i tj.^ ^ I T n I f r I'i' day ditto. (_19 under-surface <^ •' L 5 night ditto. This was the most common of the Saphirines in the ' Buccaneer ' collections. Saphirina serrata, Brady. 188.3. Saphirina serrata, Brady, Report Cliall. Copep. p. 125, pi. xlix. figs. 1, 2. Habitaf. Station 9, 25 fathoms, January 11th (day collection). Lat. 1 55' 5" N., long. 5' 55' 5" E., 200 fathoms, January 22nd (day collection). Station 23, surl'ace and 10 fathoms, February 5th (day collections). Lat. 5' 40' 8" S., long. 11" 33' 4" E., surface, February 19th (day collection), &c. This species occurred in 20 tow-nettings, 10 of which were surface and 10 under-surface gatherings. The surface comprised 5 day and 5 night collections ; the under-surface 8 day and 2 night collections, as shown in the formula : — r i 5 Tow-nettings 20 <[ ^ - . tlO under-surface 1 8 day ditto. I 2 night ditto. The under-surface tow-nettings included one at 3 fathoms, three at 10 fathoms, one at 15 fathoms, two at 20 fathoms, one at 25 fathoms, one at 50 fathoms, and one at 260 fcxthoms. The distinct, though finely serrate, margins of the abdominal segments (except the first) in the female constitute one of the most prominent characters of the species. S. serrata was one of the less common of the Saphirines in the collection. Saphirina opalixa, Dana. 1852. Saphirina opalina, Daua, Crust. U.S. Expl. Exp. p. 1254, pi. Ixxxviii. fig. 4. 1860. Saphirina Thomsoni, Lubbock, Trans. Linn. Soc. vol. xxiii. p. 18(i, pl. xxix. figs. 22, 23. 1883. Saphirina opalina, Brady, Report Chall. Copep. p. 12G, pl. xlix. figs. 3-G. Habitat. Station 9, 25 fathoms, January 10th (day collection). Off' Sao Thome Island (lat. 0 34' K., long. G 30' 4" £.), 10 fathoms, January 23rd (day collection). Station 23, 20 fathoms, February 5tli (day collection). Lat. T 38' S., long. 12 3' 3" E., surface, February 9th (night collection), etc. This Saphirine was obtained in 5 surface and 8 under-surface tow-nettings. The 8 under-surface gatherings comprised two at 10 fathoms, one at 15 fathoms, two at 20 fathoms, and two at 25 fathoms. The annexed formula shows the number of day and night collections : — f 1 day collection. 5 surface Tow-nettings 13^ , . , "^ j ^ =uxxa^^ ^ ^ ^.gj^^ collections. ^'^ ^IS under-surface I ^ day ditto. 1 3 niojht ditto. This species was readily distinguished from other Saphirines by the peculiar form of the very short caudal stylets. 16* 124i MK. T. SCOTT ON EXTOMOSTRACA Saphirina opaca, Lubbock. 1856. Saphirina opaca, Lubbock, Trans. Ent. Soc. vol. iv. p. 27, pi. v. figs. 9-11. 1883. Saphirina opaca, Brady, Report Chall. Copep. p. 127, pi. xlix. figs. 14-17. Habitat. Lat. 3' 58' N., long. 3' 42' W., 25 fathoms, January 13th (day collection). Off Sao Thome Island (lat. 0" 46' 6" N., long. 6^ 22' E.), 10 fathoms, January 23rd (day collection). Off the Gaboon River (lat. 0' 22' 8" N., long. 8^^ 16' 7" E.), surface, January 28th (two night collections). Station 23, 10 fathoms, February 5th (day collection) . This comparatively large species was obtained in 18 tow-nettings, 7 of which were surface and 11 under-surface gatherings. The under-surface tow-nettings included one at 2| fathoms, six at 10 fathoms, one at 15 fathoms, one at 20 fathoms, one at 25 fathoms, and one at 30 fathoms. 1 surface and 9 under-surface gatherings were collected during the day, Avhile 6 surface and 2 under-surface were night collections, as shown by the annexed formula : — r 1 day collection. T ff iQ ( ^ surface | q ^^^^^ collections. Tow-nettmgs 18 -^ ^- » (.11 under-surface P ^% ^^i^to. ( 2 night ditto. The large size, elongate form, and the produced inner angle of the caudal stylets serve to distinguish this from most of the other Saphirines in the collection . A few specimens carried ovisacs. Saphirina splendens, Dana. 1852. Saphirina splendens, Dana, Crust. U.S. Expl. Exped. p. 1246, pi. Ixxxvii. fig. 9. 1883. Saphirina splendens, Brady, Report Chall. Copep. p. 127, pi. xlix. figs. 11-13. Rahitat. Station 3, 25 fathoms, January 2nd (day collection). Lat. 4 31' 6" N., long. 6' 4' 44" W., 50 fathoms, January 11th (day collection). Off the Gaboon lliver (lat. 0^ 22' 8" N., long. 8 25' E.), surface, January 29th (night collection). Station 23, surface and 10 fathoms, February 5th (day collection). Lat. 7° 38' S., long. 12' 3' 3" E., surface, February 9th (night collection), &c. Saphirina splendens occurred in 16 tow-nettings — 6 surface and 10 under-surface. The surface tow-nettings comprised 3 day and 3 night collections, the under-surface 9 day collections and 1 niglit collection. The under-surface tow-nettings included one at 2 1 fathoms, four at 10 fathoms, one at 15 fathoms, two at 25 fathoms, and two at 50 fathoms. The annexed formula shows the number of day and night collections : — {3 day collections. o night ditto. xuvv -lie L tings xu ^ ® .10 under-surface j ^ ^^^y ditto. 1 night collection. FROM THE GULF OF GUINEA. 125 Saphirina metallina, Dana. (PI. XII. fig. 4.) 1852. Saphirina metallina, Daua, Crust. U.S. Expl. Exped. p. 1242^ pi. Ixxxvii. fig. 5. 1860. Saphirina cylindrica, Lubbock, Trans. Linn. Soc. vol. xxiii. p. 184, pi. xxix. figs 13-15. 1883. Saphirina metallina, Brady, Report Chall. Copep. p. 128, pi. 1. figs. 11-17. Rahitat. Station 2, 5, 25, and 50 fathoms, January 1st (night collections). Station 3, 100 fathoms, January 2ncl (day collection). Lat. 1" 55' 5" N., long. 5' 55' 5" E., 30, 00, and 360 fathoms, January 22nd (day collections). Station 23, surface, one day and one night collection ; also in one at 20, 85, 135, and 235 fathoms, February 5tli, &c. (day collections). Saphirina metallina occurred in 29 tow-nettings ; only 4 of these were surface, the other 25 being under-surface and ranging in de[)th from 5 to 360 fathoms. The surface gatherings comjirised 1 da}- and 3 night collections, and the under-surface 19 day and 6 night collections, as shown by the annexed formida : — J 1 day collection. rr .,• on/ ^^^^"^'^^^ 1 3 night collections. Tow-nettmgs 29 < ^ o I 25 under-surface [ ^^ "^""^ ^^"«- i 6 night ditto. The form of the caudal stylets in this species makes it readily distinguished from all other Saphiriues. A peculiar appendage of the caudal stylets is, by deep staining, brought prominently into view. The outline of the appendage may be perceived without staining by observing the ditfraction of light around its edges, but it is only by allowing the speci- men to be well soaked in the stain (Kleinenberg's hsematoxylin does very well to stain with) that the appendage can be seen to advantage. It is then observed to possess a narrow oval outline with an acute apex ; a thickened part extends from base to apex like the midrib of a leaf. The whole appendage has thus the appearance of a seta possessing delicate wing-like expansions. Such a leaf -like aj)pendage {cerGophyllnm) has not been noticed in any other species of Saphiri)ia in the 'Buccaneer' collections. These cercophylla probably enable the animal to move with greater rapidity through the water, and thus to be more successful in the struggle for existence. By possessing greater celerity in its movements it would be able to escape more readily from its enemies and be more certain of success in attacking its prey. Whether the cercophylla are used as an additional motive-power or not is at present conjectural, but the study of the animal in the living state should tend to throw some light on the use of these curious organs. Saphiiiina sinuicalda, Brady. 1883. Saphirina sinuicauda, Brady, Report Chall. Copep. p. 129, pi. xlix. figs. 7-10. Rahitat. Lat. 23 4 9" N., long. 5° 22' 2" E., 20 fathoms, January 21st (night collection)'. Station 21., surface, February 6th (day collection). This was one of the rarest of the Saphiriues observed in the ' Buccaneer ' collections, and is distinguished from the other species by the form of the inner branch of the second swimming-foot and of the caudal lamellse. Only two or three specimens in all were obtained. 126 ME. T. SCOTT ON ENTOMOSTEACA Genus Saphirinella, Glaus. Saphirinella, Claus, Die freilebendea Oopepodeu, 1863. Saphirinella stylifera (Lubbock). 1856. Saphirina sttjlifera, Lubbock, Trans. Ent. Soc. vol. iv. p. 28, pi. iv. figs. 9, 10. 1866. Saphirinella stylifera, Claus, Die Copepoden-Fauna von Nizza, p. 17, pi. i. figs. 13, 14. Habitat. Station 2, 5, 25, and 50 fatboms, January 1st (uigbt collections). Station 3, 25, 50, and 100 fatboms day tow-nettings, and 50 fatboms nigbt tow-netting, January 2nd. Lat. 1° 55' 5" N., long. 5' 55' 5" E., 10, 20, 30, 60, 260, aud 3C0 fatboms, January 22nd (day collections). Station 23, surface, 20, 85, 185, and 235 fatboms, February 5tb (day collections). Saphirinella stylifera was obtained in 58 tow-nettings, 37 of wbicb were day and 21 Avere nigbt collections. 47 of tbe collections were under-surface, tbe otbers were surface gatberings, as sbown by tbe annexed formula : — j 1 dav collections, r 11 surface | 7 nigbt ditto. Tow-nettings 58 <^ oq i y,, 1-17 under-surface ( 33 day ditto. 1 11 nigbt ditto. Tbe under-surface tow-nettings included gatherings from 5 to 360 fatboms, in nearly all of wbicb Saphirinella was more or less frequent. Many specimens of Saphirinella were obtained, but tbey all appeared to belong to the one species Saphirinella stylifera (Lubbock). Very few specimens were observed in tbe ' Challenger ' collections, which is the more remarkable considering the number of gatberings and the extensive area represented. Note. — Saphirinella : It has been sbown by Dr. Giesbrecbt that Saphirinella is only tbe male form of Copilia, and that Saphirinella stylifera, Lubbock, is the male of Copilia mirabllis, Dana. Saphirella, nov. gen. (Provisional name.) Anterior antenna? nearly as in Saphirina, 5-jointed. Posterior antennae 3-jointcd. Mandibles stout, each bearing a strong terminal conical tooth, serrate on both margins, and a stout plumose terminal spine. Maxilla? broadly subquadrangular and furnished with a few terminal seta?. Posterior foot-jaws stout, 3-jointed, and armed with a mode- rately strong terminal claw. The swimming-feet arc 2-branched, each branch consists of a single broadly foliaceous joint ; fifth pair rudimentary or obsolete. Saphirella abyssicola, n. sp. (PI. XIII. figs. 57, 58; PL XIV. figs. 5-10.) Length 1'2 mm. Cephalothorax robust ; the first segment, which is about as long as broad, is fully two-fifths tbe length of the whole animal ; the triangular postero-distal angles of tbe second segment are extended backwards to near tbe end of tbe fourth TROM THE GULP OF GUINEA. 1:27 segment. Anterior antennse nearly as in Saphlrina, short, stout, 5-jointed, the third and fourth joints shorter tlian the others ; tlie proportional lengths of the joints are shown l)y the annexed formula : — 12. V.K 10.8 . 12 1 2 3 4~5 ■ Tlie posterior antennae consist of three nearly equal joints, and are furnished with one or two marginal and a number of apical setae, two of the apical setae and one subapical lieing strongly curved, long, and spiniform (PI. XIII. fig. 58). Mandibles stout, armed with a strong terminal conical tooth ; serrate on l)oth edges, and a stout plumose spine ; there are also two stout subapical plumose setre (PI. XIV. fig. 6). Maxillse broadly subquadrangular, bearing one submarginal and a few terminal setie (PI. XIV. fig. 7). The basal joint of the anterior foot-jaws is considerably dilated, and is provided with two stout plumose spines on the inner distal angle ; the last joint is small, about once and a half longer than broad, and Ijears four spines on its truncate ajjex (PL XIV. fig. 8). Posterior foot-jaw stout, 3-jointed, the last joint very small and furnished with a moderately strong and nearly straight claw and a long, spiniform, plain seta ; the first joint bears three setse on its inner distal angle, and there are two setse near the middle of the second joint (PI. XIV. fig. 9). Swimming-feet stout, 2-branched; each branch consists of a single broadly foliaceous joint ; the outer liranch of the first pair carries four stout dagger-shaped marginal and subterminal spines, serrate on both edges, and three terminal plumose setae ; the inner branch carries three similar spines, two plain apical setae, and a seta near the base of the inner margin. The second pair of feet are like the first, but the three dagger-shaped spines on the inner branch are replaced by plumose setae. Only two pairs of feet were observed ; the others wer(^ wautiu!?. The last segment of the abdomen is about twice and a half lon. 23. Abdomen and caudal stvlets. X 20. Scolecithrix major, n. sp. ? . Fig. 24. Anterior foot-jaw. x 76. 25. Terminal spine of outer branch of third swimming-foot. 26. Foot of fifth pair, x 127. X 12/ Fig. 27. Male, lateral view, x 27. 28. Left anterior antenna. X 35. 29. Anterior foot-jaw. x 18. Scolecithrix dubia, Giesbrecht. ^. Fig. 30. Terminal spine of outer branch of fourth swimming foot. X 127. 31. Fifth pail- of thoracic feet. X 84. 32. Abdomen and caudal stylets. X 80. Fig. 33. Female, lateral view, x 18. 34. Anterior antenna. X 22. 35, Anterior foot-jaw. x 95. Scolecithrix tumicla, n. sp. Fig. 36. Terminal spine of outer branch of fourth swimmiug-foot. X 127. 37. Fifth pair of thoracic feet. X 127. 38, Abdomen and caudal stylets, x 27. Fig. 39. Male, lateral view, x 20. 40, Anterior antenna. X 27. 41, Posterior antenna. X 23. 42, Mandible. X 47. Amallophora typica, n. sp. Fig. 43. Maxilla, x 47. 44. Anterior foot-jaw. x 115, 45. Posterior foot-jaw, X 35. 46. Foot of second pair-, x 35. Plate IV. Fig. 1, Foot of third pair, x 35. 2. Foot of fourth pair, x 35. Amallophora typica, n. sp. Fig. 3. Foot of fifth pair, x 57. 4. Abdomen and caudal stylets, x 19* 18. 148 MR. T. SCOTT ON ENTOMOSTEACA Pig. 5. Female, lateral view. X 10. 6. Anterior foot-jaw. X 127. 7. Posterior foot-jaw. x 20. Amallophora magna, n. sp. Fig. 8. Terminal spine of outer brancli of fourth swimming-foot, highly magnified, 9. Foot of fifth pail'. X 125. Pig. 10. Male, lateral view, x 13. 11. Right anterior antenna. X 20. 12. Left anterior antenna. X 20. 13. Anterior foot-jaw. X 95. 14. Posterior foot-jaw. X G3. Amallophora dubia, n. sp. Fig. 15. Foot of first pair, x 63. 16. Foot of fourth pair, x 48. 17. Fifth pair of thoracic feet, x 40. 18. Abdomen and caudal stylets. X 27. Amallophora dubia, var. similis. Fig. 19. Male, lateral view. X 18. 20. Anterior antenna. X 27. 21. Terminal sf)ine of outer branch of fourth swimming-foot. 22. Fifth pair of thoracic feet. X 63. 23. Abdomen and caudal stylets. x 27. X 127. Fig. 24. Female, lateral view. X 13, . 25. Anterior foot-jaw. X 53. 26. Posterior foot-jaw. X 53. Amallophora robusia, n. sp. Fig. 27. Terminal spine of outer branch of fourth swimming-foot. X 127. 28. Fifth pair of thoracic feet. X 95. 29. Abdomen and caudal stylets, x 27. Pig. 30. Male, lateral view, x 22. 31. Anterior antenna, female. X 37. 32. Anterior antenna, male. X 37. 33. Anterior foot-jaw. x 20. 34. Fifth pair of thoracic feet, female X 127. Candace intermedia, n. sp. Fig. 35. Fifth pair of thoracic feet, male, x 67. 36. Abdomen and caudal stylets, female. X 27. 37. Abdomen and X 27. caudal stylets, male. Candace varicans, Giesbrecht. Fig. 38. Abdomen and caudal stylets, female. X 20. 39. Abdomen and caudal stylets, male. X 20. Fig. 40. Male, lateral view, x 9. 41. Anterior antenna, female. X 13. 42. Anterior antenna, male. X 13. 43. Posterior antenna. X 27. 44. Mandible, x 27. 45. Maxilla, x 27. 46. Anterior foot-jaw. X 63. 47. Posterior foot-jaw, female. 48. Posterior foot- jaw, male. 49. Foot of first pair. X 35. Scolecithrix securifrons, n. sp. Fig. 50. Foot of second pair, x 27. 51. Foot of fourth pair. X 20. 52. Fifth pair of thoracic feet, female. X 40. 53. Fifth pair of thoracic feet, male, X 20. 54. Abdomen and caudal stylets, female, dorsal view. X 16. 55. Abdomen and caudal stylets, male, dorsal view. X 13. 56. Abdomen, female, lateral view, x 12, X 40, X 40, FEOM TIIE GULF OF GUINEA. 149 Plate V. Scolecitkrix securifrons, n. sp. Fig. 1. Rostrum, x 27. Scolecitkrix ctenopus, Giesbrecht. S • Fig. 2. Male, lateral view, x 22. 3. Riglit anterior antenna, x 23. 4. Left anterior antenna, x 23. 5. Anterior foot-jaw. X 150. Pig. 6. Posterior foot-jaw. x 127. 7. Foot of third pair. x 46. 8. Foot of fifth pair, x 42. 9. Abdomen and caudal stylets, x 34. Scolecitkrix tenuipes, n. sp. (J . Fig. 10. Male, lateral \dew. 11. Right anterior antenna X 20. X 28. 12. Left anterior antenna, x 28. 13. Anterior foot-jaw. x 115. 14. Posterior foot-jaw. x 115. Fig. 15. Foot of second pair, x 73. 16. Foot of tldrd pair. x 73. 17. Foot of fourth pair, x 57. 18. Fifth pair. X 57. 19. Abdomen and caudal stylets. X 35. Scolecitkrix longicornis, u. sp. ? . Fig. 20. Female, lateral view, x 27. 21. Anterior antenna. X 36. 22. Anterior foot-jaw. X 127. 23. Posterior foot-jaw. X 85. 24. Foot of first pair. X 64. Fig. 25. Foot of second pair, x 76. 26. Foot of third pair, x 64. 27. Foot of fifth pair. X 250. 28. Abdomen and caudal stylets. Scolecitkrix Bradyi, Giesbrecht. X 53. Fig. 29. Male, lateral %-iew. x 18. 30. Anterior antenna, female. X 48. 31. Anterior antenna, male. X 53. 32. Posterior antenna, x 95. 33. Mandible. X 63. 34. Anterior foot-jaw. X 170. 35. Posterior foot-jaw. X 95. Fig. 36. Terminal spine of outer branch of one of. the swimming-feet, x 170. 37. Fifth pair of thoracic feet, male. X 53 38. Abdomen and caudal stylets, female. X 40. 39. Abdomen and caudal stylets, male. X 32. Scolecitkrix latipes, n. sp. ? . Fig. 40. Female, lateral dew. x 12. 41. Anterior antenna. X 18 Fig. 42. Anterior foot-jaw. x 25. 43. Rostrum, x 27. Fig. 44. Female, lateral view. Scolecitkrix major, n. sp. X 18. I Fig. 45. Abdomen and caudal stylets. X 20. Fig. 46. Male, lateral view, x 13. 47. Anterior antenna. X 13. 48. Posterior antenna. X 23. Calanus comptus, Dana. ^ . Fig. 49. Mandible, x 35. 50. Maxilla, x 35. 150 ME. T. SCOTT ON ENTOMOSTEACA Plate VI Calanus comptus, Dana. ^ . Fig. 1. Posterior foot-jaw. X 56. 2. Foot of first pair. X 35. 3. Termiaal spine of outer brancli of first swimming-foot, greatly magnified. 4. Foot of fourth pair. X 23. 5. Foot of fifth pair. X 23. Hemicalanus plumosus, Clans. Fig. 6. Anterior foot-jaw. X 27. Calocalanus plumulosus (Claus) . Fig. 7. Female, lateral view. X 35. | Fig. 8. Anterior antenna. X 53. Calocanus pavo (Dana). Fig. 9. Female, dorsal view. X 53. | Fig. 10. Fifth pair of thoracic feet. X 115. Pleuromma gracile, Claus. Fig. 11. Male, dorsal view. X 17'5. 12. Right anterior antenna of the same. X 23. 13. Left anterior antenna of the same. X 35. 14. 14th joint of left anterior antenna. X 415. Euchirella messinensis (Claus). Fig. 15. Male, dorsal view, x 7-6. | Fig. 16. Posterior antenna. X 20. Euchata barbata, Brady. Fig. 17. Male, dorsal view. X 6*5. Euchceta hebes, Giesbrecht. Fig, 18. Male, lateral view. X 13. | Fig. 19. Fifth pair of thoracic feet. X 26. Euchceta hebes, var. valida. Fig. 20. Male, lateral view. X 5-8. 21. Terminal spine of outer branch of fourth swimming-feet. X 63. 22. Fifth pair of thoracic feet. X 13. Euchceta australis, Brady. Fig. 23. Female, dorsal view. X 9. Euchceta (?) Hessei, var. similis. Fig. 24. Male, lateral view. X 18. | Fig. 25. Fifth paii- of thoracic feet, x 53. Phyllopus bidentatus, Brady. Fig. 26. Male, dorsal view, x 10. 27. Mouth as seen from the side (a, outline, seen from above), highly magnified. 28. Fifth pair of thoracic feet. X 43. J PEOM THE GFLF OP GIJINEA. Pontellopsis villosa, Brady. 151 Kg. 29. 30. 31. Male, dorsal view, x 13. Anterior antennaj male, x 20. Posterior antenna, x 26. Fig. 32. Fifth pair of thoracic feet, female. x63. 33. Fifth pair of thoracic feet, male, x 53. 34. Abdomen and caudal stylets, x 35. Phaenna spinifera, Claus. Fig. 35. Male, lateral \'iew. x 13. Labidocera detruncata, var. intermedia. Pig. 36. 37. Fig. 39. 40. Fig. 43. 44. 45, Posterior foot-jaw. x 41. Fifth pair of thoracic feet, female, x 76. Fig. 38. Fifth pair of thoracic feet, male, X 34. Labidocera Darwinii (Lubbock). Posterior foot-jaw. X 50. Fifth pair of thoracic feet, female. X 63. Fig. 41. Fifth pair of thoracic feet, male. X 50. 42. Abdomen and caudal stylets, female. X 38. Pontella mediterranea, Claus. Female, dorsal view. X 13. Anterior antenna, female (and rostrum). X 27. Hinged joints of right anterior antenna, male. X 63. Fig. 46. Posterior foot-jaw. X 48. 47. Fifth pair of thoracic feet, female (? immature), x 100. 48. Fifth pair of thoracic feet, mael. X 63. Plate VII. Phaenna spinifera, Claus. Fig. 1. Anterior foot-jaw. x 95. | Fig- 2. Fifth pair of thoracic feet. X 50. Labidocera detruncata, var. intermedia. Fig. 3. Female, lateral view, x 13. | Fig. 4. Anterior antenna, male. X 20. Labidocera Darwinii (Liibbock). Fig. 5. Male, dorsal view, x 18. Fig. 6, Hinged joints of right anterior antenna, male. X 50. Candace varicans, Giesbrecht. Fig. 7. Anterior antenna, female, x 24. 8. Eight anterior antenna, male, x 24. Fig. 9. Fifth pair of thoracic feet, female. X 95. 10. Fifth pair of thoracic feet, male. X 95. Mormonilla phasma, Giesbrecht. Fig. 11. Female, lateral view, x 27. 12. Anterior antenna, x 32. 13. Posterior antenna, x 63. 14. Mandible. X 50. 15. Maxilla. X 50. 16. Anterior foot-jaw. x 76. Fig. 17. Posterior foot-jaw. X 95. 18. Foot of first pair, x 95. 19. Foot of second paii'. x 95. 20. Foot of fourth pair. X 76. 21. Abdomen and caudal stylets. X 53. 152 ME. T. SCOTT ON ENTOMOSTEACA Acartia plumosa, n. sp. -Fig. 23. Female, dorsal view, x 32. 23. Anterior antenna, female. X 63. . 34. Right anterior antenna, male. X 63. 25. Hinged joints of male right anterior antenna, x 253. 26. Foot of first pair. X 95. 27. Foot of fourth pair, x 7Q. 28. Fifth pair of thoracic feet, female (front view). X 153. Fig. 29. Foot of fifth pair, female (side view). X 153. 30. Fifth pair of thoracic feet, male. X 153. 31. Abdomen and caudal stylets, female. X 50. 32. Abdomen and caudal stylets, male. X 50. Acartia Clausi, Giesbrecht. Fig. 33. Male, dorsal view. X 32. 34. Anterior antenna, female. X 63. 35. Right anterior antenna, male («, hinged joints more magnified) . X 63. 36. Foot of fourth pair, x 95. 37. Fifth pair of thoracic feet, female. X 125. Fig. 38. Fifth pair of thoracic feet, male. Xl53. 39. Abdomen and caudal stylets, female, X 50. 40. Abdomen and caudal stylets, male. X 50. . Paracartia dubia, n. sp. Fig. 41. Left anterior antenna of male. X 63. Fig. 42. Fifth pair of thoracic feet, male. X 127. Plate VIII. Paracartia spinicaudata, n. sp. ? . X 40. X 63. X 127. X 127. Fig. 1. Female, dorsal view 2. Anterior antenna. 3. Posterior antenna. 4. Mandible and palp. 5. Maxilla, x 127. 6. Anterior foot-jaw. X 127 Fig. 12. Male, dorsal view. X 27. 13. Right anterior antenna, x 63 Fig. 7. Posterior foot-jaw. x 127. 8. Foot of first pail-, x 127. 9. Foot of fourth pair, x 95. 10. Fifth pair of thoracic feet. 11. Abdomen and caudal stylets. X 127. X 95. Paracartia dubia, n. sp. (J . Fig. 14. Foot of fourth pair. X 95. 15. Abdomen and caudal stylets. X 63. radius armiger, Giesbrecht. Fig. 16. Female, dorsal view, x 20. 17. Male, lateral view. X 21. 18. Anterior antenna. X 21. 19. Posterior antenna, x 23. 20. Mandible and palp. X 38. 21. Anterior foot-jaw. X 47. Fig. 22. Posterior foot-jaw. x 39. 23. Foot of first pair, x 57. 24. Foot of second pair. X 57. 25. Foot of fourth pair, x 42. 26. Fifth pair of thoracic feet, x 85. 27. Abdomen and caudal stylets, x 39. J PROxM THE GULF OF GUINEA. 153 Clausocalanus latipes, n. sp. ^ . Fig. 28. Riglit anterior antenna. X 59. 29. Mandible and palj). X 115. 30. Anterior t'oot-jaw. X 115. 31. Posterior foot-jaw. X 115. 32. Foot of first pair. X 86. Fig. 33. Foot of seeond pair. X 86. 34. Foot of tliird pair. X 86. 35. Foot of fonrth pair. X 86. 36. Fifth pair of tlioracic feet. X 2-30. 37. Abdomen and caudal stylets. X 57. Clausocalanus urcuicoriiis, Dana, cj . Fig. 38. Male, lateral view, x 23. 39. Anterior antenna. X 35. 40. Posterior antenna. X 23. 41. Mandible palp. X 85. 42. Maxilla. X 113. Fig. 43. Anterior foot-jaw X 276. 44. Posterior foot-jaw. X 172. 45. Foot of first pair. X 115. 46. Fifth pair of tlioracic feet. X 115. 47. Abdomen and caudal stylets. X 57. Temoropia inaijtiinbaetisis, n. sp. Fig. 48. Right anterior antenna of male. X 88. i Fig. 49. Mandible and palp. X 63. 1. Male, dorsal view. X 53. 2. Posterior antenna. X 83. 3. Maxilla. X 95. 4. Anterior foot-jaw. X 190. 5. Posterior foot-jaw. X 63. 6. Foot of first pair. X 152. Plate IX. Temoropia mayumbaensis, n. sp Fi 7. Inner branch of seeond thoracic feet. X 95. 8. Fifth pair of tlioracic feet, female. X 95. 9. Fifth pair of thoracic feet, male. X 95. 10. Abdomen and caudal stylets, female, dorsal view. X 63. 11. Abdomen of female, lateral view. x63. 12. Abdomen and caudal stylets, male. x63. Temora Jongicornis (M tiller). Fig. 13. Fifth pair of thoracic feet, male. X 95. Oithona minuta, n. sj). Fig. 14. Female, dorsal view, x 72. 15. Anterior antenna, female, x 169. 16. Anterior antenna, male, x 230. 17. Posterior antenna, x 230. 18. Mandible, x 270. 19. Mandible palp, x 2.30. 20. Anterior foot-jaw. X 230. SECOND SERIES. — ZOOLOGY, VOL. VI. Fig. 21. Posterior foot-jaw. X 345. 22. Foot of first pair. X 230. 23. Foot of fourth pair. X 2.30. 24. Abdomen and caudal stylets, female (a, fifth pair of feet). X 127. 25. Abdomen and caudal stylets, male. X 200. 20 154 ME. T. SCOTT ON ENTOMOSTEACA Fig. 26. Female, lateral view. X 42. 27. Anterior autenua, female. X 230 28. Posterior anteuua. X 127. 29. Mandible and palp. X 35. 30. Anterior foot-jaw. X 253. 31. Posterior foot-jaw. X 253. Fig. 36. Female, lateral view, x 53. 37. Anterior antenna. X 460. 38. Posterior antenna. X 170. 39. Anterior foot -jaw. X 460. 40. Posterior foot-jaw. X 345. Ectinosoma Chry stall, n. sp. Fig. 32. Foot of first pair of swimming-feet. X 138. 33. Foot of fourth pair of swimming-feet. X 127. 34. Foot of fifth pair. X 190. 35. Last abdominal segments and caudal stylets. X 95. Bradya brevicornis, n. sp. Fig. 41. Foot of first pair. X 190. 42. Foot of fifth pair. X 190. 43. Last abdominal segments and caudal stylets. X 95. Fig. 44. Female, lateral view. X 63. 45. Anterior antenna. X 190. Amymone Andreun, n. sp. Fig. 46. Posterior antenna. X 190. 47. Anterior foot-jaw. X 380. Plate X. Amymone Andrewi, n. sp. Fig. 1. Posterior foot-jaw. X 253. Fig. 2. Female, lateral view. X 53. 3. Anterior antenna. X 253. 4. Posterior antenna. X 190. 5. Mandible and palp. X 380. 6. Maxilla. X 190. 7. Anterior foot-jaw. X 253. Fig. 13. Female, lateral view. X 53. 14. Anterior autenua. X 253. 15. Posterior antenna. X 380. 16. Mandible aud palp. X 380. 17. Maxilla. X 500. 18 Anterior foot-jaw. X 253. Stenhelia accraensis, n. sp. Fig. 8. Posterior foot-jaw. X 253. 9. Foot of first pair. X 152. 10. Foot of fourth pair. X 152. 11. Foot of fifth pair. X 126. 12. Last abdominal segments and caudal stylets. X 63. Laophonte hnr/ipes, n. sp. Fig. 19. Posterior foot-jaw. X 190. 20. Foot of first pair. X 190. 21. Foot of fourth pair, x 190. 22. Foot of fifth pair. X 190. 23. Last abdominal segments aud caudal stylets. X 95. Laophonte pygmasa, n. sp. Fig. 24. Female, lateral view, x 53. 25. Anterior antenna. X 253. 26. Posterior foot-jaw. X 253. 27 Foot of first pair. X 253. Fig. 28. Foot of fourth pair. X 253. 29. Foot of fifth pair. X 253. 30. Last abdominal segments and caudal stylets. X 127. PEOM THE GULF OF GUINEA. 155 Laophonte brevicornis, ii. sp. Fig. 31. Female, lateral view. x 53. 32. Anterior antenna, x 253. 33. Posterior foot-jaw. x 253. 34. Foot of first pair, x 253. Fig. 38. Female lateral view, x 33. 39. Anterior antenna, x 190. 40. Posterior foot- jaw. x 253. 41. Foot of first pair. x 190. Fig. 35. Foot of fourth pair, x 253. 36. Foot of fifth pair, x 253. 37. Last abdominal segments and caudal stylets. X 126. Dactijlopus lut'qws, n. sp. Fig. 42. Foot of fifth pair. x 127 last ab( stylets. X G3. 43. Last abdominal segments and caudal Dactylopus propinquus, n. sp. Fig. 44. Female, lateral view. x 53. 45. Anterior antenna, female. x 190. 46. Anterior autenuaj male. x 253. 47. Posterior antenna, x 253. 48. Posterior foot-jaw. x 253. Fig. 49. Foot of first pair, x 190. 50. Foot of fifth pair, female, x 190. 51 . Foot of fifth pair, male, x 190. 52. One of the appendages of first abdominal segment, male, x 190. Plate XI. Badylopus propinquus, u. sp. Fig. 1. Foot of second pair of swimming-feet, male, x 190. 2. Foot of third pair of swimming-feet, male, x 190. 3. Last abdominal segments and caudal stylets, x 95. Ilyopsyllus affinis, n. sp. Fig. 4. Female, dorsal view, x 60. 5. Female, lateral view, x 60. 6. Anterior antenna, female. X 250. 7. Anterior antenna, male. X 250. 8. Posterior antenna. X 330. 9. Mandible and palp, x 380. 10. Maxilla and (?) oral aperture. X 500. Fig. 11. Anterior foot-jaw. x 500. 12. Posterior foot-jaw. x 330. 13. Foot of first pah-. x 190. 14. Foot of third pair. X 152. 15. Foot of fifth pair, female, x 500. 16. Abdomen and caudal stylets, x 95. 17. Rostrum, x 300. Mir acta minor, n. sp. Fig. 18. Female, lateral view, x 53. 19. Anterior antenna, female. X 152. 20. Anterior antenna, male. X 190. 21. Posterior antenna. X 190. 22. Posterior foot-jaw, female. X 253. 23. Posterior foot jaw, male. X 253. 24. Foot of first pair. X 108. Fig. 25. Foot of second pair, female, x 108. 2Q. Foot of second pair, male, x 108. 27. Foot of third pair, x 108. 28. Fifth pair of thoracic feet, female. X 95. 29. Foot of fifth pair, male, x 190. 30. Abdomen and caudal stylets, x 76. 20* 156 MR. T. SCOTT ON ENTOMOSTKACA ^gisthus longirostris, n. sp. Fig. 31. Female, dorsal view. X 20. 32. Female, side view. X 18. 33. Anterior antenna, female. X 53. 34. Anterior antenna, male. X 32. 35. Posterior antenna, x G3. 36. Mandible. X 190. 37. Maxilla. X 140. Fig. 38. Anterior foot-jaw. X 190. 39. Posterior foot-jaw, female. X 95. 40. Posterior fout-jaw, male. X 95. 41. Foot of first pair, x 40. 42. Foot of fourth pair. X 40. 43. Fifth pair of thoracic feet. X 53. 44. Extremity of one of the stylets. X 190. Fig. 45. Adult dorsal view. X 10"7. 46. Anterior antenna. X 63. 47. Posterior antenna. X 40. Copilia Fultoni, n. sp. Fig. 48. Mandible. 9- 01 . 49. Ma.xilla. X 190. 50. Anterior foot-jaw. X 253. Plate XII. Cojiilia Fultoni, n. sp. Fig. 1. Posterior foot-jaw. X 20. 2. Foot of fourth pair of swimming-feet, x 63. 3. Abdomen and caudal stylets {a, fifth foot). X 26. Saplmina metalUna, Dana. Fig. 4. One of the caudal stylets with leaf-like appendages (cercophijlla). X 125. (?) Artotrogus abyssicolus, n. sp. (?) d , Fig. 5. Adult, dorsal view. X 27. 6. Anterior autenna. X 63. 7. Posterior antenna. X 253. Fig. 8. Posterior foot-jaw. X 253. 9. Abdomen and caudal stylets. X 84. Longipedia minor, T. & A. Scott. Fig. 10. Male, lateral view, x 53. 11. Foot of second pair. X 84. 12. Fifth pair of thoracic feet and appendages of first abdominal segment. 13. Last abdominal segments and caudal stylets. X 153. Euterpe gracilis, Claus, var. annata, n. var. X 190. Fig. 14. Female, lateral view, x 53. 15. Anterior antenna. X 190. 16. Anterior antenna. X 190. 17. Mandible. X 190. 18. Maxilla. X 190. Fig. 24. Female, lateral view, x 53. 25. Anterior antenna. X 190. 26. Foot of first pair, x 153. Fig. 19. Anterior foot-jaw. x 190. 20. Posterior foot-jaw. X 253. 21. Foot of first pair. X 190. 22. Foot of fourth pair. X 190. 23. Fifth pair of thoracic feet. X 190. Laophonie serratu, Claus. Fig. 27. Foot of fifth pair, x 127. 28. Last abdominal segments and caudal stylets. X 95. FEOM THE GULF OF GUI^VEA. Cletodes linearis, Cliius. 157 Fig. 29. Female, lateral view, x 53. 30. Anterior auteuna, female. x 190. 31. Foot of fifth pair, female. x 153. Fig. 32. Fifth pair of thoracic feet (a), and ap- pendages [b) of first abdominal seg- ment. X 153. Thalestris forficula, Clans. Fig. 33. Female, lateral view, x 53. 34. Anterior antenna, x 190. 35. Posterior antenna, x 190. 36. Anterior foot-jaw. x 253. 37. Posterior foot-jaw. x 253. Fig. 38. Foot of first pair. x 153. 39. Foot of fonrth pair, x 153. 40. Foot of fifth pair, x 153. 41. Last abdominal segments and caudal stylets. X 127. Harpacticus chelifer, Midler, var. Fig. 42. Male, lateral view, x 20. 43. Posterior foot-jaw. x 76. 44. Foot of first pair, x 50. Fig. 45. Foot of second pair, x 50. 46. Foot of fifth pair. x 127. Clytemnestra rosiraia (Brady). Fig. 47. Female, lateral view. x 32. 48. Female, dorsal view, x 32. 49. Male, dorsal view, x 32. 50. Anterior antenna, female, x 95. 51. Anterior antenna, male. x 95. 52. Posterior antenna, x 127. Fig. 53. Jlandible and palpi, x 253. 54. Maxilla. x 380. 55. Anterior foot-jaw. x 253. 56. Posterior foot-jaw, female, x 127. 57. Posterior foot-jaw, male. x 95. Plate XIII. Clytemnestra rostra fa (Brady). Fig. 1. Foot of first pair of swimming-feet, x 95. 2. Foot of second pair of swimming-feet. x 95. 3. Foot of fifth pair of swimming-feet, x 127. Fig. 4. Female, dorsal view. x 53. 5. Anterior antenna, x 53. 6. Posterior antenna, x 84. 7. Mandible, x 153. 8. Maxilla, x 153. Onccea gracilis (Dana). Fig. 9. Anterior foot-jaw. x 127 10. Posterior foot-jaw. x 95 11. Foot of fourth pair, x 95. 12. Abdomen and caudal stylets [a, fifth feet). X 50. OncdRa mediterranea (Claus). Fig. 13. Female, dorsal view, x 53. 14. Anterior antenna, x (53. 15. Posterior antenna, x 100. Fig. 16. Posterior foot-ja^v. x 95. 17. Foot of fourth pair, x 127. 158 MR. T. SCOTT ON ENTOMOSTEACA Fig. 18. Adult, dorsal view, x 18. 19. Anterior antenna. x 48. 20. Posterior antenna. x 63. 21. (?) Mandible, x 190. Fig. 25. Male, dorsal view, x 53. 26. Anterior antenna, x 100. 27. Mandible, x 190. Pachysoma punctata, Claus. Fig. 22. (?) Maxilla, x 153. 23. (?) Anterior foot-jaw. x 253. 24. Foot of fourth pair, x 50. Cyclopicera lata, Brady. Fig. 28. Maxilla, x 153. 29. Foot of fourth pair, x 100. 30. Foot of fifth pair, x 190. Hersiliodes Liviriffstoni, n. sp. Fig. 31. Female, dorsal view. x 27. 32. Anterior antenna, x 127. 33. Posterior antenna, x 95. 34. ??i.. Mandible ; w.r., Maxilla; Mouth. X 127. Fig. 35. Anterior foot-jaw. Posterior foot-jaw. X 127. 36. Foot of first pair, x 76. 37. Foot of fourth pair. x 76. 38. Foot of fifth pair, x 48. Fig. 39. Female, dorsal view, x 35. 40. Anterior antenna. x 127. 41. Posterior antenna, x 127. 42. Mandible. x 253. 43. Maxilla. x 253. Lichomolyus congoensis, n. sp. Fig. 44. Anterior foot-jaw. x 253. 45. Posterior foot-jaw. x 190. 46. Foot of fourth pair. x 135. 47. Foot of fifth pair, x 190. 48. Abdomen and caudal stylets. X 84. Fig. 49. Male, dorsal view. 50. Anterior antenna. 51. Posterior antenna. 52. Mandible, x 190. 53. Maxilla, x 253. Pseudaiithessius propinquus, u. sp. x 35. x 170. X 135. Fig. 54. Posterior foot-jaw, female, x 84. 55. Foot of first pair. x 135. 56. Abdomen and caudal stylets, female. X 40. Saphirella abysslcola, n. sp. Fig. 57. (?) Adult, dorsal view, x 25. | Fig. 58. Posterior antenna, x 125. Plate XIV. Pseudanthesshis jjropinrjuus, n. sp. Fig. 1. Anterior foot- jaw. x 190. 2. Posterior foot-jaw, male, x 53. 3. Foot of fourth pair of swimming-feet. X 135. 4. Foot of fifth pair, x 127. FEOM TILE GULF OF GUINEA. 159 Saphirella abyssicola, n. sp. Fig. 5. Anterior antenna, x 125. 6. Mandible, x I'JO. 7. Maxilla. X 152. Fig. 8. Anterior foot-jaw. X 190. 9. Posterior foot-jaw. X 170. 10. Foot of first pair of swimming- feet, x 95. Arlrotrogus abi/ssicohis, n. sp. Fig. 11. Female, dorsal view, x 35. 12. Anterior antenna, x 127. 13. Posterior antenna. x 135. 14. Mandible, x 253. 15. Anterior foot-jaw. x 152. Fig. 16. Posterior foot-jaw. X 152. 17. Foot of first pair of swimming-feet. X 100. 18. Foot of fourth pair of swimming-feet. X 95. Caliyus Murrayanus, n. sp. Fig. 19. Adult, ventral view, x 17. Caliyus bengoensis, n. sp. Fig. 20. Adult, ventral \ievi. x 19. (?) Caligus Thymni, Dana. Fig. 21. Adult, ventral view, x 8. Caligus dubiiis, n. sp. Fig. 22. Adult, ventral view, x 12-5. Nogagus validus, Dana. Fig. 23. Adult, ventral view, x 7-5. Pontojisyllus elongatus, n. g. et sp. Fig. 24. Adult, dorsal view. X 20. 25. Anterior antenna. X 135. 26. Posterior antenna. X 84. 27. jNIandible (w.) and maxilla (»2cr.). X 190. 28. One of tlie foot-jaws, x 125. Fig. 29. Foot of fourth pair of swimming-feet. X 95. 30. (?) Immature form ; (*.) sucking-disk. X 60. Cypria atlantica, n. sp. Fig. 31. Shell seen from the side, x 40. 32. Shell seen from above. X 40. Fig. 33. Shell seen from the side (young), x 46. Phlyctenophora afncana, n. sp. Fig. 34. Shell seen from the side. X 27. | Fig. 35. Shell seen from above. X 27. Pontocypris trigonella, G. O. Sars. Fig. 36. Shell seen from the side. X 27. I Fig. 37. Shell seen from above. X 27. Pontocypris subreniformis, n. sp. Fig. 38. Shell seen from the side. X 44. Fig. 39. Shell seen from above. x44. 160 ME. T. SCOTT ON ENIOMOSTEACA Bairdia inornata, n. sp. Fig. 40. Shell seen from the side. X 37. | Fig. 41. Shell seen from above. X 37. Ctjthere multicatxi, n. sp. Fig. 42. Shell seen from the side. X 32. | Fig. 43. Shell seen from above. x32. Cijthere sculptU'is, u. sp. Fig. 44. Shell seen from the side. X48. | Fig. 45. Shell seen from above. x48. Gythere rimosa, n. sp. Fig. 46. Shell seen from the side. x40. | Fig. 47. Shell seen from above. X40. Cythere thalassica, n. sp. Fig. 48. Shell seen from the side. X 30. | Fig. 49. Shell seen from above. X 30. Cythere venusta, u. sp. Fig. 50. Shell seen from the side. x28'5. | Fig. 51. Shell seen from above. x28'5. Cytherura simulans, n. sp. Fig. 52. Shell seen from the side. X 54, | Fig. 53. Shell seen from above. X 54. Cytheropteron trilobites, Brady. Fig. 54. Shell seen from the side. x40'5. | Fig. 55. Shell seen from above. x40"5. Asterojje squamiger, n. sp. Fig. 56. Shell seen from the side. X 22. | Fig. 57. Shell seen from above. X 22. Sarsiella Murrayana, n. sj). Fig. 58. Shell seen fi'om the side. X 27. Plate XV. Fig. 1. Halocypris elungata, n. sp. Shell seen from the side. X 8'5. 2. „ ,, n. sp. Shell seen from above. X 8"5. 3. „ torosa, n. sp. Shell seen from the side. X 7. 4. „ ,, n. sp. Shell seen fi'om above. X 7. 5. „ aculeata, n. sp. Shell seen from the side. X 30. 6. ,, „ u. sp. Shell seen from above. X 30. 7. „ jnmica, n. sp. Shell seen from the side. X 32. 8. „ ,, u. sp. Shell seen from above. X 32. 9. Cytherella africana, n. sp. Shell seen from the side. X 28"5. 10. ,, „ n. sp. Shell seen from above. X 28'5. 11. „ pumila, n. sp. Shell seen from the side. X 40. 12. „ „ n. sp. Shell seen from above. X 40. 13. Cythere multicava, n. sp. Antennule. X 95. 14. Asterope squamiger, u. sp. Antennule. X 54. 15. Cythere multicava, n. sp. Antenna. X 95. FKOM THE GULF OF GUINEA. 161 Fig. 16. Ci/jjria utlanlica. Shell structure higlily magiiififd. 17. Phlijctcnopliora africana, n. sp. Oue ol' the auteunules. X 95. 18. „ ,, n. sp. One of the antennae, x 127. 19. ,, „ n. sp. The post-abdomen, x 95. 20. Cypria atlantica, ii. sp. One of the anteunie. X 127. 21. „ ,, n. sp. Oue of tlie antcnuules. x 95. 22. Asterope squamiger, n. sp. One of the antenna;. X 5i. 23. „ „ n. sp. The post-abdomcu. X 27. 24. SaraleUa Miirrayanu, w. s[i. One of the antcnuules. X 54. 25. Cypria ai/anticti, n. sp. The post-abdomcu. X 127. 20. Asterope squamiger, u. sp. One of the first maxilhe. X 54. 27. Halocypris cloiigutu, u. sp. One of the autcuua;. 28. Sarsiella Murrayana, u. sp. Ovigerous foot, x 190. 29. ,, „ n. sp. One of tlie auteuuic. X 80. 30. Halocypris eloiigata, u. sp. One of tlie antcnuules. 31. Sarsiella Murray ana, u.s^. The post-abdomen, x 127. 32. Halocypris torusa, n. sj). Oue of the antcnuules. x 13. 33. „ aculeatu, n. sp. Oue of the autcuuules (female), x 54. 34. „ „ n. sp. Oue of the autenuaj. X 27. 35. „ torosa, u. sp. First foot. x 13. 30. Cytlierella africana, n. !ip. One of the anterior antciui;e. X 95. 37. Halocypris torosa, u. sp. One of the antenuic. X 13. 38. „ «c'«/('a/«, n. sp. One of the antcnuules (male), x 40. 39. .., pmiica, n. sp. One of the autenuulcs. x 51. 40. „ „ n. sp. Oue of the autcuuffi. x 54. 41. Cytfierella a/ricana, n. up. Oue of the posterior autennie. X 95. 42. „ „ u. sp. The post-abdomen, x 95. SECOND SERIES. — ZOOLOGY, VOL. VI. 21 T-RANs LiNN-Soc .5ee..2.Zool.VoiM.T1.1. •-r(7vr ^jc^ , aei. . eo. r-ar ilNTOMOSTRACA FROX GULF OF C-LTIl^niA. \ Trai^s.Linn.Soc.Ser^?. Zool yohVlPi..2 1/ m / X'AW^ jfe..;r<^.- S..,-.,,l£.^^. TraNS.L inn. SoC . Sf.R.2;.Z0OL YoL YI .PI , 3 . \ I llii/m ; J Cartev s.c ENTOMOSTRACA FROM GULF OF GUINtA ■Wf^-.H^wmantCimp Traus.Linn.Soc .Ser.E.Zool.Vol^^^'.PI. 4 ■"- -ot-t ,iiel .ad iji..\.. ENTOMOSTKACA -pROM GULF OT GUINEA Wt-t*. l-I^v/iiian a. O Scoll TRANS.LTNN.S0C.SER.2.Zo0L.V0Lyi.PL.5. EMTOMOSTRACA ?R01./r GULF OF GUINZA. - '., :irvnT>'T\ i. ,5 uno 3 coll 1 A AN: \ ^^~^?ijy^i^i^^,ifcliS3>- ;'« / ir- \ J3 ^Ult»ff ■- iL^xe^v . car*. .deliSci- nait . ENTOMOSTKACA FROM GulI-OP GUINEA. bcolL. TransIinn .Soc .Ser.2.Zool .VolM-PI .7. -' Carter sc. EWTOMOSTRAC^ TROM GULF OP GUINEiV V/r-,*,,M<:wmar! S. C'lmp . ScoU T RANs.L INN . Soc . Ser.2 .ZooLYoLT'/r . P 1 . 9 . C. Carter «. £NTOMOSTRACA PROM GIILT OF G tJTNIA ■s' JIs-,vavan ', C 'mp Scott. Trans. Linn. Soc.SerP Zool.Vol.'^-IPI.JO. y'-i'ii-Dv-- ;'•■.■!£. Oel a6 r^i V^fft,Nffv,Tnar-- ■. ENTOMOSTRACA FROM GULP OF GUrNRA. Soott. Trams. Limit Sc:-. ?e.-r2. VL.Fin. Andrew Scott del ai Tiat. F.NTOMOSTRACA FPvOl/T GULF OF GUINEA Wesx. r'ie>i-ji3J3 5:C? .)Ci 'I,, I. Trans. Lin N. Soc . Si:r.2 , ZoohNoh}!] PL 12 . 'iffejt,N-wni,5ii «. C : ENIOMOSTRACA FROM GULP OP GUnKTEA. 'I'RAtlsLlMN.Soc.OER S.ZOOL VolV[.1-'1 13. EMTOMOSTRACA FROM GULF OF GUINEA "//cTt.NfWEfiaiJ J.'- ' ScoLL. TRANs.LrNN.Soc.Zool.SEB,.2.VbI\'iP1.14. ^^.> 'f 21 # 21 a K ■^:|- ^•9 %: ^- ',-'^ ■^. A/ J; 2:3 ' I ^f l-^- f ?8 "^in -/■■ rtii ,«^ V, trf^ X W 6 f% .iJ'?-!. f% J2 ^^ '^ ^e? ■Hir" ^^E Xii^- , 50 '> 1. 51 AnoLre-w Sg- :>tx d^.adi \i 3J J^J J6 '*■•- ■ «rA^ ENTOMOSTRACA FROM GULF OF GUmEA. 5« ■.v^t :^£r.-/TW^Ln,litl\. Scott. Trails. LiNTsr. Soc.Zoo1.Ser. 2 .Vol\ .PI 15. 4V\ 5 X li — «^-4;i. X ,<«i ^^ ,rv * .V-?^V! ■4, V v. ./ / kTT^/' v-s A-TKice^^ Sf-ott dp-l -ad na' WeBt. .Nevcm^-tr- lim. EKTTOMOSTRACA FROM GUIF OE GUINEA. LINNEAN SOCIETY OF LONDON. MEMORANDA CONCEllNING TJIANSACTIONS. Tlie First Scries of tho Transactions, containing both Botanical and Zoological contributions, has been completed in 30 Vols., and a few entire sets are still for sale. Only certain single volumes, or parts to complete sets, may be obtained at the original prices. The price of the Index to Vols. 1-25 is 8s. to the public, and 6s. to Fellows ; to Vols. 26-30, 4s. to the public, and 3s. to Fellows Tho Second Series of the Transactions is divided into Zoological and Botanical sections, various parts wliich have been published of these are aa undermentioned : The prices of the Volume. VThen Published. Price to the Public. £ s. d. Second Series.— Zoology. I. Part I. 1875 1 4 0 . . Part II. 1875 0 6 0 . . Part III. 1876 ] 8 0 . . Part IV. 1877 0 16 0 . . Part V. 1877 0 18 0 . . Part VI. 1877 1 2 0 . . Part VII. 1878 1 16 0 . . Part VIII. 1879 1 0 0 .. II. Part I. 1879 1 4 0 , . Part II. 1881 0 15 0 . . Part III. 1882 1 8 0 . . Part IV. 1882 0 7 6 . . Part V. 1882 0 3 0 .. Part VI. 1883 1 0 0 . . Part Yll. 1883 0 5 0 . . Part VIII. 1883 0 3 0 .. Part IX. 1883 0 3 0 . . Part X. 1884 0 4 6 . . Part XL 1884 0 10 0 . . Part XII. 1885 0 6 0 . . Part XIII. 1884 0 6 0 .. Part XIV. 1885 0 6 0 . . Part XV. 1885 0 4 6 . . Part XVI. 1885 0 5 0 . . 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THE G^^-L TRANSACTIONS OF A THE LINNEAN SOCIETY OF LONDON. THE SUBTERRANEAN CRUSTACEA OF NEW ZEALAND; WITH SOMK GENERAL REMARKS ON THE FAUNA OP CAVES AND WELLS. BY CHAULES CHILTON, M.A., D Sc, F.L.S., RECTOR, DISTRICT HIGH SCHOOI., PORT CHALMERS, NEVf ZEALAND. LONDON PRINTED FOE, THK LINNEAN SOCIETY BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. SOLD AT THE SOCIETY'S APARTMENTS, BURLINGTON-HOUSE, PICCADILLY, W., AND BY LONGMANS, GREEN, AND CO., PATERNOSTER-ROW. ■^ 3I(nj 1894. [ 163 ] II. The Subterranean Crustacea of New Zealand: with some general Remarks on the Fauna of Caves and Wells. By Charles Chilton, M.A., B.Sc., F.Z.S., Rector, District High School, Port Chalmers, Neto Zealand. Eead 20th April, 1893. (Plates XVI.-XXIII.) Contents. Page I. Introduction 163 II. Historical Sketch 165 III. History, Distribution, and Occurrence ol the New Zealand Subterranean Crustacea 180 IV. Detailed Descriptions of the New Zealand Subterranean Crustacea 185 Isopoda. The Genus Phreatoicus : P. assiinilis, sp. nov. ; P. ti/picus, Chilton ; Comparison of the three known species of Phreatoicus ; Special points in the structure of Phreatoicus ; Affinities of Phreatoicus 185 The Genus Cruretjens : C. fontanus, Chilton 209 Amphipoda. The Genus Crangonyx : C. compactus, Chilton 218 The Genus Oammarus : G. frufjilis, Chilton 226 The Genus Calliopiiwi : C. siibtcrrancrts, Chilton 2.33 Summary of the more important points in Part IV 244 V. The General Fauna of the Subterranean Waters of Canterbury 246 VI. The Canterbury Plains and their Underground Waters 248 VII. Origin of the Subterranean Crustacea 253 VIII. The Special Characteristics of the Subterranean Pauna : Colour ; Loss of Eyes ; Compensation for Loss of Eyesight ; Food : Arrested Development ; Habits 259 IX. Bearing.s of the Phenomena of Subterranean Life on the Theory of Descent 266 X. Conclusion 272 XI. Bibliography 273 XII. Explanation of the Plates 281 I. Introdijction. In the following paper an attempt is made to give a fuller account than has yet been published of the Blind Crustacea found in the underground waters of the Canterbury Plains in the South Island of New Zealand. The existence of siroilar Crustacea in the caves and wells and in the deep waters of lakes in Europe and North America Las long been known, and has attracted much attention, both because of the inherent interest of the subject, and because of the bearing that the facts have on some general questions of Biology connected with the Theory of Descent, particularly on the effects of use and disuse, and on the influence of the environment on the animals. SECOND SERIES. — ZOOLOGY, VOL. VI. 22 164 DE. C. CHILTON ON THE SUBTEERANEAN The existence of these animals in New Zealand was first recorded by me [22] about eleven years ago, but the original descriptions, though fairly accurate so far as they go, were yery short and meagre, and the figures were rough and crude, and many points were left on which fuller and more complete information was much to b3 desired. Moreover, during the time that has elapsed since they were first discovered, much additional information has been gathered as to their occurrence and distribution, and no connected account of these has as yet been published. During tha same time, too, some important works on the Blind Subterranean Crustacea of other parts of the world have appeared, particularly Packard's work on the Cave Fauna of North America [83], and Wrzesniowski's very important memoir on "Three Subterranean Amphipoda" [12i]. If we consider the peculiarities of the New-Zealand fauna and flora, and remember that New Zealand forms by itself a distinct zoological province, which has long been more or less ^lerfectly isolated from other provinces, we should naturally expect that the Subterranean Crustacea of New Zealand would present us with some new interesting facts, and that they would differ largely from the similar Crustacea found elsewhere. This proves to be the case. The Subterranean Crustacean fauna is peculiarly rich, and much more varied than that of either Europe or North America ; so far as at present known, it consists of six distinct species, three Amphipods and tlii*ee Isopods, belonging to five different genera. Of these genera Crangonijx is already known from the subterranean waters of Europe and North America, but none of the others have been recorded from underground habitats elsewhere, though one, Gammariis, is more or less allied to the blind Niphargus of Europe, the species of which were indeed originally assigned to Oamniarus, and are still so assigned by some writers. Two genera are new : one, Cruregens, belongs to a family, the Anthur'ulx, no members of which were previously known to inhabit underground waters, and the other, Phreafolous, which now contains three species (two from the subterranean waters of New Zealand, and one freshwater one from the top of the Mt. Kosciusko plateau in Australia), is so peculiar that it forms the type of a new and very remarkable family of the Isopoda. In the following pages I give a full detailed description of the external anatomy of each of these six species, in addition to the brief specific diagnoses and, usually, a discussion on the characters of the genus. I have given what is known of their occurrence and distribution, of their habits, and of the p:^culiarities which they present in common with or in addition to other Subterranean Crustacea ; their probable origin is discussed at some length. I have given also a short historical introduction showing the growth of our knowledge on t!ie subject of Cave and Well Sessile-eyed Crustacea; and have concluded with some remarks on the bearing of the facts presented by them on the general questions of Biology. For their kindness in providing me with material, I have to record my best thanks to Mr. E.. M. Laiug, of the Christchurch Boys' High School, Mr. E. Wilkinson, of the School of Agriculture, Lincoln, Messrs. J. B. Mayne and W. W. Smith of Ashburton, Mr. D. L. luwood and Miss Young of Winchester. Mr. W. P. Hciy of Irvington, Indiana, U.S.A., lias kindly supplied me Avith specimens of some North-American Subterranean Crustacea. Mr. Smith, of Ashl)urt<)u, has been particulai-ly zealous and CEUSTACEA OF NEW ZEALAND. 1G5 iiiiwctiiyiiig in liis efforts to obtain specimens for me, and I am much indebted to ])im tor additional knowledge on their distribution and on the general question of the underground -waters of the plains. My friend and fellow-worker, Mr. G. M. Thomson, Science Master of tlie Dunedin High Schools, has assisted me in many ways by his advice and criticism, and by bis kindness in supplying me with works from his library that I could not otherwise have obtained. To many writers I am indebted for copies of their various papers, particularly to Professor A. S. Packard and to Dr. E. Monicz, wlio have sent me copies of important works by them on the subterranean fauna of their respective countries; while, in common with all other workers on the Amphipoda, I am greatly indebted to the Rev. T. R. R. Stebbing for the very full and valuable Bibliographical Introduction to his Report on the ' Challenger ' Amphipoda. Situated as I am at the Antipodes, far from tlie chief biological libraries of Europe and America, to which one would have Hked to have recourse, I can perhaps appreciate the full ^alue of this introduction better than those who are more favourably circumstanced in this respect. II. Historical Sketch. The following historical sketch of the growth of our knowledge of the Sessile-eyed Crustacea inhabiting caves and wells is in many respects very imperfect, for I am unable to consult many of the original papers and works quoted; it contains, however, 1 trust, references to most of the more important works on the subject. In its compilation I have derived much assistance from Alois Humbert's paper on Niphargus indemms, var. Fovelu [62], Professor Packard's paper on the " Cave Fauna of North America" [83], from Wrzesniowski's work on " Three Subterranean Amphipoda" [121], and fiom the bibliographical introduction to Stebbing's " Report on the ' Challeno"er ' Amphii oda " [108]. 1 have endeavoured to include the Subterranean Isopoda as well as the Ami)hipoda, but the parts bearing on them are, I fear, much more incomplete than those on the Amphipoda, as there is no general bibliography on the Isopoda at all comparable to that which Stebbing has compiled with so much care and labour for the Amphipoda. Feanz von I'abla Schkank, in his account of Gammarus pidex [98, p. 535] says, "Habitat in aquis, rivis,fontibns ; albissimu.s dum iicitat." From the -Nvorils " in fontibus ; albissimus dum natat " Stebbing [108, p. 31] thinKs it is fair to infer that Scbrank had seen one of the well-shrimps. I£ this be so it would appear that we have in this work of Schrank (1781) the first mention of Subterranean Crustacea. W. E. Leach [72]. The first undoubted reference to "well-shrimps" ajjpears to have been made bj Leach. In the article " Crustaceology " in the ' Edinburgh Encyclopaedia,' published probably in 1813-1814, after Gaviiitarus pulex a species is mentioned [72, p. 403] which is not numbered but " which Mr. Leach considers to be different from pulex." It came from a well in London. " It diflers principally from Gummarus imkx in having the upper process of the tail much longer. The colour, when alive, was cinereous, but so translucent that the eyes could not be distinguished. It stimds in Mr. Leach's cabinet under the specific name subterraneus." It is evident from this brief description that the animal in question is not a true Guvnnarus, but is a subterranean species, probably a Nipfiargus. Stebbing [108, [>. 84] thinks it is probably identical with Niphargus aquilex, Schiodte, 22* 166 DR. C. CHILTON ON THE SUBTERRANEAN and it is assigned to tliis species also by Spence Bate and Westwood [4, p. 316]. Wrzesniowski [121', p. 6021 thinks that the description given is scarcely sufficient to enable us to decide whether the animal belongs to Niphargus aquilex, Schiodte, or Crangowjx compactus, Spence Bate ; but in the latter species the terminal uropoda are not very long, and, as Leach specially mentions that they are long in his specimen, it appears more likely that it is a Niphargus. I. C. Zenker. From a remark made by Zenker in connection with Gammarus pulex, Leydig infers [73, p. 245], and according to Wrzesniowski [124, p. 602] with good reason, that Zenker had met with Niphargus puteanus in Thuringia. Paul Gervais, in 1835, in a paper [46] describing the freshwater Gammarids of Paris, after giving the two species Gammarus pulex, Fabr., and G. Roeselii {=G. fluviatills, Roesel), says: "There is also found in the environs of Paris, but only in the water from wells, a third kind of shrimp, remarkable for its small size, which does not in fact exceed 3 or 4 mm." He considers this simply a " variete de sejour," and draws attention to its slender appearance — " est constamment etiolee " — and to the fact that its eyes are without pigment and not apparent. He names it Gammarus pulex minutus [46, p. 127]. This name he afterwards altered to Gammarus lacteus, but without giving any further description of any value [47, p. 488] . C. L. Koch [69]. About the same time Koch described a species under the name Gammarus puteanus from wells at Ratisbon (" Regensburg "), giving the following diagnosis: " G. diaphano- albus, lateribus suboehraceis, testis caudse iuermibus ; articulo penultimo pedum 4 anteriorum quadrato." He does not describe it as blind, but says "Die Augen sind gelb" [69, h. 5, n. 2]. Wrzesniowski gives the species under the provisional name Niphargus ratisbonensis ? [124, p. 673]. Later on Koch describes a variety found " in den Brunnen der Stadt Zweibriicken," differing from the specimens from Ratisbon in colour and in the shape of the hands of the guathopoda [69, h. 36, n. 22] . KocVs work was issued in parts, and it appears to be very difficult to determine the exact date at which each part appeared. See Stebbing [108, p. 158] . H. Milne-Edwards, in 1840, describes Gammarus pungens [77, iii. p. 47], from " les eanx thermales du Mont Cassini en Italic," as having " le petit appendice terminal des dernieres fausses pates tout-k-fait rudimentaire, et le grand appendice ti-es-poilu et il peine epineux." Spence Bate [5, p. 217, & 4, p. 314] and Stebbing [108, p. 253] consider this a Niphargus. At the same time Milne-Edwards also describes another species, Gammarus Ermannii \77, iii. p. 49], from warm springs of Kamtschatka; Spence Bate, who saw the specimen preserved in the Museum of the .Tardin des Plantes, afterwards placed this species under the genus Crangonyx [5, p. 179]. Theodor G. Tellkampf, in 1844, in describing some new species of Arthropoda from the Mammoth Cave of Kentucky, gives, under the head of " Crustacea, Malacostraca," the species Triura cavernicola [109, pp. 321, 322, pi. 18]. Schiodte and afterwards Boeck suggested that the species belonged to the Amphipoda, and Dana (Choristopoda, p. 306), in a note says : — "Genus Triura, Tellkampf, Rhoeee forsan affinis." Stebbing [108, p. 208], after giving a portion of TellkarapPs description, gives also a copy of his figure, and says that it will suffice to show that tiic animal cannot belong to the Amphipoda. A. S. Packard, junr., had, moreover, already shown in 1871 that the animal is not a Crustacean at all, but belongs to the Thysanurous Neuroptera, and that it is probably the same as Marhilis variabilis, Say : Tellkampf's erroneous reference of the animal to the Crustacea having been caused by his mistaking the labial and maxillary palpi for feet, and regarding the nine pairs of abdominal spines as feet [82, p. 14] . J. C. Schiodte, in 1847, briefly communicated to the Academic des Sciences dc Copeuhague the results of his researches on the fauna of the caves of Carniola and Istria, and gives a short diagnosis of Gammarus stygius [93, p. 81]. In a later work, published 1849-51, he minutely described the species, figured it, and formed for it the new genus Niphargus [91, pp. 26-28]. According to Humbert [62, p. 283] he did not notice the great resemblances between his species and Gammarus puteanus, Koch. CRUSTACEA OF NEW ZEALAND. 167 In the same paper, Schiiidtc also describes with great fulness, and figures, Pherusa alba, Koch, an isopod belonging to the OniscidiE. As the name Pherusa was preoccupied, he renames the species Titanethes albus, placing it in " Ordo Isopoda — Familia 0«/sc('— Tribus Oniscini." Owing to Koch's use of the name Pherusa, earlier employed among the Anijjhipoda, it appears that Schiodte's Titanethes has itself been spoken of as an Amphipod. With regard to this species, Spence Bate [4, ii. p. 440] gives the reference "' Herrich Schaffer, Contin. of Panzer,' fasc. 180, pi. 24," and this, together with the above quoted from Stebbing [108, p. 24], is all the informatiou I can gather on this species. HoBERT Caspary [19], in 1849, gave a full account with figures of Gammarus puteanus, Koch, from specimens found at Elberfeld. He was not able to discover eyes, although he examined more than 30 specimens. The small size of his specimens (4-6 mm.) and the absence of eggs from the brood-pouches of the females show, says Wrzesniowski [124, p. 603], that he had to deal with very young specimens. He considers the mouth-parts, but, according to Wrzesniowski [124, p. 603], gives an incorrect figure of the palp of the first maxillae. In his list [15] giving the synonymy of Asellus sieboIdU, de Rougemont { = A. cavaticus, Schiodte), Bovallius gives a reference to this pa])er by Caspary, as follows : — " 1849 Fulilrott. (Caspary), in Verhandl. des naturh. Vereins dcr preuss. llheinlande uud Westfalens, Jahrg. 6, fig. ; " thus without mentioning any name as used by Caspary. I am unable to consult Caspary's paper, and therefore cannot say what information, if any, he gives on Asel/ns cavaticus. Accoi-ding to Packard [83, p. 146], Caspary gives a " figure, without name, of Asellus cavaticus, Leydig." The next entry in Bovallius's list of synonyms is under the date 1871 [15, p. 11]. A. Hosius [61], in 1850, sets forth very fully the characters which separate the three species, Gam- marus pulex from running waters, Gammarus fluviatilis ( = G. Roselii, Gervais) from still or weakly flowing waters, and Gammarus puteanus from wells. He compares the three species as regards the maxillae, and gives two drawings of the maxilhe of G. puteanus, taken from Caspary, and retaining the erroneous figuring of the palp. The incorrectness was also pointed out by Spence Bate and Westwood [4, i. p. 311]. A. Costa [32], in 1851, gives, among others in his list of Amphipoda, Gammarus lomjicaudatus from the drinking-water of Naples, and G. montanus from the Lago del Maltese. Afterwards he admitted that the two were the same, and the first as " Gammarus longicaudata," A. Costa, appears alone in his Catalogue [see Stebbing, 108, p. 249]. Wrzesniowski gives the species under Nipharyus [124, p. 696-7]. Spence Bate and Westwood, without comment, give it as a synonym of Niphargus aquilex, Schiodte [4, i. p. 316]. J. 0. Westwood [120], in April 1853, communicated to the Linneau Society the discovery of a well- shrimp in a well near Maidenhead, England. This was at the time referred to Niphargus stygius, Schiodte, hut was afterwards separated under the name Niphargus aquilex by Schiodte [95, pp. 349- 351]. Bate and Westwood point out that Schiodte has been misled into describing it with " dorso carinato " by examining dried specimens, but they retain his name Niphargus aquilex on other grounds [4, i. p. 317]. In an anonymous paper on some Crustacea [57], quoted by Stebbing thus : — "Anonymous (? Halli- day)," Latin diagnoses of the genus Niphargus and the two species iV. sti/gius and A'^. aquilex are given. The full account of the former is given in English as applying equally well to the latter, except for the differences mentioned in the diagnoses. As these amounted to little more than applying a smooth back to A^. stygius, and by mistake a keeled one to N. aquilex, Spence Bate was, he says, misled by this to assume the identity of the two species. Adam White [121] in Lis ' Popular History of British Crustacea,' in 1857, omits the Gammarus subterraneus. Leach, which he had previously suggested might be " Gammarus pulex, var. jun. ?." He changes Niphargus stygius, Westwood, into Niphargus aquilex, Schiodte, and asks whether this may not be the Gammarus subterraneus of Leach [see 108, p. 305]. 168 DR. C. CHILTON ON THE SUBTEREANEAN A. DE LA Valette St. George [112], ill 1857, publislied a very minute account of tlie external and internal anatomy of the well-sbrimps found at Cologne and Munich. He calls the species examined by him Gammarus imteanus, but they are referred by Bate and Westwood to Niphargus aquilex, Schiiidte [4, i. p. 315]. His work is illustrated by fine figures, and among other points he draws attention to the sense-organs found on the autenuse, remarking, howevei', that the caleeoli increase in size towards the end of the antennse, which, as Stebbing points out [108, p. 304], is certainly not the case iu all Ampliipoda. C. Chyzer, iu 1858 [28, p. 4], announces Toth's finding Gammarus puteanus and G. fossarwm, Koch, " im Orczy-Garten zu Pest." C. Spence Bate [6] in 1859, in a paper on the genus Niphargus, Schiodte, establishes two new species, A^. fontanus and N. Kochianus, and also describes a new genus, Crangony.r, with the species C. subterraneus. Some discussion on the genus Crangonyx will be found further on (pp. 215-326). R. M. Bruzelius [17], in 1859, established the new genus Eriupis, vi'\t\x the species E. elongata, " habitat in loeis profundis maris Bohusise." The genus Eriopis is evidently very close to Niphargus, Schiodte, with which it was identified by Boeck. Stebbing also accepts this view; Wrzesniowski, how- ever, retains it as a separate genus, but alters the name to Eriojjsis, as Eriojns was preoccupied [124, p. 634]. A. R. HoGAN [59 and 60], in 1859, published a paper on the habits, food-supply, and habitat of the species described by Spence Bate, viz., Niphargus Kochianus, N. fontanus, and Crangomjx subterraneus. In his notice of this paper Stebbing mentions that specimens of Niphargus aquikw, from a well near Tunbridge Wells, lived in his (Stebbing's) room from January 1886 till March 3rd, 1880, wheu they all died at about the same time, perhaps from the coldness of the night. Although they were very active in walking aljout the bottom of their jar, Stebbing never saw them attempt to swim. Another set of about a dozen were placed in a small jar on June 15th, 1880. Two were females with eggs ; these died within a couple of days, surrounded by some rapidly developed parasitic growth ; the others lived on for a considerable time, the last not dying until November 24th, 1880 [108, p. 310]. Wrzesniowski [124, p. 604] refers to these observations on the habits of Niphargus aquilex in captivity as though they had been made by Hogan — a mistake natural enough, considering the way in which they are incorporated with the notice of Hogan's paper. Hogan published another paper on the same subject in 1801 [00]. Johannes Lachmann [71], in 1859, describes parasites found in the intestine of the well-shrimp {Gam- tuarus puteanus) , the name being, however, misspelt "Grammarus" throughout the paper. The parasites are said to belong to the puzzling group of the Gregarines. (Quoted from Stebbing [108, p. 317].) Joseph Schobl [92] in 1800 published an elaborate monogra^ih, illustrated by 10 plates, on " Typhlo- niscus — eine neue bliude Gattuug der Crustacea Isopoda," in which he describes the new species Typhlo- niscus Steinii. This species, which belongs to the Oniscidse, is not an inhabitant of wells or caves, but lives, like Platyarthrus, iu ants' nests. It, however, resembles cave-species in the want of eyes, colour of the body, &c., and has been often mentioned as a blind Isopod along with Titanethes albus. This species was afterwards referred to Platyarthrus Huffmannseggii by Budde-Lund [18, p. 199]. Victor Sill [100], in 1861, repeats Koch's description of^ Gammarus puteanus, but without adding anything new. Spence Bate, in the 'Catalogue of the Amphipoda in the British Museum,' published iu 1862 [5], gives the following subterranean species, all of which have been already referred to : — Niphargus stygius, SeliiiJdte, with which he combines N. aquilex, Schiodte (though on further examination this was retained as a separate species) ; N. fontanus, Spence Bate; N. Kochianus, Spence Bate; N. puteanus, Koch; Cran- qonyx subterraneus, Spence Bate; and C. Ermannii= Gammarus Ermannii, M.ilne-l!ldwa,rd&. He leaves Gammarus pungens, Milne-Edwards, under the genus Ganmiarus, but adds as a footnote, " This species appears closely to resemble a Niphargus " [5, p. 217]. CEUSTACEA OF NEW ZEALAND 169 Bate and Westwood [4]. The parts of the' History of the British Sessile-eyed Crustacea,' by these authors, wliich contained the account of the subterranean forms, apjieared in 1862 [Stebbing, 108, p. 340], though the titlepage of volume i. bears the date 1863. A fuller account of the species already mentioned is given, there is a sliort account of some of the previous works on the subject and of the habits of some of the species, and Nipkiirr/iis aquilc.r, Schiodte, is reinstated as a separate species distinct from N. stijfjius, Schiodte. Under N.fontaniis, the authors say : — " Professor Westwood thinks that this species may be identical with the iV. sfi/ffius of Schiiidte, since both agree in the more robust form of the animal and the shape of the hands; there are, however, other important differences ; as, for instance, the form of the second and third segments of the tail, which, together with the diversity of liabitat, will probably prove to be of specific value" [t, i. p. 322]. Again, under N. Kochianus they say : — "We are inclined to think this species identical with the specimens captured at Bonn, described and figured by Caspary and Hosius, referred to in the synonyms under JSf. aquUe.v, but want of specimens from tliat locality prevents our determining this point" [4, i. p. 325]. In speaking of the three species N. af/ni/ce, iV. fontanus, and N. Kochianus, Alois Humbert very shrewdly remarks : — -"A n'en juger que par les descriptions et par les figures intercalees dans le texte ces trois especes semblent etre bien tranchees et faciles a distinguer, mais dans la pratique la determina- tion n'est pas facile " [62, p. 287]. De Rougemont has, indeed, united N. font anus and N. Kochianus, as well as Cranqonyj: subtcrraneus with Gammarus puteanus,}Loc\\; but, as will be seen from the remarks below, his identifications can hardly all be accepted. Stebbing says, in connection with this point that " the matter, perhaps, is not yet ripe for final determination" [108, p. 312]. It is strange that so little has been written on the Subterranean Crustacea of England : thus I know of no special work on them since the publication of the ' History of the British Sessile-eyed Crustacea ; ' this is the more peculiar when we remember that many points in connection with them were left uncer- tain {Cramiomjx suhterraneus, for instance, being described from a single specimen), and that they are widely distributed in England and Ireland, and probably abundant. Camil Heller [58] , in his list of the freshwater Amphipoda of South Europe, says that they all belong to the genus Gammams, Fabric., of which he makes Crangonyx and Niphargus subgenera. He omits Costa's G. Jongicaudatus, and unites Gammarus puteanus, Caspary, Niphargus stygius, Schiiidte, and N.aquilex, Schiiidte, but, according to Wrzesniowski, without giving good reasons for so doing [124, p. 604]. Among the freshwater Crustacea mentioned by Heller is Crangonyx recurvus, Grube, which had been found by Grube in 1861 in the Vrana lake in the Island of Cherso, on the Illyrian coast, and described under the name Gammarus recurvus, and was afterwards redescribed by him and placed under Vranqonyx. I regret that I have been unable to get a description of this species, as it would have been interesting to see what relation it bears to the various Subterranean Crustacea of Europe. Pratz [88], in 1867, described under the name Gammarus Caspary a new species from a well at Munich, and mentions several remarkable differences between the male and female. In view of the " caracteres contradictoires " presented by this species, and the " polymorphisme " of the Gammari found in the same town by de Rougemont, Moniez tliinks [78, p. 18] that it is very desirable that the Gammari of the wells at Munich should be re-studied. W. CzERNiAvsKi [33] , in 1868, described a new species of Niphargus, from the Black Sea, under the name N. ponticns. This species differs from the usual species of Niphargus in the presence of well-developed eyes, in the colour, the gnathopoda, &c. ; and from the small size (2'1 millim.), and the small number of joints in the flagella of the antennae, it is probable that the single specimen obtained was, as Wrzesniowski points out [124, p. 605], a young specimen, and further information regarding the sjiecics is desirable. F. Plateau [86] . in his researches on the freshwater Amphipoda of Belgium, inakes special mention of 170 DR. C. CHILTON ON THE SUBTEREANEAN the well-shrimps which he had taken at Ghent, and which had also been collected by Professor Bellynck at Namur. He calls his specimens Gaminarus puteanus, Koch, and states that they have triangular, pigmentless eyes. Plateau appears to have been acquainted only with Koch's work on Niphargus, and ignores the works of later writers. GusTAV Joseph [65], in 1868, recorded the finding of a new species of Niphargus, N. orcinus, in the brooks of the hill- grottoes of Carniola, "which probably from these reaches the lake of Zirlenitz [Zirk- nitz], where it can be freely gathered. It comes to the surface after sunset in calm weather." — See Stebbing [108, p. 384]. The full description of this species was not given till 1882. F. A. FoREL [38J, in 1869, indicated for the first time the existence of blind Gammarids from the deep waters of the Lake of Geneva. Afterwards, in 1873, similar animals were found in the Lake of Neuchatel. BoECK [14], in his work published in 1870, gives the genus Niphargus, Schiodte, for the single marine species Eriopis elongatus, Bruzelius. Paul Godet [48, p. 153], in 1871, described three specimens of a Gammarus found in a well at Neuchatel, pointing out the characters by which they differ from Gammarus fluviaiilis, and comparing them with G. puteanus, Koch, and G. puteanus, La Valette. Stebbing says that, judging by the figui'C, it cannot be far removed from Niphargtis aquilex, Schiodte [108, p. 1630]. A notice of Godet's observations on these well-shrimps had been previously communicated to the Societe des Sciences natureUes de Neuchatel, by P. Coulou, in 1867. See Wrzesniowski [124, p. 605] . S. I. S.vuTH [102], in 1871, among other Crustacea dredged from Lake Superior, in North America, describes Crangonyx gracilis. Smith, n. s., and says that it much resembles C. recurvatus [yecurvus^, Grube, " in the form of the antennulte, antennae, gnathopoda, &c., while it differs much in the ultimate pleopoda and in the form of the telson." It is important to note the occurrence of this species, though not blind, in connection with the question of the distribution and origin of the subterranean forms. A. S. Packard, Jun. [81], 1871, iu describing the Crustaceans and Insects of the Mammoth Cave, describes an Isopod as a new genus and species under tlie name Ccecidotea stygia. This species was described from imperfect specimens, and its structure and affinities were consequently completely misunderstood. In point of fact it has nothing whatever to do with Idotta, but comes very close to Asellus, with which it is indeed united by Forbes [41, p. 11]. It will be further noticed in the account of Packard's larger work on the ' Cave Fauna of North America ' [83]. E. D. Cope [30, pp. 6 and 14], in 1872, found iu a cave adjoining the Wyandotte Cave an Isopod which he refers to the genus Ccecidotea, previously established by Packard, but describes it as a new species, C. microcephala. He gives a description and figure of the species, but owing to imperfect specimens his account is even more unsuccessful than Packard's : thus he describes and figures the uropoda as " egg-pouches full of eggs." This is the species which had been referred to by Cope in a previous paper as an " unknown Crustacean with external egg-pouches " [29] . Packard has since united it with his Ctecidotea stygia [83, p. 29]. In the same paper [30, pp. 8 and 17] Cope also describes a blind Amphipod under the name Stygo- bromus vitreus, nov. gen. et sp. He says that his genus is nearer to the true Gammarus than to Niphargus, Schiodte ; but his description is very unsatisfactory, and gives no assistance in the attempt to ascertain the true position of the animal. S. I. Smith afterwards referred this species to Crangonyx under the name C. vitreus. Cope, and it appears under this name in Packard's larger work [83, p. 34]. CRUSTACEA OF NEW ZEALAND. 171 AltLougli tlescribcd iu Cope's paper " Ou the Wyandotte Cave and its Fauna," this species is not from that cave, but from the Mammoth Cave, and had been referred to as a " Gammaroid Crustacean " iu an earlier paper by Cope [29] . F. Leydig [74, p. 2G9] had, in 1871, i-ecorded the existence of Asellus cavaticus in the Falkenstein Cave. This species is usually referred to as Asellus cavaticus, Schiodte, and consequently was, I presume, first mentioned under that name by Schiodte ; but, unfortunately, the works at my disposal do not enable me to say where Schiodte mentions it, or what information, if any, he gives about it. Bovallius, in his "Notes on the Family Asellidae," in his list of synonyms of the species, gives no reference to any paper on the subject by Schiodte, and says, " As Schiodte never has given a diagnosis of A. cavaticus, and none of the following authors, using that name, did describe the animal, the name A. cavaticus must be rejected, and substituted by A. Sieboldii, Ph. de Rougemont" [15, p. 11]. A. Fkic [42, p. 246, fig. 95], in 1872, recorded the existence of Gammarus puteamis in wells at Prague, Bohemia; but, according to Wrzesniowski [124, p. 605], his observations on the subject are of little value, the third uropods, for example, being represented as seven-jomted ! R. WiEDERSHEiM [122] fouud iu 1873, in a small lake in the Falkenstein Cave, about 600 ft. from the mouth, an eyeless Gammarid which he does not describe, but believes to be the same as Gammarus puteamis from wells at Tiibingen. Apparently also in the same paper he gives an account of the habits of Asellus cavaticus. See Packard [83, p. 149]. S. Fries [43], in 1874, also studied the fauna of the same cave, but found only one example of a bHnd Gammarid. lie thinks this to be the descendant of the eyed Gammarus jjule.i: Vw'mg in the neighbourhood outside the cave, and strengthens his opinion by observations on Gammarus fossarum kept during the winter in the dark, which lost pigment and whose eyes paled ; but, as Humbert points out, Fries does not appear to have been acquainted with the genus Nipliart/us and tlie characters bv which it is distinguished from the true Gam/narus. Sec Humbert [62, p. 289]. Fries also appears to have referred in his paper to Asellus cavaticus, Schiodte. F. A. FoREL, in a series of works on the deep-water fauna of the Lake of Geneva, repeatedly mentions an interesting crustacean under the name Gammarus ccecus. This, I presume, is the species afterwards fully described by Humbert under the name Niphargus puteanus, var. Forelii [. 19]. The species was afterwards fully described in the ' Records of the Australian Museum ' under the name Phreatoicus australis [26]. In the present paper I have compared it with the two subterranean species P. ti/picus and P. assimilis. Subterranean Crustacea have now been actually obtained from the following localities in the Canterbuiy Plains : — 24* 182 DR. C. CHILTON ON THE SUBTERRANEAN 1. East Eyretoi), about 15 miles north of Christcliurch, altitude about 120 feet above sea-level *. 2. Lincoln, about 12 miles south of Christchurch, altitude about 28 feet above sea- level. 3. Leeston, about 27 miles south of Christchurch, altitude about 60 feet above sea- level. 4. Ashbnrton, about 50 miles south-west of Christchurch, altitude about 323 feet above sea-level. 5. Winchester, about 85 miles south-west of Christchurch, altitude about 136 feet above sea-level. I have also heard of Crustacea being seen from wells at several other localities in addition to those given above ; but leaving these out of consideration, the localities given, from all of which I have actual specimens, are sufficient to show that these Crustacea are widely distributed in Canterbury, so far as distance north and south is concerned ; the distribution from east to west, so far as at present known, appears to be much more restricted, and it is perhaps worthy of notice that all the places mentioned are within short distances of the sea, none of them being more than 10 or 12 miles from it. No doubt further research will demonstrate the occurrence of these Crustacea at many other places ; at the same time it is to be remarked that they do not occur in the artesian waters of Christchurch. Tlie area in which artesian wells can be sunk with success is a narrow belt parallel to the sea, extending from Flaxton, north of the Waima- kariri, to Lake Ellesmere, the inland boundary being the contour of about 50 feet above the sea. The depth below the surface of the first water-bearing stratum varies from about 55 feet at E,iccarton to 136 at New Brighton, on the sea-coast, and there is a second water-bearing stratum at about double the depth of the first in each locality. Crustacea appear to be absent from both of these water-bearing strata ; I have frequently sought for them in vain in water from wells to the first stratum, and others have been equally unsuccessful ; moreover, as the water of these wells is used throughout the whole district for drinking-purposes without previous filtering, the animals would certainly have been noticed had they been present. With regard to the wells reaching to the second stratum, Mr. E.. M. Laiug tells me that he endeavoured to collect Crus- tacea from a well of this kind at the Christchurch Boys' High School, Bath, by fixing a muslin bag over the mouth of the pipe for some hours, but that no trace of any Crustacea was obtained. Of course, this evidence, though very satisfactory so far as it goes, is by no means conclusive, and it would be well to repeat the experiment in other wells and at different times, in order to confirm or disprove the results of the single trial already made. In the above-mentioned ' Handbook of Cliristchurch ' [63, p. 33] it is pointed out that although it is commonly thought that the main source of the water-supply of the artesian wells is the leakage of the bed of the Waimakariri, the few careful observations that have * This height has been obtained from the Survey Department tbrough the kindness of Mr. C. W. Adams, Chief Surveyor, Dunediu. The other heights are taken from the iigures given in the time-tabk>s published by the Now Zealand Railway Commissioners. CRUSTACEA OF NEW ZEALAND. 183 been made do not confirm tliis hypotliesis at all, as floods in the river never aff'oct the height of the water in the wells, while heavy rain makes them rise, and a continuance of dry weather makes them fall. The absence of subterranean Crustacea appears to confirm the opinion that the water of the artesian wells is not derived from the leakage of the Waimakariri, for the water in which they are found at Eyreton is almost certainly derived, partly at any rate, fi-om the Waimakariri, and if they exist there we might reasonably expect to find them distributed all over the water affected by leakage from that river. All the subterranean Crustacea hitherto collected from the underground waters of the Canterbury Plains have been obtained by means of the ordinary suction-pumps with which the w^ells are usually fitted. In the same way similar Crustacea have been obtained in England by Spenco Bate and others, in France by Moniez, in various parts of Europe by numerous observers, and in North America by Hay, Forbes, and others. In Europe and North America these Crustacea have also been procured from underground streams in caves and from the deep u aters of lakes, but none have as yet been ol)tained in this way in New Zealand. These situations have not yet been properly searched, and it is qiiite possible that the blind Crustacea may yet be obtained by exploring the caves in different parts of the colony, and by dredging in the deep alpine lakes of Otago. The pumps referred to are mostly ordinary suction-pumps, and consequently do not go down to a depth of much more than 30 feet. In some cases, however, owing to a con- tinuance of dry weather for several years, the pipes have had to I^e driven deeper, and fitted with a cylinder-pump, and Crustacea have still been occasionally taken from them ; but it would be obviously rather more difficult to ])riug up Crustacea from greater depths in this way than from less depths by an ordinary suction-pump, even although they were equally numerous in the waters underground in the two cases. In some cases there is an actual well, the soil having been excavated to a depth of 25 feet or so, and a hole thus formed in which the water can accumulate; in the majority of cases, however, the suction-pipe has been simply driven into the ground like that of an ordinary artesian w^ell. The Crustacea are obtained quite as freely from wells of the one description as of the other. I have myself noticed that the Crustacea are often brought up most abundantly when pumping is first commenced, and that jerking tlie handle of the pump somewhat violently is often more successful than pumping at the ordinary rate. Mr. J. B. Mayne has noticed the same thing in connection with pumps at Ashburton, and Mr. E. Wilkinson, of Lincoln, states that the Crustacea come up most abundantly after the pump has been left for a time, especially in the early morning. Of course, these facts can be easily accounted for if we consider the character of the small animals with which we have to deal, for a sudden upward flow of the water would be more likely to carry them with it than a more gradual flow, and they would be more likely to be found in the neighbourhood of the pipe, or indeed in the pipe itself, when the waters had been for some time undisturbed by pumping. In order to collect them I have generally taken a small hand-bowl, pumped it full by a few vigorous or jerking motions of the handle, then examined it to see if any Crustacea 184 DE. C. CHILTON ON THE SUBTEERANEAN have been brought up, catching any that there may be with a dippiug-tnbe, and pumping the bowl full again after the lapse of a few minutes ; and where the Crustacea have been fairly numerous I have found this intermittent method of pumping more successful than continuous ])umping. In other wells where the Crustacea were fpund only sparingly, Mr. Smith of Ashburton found it better to collect them by tying a muslin net over the spout of the piimp ; and in order to prevent the animals being injured he floats the net in a bucketful of water, the bucket being raised so that the level of the water in it is liigher than the spout of the pump. Mr. Smith reports from Ashburton that all the subterranean animals appear to have been brought up by the pumps most abundantly some eighteen months or two years ago, when, owing to the continued drought, the water in the wells was sinking ; but that since the wells were sunk deeper, and up to the present time when the water is now rising atrain in most wells, the animals have been much rarer. Thus in one of his letters he says : — " I generally enquire wherever I go if any animals come up in the water, the answer being that there were plenty twelve months ago hut none lately." In another he says that one gentleman informs him " that they frequently saw minute ' pale shells with white slugs in them ' before the pump went dry eighteen months ago; since sinking the pump 15 feet more, they have not detected any animals in the water." In another letter, dated 29th June, 1892, Mr. Smith says Mr. Dolman, a practical well-sinker of the district, informed him " that he had not seen a single animal in well-water for some months. There is, however, not much well-sinking going on, as the water is almost up to its usual height." My own experience tends to strengthen the conclusion that the animals are brought up most abundantly while the level of the water is sinking, for I found them very abundant at Eyreton from 1881 up to about 1886, during the whole of which time the water was sinking, and the wells had to be deepened several times. I have had few opportunities of collecting at Eyreton since, but I am told that very few animals have been seen during the last two or three years. In 1891 Mr. R. M. Laing sent me quite a number of sub- terranean Crustacea from one of the Avells at Leeston, and he states in a later letter that the well has since become dry. Erom the one well at Eyreton in which I first noticed the Crustacea I have collected the following five species : — Qammarus fragUis, Crangomjx compactus, CalUopius suh- terrancus, Cruregensfontunus^ and I'hreatoicus typicus. Of these CalUopius subterraneus, the female, has always been much more abundant than any of the others ; for two or three years from 1881 I seldom had to pump for more than 10 or 15 minutes without obtaining some specimens of this species. After the well was deepened it was less abundant, and did not preponderate over the others so much as before. The male of this species is very rare ; I have seen only about half a dozen specimens altogether. "Whether this species is really so much more abundant than the others in the underground waters is, perhaps, a little doubtful, as from its smaller size it would naturally be drawn up the pijie more easily than the larger forms. Of the other species, Gammarus fragilis and Crangonyx compactus have been about equally abundant on the whole, but sometimes one form has preponderated and sometimes the other ; Gruregens fontanus, though somewhat numerous, CEUSTACEA OF NEW ZEALAND. 185 has not been so commonly obtained as the others ; this may perhaps be accounted for by its habit of creeping instead of swimming like the Amphipods. Moniez notes the same thing with regard to Asellus cavaticus, Schiodte, which is frequently found along with Gammarus puteaniis, bnt has not been met with from the district of Lille nor from Prague, although the latter species is found at both places ; he accounts for this by stating that, owing to the habits of the animal, it would rarely be brought up by the pumps [78, p. 51]. The occurrence of Pht^eatoicns typicus has been somewhat peculiar. Although the Crustacea coming up the pump were pretty carefully watched and collected from January 1881, no specimen of Fhreatoicus was observed until the beginning of September 1882, while in a month from that date some six or seven other s^iecimens, all females, were obtained. I have not taken it again since then ; but in the year 1892 a single specimen, also a female, was taken at Ashburton by Mr. Smith. This species is represented at Winchester by a closely allied sj)ecies, described in this paper as Fhreatoicus assimilis, and of this I have three specimens only, two males and one female. From Leeston the following species are so far known — Gammarus fragilis, Crangonyx compactus, and Cruregens fontanus ; from Lincoln, Calliopius suhterraneus ; from Ash- burton, CalliopiHS suhterraneus, Gammarus fragUis, Cruregens fontanus, and Fhreatoicus typicus ; from Winchester, Calliopius suhterraneus, Gammarus fragilis, Cruregens fon- tanus, and the representative species Fhreatoicus assimilis. IV. Detailed Descriptions of the New Zealand Subterranean Crustacea. ISOFODA. Family PHREATOICID.E. Genus Fhreatoicus, Chilton. (Transactions New Zealand Institute, voL xv. p. 89.) The folloAving are the characters that I originally assigned to this genus in 1882, when I had only one species, Fhreatoicus typicus, before me. They apply, with the slight limitations given below, to the three species of the genus now known, and may therefoi'e still stand in the form in which they were originally put : — " Body long, subcylindrical, laterally compressed. Upper antenna short, lower long, with flagellum. Mandible with an appendage. First pair of legs subchelate, others simple ; first ybr^r pairs articulated to body at the anterior ends of their segments and directed forward ; last three articulated at posterior ends of their segments and directed backward. Abdomen long, of sis distinct segments, last joined to telson. Sixth pair of pleopoda biramous, styliform. Telson large, subconical." On this description I may make the following remarks : — 1. The lateral compression of the body is not great and is seen chiefly in the pleon, where the pleura of the segments are produced downward. 2. With regard to the legs, the first pair is subchelate in both sexes, but is larger in the male than in the female, and the fourth pair in the male is slightly modified so as to 18G DE. C, CHILTON ON THE SUBTEEEANEAN be almost subcbelate ; in tbe female tbe fouvtb pair is simjjle like tbe preceding. The statement that tbe first four are attacbed to tbe body at tbe anterior ends of their seg- ments and the last three at the posterior ends, although true enough of tbe typical sjiecies, required some modification in the case of P. australis, for tbe last three pairs in this species are attached to the centres of tlieir segments, tbe epimera occupying almost all the inferior margins, and tliis is also true in a modified degree of tbe other species. The point that I wished to bring out would be better expressed by saying that the legs arc divided into an anterior series of four and a posterior series of tbree, and this would apply equally well to the tbree species. 3. " Abdomen long " sbould perhaps read " pleon long " in order to be consistent with tbe term " pleopoda " used afterwards. The term " uropoda " is again a very convenient one to use in place of " sixth pair of pleopoda." 4. Tbe j)eculiarities of tbe pleopoda, as shown in tbe descriptions given below, are, no doubt, quite worthy of being mentioned among the characters of tbe genus, but they cannot be observed without dissection, and so long as tbe genus can be sufficiently dis- tinguished by other points more easily observed, there is no necessity to introduce them. Perhaps some of them, sucb as tbe possession of an " epipodite," will prove to be cbaracters of tbe family and not merely of the genus. Phreatoictjs assimilis, sp. nov. (Plates XVI. & XVII.) Phreatoicus typicus, Chilton, New Zealand Journal of Science, ii. p. 89 (March 1884). Phrealoicus typicus (pars), Thomson and Chilton, Transactions New Zealand Institute, vol. xviii. p. 151. Specific di(tg)wsis. Body somewhat stout. Pleura of tbe second, third, fourth, and fifth segments of tbe pleon very largely developed, much deeper than then- respective seo'meuts ; tbe inferior margins somewhat sparsely fringed with small spinules. The projection at the extremity of the telsou not much produced, broader than long ; upper angle of its extremity sharp and tipped with a few setge ; lower angle rounded. Lower antennee about half as long as the body ; peduncle with the fifth joint only about half as long again as the fourth ; flagellum much longer than tbe peduncle. Legs stoutish, with tbe joints somewhat expanded, all the pairs well supplied Avith setae. Lower lip wdth each half ovate, with the extremity well rounded. Inner lobe of the first maxilla rather narrow and with only four plumose setae at its extremity. Colour. Translucent. Length. About half an incb (10 to 12 mm.). Habitat. "V\'incbester, South Canterbury, in wells {D. L. Inwood). Detailed Description. Tbe following detailed description is mainly taken from a male specimen that was dissected for tbe purpose. A few points regarding tbe surface of tbe body &c. have been taken from a female specimen that was mounted dry on a slide. Body (PI. XVI. fig. 1). Tlie female specimen has tbe body 10'5 mm. long, and tbe perceon about 1'5 mm. deep. The body is of uniform breadth throughout its whole leugtb. In CKUSTACEA OP NEW ZEALAND. 187 the perseon the depth is about equal to the breadth, the ventral surface being more or less flat, so that here the body is semi-cylindrical ; in the pleon the segments (except the first and sixth) have the pleura much produced below into smooth, flat, thin plates protecting the pleopoda ou either side. The surface of the body is smooth throughout, with a few setae scattered here and there either singly or in small tufts, cliielly on the dorsal surface. Eead (I'l. XVI. fig. 1). The dorsal surface is convex, curving downward in front, making the outline of the head in lateral view roughly subtriangular. The anterior margin, as seen from above, is concave behind the bases of the antennse. A depressed line on the side of the head toward the posterior end runs down more or less parallel with the posterior margin and runs out into the inferior margin ; it does not extend over the dorsal surface of the head. Behiud the base of the lower autennte there is a slio-ht cleft in the front margin, and behind this a slight depression on the surface which extends backward a little distance and then turns downward. The inferior maro-iu of the head is nearly straight. In the dried specimen there is no trace of the eyes, the exoskeletou being apparently continuous over the place where the eyes would be situated if they were present. Ferceon (PI. XYI. fig. 1). The first segment is only half as long as the second ; it widens a little iuieriorly and has the antero-iuferior angle somewhat produced, so that the front margin slopes forward and brings the lower part of the segment very close up to the head. The inferior margin is slightly convex and not hollowed for the reception of the epimeron, which appears to be ankylosed to the segment, the suture being indistinct. The second, third, and fourth segments are all similar and subequal, and of the same length at the inferior margin as on the dorsal surface. The inferior margin is nearly straight, but slightly concave anteriorly for the reception of the shallow epimeron ; the anterior angle produced into a rounded knob, tipped with a few setae ; the posterior auo-le rounded, with a few setse in the third and fourth segments. The fifth segment is some- what shorter than the fourth ; the anterior angle of the inferior margin is rounded and bears a few setae, Avhile the rest of the inferior margin is deeply emargiuate to receive the triangular epimeron ; the sixth and seventh segments are similar to the fifth, but each is shorter than the preceding one. Fleoii (PI. XVI. fig. 1). The first segment is shorter than the last segment of the perseon, but of nearly the same depth ; the inferior margin is rounded off at both angles and bears about G to 8 minute spinules scattered along the margin. The second, third, and fourth segments are subequal and somewhat longer than the first ; they have their pleura produced inferiorly into large, thin plates, considerably deeper than the respective segments. The pleuron of each segment has the anterior angle of the inferior margin rounded ; posteriorly the pleuron is slightly produced so as to overlap that of the succeeding segment ; that of the second segment is also produced anteriorly as far as the anterior margin of the first segment, fitting in below its small pleuron; the posterior angles are slightly produced and usually bear a few minute spinules. The fifth segment is nearly as long as the three preceding; its pleuron has the posterior angle well rounded, tiie posterior margin and part of the inferior margin being sparingly supplied with spinules. SECONB SElllES. — ZOOLOGY, VOL. VI. 25 188 DE. C. CHILTON ON THE SUBTERE AN EAJM The sixth segment is completely coalesced with the telson, forming a somewhat conical tail-piece, which ends posteriorly in a small projection broader than long, its upper angle at the extremity sharp and tipped with a few small setae, the lower angle being rounded and free from setse. Below this projection the inferior margin on each side is slightly irregular, more or less dentate, and is fringed with spinules. The posterior margin in front of the articulation of the uropoda is convex and bears four stout spiniform setae. The tipper antennce (PI. XVI. fig. 2) consist of about 9 or 10 joints, of which the three at the base may be considered tlie peduncle, although there is little or nothing to distinguish them from the succeeding joints. The first and second joints are subequal and somewhat larger than the third ; all three bear several small setae at the distal end ; the first three joints of the flagellum are subequal and a little shorter than the last joint of the peduncle ; the remaining joints are longer and thicker, being usually considerably swollen, especially towards the distal end, the swelling being chiefly due to a thickening of the chitinous integument ; the penultimate joint is usually the thickest, the terminal one being small. The joints of the flagellum bear a few minute spinules distally, and the last four joints have in addition one or two small "olfactory cylinders." The number of the joints in the antennae and their relative sizes are subject to considerable variation. The one drawn (PI. XVI. fig. 2) has the terminal joints less swollen than usual ; the penultimate joint is slightly constricted at the middle and bears two groups of "olfactory cylinders;" hence it probably represents two joints, and in that case this antenna would contain altogether ten joints. The other antenna of the same specimen was more normal; it also contained ten joints, and those toward the end were more swollen, the antepenultimate being the largest. he loicer antennce (PI. XVI. fig. 3) are about half as long as the body. The peduncle is somewhat longer than the upper antennae. The first two joints ai^e short and subequal ; the third is about as long as the first and second together, curving slightly upward, the upper margin being concave and the lower convex, while there are two small groups of setae on the lower margin and one on the upper margin at the extremity ; the fourth joint is half as long again as the third, having a few spinules along each margin and a tuft at the extremity in the middle; the fifth joint is consideral)ly longer than the fourth, bearing three or four small tufts of setae along each margin and tufts of longer setae at the extremity. The flagellum contains about 30 joints, each bearing at the extremity a circlet of setae about half as long as the joint from which they spring; some are placed singly, others in small tufts. At the base of the flagellum each joint is as broad as long, but they gradually become longer and narrower until at the end each joint is about four times as long as broad. The upper Up (PI. XVI. fig. 4) is rather large and strong, being thick and chitinous. It is broader than long, rounded distally, the middle of the distal margin very slightly produced ; the extremity is covered very densely with fine short setae, directed chiefly towards the centre and forming a thick fur. The mandibles (PI. XVI. figs. 5, 6) are very similar in general structure to those of Phreatoicus australis [26, pp. 156, 157, pi. xxiii. figs. 5 and 5 a]. In a lateral view of the head the large basal joint is seen extending along the anterior portion of the lower CEUSTACEA OF ISHEW ZEALAND. 189 margin of the head, which, however, is nearly straight and is not hollowed out for the reception of the mandible as described by Sars [91, j). 94] in Asellus aquaiicus. Below the base of the lower antennae arises the 3-jointed palp, which extends forward beneath the antennae, its third joint being usually bent sharply inward, nearly at right angles to the second. Prom this point the basal joint extends downward and curves fornrard. and inward to form the cutting-edge. The molar tubercle arises from the concave inner surface of the basal joint and extends inwards to meet its fellow on the other side, at a point above and somewhat posterior to the cutting-edge ; it is large and strong, but not so stout as in Phreatoicus australis. A view of the outer convex surface of the mandible with the palp attached is shown in fig. 5 ; in this the molar tubercle is of course com- pletely hidden from view ; it will be seen that there are a few setae at the base of the palp on the side toward the base of the mandible, a small row of fine hairs on the other side of the palj), and another on the inferior edge of the basal portion of the mandible. The figure that I origiiially gave of the mandible of Phreatoicus typicus [23, pi. iv. fig. 5] is almost the reverse of the one now referred to, and shows it from the inner side as it rests on its rounded outer surface — its most natural position when dissected out ; the molar tubercle then projects directly upward and only its extremity is shown. As usual, the two mandibles difi'er slightly in the cutting-edge. In the right mandible there is only the one cutting-edge formed by the extremity of the basal joint itseK ; this appears usually to consist of three teeth only. In the left mandible (fig. 6) the corresponding part is formed of four teeth, two long ones of equal length and the other two shorter; in addition to this there is the secondary cutting-edge, comj)Osed of three teeth on a process which arises inside and extends parallel to the outer cutting-edge almost as far as its extremity. At the base of this and between it and the molar tubercle is another projection nearly as broad as long, having its extremity rounded and bordered by a double I'ow of stout setae ; the outermost of these are short, stout, and denticulated ; the inner ones, nearer the molar tubercle, become gradually longer, more slender, and plumose instead of denticulate. This process is the same in both mandibles. The mandibular palp (see fig. 5) is the same in both mandibles ; the first joint is short, only half as long as the second, and bears several long setae at its extremity ; the second joint is oblong and bears three tufts of setae ou its lower margin toward the eud and another tuft at the extremity ; the third joint is fully as long as the second, and is usually bent upward and inward at right angles to it. Its anterior margin is slightly concave toward the distal end, and bears two regular rows of slightly curved, coarsely plumose setae ; those at the basal end of the row are very short, but the others gradually lengthen distally till the terminal one is about as long as the portion of the joint bearing the row. The lower Up (fig. 7) consists of two lobes narrowed at the base, ovate in shape, with the extremity rounded ; the inner margins are fringed mth long setae projecting radially inward, those toward the extremity being the longest. On the outer margins about the middle is a thick tuft of finer setae, and nearer the base another group of shorter setae forming a sort of fur, Avhich extends ou to the surface of the lip. The two lobes are quite divided aluiost to the base, where they appear to be connected with a soft membrane ; 25* 190 DE. C. CHILTON ON THE SUBTEREANEAN each has fine setae arranged on the surface near the base of the inner margin. The outer margins appear thick and chitinous, but the rest of the lip is thin and delicate. The first maxilla (fig. 8) consists of two lobes, which appear somewhat indistinctly articulated to a basal portion, whicli may perhaps represent the combined basos and ischium, the two lobes representing the internal and external lacinice arising from the basos and ischium respectively. See Boas [13, pp. 495-8] and Parker [84, p. 22]. There is a tuft of fine setae on the outer margin of the base near the articulation of the outer lobe, and another on the inner margin at the base of the inner lobe. The outer lobe is long, its articulation with the base very oblique ; the distal portion curves slightly inward, having the mai'gins parallel and both fringed with numerous fine setae ; the end, which is oblique, is crowned with numerous short spiniform setse, the innermost of which are more or less denticulate. The inner lobe is narrow at the base, but expands some- what toward the distal end ; it has both margins and a portion of the outer (posterior) surface covered with rather long but very fine setae. At the rounded extremity there are four long setae, rather distant from each other ; they appear segmented, and are densely plumose and somewhat denticulated toward the extremity ; at the base of each of the two innermost is a single simple seta. Bands of muscles can be seen attached to the bases of each of the lobes, but no muscles extend into the lobes themselves, a fact which, without further evidence, would be almost sufficient to show that the two lobes cannot represent the exopodite and endopodite of the typical crustacean limb, as some authors have held. The second maxilla (fig. 9) is of the usual shape, and consists of a broad, somewhat rectangular basal portion, having two lobes articulated to its distal end, and being pro- duced distally on the inner side so as to form a third lobe, which, however, is not divided off from the basal portion. The outer margin of the base is straight, and is fringed almost throughout with numerous fine, stiff setae ; the inner margin is slightly concave, and is fringed with two rows of setae. The outer (posterior) row consists of about 15 setae, not very closely packed, and denticulate at the ends ; at the distal end of this row succeeds a number of fi.ner stiff' setae, forming at first a kind of continuation of the row and then spreading out so as to cover the surface of the end of the inner lobe. The inner (anterior) row consists of a much greater number of setae, apparently simple, with thickened bases, the setae being so closely packed . that the bases almost adjoin ; towards the proximal end of the row the thickened base of each seta is rather long, but in the others it o-radually decreases till in the setae at the distal end of the row the base is quite short. This row of setae is situated along the edge of the inner margin ; but at the distal end, when it has reached about halfway along the inner lobe, it leaves the margin and is continued for a short distance along the inner (anterior) surface of the lobe ; beyond the end of the row is a single simple seta. The inner lobe curves slightly inward ; its extremity is truncate, with the corners rounded off, and it bears about 12 long setae, the outermost being the longest and simply plumose, while the inner ones are shorter and in addition to the plumes bear denticulations toward the ends, the denticulations increasing in distinctness and strength as they proceed inward. CRUSTACEA OF NEW ZEALAND. 191 The two articulated lobes are similar and subequal ; they are oblong, with the extremi- ties rounded. Each bears at the end and alon2^ the distal portion of the inner margin a large number of long pectinated setae, which curve somewhat inward. On the outermost setae, which are the longest, the pectinations which project at right angles to the setae are very fine, but they become much coarser on the inner shorter setae. Various portions of the second maxilla bear very fine but rather long straight setae, like those on the first maxilla. Those on the outer surface have already been described. On the inner surface there is a large tuft on the l)asal portion toward the inner edge, and two other tufts near the base of the outer articulated lol)e ; the inner margin of the inner articulated lobe is also fringed with fine setse. The maxillipedes ffigs. 10, 11) ai-e large and appear more perfectly developed than in most other genera of the Isopoda. In general structure they closely resemble those of Phreatoicus av.stralis as well as those of P. typicus, but my original description and figure [23, pi. iv. fig. 9] of the maxillipedes of the latter species are imperfect and based on a partial misconception of the appendage. The first joint, the coxa, is irregular in outline, appearing more or less circular when seen from the anterior side ; from it arises the large basos and, on the outer side, the e])rpodite. This is a large flat plate reaching beyond the end of the ischium, irregularly elliptical in outline, slightly emarginate at the distal end, the mai'gins being entire; along the inner edge, when' it impinges against the basos, the margin itself and the neighbouring portion of the outer surface are covered with very fine setae. Tlie basos, when seen from the outside, is quadrangular, about twice as long as broad, the outer margin fringed with fine delicate setse like those on the neighbouring portion of the epipodite ; besides the portion of the basos thus seen, another portion almost at right angles to it projects inward, and this is produced distally beyond the basos proper into a large concave plate, reaching beyond the inner extremity of the meros and having its convex surface tiu-ned inward toward the median line. The inner margin of this plate up to the end of the basos proper is thickly fringed with fine delicate setae; beyond this the whole margin of the distal portion of the concave plate is thickly fringed with large plumose setae, those at the extremity being shorter than the others and more or less pectinate instead of plumose. Many other setae, similar to these at the extremity, are scattered over the distal end of the convex side of the plate. These setae probably form straining apparatus of some kind. Near the base of the plate, a little beyond the extremity of the basos proper, are two long " coupling-spines," slightly hooked at the extremity, very similar to those of Asellus aquaticus, as described and figured by Sars [91, pi. ix. fig. 5"]. The iscJiium is short, transverse, with one or two setse at the extremity on the inner edge. The meros is subtriangu.lar, produced at the outer side about halfway along the carpus, and is somewhat hollowed distally to receive the carpus ; there are a few rather stout setae on the outer margin at the extremity, and the inner margin is convex and fringed with rather long setae. The carpus is somewhat sunk in the meros, slightly narrowed at the base, the outer margin slightly sinuous and with a small tuft of setae at the extremity, the inner margin convex and densely fringed with long setse. 192 DE. C. CHILTON ON THE SUBTEEEANEAN The projjodos is oblong; outer margin slightly convex, with one or two setae at the extremity only ; inner margin slightly convex and densely fringed with setae, except at the base. The dactylos is similar to the propodos, but much shorter and narrower ; it bears setfB arranged as in the propodos, two or three of those at the extremity being very long and robust. First appendage of pero'on (PI. XVII. figs. 1, 2, 3). In the male these form large well-developed subchelate gnathopoda, very similar in general appearance to those found in many Amphipoda. In the female they are similar, but much smaller. Unfortunately, the only female specimen that I have of this species has been mounted dry on a slide, and I am, therefore, unable to give a full detailed descrii^tion of its gnathopods, but so far as I can see they are very like those of Phreatoicits typicus as described later on [see p. 199, PI. XVIII. figs. 7, 8], except that they are stouter and rather better supplied with setaj. The following description therefore apj)lies to the male only. The coxa (epimeron) is small, attached to the anterior portion of its segment, and is more or less ankylosed to it ; it is free from setse, and is emarginate below to receive the basos. The hasos is longer than the ischium; it is constricted at the base and has three small tufts of setae on the posterior margin. The ischium is similar to and nearly as lono- as the basos ; it has two or three tufts of setse on the posterior margin and two stout setse at the middle of the anterior margin, where it is slightly convex. The meros has a smaU tuft of setce at the extremity of the posterior margin, which is straight : this joint is expanded distally, produced anteriorly and inward, and is hollowed out at the end to receive the rounded end of the large propodos ; the inner margin of the cup-shaped socket thus formed is very densely fringed with long straight setas projecting radially inward (PL XVII. fig. 3) . The carpus is small, sub-oblong, the posterior margin with a tuft of setEe towards the extremity and one or two separate setse placed more proximally, the anterior margin completely covered by the propodos and meros. The propodos is very laro-e, forming much the largest portion of the whole limb ; it is produced backwards beyond the carpus into a rounded lobe which rests back on to the meros ; the whole joint is oval in outline, the anterior margin very convex and without setse, with the exception of a small tvift at the extremity ; the posterior margin slightly sinuous, fringed with short setse ; the palm oblique and well defined, armed with a rounded lobe near the base of the dactylos, followed by four very short triangular spines placed on slightly rounded lobes : these spines decrease in size as they recede from the dactylos ; between the base of the dactylos and the rounded lobe is a row of 7 to 8 setae, and from the lobe toward the end of the palm is a row of simple setse, each with a distinctly enlarged base, and near this row a few scattered setae on the surface of the propodos. The dactylos is strong, as long as the palm, both margins fringed with a few minute spinules, the extremity forming a distinct nail, with a small secondary nail on the inner margin at its base. The second appendage oftheperceon (PI. XVII. fig. 4).— The coxa is similar to that of the first appendage, but is slightly larger and is distinctly marked off from its segment. The hasos is narrow at the base, but widens out at the middle, where the breadth is nearly half the length, and it narrows slightly again toward the distal end ; the anterior margin is fringed throughout its whole length with short, stout setse ; the posterior margin bears CEUSTACEA OF NEW ZEALAND. 193 one or two similar setae about the middle and a tuft of fluer setsB at the extremity. The ischium is about three-fourths as long as the basos: it is narrow at the base but con- siderably expanded distally ; the anterior margin is convex, slightly irregular, and bears five spiniform setae, followed by a series of three or four finei- setae towards the extremity ; the posterior margin is nearly straight, bearing five or six small tufts of one or two setae each, and a larger tuft of longer seti:e at the extremity. The meros is about three-fourths as long as the ischium, subtriangular, and produced at the antero-distal angle; the anterior margin is strongly convex, bearing live spiniform setse, with a row of six or seven along the distal end ; the posterior margin straight and fringed with numerous setae. The carpus is somewhat smaller than the meros, similar in shape, but not produced at the antero-distal angle ; the anterior margin convex, with setae toward the extremity only ; posterior margin straight and fringed externally with spiniform setag. The propodos is oblong, slightly longer than the carpus and a little narrowed distally; the anterior margin is slightly convex and bears a few fine setse, chiefly toward the extremity ; the posterior margin straight, bordered with five spiniform setse and a number of finer hairs : at its extremity the propodos is produced alongside the base of the dactylos into a small triangular projection (PL XVII. fig. 5) similar to tliat described by Sars [91, p. 100] in Asellus aqiiaticKS. The dactylos is slender : the end forms a distinct nail with three or four setae on the surface of the dactylos at its base : on the inner margin is a small secondary nail at the base of the large one, with a seta arising in the angle between the two. The third appendage of the perceon is almost exactly the same as the second in all respects, and tig. 4, drawn from the second, will equally well delineate the third. The fourth appendage of the perceon (figs. 6, 7) is like the second and third in the female, but it is slightly modified in the male to form a grasping-organ, instead of being merely adapted for walking. The whole leg is somewhat shorter than the pre- ceding ; the basos is the same ; the ischium also the same, except that it is shorter than in the preceding legs ; the meros and carpus are much shorter, but otherwise similar, and with the same general arrangement of setoe ; the propodos has the anterior margin very convex, the posterior margin being developed into a slightly concave palm, distinctly defined by a small group of three or four very stout spiniform setse, and occu2)ying nearly three-foiu-ths of the whole margin ; the dacttjlos is rather short, and is considerably curved. The first four pairs of appendages to the perseon form an anterior series, differing very considerably in structure from the last three pairs, forming the posterior series. In the anterior series the dactylos is directed backward, while in the posterior pair it is directed forward, as in the majority of the Amphipoda. The fiftli, sixth, and seventh appendages of tlie peneoa (figs. 8, 9) are similar to each other, but ditter in size, the sixth being larger than the fifth, and the seventh as much larger than the sixth. I shall describe the sixth, pair only, and it must be under- stood that this pair represents the mean between the fifth and seventh pairs, not in size only, but also in the number and size of the setae found on the various joints. The coxa is subtriangular in outline, and fits into a triangular emai'gination in the 194 DE. C. CHILTON ON THE SUBTEEEANEAN segment, the lower margin of the coxa being straight or somewhat concave. In the fifth segment the coxa occupies only the posterior half of the lower margin of the segment, but in the sixth and seventh segments, which are considerably shorter, the coxa occupies nearly the wiiole of the lower margin. The basos is oblong, about twice as long as broad, its slightly convex anterior margin supplied with eight or nine short but rather stout setae and a tuft of finer hairs at the extremity ; the posterior mai'gin produced somewhat backAvard, as in the Amphipoda, irregularly serrate, and armed, except towards the extremity, with about a dozen strong spiniform setae. The ischium is as long as the basos, its anterior margin straight, obscurely serrate, and with five small tufts of setae marking the serrations, and a transverse row along the distal margin ; the posterior margin is convex, with five serrations, each of the first four bearing a strong sjnniform seta, and the last a row of about four or five. The meros is rather more than half as long as the ischium, the anterior margin straight and bearing three groups of stout setae, the distal one being the largest ; the posterior margin bears two or three spiniform setae, and a row of three or four along the distal margin at the posterior angle, A\ hich is somewhat produced. The carpus is as long as the propodos, but broader : both are oblong, slightly expanding distally, with groups of stout setae along both margins, but more especially along the anterior margin, and a row along the end at each angle. The dactylos is about as long as the setae at the end of the propodos, similar to the dactylos of the second pair of legs, but more slender. The pleopoda of Flireatoicus are large and well developed, and present such pecu- liarities that they are well worthy of careful examination and description. The five pairs all appear to be branchial in function, and though the first pair difi'er in shape from the others, they appear to be the same in minute structure, probably fulfil the same function, and do not act as an " imperfect operculum " to the otliers as I originally stated [23, p. 91]. All the pleopoda hang vertically from the ventral surface of their segments, and are protected laterally by the greatly developed pleura. The first pair of pleopoda (PI. XVII. fig. 10) have the basal joint ov protopodite sub- rectangular, with one seta at the extremity on the outer margin, and several similarly placed on the inner margin. Prom the protopodite arise two rami, both long and narrow ; the inner one, endopodite, is narrow-elliptical, about five times as long as broad, with the margins quite entire and without setae, and the extremity subacute ; the outer ramus, exop)odite,\s, oblong, longer than the endopodite, the inner margin nearly straight, outer margin irregularly curved at each end ; the whole of the inner margin and the extremity fringed with rather long setae ; on the outer margin the setae are long at the end, but they become smaller tow'ard the base and disappear altogether before the base is quite reached. All the setae on the inner margin are simple, those at the extremity and on the neighbouring portion of the outer margin are plumose ; the others on the outer margin become gradually less plumose as they approach the base, until at about the middle of the joint they are quite simple. '^rhe second pair of pleopoda (fig. 11) differ in the two sexes, being specially modified in the male so as to serve as an accessory copulatory organ. It will be convenient to describe that of the male first. The p)7'otopodite has the same general shape as in the CRUSTACEA OF NEW ZEALAND. 195 first pair, and bears a few setJB at its extremity on the inner margin ; the endopodite is similar to that of the first pair, but bears on the inner side a long, narrow, curved appendage, the " penial filament," which docs not reacli so far as the end of the endo- podite ; it appears to be semi-cylindrical, being concave on the outer side, and bears four or five short setae at its extremity. Tlie portion of the endopodite between its base and the base of the "penial filament " is about one-fourth the length of the whole endopodite; it is slightly enlarged, and bears toward the inner margin a powerful muscle attached to the base of the " penial filament." It will be seen from fig. 11 that the "penial filament" of JPhrcatokus assimilis, as drawn, is much shorter than in P. cutstralls [26, pi. xxvi. fig. 2] ; it is, however, quite probable that, like other secondary sexual characters, it may vary vmy greatly in deve- lopment at different seasons. The eocopodite is large, and consists of two joints ; on the outer side it is produced backward at the base into a rounded lobe which lies alongside of the protopodite ; the outer margin of the first joint is fringed rather sparingly with short simple setse, its inner margin is straight and more thickly fringed with similar setse; the second joint is triangular, articulated to the first joint by a very narrow base; the inner margin is straight, and, like that of the first joint, is fringed with simple setae, but these are much longer than on the first joint ; the extremity, which is oblique, is bordered on the outer margin by about 10 long delicately plumose setae. The endopodite does not hang by the side of the exopodite, but overla})s it, and the exopodite is curved so as to receive it ; a raised ridge runs from the outer extremity of the protopodite toward the outer margin of tlie first joint of the exopodite, meeting it at about the middle, and thus bordering the depression within which tlie exopodite lies. The endopodite usually overlaps the exopodite to a greater extent than is shown in fig. 11, where it was purposely somewhat separated from the exopodite to allow the form of the latter to be more clearly seen. The more natural position of the two is shown in fig. 12, which represents the third pair of pleopoda. I have had no opportunity of examining the pleopoda of a female specimen of Phreatoicns assimilis, but from the analogy of P. cmstralls and P. ii/idcus I have no doubt that the second pleopoda would resemble that of the male, as above described, except that there would be no penial filament. The third pah- of ^^leojxjda (fig. 12) are similar to the &econA, hut i\\Q endopodite \& rather smaller in proportion to the exopodite, and does not reach beyond the base of the second joint of the latter. From the outer margin of the protopodit(! arises a sub- triangular lobe projecting nearly at right angles to the protopodite, and apparently representing the epipodite ; its margins bear long simple seta?, \\ idely separated from each other, and its integument, though apparently thicker than that of the rest of the pleopod, is more or less membranaceous, so that this epipodite is perhaps also branchial in function. The significance of the occurrence of an epipodite in the pleopoda of Fhreatoicus is considered later on (see p. 214<). The fourth and fifth pairs of pleopoda contain precisely the same parts as the third pair, but each is much shorter and broader than the preceding. SECOND SERIES. — ZOOLOGY, VOL. VI. 26 196 DE. C. CHILTON ON THE SUBTERRANEAN Tlie uropoda (fig. 13) arc long, the peduncle as long as the inner ramus, and reaching considerahly beyond the end of the telson. Its lower margin is straight and bears three tufts of setae on the proximal portion and another tuft at the extremity ; the upper surface is flat or slightly concave, the outer margin with a few small setae scattered along the whole length ; the inner margin with few setae, except towards the end, where it is somewhat raised and bears two stout spiniform setae on the projection. The outer ramus is considerably shorter than the inner, but of the same shape ; each is lanceolate, a little constricted at the base, and bears numerous tufts of one or two stout setae and many fine hairs ; the extremities narrow somewhat abruptly and are free from setae. Male reproductive organs. I came across the male reproductive organs in the specimen from which I was dissecting out the appendages. They seem to have the same general shape as in Asellus aquaUcus [91, pi. x. fig. 7], but there appears to be a great number of the oval cnl-de-sacs, apparently five or six. The vas deferens was quite crammed with spermatozoa, which resemble those of Asellus. I have been unable to find an external male organ in either of the two specimens I possess. Phreatoicus ttpicus, Chilton. (PL XVIII. figs. 1-12.) Phreatoicus typicus, Chilton, New Zealand Journal of Science, vol. i. p. 279 (Nov. 1882) ; id. Trans- actions New Zealand Institute, vol. xv. p. 89, plate iv. ; Thomson & Chilton, Transactions New Zealand Institute, vol. xviii. p. 151; T. R. R. Stebbing, Report on the 'Challenger' Amphipoda, pp.513, 587; R. Moniez, " Faune des eaux souterraincs du departemeut du Nord &c.," extrait de la Revue Biologique du Nord de la France, tome i. (1888-1889), p. 53. Specific diagnosis. Body somewhat slender. Pleura of the second, third, fourth, and fifth segments of the pleon moderately produced, not deeper than their respective segments ; their inferior margins well supplied with setae, especially in the fifth segment. Extremity of the telson forming a narrow projection much longer than broad, narrowing distally, the truncate extremity tipped with rather long setae. Lower antennte about three-fourths as long as the body ; flagellum much longer than the pedvincle, which is slender and has the fifth joint twice as long as the fourth. Legs slender; joints scarcely expanded, the first four pairs not very abundantly supplied with setae. Lower lip with each half subtriangular, with the inner distal angle somewhat acute. Inner lobe of the first maxilla broad, expanded distally, and bearing about nine long plumose setae. Colour. Translucent. Length. Rather more than half an inch (15 mm.). Habitat. Eyreton {Chilton) and Ashburton (W. W. Smith), in wells. Detailed Description. Unfortvmately I have no male specimen of this species, all the few specimens I liave seen, about ten altogether, being females. The following detailed description applies CEUSTACEA OF NEW ZEALAND. 197 therefore to the female only, though doubtless it will apply cqvially well to the male, except as regards the first and fourth appendnges of the pera?on and the second pleopoda, which are specially modified in the male. I described this species pretty fully in my original paper [23], and in the present paper I have given a full detailed description of the new species P. assimilis, and I shall therefore give only such further details of P. iypicus as are necessary to exhibit clearly the differences between the two species. Pof/y (PI. XVIII. fig. 1). It will be seen, from a comparison of PI. XVI. fig. 1 and PI. XVIII. fig. 1, that the body is much more slender than in P. assimilis ; thus iu one specimen that I bave mounted dry on a slide, and from wbich fig. 1, PL XVIII. is taken, tiie body is fully 15 mm. long, yet the depth is only 1'5 mm., the same as the depth of a specimen of P. assimilis that was only 10"5 mm. long. The surface of the whole body is smooth, and though there are a few fine setae scattered over it, chiefly in the pleon, they are not so numerous nor so distinctly arranged in small tufts as in P. assimilis. FercEon (PI. XVIII. fig. 1). The first segment is very short, not half so long as the succeeding; it widens inferiorly, and has the inferior angle somewhat produced and brought close up to the head, so that the first pair of appendages of the pera3on seem almost to arise from the head. The next three segments are subequal and rather longer than deep ; they are quite rectangular in outline, the inferior margin being almost straight and scarcely hollowed, except slightly iu the first segmeut for the reception of the coxa of the appendage, which is small and placed well to the anterior end of each segment. The next three segments are similar, but each is shorter than the preceding segment ; the inferior margin of each is emarginated towards the posterior end for the triangular coxa. Pleon (figs. 1, 11). In the pleon this species resembles P. assimilis as above described, but the pleural portions are not so largely developed, being somewhat shallower than their respective segments, and their inferior margins are more abundantly supplied with sette. In each segment there is a slight ridge where the pleural portion leaves the body -ring proper, but the integument is quite continuous, and there is no buture or line of division of any kind. The projection at the end of the telson (tig. 12) is narrow, longer than broad, projects slightly upwards, and has the truncate extremity tijiped with a fcAV setae ; there is a stout seta below at its base ; the inferior margin of the telson on each side from this projection to the articulation of the uropoda is irregular and fringed with very fine setae. The upper anteuna (fig. 2) extends a little beyond the extremity of the third joint of the peduncle of the lower antennae ; it usually contains eight joints, but is not distinctly divided into peduncle and flagcUum. The first three joints are similar, but each smaller than the preceding, oblong, about twice as long as broad, with a few setse at the distal end ; the fourth joint is like the third, but shorter ; the fifth shorter still, but somewhat expanded distally ; the sixth and seventh are subequal to each other and to the first joint and are considerably swollen ; the eighth joint is usually small, but swollen ; the last 2G* 198 DE. C. CHILTON ON THE SUBTEREANEAN three bear at. the extremity one or two small " olfactory cylinders" of the usual shape in addition to a few simple setse. The lower antennoi (fig. 2) are about three-fourths as long as the body, the flagellum being much longer than the peduncle. The first two joints are subequal, short, as broad as long, without setse ; the third is as long as the first and second together, its upper margin slightly convex, lower margin straight, one or two small setae on the lower margin at the distal end ; the fourth is about half as long again as the third, but slightly narrower, sides straight and parallel, one or two small setie on the margins, and tufts of longer setae above and below at the extremity ; the fifth joint is similar to the fourth but about twice as long, each margin bears about four small setse and there are tufts of longer setse at the end ; the first joint of the flagellum is about twice as long as the second, which is about as broad as long ; the remaining joints (about 35 altogether) gradually become longer and narrower till at the end each is about six times as long as broad, each bears one or two small setae at the distal end, but toward the extremity of the flagellum these become very small. The upper lip does not difl'er in any important respect from that of P. assimilis. The mandibles (fig. 3) also appear to resemble those of P. assimilis, but the left mandible has only three teeth on the terminal cutting-edge, with three also on the secondary cutting-edge. In the specimen from which I have taken the drawing (fig. 3), these teeth are much sharper and more acute than those showTi in the figure of P. as- similis (PI. XVI. fig. 6), but this is probably due to the fact that they belong to a younger specimen. In the figure they are flattened out so as to be seen full in front, while those of P. assimilis are seen in profile. The lower lip (PI. XVIII. fig. 4) differs considerably in shape from that of P. assimilis. Each lobe is triangular, inner margin straight, outer margin very convex, especially toward the base, the extremity being more or less acute, not rounded, and there is a small projection on the inner margin at some little distance fi*om the extremity. The extremity is densely covered with long setae ; the inner margins and the distal portions of the outer margins are fringed with fine setae. The first maxilla (fig. 5) bears a general resemblance to that of P. assimilis, but the inner lobe is much broader, especially toward the extremity, which is rounded and bears about 9 or 10 long plumose setiB, about twice as many as in P. assimilis. The two simple setfB also present at the extremity are situated near the base of the third and fourth setae respectively from the outer margin of the lobe. In P. assimilis they are situated at the base of the two inner setae. The second maxillcB (fig. 6) differ from those of P. assimilis in the following points : — The inner margin of the basal portion is more convex, and bears a very distinct row of long plumose setae, which have thickened bases ; those at the distal end have the base quite short, but toward the proximal end of the row the bases become gradually longer. At the lower end of the row on the surface of the base is another somewhat imperfect row of simple setae. The inner (fixed) lobe is longer than in P. assimilis and has the end more rounded, and the long plumose setse, instead of being confined to the extremity, extend for some distance along the inner margin toward the base. CRUSTACEA OP NEW ZEALAND. 19!) The maxillipedes are practically identical with those of P. assimilis, but the " grappling setse " are slightly different, being long curved setae slightly hooked at the end ; they thus resemble those of P. australis, but are more slender. In the specimen dissected there are two on one side and tliree on the other. P. assimilis has two on each side, and they are straight, with hooks at the end. 'Ihe. first pair of legs of the female (PI. XVIII. figs. 7, 8) are much more slender than in P. assimilis. The coxa is small, shallow, partly cleft below and ankylosed to the body- segment. The bases is narrow oblong, about threa times as long as broad, and is almost free from seta3 except a small tuft at the extremity on the posterior margin. The ischium is nearly as broad as the basos ; posterior margin straight, with three or four miuute spinules ; anterior margin slightly produced in the centre and bearing a stout seta at this point. The meros is subtriangular, and bas the posterior margin straight, with a few setae at the extremity ; the anterior margin is convex and produced distally into a rounded loloe extending about halfway along the carpus, the edge of this lobe next the carpus l)eing fringed with stout setge. Tlie carpus is suboblong, its junction with the meros being oblique ; on the posterior margin there is a small seta near the base and a small tuft of larger setae toward the extremity. Ihc propodos is subtriangular, expanding distally, longer than the meros ; the anterior margin convex, especially toward the base, and bearing one or two minute sette and a small tuft at the base of the dactylos ; the posterior margin is straight, produced at the extremity to define the palm, the postero- distal angle being thickly covered with setae. The palm is oblique, concave, and bears five or six very acute setae with expanded bases, those nearest the base of the dactylos being the best marked, the others gradually becoming more slender until they are indis- tinguishable from tbe ordinary stout setae at the postero-distal angle ; in addition to these the palms bear a few simple setae. The dactylos is somewhat stout, longer than the palm, both margins bearing a few spinules, the extremity being separated off as a distinct tooth. The peculiar setae on the palm are of the same kind as those described in the male of Phreatoicus austraUs [26, pi. xxiv. fig. 5 a], but they are not so stout and well marked. The female of that species has the first pair of legs very like those described above, but shorter and stouter and more spiniform, and the palm more oblique and not concave. Th.e second pair of legs {'n^. ^y in vs.i\\eY longer than the first pair; the coxa, hasos, and ischium arc similar to the corresponding joints of the first pair ; the meros is sub- triangular, about three-fourths as long as the ischium, posterior margin straight and fringed with a few setae, the anterior margin slightly convex, and with the antero-distal angle slightly produced, a few setae on the margin and at the extremity ; the carpus is oblong, not so long as the meros, posterior margin straight and with a few setae, anterior margin nearly straight, and with setae at tbe extremity only ; fropodos similar to the carpus but usually a little longer, the extremity produced into a small triangular lobe at the side of the dactylos ; dactylos nearly half as long as the propodos, extremity forming a distinct nail, with a small tooth at its base. The third sinA. fourth pairs of legs are similar to the second and of the same size. The fifth, sixth, and seventh pairs of legs (see fig. 10) are similar to each other, but 200 DE. C. CHILTON ON THE SUBTEEEANEAN each is larger than the preceding. The coxa is deepei- than in the first four pair of legs and is triangular, fitting into a triangular euiargination in the inferior margin of the segment ; in the fifth segment this is at the posterior end, but in the sixth and seventh it approaches nearer the centre, though still in the posterior half of the margin. The basos is only slightly expanded, being oblong, about three times as long as broad, both margins somewhat scantily supplied with setse. The ischium is very long, being consider- ably longer than the basos, narrow oblong ; front margin straight, with five or six setae ; posterior margin a little convex, with a few spiniform sette. The meros not half so long as the ischium; postero-distal angle a little produced; both margins with spiniform setae, those at the extremity being very strong. The carpus and propodos similar, the carpus usually longer than the propodos; both oblong, and both margins supplied with spiniform setae arranged in tufts, those on the anterior margin being larger than those on the posterior. The dactylos as in the preceding legs, but longer and more slender. The above description applies to the fifth, sixth, and seventh pairs of legs, but it is to be remembered that tiie spines as described above are larger and more numerous in the sixth than in the fifth, and in the seventh than in the sixth. The pleopoda appear to be similar to those of P. ussimilis, but are rather more slender ; the fifth pleopoda are very short and small. The uropoda (fig. 12) differ from those of P. assimilis only in being longer and more slender, and in having the seta' on the inferior margin of the peduncle smaller and not arranged in distinct tufts, but evenly distributed along the whole margin. In one of the females examined, brood-plates were beginning to appear at the bases of the appendages of the perseon; one of these is shown in the drawing of the second pair of legs (fig. 9) . Comparison of the three known Species of Phreatoicus. When I first received the specimens of the Phreatoicus from Winchester along with the other species which were known from Eyreton (i. e. Calliop'ms subterraneus, Gam- marusfragilis, and Cruregens fontanus), I naturally thought that they would belong to the Eyreton species Phreatoicus typicus ; and thougli at the time I noticed that there were a few variations, I thought that these might jirove to be due to differences of age or sex. I was therefore somewhat surprised to find on a close examination that this was not the case, but that the differences were quite sufficient to warrant the creation of another species, viz. P. assimilis. Besides being found at Eyreton Phreatoicus typicus is also known from Ashburton, only about 30 miles from Winchester, where Phreatoicus assimilis is found ; and the existence of two subterranean species of the same genus being so near each other is a fact of considerable importance, and it would be interesting to know whether the species have differentiated since adopting a subterranean life, or whether they have descended from two difierent surface species. It is therefore desirable that the differences between them should be clearly set forth, and that they should be compared not only with each other but also with the species Phreatoicus aiistralis [26], found on the top of the Mt. Kosciusko plateau in Australia, and at a height of nearly 6000 feet above the sea. CRUSTACEA OF NEW ZEALAND. 201 It is quite possible that on an examination of a greater number of specimens from various localities the differences between P. tijpious and P. assimilis may partially or wholly break down ; but, so far as my observations at present go, the Ashburton specimen of P. tupicKS is practically identical with those from Eyreton and differs from P. assimilis in the following points : — (1) The body and the appendages are much more slender than in P. assimilis. This character is of course only a relative one and therefore difficult to estimate with accuracy, but in my specimens the differences, especially in the legs and the lower antennre, are very mai'ked. (2) The pleura of the second to fifth pleon-segments, inclusive, are not so greatly deve- loped and have all the inferior margins regularly supplied with moderately stout setae. In P. assimilis the pleura are considerably deeper than their respective segments and have the inferior margins only sparsely fringed with spinules. (3) The shape of the projection at the end of the telson is quite different in the two species. (4) The shape of the lobes of the lower lip also differs to some extent. (5) The inner lobe of the first maxilla is broader distally and bears fully twice as many long plumose seta? as in P. assimilis. (6) There are slight differences in the second maxilla? ; thus the long plumose setse on the innermost lobe extend some distance along the inner margin, while in P. assimilis they are pretty well confined to the extremity ; the rows of setye along the inner margin of the basal portion also differ in character. (7) The grappling-setae of the maxillipedes also differ slightly. The differences in the mouth-parts are somewhat peculiar, and were quite unsuspected when I had from other reasons already perceived that there were two species. The differ- ences in the inner lolie of the first maxillae are very noticeable. Of the two, P. assimilis approaches more nearly to P. anstmlis than P. typicus does, and I am inclined to think that, leaving out of account the special characters which are due to their subterranean life, P. assimilis is more closely related to P. australis than it is to P. typicus. The two former agree with each other and differ from P. typicus in the following points : — (1) The stouter body and appendages. (2) The shape of the lobes of the lower lip. (3) The inner lobe of the first maxilla bears only 4 or 5 pkimose setae. (4) The pleura of the jileon-segments are almost equally well developed in both. On the other hand, P. australis has the projection at the end of the telson rather more like that of P. typicus, and in the second maxillae and the maxillipedes it is also quite as close to P. typicus as to P. assimilis, if not closer ; but in the last two points the differences of all three species are very trivial. Phreatoicus australis di&ers from both the subterranean species in the following points, in addition to those which are evidently due to the different modes of life: — (1) The body and especially the legs and pleura of the pleon are more abundantly supplied with setae. 202 DK. C. CHJLTON ON THE SUBTERRANEAN (2) The telson proper is much shorter and rounder. (3) The inferior margin of tlie sixth segment of the pleon bears about 15 setae instead of only 4 in front of the articulation of the uropoda. (4) The first pair of legs in both sexes differ slightly in the shape of the propodos and in tlie armature of the palm. (5) There are also slight differences in the maxillipedes. (6) The body is much stouter than in either of the subterranean species. Without a much fuller knowledge of tlie habits of each species than we possess, it is difficult to see the reason for the dilferences between them ; aud until we are able to do this, to some extent, it will be almost impossible to assign its true importance to each difference and thus to discover the true relationships of the species. The abundant setse on P. australis are perhaps j)rotective ; and, if so, we can see why they should be less abundant in the subterranean forms, though even in these species they are pretty numerous, especially on the last three pairs of legs. The slender body and appendages of JP. ti/incus may also be an adaptation to a subterranean moLie of life, aud, if so, it would ajDpear that P. ty^icuis has been longer underground than P. assimilis ; but in the present state of our knowledge all speculations of this kind must be received with the greatest caution. The questions suggested may perhaps be some day solved by the discovery of species of Phreatoicus still living above ground in the mountain-streams of the Southern Alps, places where very little search of the kind required has hitherto been made. It is worthy of notice that the species of Phreatoicus do not show the increase in the number of sensory setae, &c., in compensation for the loss of eyes that has been observed in some other subterranean species. (See p. 262.) Sjjecial points in the Structure q/' Phreatoicus. In many respects Phreatoicus appears to be a very generalized type of the Isopoda, possessing all the segments of the body and their appendages in a more perfect form thaii any other Isopod I know. Thus in the body all the segments both of the peryeon and the pleon are well developed and separate, except of course that the telson is joined to the sixth segment of the pleon as in nearly all Isopoda. The antennte, thougli well developed, do not present any peculiarity, and tlie lower antenna does not possess the rudimentary exopodite found in some genera of the Aseliida?, such as Janira, lanthe, Stenetrium [9, p. 9]. The mouth-parts are all particularly well developed, no parts usual in the Isopoda being absent or coalesced ; the maxillipedes especially have all the joints perfect and separate. The legs of the peraeon all have the coxae more or less separate from the segment, showing, 1 think, clearly that they are really the iirst joints of the legs, and not outgrowths of the body-ring (" epimera "). This view was first advanced by Spence Bate in 1855 [7], and has, I believe, since been pretty generally adopted, though, as Stebbing says, " It is a disputed question whether we have at the base of the leg an outgrowth of the body -ring carrying the more or less obsolescent first joint of the leg soldered to it, or whether the side-plate is itself a protective expansion of the first joint" [108, p. 1730]. In quoting Spence Bate's arguments to show that the CEIJSTACEA OF NEW ZEALAND. 203 so-called " epimera " are really the coxre of the legs, Stebbing [108, p. 289] appears rather to favour the first vievr. Against this I may call attention to the fact that, in Phrcatoicits, in the segments of the pleon the pleural portion of the body-ring lias grown out to form a protection to the pleopoda, the coxal portion of which is present, but is in no way attached to this outgrowth of the body-ring, and the outgrowth is quite continuous with the body-ring, not being marked off by any suture or line of division. The same tiling is of course true of the pleon of most Amphipoda. Thus tbese true outgrowths of the body-ring npjjcar clearly marked off from the " epimera," which are either quite separate from the body-ring, or have a suture clearly showing the line of division, a fact that can be easily accounted for if the " epimera " are formed solely from the coxa3 of the legs. In the pleopoda of Phreatoiciis we find several peculiarities which will probably be useful in helping us to trace out the homologies of the pleopoda of other Isopods. All the pleopoda have the basal portion, the " protopodite," present and of moderate size, and in the third, fourth, and fifth pleopoda this bears a fair-sized " cpipodite." The existence of this epipodite is a point of considerable interest. I am not aware of any other case where the epipodite is present in any of the pleopoda of Isopods. In the ' Journal of the Royal Microscopical Society ' for October 1891 (p. 593), in an abstract of a paper by Dr. J. Nusbaum [80] on "The Morphology of Isopodan Feet," it is stated that, according to the author, the epipodite of the thoracic legs has fused Avith the ventral wall of the body-segments. If this should be so in the pcroeon it certainly does not apjiear to be the case with the posterior pleopoda of Fhreatolcus. There is no trace of the epipodite in the first and second pairs of pleopoda, nor can I suggest any reason for its absence. Both the exopodite and the endopodite are present in all the pleopoda, both being large flat j^lfites, apparently branchial in function. In all the pleopoda, except the first pair, the exopodite consists of tAvo joints. This character is also possessed by some of the pleopoda of lanthe [16], Mhhiui [27, p. 11], and some allied genera, but the more general rule among the Isopoda is that the exopodite consists of one joint only. In the second pleopoda of the male, although there is a " peiiial filament," the whole pleopod has been very little modified, and it is quite easy to recognize the various parts, and to see that the penial filament is only a specialized portion of the endopodite. In Luithe [16], Ilnnna [27, p. 10], Iclinosoma, and Acaiitlioinnnna [9, p. 40] much further modifi- cation of the pleopod has taken place, and it is not so easy to see the homologies of the various parts. Thus both Bovallius and Beddard consider the large triangular portion which forms the main part of the pleopod to be the protopodite, and Beddard considers the penial filament to be the endopodite, and the exopodite to be represented by a small membranous portion at its base. Whether this is really so, or whether this view AviU require modification, is a question that must be left for future determination ; but this interpretation of the various parts does not appear to harmonize Avell Avith Avhat we find in Phreatoicus. SECOND SERIES. — ZOOLOGY, VOL. VI. 27 204 DR. C. CHILTON ON THE SUBTEEEANEAN Affinities q/'Plireatoicus. Phreatoicus presents so many peculiarities that it is difficult to determine its exact systematic position, and its affinities must therefore be discussed at some length. The followin"- account is partly reproduced from my jiaper on Phreatoicus australis [26], but it has been revised and to some extent made more complete. When I originally described the genus Phreatoicus in 1882 [23], I placed it in the Isopoda, and pointed out various separate resemblances to the Idoteidse, the Anthuridoe, and the Tanaidae, and also drew attention to the several resemblances to the Amphipoda ; but after doing this I left the exact position of the genus among the other Isoj)oda an open question for the time. When preparing the " Critical List of the Crustacea Malacostraca of New Zealand" [111, p. 151] Mr. Thomson, judging from the general api^earance (he had not had an opportunity of examining specimens), was inclined to place it under the Amphipoda, and, as I did not agree with this opinion, it was arranged that the genus should be placed between the Amphipoda and the Isopoda under a separate heading with the following note: — "The systematic position of this singular Crustacean is doubtful. In general appearance I was inclined to place it among the Amphipoda, but from the fact of the first five pairs of 2'>t<^opoda acting as branchial organs, and from the absence of any such organs attached to the ];>ereion, Mr. Chilton places it among the Isopoda. — G. M. T." [Ill, p. 161]. Unfortunately, however, the separate heading was omitted by some error, probably on the part of the printer, and the genus therefore appears under the last family of the Amphipoda, viz. the Platyscelidce, as though it belonged to that family. It is no wonder, therefore, that the Rev. T. Pi/. R. Stebbing, in his notice of the " Critical List," says, in speaking of Phreatoicus, " I do not know what are the special reasons for classing it among the Platyscelidge." He also says, " The list [?. e. our ' Critical List '] continues with ' Suborder II. Isopoda. Tribe I. Anisopoda. Pam. I. Tanaidje ; ' and probably the affinities of Phreatoicus will eventually prove to be rather with the Tanaidse than with the Hyperina" [108, p. 587]. In another reference to the species Phreatoicus tijinciis, Mr. Stebbing calls it " a singular well-shrimp of a new genus and species, which appears to be an Isopod with some remarkable Amphipodan affinities " [108, p. 543]. At first sight Phreatoicus certainly does look very like an Amphipod, but on exami- nation this is found to be due to superficial resemblances only, and not to any real affinity to that group. These resemblances appear to be as follows : — (1) The body, especially in the pleon, is more or less laterally compressed. (2) The pleura of the segments of the pleon are produced downwards, so as to protect the pleopoda on either side, just as in the Amphipoda. (3) The legs of the pera^on consist of an anterior series oifour and a posterior series of three. (4) The general appearance of the legs and of the uropoda is not unlike that common among the Araphij^oda. (5) The pleon is formed of six separate segments, and is better developed than in most Isopoda. CEUSTACEA OF NEW ZEALAND. 205 I think these are aU the points in which Fhrcatoicus specially resembles the Amphi- poda, and an examination of them shows that none is of any particular imiiortance in its bearing on the systematic position of the genus. I will take the points one by one under their appropriate numbers as given above. (1) Most of the Isopoda are, it is true, more or less dorso-ventrally compressed, and I do not know of any one in which there is any lateral compression as in Fhreatoicns ; but here the lateral compression is not great, and is chiefly confined to the plcon, where the downward prolongation of the pleura is no doubt a special adaptation for the protection of the pleopoda, and may very well have arisen quite independently of the similar adaptation in the Amphipoda. The pencon of Fhreatoicns is subcylindrical, and thus resembles Anthura and Faranthura, and other genera of the Anthuridte [lOG], and some species of Idotea, such as Idotea elongata [24, p. 198], in which there is no dorso-ventral compression. On the other hand, lateral compression is by no means universal among the Amphipoda ; there are many genera where the body is more or less cylindrical, as in Caprella &c., Coi'opJdiim, Haplocheira, and many others, while there are also some, such as Icillus, Iphigeiila, and Cijamiis, in which the body is much flattened, as in most Isopoda. (2) This point has practically already been disposed of in the consideration of (1), and I need only add that Phreatoicus has the pleura of the first five segments of the jileon produced downwards, while in the Amphipoda it is only in the first three segments that the pleura are so produced. (3) The division of the appendages of the pera^on into an anterior series of four and a posterior series of three has been used by Dana in separating the Anisopoda from the typical Isojioda, and it is by no means a special Amphipodan character. It is, more- over, probably of little importance from a systematic j'oint of view, seeing that it is found in such widely different genera as FJireatoicus, Stenetrium, Iliinnopsls, Tanais, and Arcturus, and its adojition as the chief bond of connection between a number of forms results, as Professor Haswell bas pointed out, in " an extremely artificial arrange- ment " [55, p. 10]. (4) The appendages of the joeraeon appear at first sight undoubtedly Amphipodan, but here, again, a closer examination shows that the resemblance is merely superficial, for in all the legs we find that the ischium is faiidy long, often as long or even longer than the preceding joint, the basos, w^hile in almost all the Ampliipoda the ischium is quite short, often transverse. In the possession of moderately long ischia, Fhreatoicns agrees with most other Isopoda. I am not aware that anyone but myself has drawn attention to this difference between the Isopoda and the Amphipoda ; but it appears to lie one of very general application, though, of course, there are some exceptions to it as to every other rule in Natural Science. Thus, in the Apseudida^ and the Tanaidie [106], the ischium is usually short, while in a few cases in the Amphipoda it is long, as in the second gnatlio- poda of the Lysianassidte, and also in the second gnathopoda of Seba [108, p. 783], and perhaps in a few others. But in all these cases that I know of in the Amphipoda the long ischium is found in one pair of legs only, and I know of no Amphi^jod that has the ischium in each pair of legs long as in the Isopoda ; so that, while the possession of short 27* 206 DR. C. CHILTON ON THE SUBTEERANEAN iscliia would not necessarily prove that the animal is not an Isopool (unless, indeed, we remove the Apseudidte and the Tanaidae to the Amphipoda, and this, notwithstanding Gerstaecker's opinion, does not seem to be desirable), the fact that it possesses long ischia in all the appendages of the perseon is a pretty clear indication that it is not an Amphipod. It may also be pointed out that although the first appendage of the perfeon of Phrea- toicns is subchelate, as in the Amphijioda, the second appendage resembles the third in being quite simple, while in the Amphipoda the second appendage is usually subchelate like the first, or, if not actually subchelate, it shows a greater tendency to resemble the first leg than the third. (5) In the possession of a long pleon of six separate segments, Phreatoicns certainly resembles the Amphipoda, and differs from most Isopods, but the same character is also possessed by the Apseudida? and the Tanaidae, and by the genus Hysswra [106, p. 128] in the Anthuridpe ; and in many other Isopods, such as Limnoria and many of the Cymo- thoidfe, Oniscidaj, &c., the plcon, though not long, is composed of more or less separate segments. The reasons given above will, I think, be quite sufficient to prove that there are no good grounds for classing Plireatoicus with the Amphipoda ; for positive evidence that it is an Isopod it will be sufficient to take the following : — (1) The first five pairs of pleopoda are branchial, and there are no branchial plates attached to the ap^iendages of the peraeon. The pleopoda themselves are quite different in form from those of the Amphipoda. (2) The whole of the mouth-j)arts are distinctly Isopodan in character, and quite different from those of the Amphipoda. (3) As shown above, the legs are really Isopodan, though at first sight they may appear to be Amphipodan. (4) The telson is joined to tlie sixth segment of the pleon, as is usually the case with the Isopoda, but not with the Amphipoda. It is quite true, as Stebbing [108, p. 549] has pointed out, that this is also the case with certain Amphipoda, the Hyperina for example ; but this is exceptional, and since Plireatoicus is certainly not one of the Syiicrina, it does not affect the present argument. The large size and the form of the telson itself also clearly mark it off from the Amphipoda. It will be noticed that, in considering the differences between the Isopoda and Amphi- poda, I have confined myself to external characters. Other important differences in the internal anatomy have l)een pointed out by Blanc [12], but the material at my disposal did not permit of my testing Plireatoicus by these points, even if I had possessed the necessary skill to do so. We have now to compare Plireatoicus with the other Isopoda to see what place it should take among them. It will be sufficient if we compare it with the Tanaidae, AnthuridtB, Idotcidae, and the Asellidae. It agrees with the Tanaidte in the cylindrical form of the body, in the direction of the CRUSTACEA OF NEW ZEALAND. 207 leo-s, and in the possession of a pleon formed of six separate secjments. All these characters are, however, separately shared hy other groups, and the differences in other respects are very considerable, and we may safely conclude that Phreato'icus has no very close affinity with the Tanaidae. The Apseudidro, which rank close to the Tanaidre, do not seem to present any greater affinity to Phreatoictis. The resemblance of the Anthuridfe is, however, somewhnt greater. There is a fairly good general resemblance in the shape of the body and in the legs, and though the pleon is usually short in the Anthurida?, it is often composed of separate segments, and these may be of fair length, as in the genus Hyssura, Norman and Stebbiug [lOG, p. 128]. The mouth-parts are very different, being specially modified in the Anthuridfe for the purpose of suction, and this, combined with differences in the pleopoda, uropoda, &c., is sufficient to make a pretty wide difference between the two. With tlie Idoteida3, Phreatoicus agrees in the shape of tlie body, in the antennae, and to some extent in the mouth-parts. In the Idoteida? these are more modified tlian in Phreatoicus, though formed on the same plan, and the mandible has no palp. It is probable, however, tliat the presence or absence of a mandibular palp is not a point of great systematic importance, for in the Amphipoda we have genera, in other respects closely similar, differing in this point ; thus tlie old genus Ilontagua, Spence Bate, has been divided into Stenothoe, in which the mandible has no palp, and 3Ietopa, in which the palp is present [108, p. 293]. A much more important difference is found in the structure of the pleon and the uropoda. In the Idotcidtc the segments of the pleon, except the last, are usually very short and more or less coalesced and the uropoda form flat plates covering up the pleopoda. There are, however, sufficient signs that the pleon of IdoteidtB has been derived from a pleon formed of separate segments, and that the uropoda, though now very different, are simply a modified form of the typical uropoda consisting of a peduncle and two rami ; and it is quite probable that the special modifications of the Idoteidse in these respects are of comparative recent date, and that their ancestors presented a much closer resemblance to Phreato'icus tlian the present Idoteidae do. The Arcturidae, again, might be compared with Phreatoicus in much the same way, but they present a further resemblance in the legs, which, though very different in form, are very distinctly divided into an anterior series of four and a posterior series of three. When we come to compare Phreatoicus with the Asellidre we at once see a very "-reat difference in the form of the body, but on closer examination the resemblances are seen to be much more numerous and much closer than might at first siglit be expected. The head, antennce, mouth-parts, and the legs are all in pretty close agreement; the resem- blance in the mouth-parts is indeed somewhat striking, and altliough the legs of the last three pairs are more Amphipodan and flattened, there is a general resemblance in the relative lengths of the different joints to those of Asellus. In describing P/«-f«/oit';/s australls I took Sars's description of Asellus aquaticus [91, pp. 96-100] as my guide, and was able to follow it pretty closely. The uropoda, again, are not very unlike those of Asellus, and the pleopoda of Phreatoicus appear to present more resemblances to those 208 DE. C. CHILTON OX THE SUBTEEEANEAN of the Asellidse tliau to those of any other Isopods that I know. Besides differing very greatly in the shape of the body, Phreatolcits differs greatly from the Asellidse, as from the Idoteidse, in the structure of the pleon. In the Asellidse this is short, usually composed of a single flattened piece, and the pleopoda lie horizontally under it, and are protected by a more or less perfect operculum formed of the first pair. In Fhreatolcus the segments of the pleon are all separate, and tlie pleopoda hang vertically down, and are not protected below; indeed the shape of the pleon renders protection of the pleopoda below unnecessary. These differences are pretty considerable and quite enough to show that Fhreafoicus cannot be placed under the Asellidse, but they are of such a nature that they do not prevent us from considering that the affinities of Phreatoicus are with the Asellidse. For it is quite clear that the latter must have arisen from ancestors possessing a pleon formed of six separate segments, and that these have gradually coalesced to form a single plate ; just as we see the same process going on at the present time in the Idoteidse, where some species have the pleon formed of four or five segments, others of only two or three, and others, again, like Idotea elongata, Miers, with the pleon formed of a single piece [2tl, p. 198]. The horizontal position of the pleopoda and the development of an operculum from the first pair would naturally follow from the flattening of the body in the Asellidse, which would otherwise leave the pleopoda much exposed below. Thus Phreutoiciis appears to differ from the Asellidse chiefly in having preserved the fully- developed pleon which must have been possessed by the ancestors of the Asellide, while in the latter this has been specially modified in accordance with the general flattening of the body, which would render a long-jointed pleon unsuitable and a source of danger to the animal, especially by the exjiosure to which it would subject the pleopoda. The flattening of the body in the Asellidae would naturally follow as the result of their adopting a creeping mode of life ; Phreatoicus wallas erect or swims much in the same way as the Amphipoda. There is one genus, Limnoria, formerly classed with the Asellidse, which differs from them and resembles Phreutoiciis in having the pleon composed of six separate segments with the pleopoda unprotected. Limnoria, however, resembles the normal Asellidse in the flat depressed body, and the segments of the pleon, though separate, are short, and it may perhaps be looked upon as an approach toward the ancestral form of the Asellidse, though its structure has been modified to some exteut to suit its mode of life ; thus the antenuse are very short, and the legs are short and perhaps little used for walking, and the mouth-parts are somewhat modified. Unfortunately, I do not know sufficient of the pleopoda of Limnoria to compare them with those of Asellus and Phreatoicns, but from the other resemblances we may with good reason look upon Limnoria as an intermediate link, to some extent connecting Phreatoimis with the AsellidEe. The very great difference in appearance between the two latter is due to the fact that the body of the Asellidse is flat, depressed, and the animals are tho-efore represented as seen from above, while, owing to its body being somewhat laterally compressed, Phreatoicns is usually seen in side view. This difference in the form of the body is, however, probably not of much CEUSTACEA OF XEW ZEALAND. 209 importance from a systematic point of view, for we have great differences in this respect in species of Idotea and in some of the Cymothoid;ie, and, on tlie whole, I think we must place PhrcatoicMS somewhere near to the Asellidte, hut forming a separate family, the Phreatoicidte, which bears to the Asellidse somewhat the same relation that the Caprcllidae do to the Cyamidas in the Amphipoda. Limnoria may perhaps be placed, as is done by many authors, in a separate family, the Limnoriidte, possessing some of the ancestral characters of the Asellida?, and thus approaching nearer to the Phreatoicidse. Gerstaecker puts Limnoria under the Sjihreronida?, hut forming a separate section, the Limnorhui [45, p. 220]. Prom what has been already said it will be seen that Phreatoicus occupies a fairly central position among the Isopoda, retaining to a greater extent than any others the typical characters of the Isopoda. The following are the characters which I have provisionally advanced for the new family Phreatoicida). These are simply given for the sake of comparison, and will no doubt require revision when other forms allied to Phreatoicus are discovered : — Family PHPEATOICID.E. " Body subcylindrical, more or less laterally compressed. Mandibles with a well- developed appendage. Legs distinctly^ divided into an anterior series of four and a posterior series of three. Pleopoda broad and foliaceous and branchial in function, but not protected by an operculum. Pleon * large, of six distinct segments. Uropoda styUform." [26, p. 151.] Pamily ANTHURIDiE. Genus Cruregens, Chilton. (Transactions New Zealand Institute, vol. xiv. p. 175.) The following characters were assigned to this genus when I originally described it : — " Body subcylindrical. Head small. First six thoracic segments subequal, the seventh small and 'withont appendages. Antennte subequal, neither having a flagellum. First pair of thoracic legs large and subchelate, the second and third subchelate but smoller ; the three posterior pairs simple. First pair of abdominal appendages formmg an operculum enclosing the branchial plates, last pair biramous. Telson squamiform." It is scarcely necessary^ to explain that the above description w^as drawn up by^ a tvro in the study of the Crustacea, and that though modelled on the descriptions given by others of allied genera, it contains much that is unnecessary and little that is essential. The genus appears to fall under Norman and Stebbing's [106] " Section B," though the mouth-parts are even more modified than in the species assigned to this section by these authors. The following generic diagnosis may be given for the sake of comjiarison * I have substituted " pleoii '" for " abdomen,"' which I had inadvertently put Ln my original diagnosis. 210 DE. C. CHILTON ON THE SUBTEREANEAN Avith Norman and Stebbing's descriptions; but even this must be considered merely provisional, as only the one species is known, and nothing is known of tlie distinctive characters of the tw^o sexes : — Eyes wanting. Segments of the jileon separate (in both sexes ?). Both pairs of antennoe Avithout distinct flagella (in adults ?). Mandibles without palp. Maxillipedes not divided into separate joints. Last segment of the perseon small and without ajipendages (in adults ?). All the specimens that I have seen, many scores in number, agree in having the seventh segment of the 2iera3on small and without apjiendages ; but as I have never seen a specimen that I could be certain was sexually mature, I am doubtful whether this character would hold in the adult also or not. My specimens have been obtained from several wells in different localities, and were collected at different times during a period of about ten years, and it seems scarcely likely that all the specimens should be immature, and that during the whole time not a single mature sjiecimen should be obtained, unless, indeed, the adult differs from the immature form in habits in such a way as to prevent it being liable to be drawn up by the pump. I have one specimen that has the integument of the under surface of the perseon much expanded, somewhat in the same way as shown by Stebbing in his figure of the " gravid female " of Faranthura nigro-punctata [106, pi. xxvi. fig. ii. D, ? ] ; but in my specimen I can discover no trace of eggs or young, and it appears to be the integument itself that is distended, and not a pouch formed by brood-plates attached to the bases of the legs in the usual way ; so that I am uncertain whether this specimen is really an adult female or is abnormal in some way, o\v^ing perhaps to half-completed ecdysis or some similar cause. All this uncertainty makes comparison of Cruregens with other genera of the Anthuridse a very difficult task, but it aj^peavs to approach to Taranthura more nearly than to any other. It resembles this genus generally in the antennoe (leaving out of consideration the special brush-like antenna of the adult male in Parcmthiira), in the perseon and its appendages, and in the pleon and the pleopoda, though the uropoda are much more slender in Crnregeiis. It differs, however, in the mouth-parts, for the mandibles have no palp and the maxillipedes have lost all trace of sejiarate joints. If the absence of tlie seventh pair of legs is a character that holds in adults, this would form another difference between the two genera. It is to be noted that the seventh pair of legs appears to be developed at a later period of the life-history in the Antliuridre than in other Isopoda, for sjiecimens without them, but ap2)arently mature in other respects, are not infrequently met with. Besides Ci'uregens w^e have the following examples : — Hyssura ■])roducta is founded on a single specimen about a quarter of an inch long, of which Stebbing and Norman say " the last segment of the person in the type specimen has no legs, nor can we see any sign of scars where they would have been attached, and the specimen was otherwise quite perfect " [106, p. 128] ; Faranthura neglecta, Beddard, is said to have the seventh segment of the perfEou absent, the specimen is 6 millim. long, and from the absence of the last pair of legs Beddard considers it to be immature, though he does not mention any other point of immaturity about it [9, p. Ill] ; I have also a small specimen of an Anthurid from Port CEIJSTACEA OF NEW ZEALAND. 211 Jackson, probably Paranthura austrcdls, Ha.svvell, which lias only six pairs of legs, the seventh segment of the pera^on being small and without appendages, as in Cruregens ; my specimen is, however, only 3"5 millim. long, and is evidently immature. Cruregens fontanus, Chilton. (PI. XIX. figs. 1-22.) Cruregens fontanus, Chilton, New Zealand Journal of Science, vol. i. p. 44 (January 188.2) ; id. Transactions New Zealand Institute, vol. .\iv. p. 175, pi. x. figs. 1-12; id. ibid. vol. xv. p. 88; Humbert, Archives des Sciences physiques et naturelles, t. viii. p. 25G (September 1882) ; Chilton, New Zealand Jom-nal of Science, ii. p. 89 (March 1884) ; Thomson & Chilton, Transactions New Zealand Institute, vol. xviii. p. 152; Moniez, " Faune des Eaux souterraines du Departement du Nord &c.," extrait dc la Revue Biologique du Nord de la France, tome i. (1888-89) p. 53. Specific diagnosin. No trace of eyes. Antennae subequal, upper slightly shorter than the lower, and with four joints ; lower with the third joint only half as long as the fourth. Pirst pair of legs with powerful subchelate hand; propodos triangular, broadest at base palm straight, armed with two rows of setaj. Uropoda slender, inner branch narrow, almost rod-like, not enclosing the end of the pleon. Telson linguiforin, extremity tipped with three or four short setse. Colour translucent, slightly yellowish, owing to the liver-tubes showing through the transparent integument. Length of largest specimens about 12 mm. Rabitut. Eyreton, North Canterbury {Chilton); Leeston {Ii. M. Luing) ; Winchester, South Canterbury {JJ. L. Imoood) (in wells). Detailed Description. The following detailed description is derived from the comparison and examination of a considerable number of specimens. I can detect no differences between the specimens from the various localities mentioned above. Body (tig. 1). The body is cylindrical throughout; the head is slightly flattened vertically and is smaller than the first segment of the peraeon. The first segment of the perseon is rather shorter than the second and is rather loosely articulated to it, the body being narrowed at this point, thus allowing free movement between the two ; the second segment is in the same way loosely articulated to the third, though not quite to the same extent ; the third, fourth, fifth, and sixth segments subequal, about as long as the second, oblong in outline as seen in dorsal view, about half as long again as broad, and firmly articulated together, the body not being narrowed at the articulations ; the seventh segment is small, only about one-third as long as the sixth, and bears no appendages. Pleon (tig. 20). The pleon to the end of the telson is rather longer than the sixth and seventh segments of the perseon. The first segment is longer than the succeedino', the second, third, and fourth are subequal, the fifth longer than the first ; each of these five segments quite separate and bearing a seta on each side ; the sixth segment is SECOND SERIES. — ZOOLOGY, VOL. VI. 28 212 Dl^ C. CHILTON ON THE SUBTEERANEAN lono-er than the fifth, widest in the centre, where its posterior margin is deeply cleft, and in a dorsal view it does not extend quite to the sides of the pleon. It is apparently clearly divided off from the telson, although this seems to be very exceptional in the Isopoda. The surface of the whole body is smooth and bears a few short separate setae scattered over it, especially on the dorsal surface. The upi^er antenna; (figs. 2, 3) are rather shorter than the lower; peduncle of three joints : first joint the largest, with an " auditory seta " on its outer margin and one or two simple setae at the extremity ; second joint about two-thirds the length of the first and narrower, with two " auditory setae " and one or two simple setae at the extremity ; third joint longer than the second, nearly as long as the first, extremity bearing simple setae and one auditory seta. The remaining portion of the antenna appears to represent the flagellum ; it consists of one very short, iiidistiuct joint, followed by one as long as the second joint of the peduncle ; this joint bears at its extremity a few simple setae and about four or five "olfactory cylinders " ; it is followed by two or three very minute joints, of which the first bears an " olfactory cylinder " and the last ends in a small pencil of three very long simple setae. The lotcer antennce (figs. 2, 4, 5) have the first joint very small, nearly rectan- gular, broader than long ; this joint can be seen only when the antenna is viewed from below, as in fig. 5 ; it is quite concealed in a view from above by the base of the upiier antennae. The second joint is large and broad, considerably longer than the first joint of the upper antennae, which rests on the top of it in an oblique groove ; it bears a minute seta at the extremity on the inner side. The third joint is short, narrow at the base, more or less geniculate with the first, and bears one or two minute setae at the extremity on the inner side. The fourth joint is twice as long as the third; it bears several long setae at the extremity and one or two small ones on the inner margin. The fifth joint is rather longer than the fourth, but slightly nai'rower ; at the extremity it bears several simple setae, some of them very long, and three " auditory setie." The remaining part of the antenna may by analogy be considered as the flagellum ; it consists of one joint about as long as the second joint of the peduncle, and at its extremity a minute joint ending in a pencil of long setae. Movth-parts. The mouth of Cruregens fontanus, like that of other Anthuridae, is adapted for suction. It is situated near the anterior end of the head, and the various parts project forwards and can usually be seen in a dorsal view between the bases of the antennae. To form the sucking-apparatus the various parts are much modified, and have coalesced to such an extent that I have found considerable difficulty in deter- mining the homologies of all the parts. My difficulty has been increased by the want of the necessary works of reference. Speuce Bate and Westwood give very little information on the subject in their ' British Sessile-eyed Crustacea' [4]. JS^orman and Stebbiug [106], in their account of the " Isopoda of the ' Lightning,' ' Porcupine,' and 'Valorous' Expeditions," supply figures of the mouth-parts of some of the Anthuridae, but, unfortunately, they give no description beyond the brief accounts comprised in the generic diagnoses. I regret that I have not been able to consult CEUSTACEA OF KEW ZEALAND. 2l;J Schiodte's paper on the moutli-parts of Cyathura carinata referred to by Norman and Stebbing *. I have consulted Dohrn's paper on Parcudhura costana [36] with much benefit. Cruregeiis, however, diiTers from all other Anthuridae that I know in having the mandibles entirely without palps, and the mouth-parts seem more specialized than in other species. The projecting tube formed by the mouth-parts is closed above by the upper Up (fig. 6), which projects downward and forward from below the bases of the lower antennae. It consists of a triangular plate with doubly-curving sides and an acute extremity, which is chitinous throughout and seems veiy hard and .strong. The sides of the tubes are enclosed by the greatly modified mandibles (fig. 7) and by the distal portions of the much simplified maxillipedes, which also form the covering for the tube below. The mandiljles, which show no sign whatever of a palp, appear more or less completely ankylosed to the wall of the head and almost incapable of independent movement. Fig. 8 is a view of them from l)elo\v and partly from the side, to show how they are attached to the ends of the maxillipedes and form the covering on the sides between them and the upper lip. The mandibles are subtriangular, running out to a sharp point distally ; the distal portion bears on the inside a thin chitinous plate with rounded margin, which is very thin and sharp, and perhaps acts as a lancet or cutting- organ of some kind. Within the tube of the mouth, enclosed as above described, we should expect to find a lower lip and two pairs of maxilla;. Tig. 12 represents what I suppose to be the lower lip ; it consists of an oblong plate narrowed at the base, with the distal extremity truncate, the corners being rounded off and the extremity fringed with a few fine setae directed forward. The margins ajopcar to be curled in or thickened, and the centre is strengthened by a thickening w hich extends distally from the narrow base and gradually thins out. The first viaxillce (figs. 9, 10) are easily recognized and are of the form usual in this section of the Anthuridae ; they are very long, extending back at the base nearly to the posterior end of the head ; each consists of a long, slightly curving, and gradually tapering shaft, which bears at the extremity on the outside a fine saw-like edge made up of a number of sharp teeth ; on the opposite side is a thin flange curving out from the maxilla and having a very sharp razor-like edge. The maxilla is acutely pointed at the extremity : at the base it is jointed on to a short chitinous piece, Avhich is again jointed on to a curving transverse bar ; to the distal end of the first ^jiece is attached the tendon of a strong muscle, by the contraction of which the maxilla is protruded, while it is drawn back again by muscles attached to the base of the maxilla itself ; possibly also the maxilla can be somewhat rotated on its base so as to bring the two saw-like edges together. In any case they evidently form most efficient lancet-like organs. It appears probable from Dohrn's figure [36, pi. ix. fig. 8] that at the base of the first maxilla of Puranthura costana there is an apparatus similar to that here described, but his' figure is not very clear and shows the transverse bar as though continuous with the maxilla itself. * •' Kiebsdyrenes Sugemund," Naturhistorisk Tids>krift 3 II. 10 B. (1875), p. 211, tab. iv. 28* 214 DE. C. CHILTON ON THE SUBTEBEANEAN I have not been able to make out the second maxillce quite satisfactorily, for they seem to be closely connected at the base with the part I have considered the lower lip, and it is difficult to separate the two without injuring them; the first maxillse are not connected with these, simply working between them and being articulated to the head much posteriorly. Usually the loAver liji and second maxilla come away together and then present the appearance shown in fig. 11 ; this evidently corresponds to Dohrn's " fig. 9," which he calls the " Verwachsenes zweites Maxillenpaar (?) " ; but in the species he describes the central portion (lower lip ?) is deeply cleft, while it is not so in Cruregens. In this figure 11 the base of the second maxilla can be seen as a strongly curving bar proceeding from a central portion that lies just along the base of the lower lip, and is perhaps joined to it ; on each side this bar afterwards curves inward and ends in an expanded distal portion bearing numerous fine setae. Tlie whole of this end is soft and delicate ; it is difficult to make out its exact form, but it appears to widen out verti- cally, and probably helps to close in the sides of the suctorial tube formed by the mouth (see fig. 13). The maxillipedes (fig. 14) have the basal portion completely aukylosed to the under- side of the head ; about the middle there is a small and chitinous plate similar to that figured by Dohrn in Paranthura costana and by Norman and Stebbing in Anthelura elongata [106, pi. xxv. fig. 1, c, l]. In the latter species the corresponding plate is slightly pointed at the extremity, and is situated nearer the posterior end of the head, at the base of the maxillipedes. Hence it appears probable that this plate represents the large chitinous plate found in Phreatoicus, the IdoteidtB, Asellidse, &c., and is therefore the epipodite. In Cruregens, however, this plate is situated much further from the posterior margin of the head, and the remainder of the maxillipede has been so modified that all trace of its separate joints has been lost. Anteriorly from this the two maxillipedes are contiguous for a short distance, but then rapidly separate, a seta being placed in the middle of the inner concave margin. The extremity narrows nearly to a point, and has at the end a very small terminal joint bearing a number of rather long setcB, one or two others being situated on the outer edge at a little distance from the extremity. The^rs^ pair of legs (figs. 15, 16) forms powerful subchelate claws, which can be extended considerably beyond the head and even beyond the ends of the antennae. The coxa is indistinguishable and appears completely ankylosed to the body-segment. The bases is narrow at the base and rapidly widens out to its greatest breadth at the middle, where the breadth is rather more than one-third of the length ; it narrows again slightly towards the distal end ; the j)Osterior margin is regularly arched, the anterior sinuous ; near the base there are two rather long " auditory setae." The ischium is equal in length to the basos and is similar in form ; the posterior margin is convex and bears four small spinules ; the anterior side is hollowed out into a longitudinal groove to receive the rest of the limb when bent back upon it. The mei'os is short, transverse; at its junction with the ischium it is narrow, but it rapidly Avidens out, forming anteriorly an oval lobe, which bears at the end a few small setae ; the posterior margin is straight, lies in the same line as that of the ischium, and bears two setae at the extremity. The carpus is small, sub- CRUSTACEA OF NEW ZEALAND. 215 rectangular, and is surrounded by the propodos, except on the posterior side, where it is produced at the extremity into a small rounded lobe bearing a few long setae and covered with a thick fur of very short setae. The propodos is very large, about as long as the three preceding joints together; it is subtriangular, widest towards the base, where it is more than half as broad as long ; the anterior margin is very convex and bears no setae except a small one at the base of the dactylos ; the posterior margin is straight and is produced along the end of the carpus into a small x'ounded lobe ; all the rest forms a rather broad palm, fringed throughout its whole length on the outside with a row of serrated setae of fair length, one or two of these being considerably longer than the others, and two or three long ones being situated at the extremity. The dactylos is as long as the propodos, is considerably curved, and tapers gradually to the acute extremity ; the inner margin bears about 15 minute spinules at regular distances ; the tip is brown in colour, but is otherwise not clearly marked off into a distinct unguis. When the limb is seen from the inner side (fig. III. p) only a triangular portion of the carpus is seen, the rest being overlapped by the propodos. The inner margin of the palm appears slightly convex and is fringed with a thick row of setae, which appear simple and are much more numerous than those in the row^ on the outer mai-crin. At the base this row leaves the margin of the propodos, and curves along the side, thus marking the place where the tip of the dactylos overlaps the propodos. The second pair of legs (figs. 17, 18) is slender and subchelate. The basos is longer than the ischium, narrow at the base, Avidening distally, greatest breadth rather more than one-fifth the length ; two " auditory setae " near the base as in the first pair of legs, both mai'gins with a few small spinules. The ischium is similar in shape to the basos, widest at the middle, where the breadth is about one-fourth the length, narrowing toward both ends, a few spinules on each margin. The meros is triangular, very narrow at the base ; posterior margin straight, with two or three long setae at the extremity ; antero-distal angle produced and tipped with two setae. • The carpus is small, with three setie at the extremity of the posterior margin ; the junction with the propodos oblique. The propodos is narrow ovate, as long as the ischium, length about two and a half times the greatest breadth ; anterior margin convex, with a few small setae, and at the base of the dactylos a small group of two longer ones and an " auditory seta " ; the palm occupying about two-thirds the posterior margin, not clearly defined, slightly convex, armed with about eight stout setae, each bearing a subapical hair and being serrate on the opposite side ; besides these there are also a few simple setie. The dactylos is slightly curved, fitting closely on to the palm ; inner margin wdth a few minute spinules, and towards the end one or tw3 small setae marking off the terminal unguis. The thii'cl pair of legs is similar to the second in size and form. The fourth pair of legs (fig. 19) is about as long as the third, but they are simple and not subchelate. The basos and ischium are similar to those of the second and third pairs, but the basos is a little more widened in the centre and bears three " auditory setae." The meros is rather more than half as long as the ischium, triangular, narrow at the base ; anterior margin straight, with a seta about the middle and two longer ones at the extremity ; posterior margin slightly convex, somewhat produced distally, and hearing 216 r>K. C. CHILTON ON THE SUBTERRANEAN at the end three or four setse. The carpus is rather longer than the mcros, ohlong; the anterior margin with three spiniform setse and two or three simple setae at tlie end ; the posterior margin straight, with a few simple setse, and in the middle a long " auditory seta." The propodos is similar to the carpus, hut considerahly longer ; the anterior margin armed with four or iive spiniform setse and a few simple ones, the posterior margin having at the extremity a group of two or three simple setse and one " auditory seta." The dactylos is similar to that of the third pair of legs. The spiniform setse on the anterior margins of the carpus and propodos are similar to those on the palms of the second and third pairs of legs, but are smaller and not quite so well marked. The fifth and sixth pairs of legs are similar to the fourth, but may sometimes be a little longer. The seventh pair of legs is entirely absent in all the specimens that I have examined. The first pleopoda (fig. 21) form an operculum completely closing in the branchial plates below. The protopodite appears to consist of two joints, a very short coxa, and a rectangular basos, which is broader than long, and bears on the inner margin three stout sette, dentate at the extremity ; these aj)pear to act like tlie " coupling-spines " to which Stebbiug has drawn special attention in the Amj)hij)oda. The exopodite which forms the operculum is an oval plate bulging downward ; it is about twice as long as broad, its inner margin nearly straight, outer margin very convex, bearing on the distal half about six very delicate plumose setse, with three or four shorter ones at the extremity. The endopodite is narrow styliform, slightly enlarged at the base, somewhat sinuous, sides parallel, extremity rounded and tipped with three or four plumose setse. The second, third, fourth, and fifth pleopoda (fig. 22) are all alike and of the usual form. Each consists of a short transverse j)rotopodite, an oval endopodite well rounded at the end and with the margins free from setse, and a longer and rather narrower expedite, which is slightly constricted on the outer margin toward the extremity ; the margin is rather irregular, and bears a few finely plumose setse on the inner side and at the end, with sometimes one on tlie outer side. The number of these setse appears to vary somewhat in the different pleopoda, but 1 have not noticed any other differences between them. I have not hitherto met with any special modification of the pleopoda of the male like that occurring iu the Asellidse, ^'^c, and do not know whether such a peculiarity has been recorded in the Anthuridoe. The iiropoda (fig. 23) are articulated to the end of the sixth segment of the pleon. The basal portion or peduncle is large, fiat, and nearly rectangular, and reaches nearly to the end of the telson ; it is about two and a half times as long as broad ; the outer margin is straight and bears a few setse on the distal half; the inner portion extends as a fiat plate to the median line of the body, the right or the left uropods often having their inner margins in contact below the telson ; the inner distal angle bears a single small seta. The endopodite is articulated to the posterior margin of the peduncle on its outer half ; it is oblong, more than three times as long as broad, extremity rounded, the end and the two margins being fringed with long setse, which are thickest and longest at the extremity ; CRUSTACEA OF NEW ZEALAND. 217 these setas appear to be simple, but among them are two small groups, each containing two " auditory setae." The expodite is articulated to the dorsal and outer surface of the peduncle near its anterior end : it is slender, and consists of a thin rod or narrow plate, a little deeper than broad, and shows no tendency to enclose the hinder end of the pleon as in Anthura, &c. ; it reaches slightly beyond the extremity of the peduncle, and has its upper and lower margins and the extremity fringed with setae, those at the end being the longest. The fclson (see fig. 20) is sliglitly longer than all the preceding part of the pleon ; it is squamiform, rather more than half as broad as long, the distal portion ovate, the extremity tipped with five or six small setae. The telson is distinctly separated from the sixth segment of the pleon, a very unusual feature in the Isopoda, which generally have the sixth segment of the pleon and the telson confluent ; this character is, in fact, so constant that it is given by Blanc [12] as one of the points of difference between the Isopoda and the Aniphipoda. Most authors have drawn the telson of Anthnra and other species as separate from the sixth segment of the pleon, but I am not aware that anyone has drawn special attention to this unusual character. It will be seen that I have described the uropoda as consisting of a peduncle and two branches, each consisting of a single joint, whilst most authors have described the inner brancli as (;?oo-jointed, considering the part I have taken as the flagellum to be the first joint of the endopodite. If the eudopodite were really two-jointed it would be an excep- tion from all other Isoi)ods. It may consist of several joints in the Tanaidae and the Apseu- didse, which differ in several well-marked features from the Isopods, but in all others, so far as my knowledge goes, the endopodite never consists of more than a single joint. The interpretation of the uropod that I have given is certainly correct for Cruregens, for in this genus the exopodite can be plainly seen to be articulated to the dorsal side of the peduncle, and the peduncle is quite continuous past the base of the exopodite to its junction with the sixth segment of the pleon ; this can be seen both al)ove and still more easily below. In most other species of the Anthuridae the exopodite is broad and its articulation extends right across the peduncle, thus concealing its true nature. Gerstaecker [dS, pi. xiv. fig. 26] certainly figures the uropod of Paranthura costana, Sp. Bate, with a short separate peduncle bearing two branches, one of which is ^<(JO-jointed ; but his figure is not very clear, and I think he has probably been misled in the way suggested above. Dohrn [36], dealing with the same species, interprets the uropod in the same way that I have done, and as I had formed my own conclusion before con- sulting Dohrn's paper, I was particularly pleased to find my opinion confirmed by him. This portion of his paper appears to have been overlooked by systematic writers on the Anthuridae. The great enlargement and elongation of the peduncle in Cruregens, Anthuria, &c., are only exaggerations of what we find in most of the Oniscidte, where the two rami are widely separated ; and in Hz/ssiira, Norman and Stebbing [106, i^p. 128, 129, pi. XXV. fig. v.), we have evidently an intermediate form where the peduncle is quite short and the two rami therefore much more closely approximated at their bases. Even in tliis genus, however, Stebbing and Norman speak of the endopodite as iico- 218 DE. C. C'HILTOX ON THE SUBTEEEANEAN jointed, tliougli according to their figure their " first joint " of the endopodite is quite continuous with the true ^^eduncle and evidently a part of it. Gerstaecker considers the hranch I have described as the exopocUte to be the endopodite or inner branch ; and in this he may perhaps be right, though without an appeal to embry- ology there seems to me little to help us to decide which is the exoiwdite and which the endopodite, and I have therefore followed the majority of authoi's. In Hyssura as figured by Stebbing the shorter branch certainly appears to be the endopodite ; but this may be apparent only, and due to the fact that in the figure the animal is " viewed dorso- lateraDy " [106, pi. xxv. fig. v. P/.]. AMPHIPODA. Genus Ckangonyx, Spence Bate. (British Sessile-eyed Crustacea, vol. i. p. 326.) The following is the definition given by Spence Bate when establishing this genus : — " Superior antennae having a secondary appendage. First pair of gnathopoda rather larger than the second. Posterior pair of pleopoda unibranched, not longer than the preceding pair. Telson single, entire." In his subsequent explanation he gives tlie additional information that the eyes are imperfectly developed, that the superior antennae are not much longer than the inferior, but rather more robust, and that tlie first two pairs of legs are small, rather unequal in size, and subchelate. Numerous species belonging to this genus have been described by Pacivard, O. P. Hay, S. I. Smith, Grube, &c., but, so far as I am aware, no one has revised the characters of the genus, although it is evident that this must be done before it can be made to suit all the species that have been assigned to it. The genus Stygobromus, Cope [30], is con- sidered by S. I. Smith [104] to be equivalent to Craiigonyx ; but Cope's description is very imperfect, and does not in any way add to our knowledge of the genus. Wrzesni- owski points out that no description of the mouth-parts of Grangonyx is known to liim [124, p. 635]. I am able to give below some account of the mouth-parts of Grangonyx compactus ; and from this it will be seen that in the mouth-parts the genus approaches very closely to Niphargus, which it resembles also in many other points, such as in the antenna?, the guatlio^wda, and the uropoda. Although Spence Bate described the terminal pair of uropoda as 2hargns puteanus, figured by Humbert, and resembles in shape an open hand with the fingers close together ; the part corresponding to the thumb is denti- culated throughout, while that corresponding to the fingers has the distal extremity oblique and finely serrate. At the base of this secondary cutting-edge are two stout spiniform setae denticulated similarly to the thumb, and following these is a stout plumose seta (see fig. 7). The secondary cutting-edge of the right mandible usually has the form just described, but it is evidently sul)ject to some variation, for in one specimen, which otherwise appeared quite normal, it had the form rejiresented in fig. 8, which, it wdll be seen, is very different from the usual form. Whether this was the result of accident or not I cannot say, but it shows how careful one ought to be before laying much stress on the form of tliese minute mouth-parts unless they are found to be constant by the examina- tion of a large number of specimens. In the left mandible (fig. 9) the secondary cutting-edge resembles the outer cutting- edge, and consists like it of five separate teeth ; at its base are stout denticulated setae similar to those in the left mandible. It will be seen that this figure is inverted. The molar tubercle, which appears to be the same in both mandibles, is small and presents no remarkable feature. The lower lip (fig. 10) is very delicate, broad ; extremity of each outer lobe very broadly rounded and covered with fine seta? ; inner lobes small and very delicate ; the lateral backAvard processes are short and rather ol)tuse. Thej^rs^ maxilla (figs. 11, 12, 13) is very similar to that of Niphargus puteanus. The palp has the first joint short, its extremity oblique; the second joint slightly narrowing CRUSTACEA OF NEW ZEALAND. 223 towards the extremity, whicli bears three stout setfe at the end and one more slender placed a slight distance from the end ; the three stout setae are finely serrate at the ends (fig. 13). The middle lobe of the maxilla is broad, nearly as broad as long, the extremity slightly oblique, bearing seven stout spiniform setup, of which the innermost one is the largest and is a little separated from the others ; it is serrate on the inner margin towards the extremity, on the surface of the lobe at its base are several fine hairs ; the seta next to it is only about half as long and bears one strong tooth on the inner margin, the remaining sette bear one or more deuticulations or serrations, as shown in fig. 12. Tlie inner lobe is small and delicate ; its extremity is rounded and bears one or two finely plumose setae. A few very fine hairs are scattered over the surface of the whole maxilla. The extremity of the palp appears to be the same both in tlie right and left mandibles, and does not take different forms as in some species of Ganimarus. Tlie second mcLiilla (figs. 11 & 15) is very similar to that of N/p7iarffi's. Its oiiter lobe is slightly longer and broader than the inner, and bears at the extremity a great number of slightly curved seta; ; the inner lobe bears about six large setae, the innermost one of which is much the largest, and is situated a little distance from the extremity on the inner margin, the basal j^oi'tion of it is s]iaringly plumose, and its extremity is plumose or almost dentate on one side. Some of the remaining setas are similar to this one, but others appear to want the plumes at the end (fig. 15). A few fine liairs are sparingly scattered over the whole surface of the maxilla. The maxlllipedes (figs. 16, 17, 18) do not present any remarkable feature. The lobe . attached to the basos ("inner lobe ") is rectangular, the extremity truncate and bearing about four stout setae much curved inwards ; there are two fine setae on the inner margin and a few fine hairs on the surface towards the outer margin (fig. 17) ; the lobe attached to the ischium reaches nearly as far as the extremity of the outer margin of the next joint, the meros, its inner margin is neaidy straight and bears about ten to twelve setae, of which two near the extremity are pretty stout, the others being rather slender ; besides these spiniform setae there are a few finer setae or hairs along the inner margin (fig. IS). When seen from below, the basos bears no setae on its outer margin, but there are three at the extremity near the inner angle ; there are three or four setae on the inner margin of the ischium and one at the extremity of the inner margin of the meros ; the last- mentioned two joints have no setse on their outer margins. The carpus has the outer margin much curved, with a single seta at the extremity, its inner margin is curved and thickly fringed with long setae; on the upper surface of this joint there is a distinct row of six seta? running parallel to the inner margin near the extremity. The propodos has the outer margin very convex, and produced on the upper surface into a small lobe at the base of the dactylos; on the upper surface (fig. 17) towards the end of the joint is a dense mass of long setae, arranged chiefly in three longitudinal rows ; the inner margin has the basal portion free from setae, but the distal half thickly fringed with long setae ; on the under surface of the jiropodos there are two or three long setae at the base of the dactylos. The dactylos is as long as the propodos, and is very acutely pointed; on 224 DE. C. CHILTON ON THE SUBTEERANEAN the outer margin near the base it bears a single seta; its extremity is marked off into a distinct unguis, at the base of which is a small seta on the inner margin. First gvathopod (fig. 20). The coxa (side-plate) is almost rectangular, sloping a little forward, its anterior edge bearing five or six short setse. The basos is narrow at the base, but rapidly widens until it is quite half as broad as long ; its anterior edge is nearly straight and bears a tuft of five long setse near the base and a single seta at the extremity ; the posterior margin is very convex and bears four or five setae, the longest being at the extremity. The ischium is short, broader than long, and bears five or six setae at the extremity of the posterior margin. The meros is rounded distally, and has the whole extremity thickly fringed with long, rather stout setse. The carpus is triangular, extremity nearly straight, with a row of long setse running parallel to it along the posterior half of the inner surface; the short posterior margin densely covered with setae, apparently arranged in three or four transverse rows. The propodos is ovate, about as long as the three preceding joints together, scarcely wider than the carpus ; anterior margin convex, with four or five setae separately situated along the inner surface near it and a small tuft at the base of the dactylos ; posterior margin with numerous setae partially arranged in five or six tufts ; palm oblique, occupying rather more than half the posterior margin, defined by two stout spines and fringed with numerous short setae, a few longer setae being situated on the surface of the propodos near the palm. The dactylos is slightly curved, fitting closely on to the palm ; the terminal uuguis distinct and marked ofi^ by a small tooth on the inner margin at its base ; on the outer margin the dactylos bears a plumose seta at a little distance from the base. The second gnatliopod (fig. 21) is aboitt as large as the first and closely resembles it in form. The coxa is similar but someAvhat larger, the basos sli^'htlv lona-er in proportion to its breadth. The carpus much longer than in the first gnathopod, with more numerous tufts of setae on its posterior margin and a shorter row along the extremity. The propodos is like that of the first gnathopod, but the palm does not occupy so much of the posterior margin, and there is a larger number of tufts of setae between the end of the pabn and the base of the posterior margin. In both gnathopoda the outer surface bears fewer setae than the inner. The first pera'opod (fig. 22) has the coxa like that of the second gnathopod. The basos is longer, and widens considerably about the middle, where the breadth is rather more than one-third the length ; it is much constricted on both sides near the base, and after widening narrows again slightly at the extremity ; the anterior margin bears a few small setae, and the posterior margin bears six stout setae, each situated in a slight serration. The ischium is similar to that of tlie second gnathopod. The meros is slightly longer than the carpus, and is a little produced at the antero-distal angle ; the anterior margin slightly convex, and bearing one spiniform seta at the centre and another at the extremity ; posterior margin straight, with a few long setae, the longest two being at the extremity. The carpus is oblong, narrowed at the base; anterior margin with one or two minute spinules ; posterior margin straight, with five stout setse. The propodos is shorter and narrower than the carpus but of similar shape ; posterior margin with a row of six or seven short setse, the last being the longest; CRUSTACEA OF NEW ZEALAND. 225 anterior marp;in with a small tuft at the base of the dactylos aud a single seta situated more proximally. The dactylos is short. The second perccopod is exactly similar to the first in size and form. The third, fn)irtli, and fifth pera^opoda are all similar to each other, but eacli is slightly larger than the preceding ; they are all somewhat remarkable in having the basos rather narrow and not expanded posteriorly into a semicircular plate as in most Amphipoda. Eig. 23 represents the fourtli peraeopod, and it will be convenient to take this one for description, as it represents a mean between the fifth and seventh. The coxa is almost semicircular, upper margin straight, the lower convex margin thickly fringed with short spines, which are most numerous posteriorly. Tlie basos is narrowed a little at the base ; it is oblong, the breadth being slightly more than one-third the length ; anterior margin Avitli two setae, one at the extremity and one above it; posterior margin straight, with two or three stout setoe about the middle and one or two longer ones at the extremity. The ischium is very similar to that of the preceding perseopoda ; the meros oblong, about three times as long as broad, both margins bearing stout setae, especially at the extremity ; the carpus slightly lons^er than tlie meros, but a little narrower, the seta? on it more numerous and lar^-er than in the meros; the propodos as long as the carpus, but narrower, aj)parently twisted so that the dactylos projects backwards, both margins having stout sette or spines, those on the posterior margin being most numerous ; the dactylos is short, not much longer than the setae at the end of the propodos. The pleopoda (figs. 24, 25, 26) are small and are very remarkable, in that each bears only one branch, which appears to be the outer one, there being no trace whatever of the second branch. I do not know of any other species of the Amphipoda where this is the case : in the CempUicB the inner branches may be rudimentary and even entirely absent in the case of the third pleopod ; but it is easy to see that this is due to the habit of the animal living in a tube, which has to some extent modified all its pleopoda aud the tail-part. In the present species the portions of the pleopoda that are present appear quite perfect, and I know of nothing in the habits of the animal to explain why these pleopoda should have only one branch while those of Gammarus fragilis and Calliopius subterraneus have the normal two branches. The first pleopjod (fig. 24) is the longest ; the basal portion is oblong, slender, without setae, except the two " coupling spines " at the extremity of the inner marf^in • these seem not unlike those of Niphargus, each bearing two or three tubercles on the one side and being slightly hooked at the end. The single branch is nearly twuce as long as the peduncle and consists of eleven joints, each bearing the two long plumose setae in the usual way. I cannot find any trace of the " cleft spines " mentioned by Stcbbing [108, p. xiv &c.], Sars [91, p. 53J, Humbert [62, p. 351], &c., on the inner margin of the first joint of this branch, and it is therefore probable that it represents the outer branch, the inner one being absent. Stebbing [108, p. xiv] has drawn special attention to these " cleft-spines " and also to the "coupling-spines," and, with regard to the latter, points out that they have been described aud figured by Sars in his account of Gammarus neglectiis [91, p. 53], and 226 DE. C. CHILTON OX THE SUBTEEEANEAN indicated by S. I. Smith in his figure of Cerapus tuhularis, bnt not, he thinks, alluded to by any other writers. It is but just to Humbert to mention that he had drawn and described the "coupling-spines" ("deux petits crochets") oi Niphargus puieanus, Yar. Forelii, in 1876 [62, p. 350]. The second pleopod (fig. 25) has the peduncle considerably longer and broader than in the first, the basal part of it being pretty distinctly marked off as a separate joint, probably representing the coxa. The outer margin bears four small spines on the distal half, the inner margin having only the coupling-spines at the extremity. The branch is only as long as the peduncle and contains only six joints, of which the first is much the largest. The third pleopod (fig. 26) is similar to the second, but smaller and more reduced; the peduncle is similar, but narrowed at the base ; the branch is not so long as the j^eduncle, and consists of three joints only, the first being much larger than the other two together. The tirojwda are all short and rather stout. The first uropod (fig. 27) has the peduncle much longer than the rami, stout, broad above, the upper surface being somewhat concave, its outer margin bearing seven small spines ; the outer ramus is slightly smaller than the inner, both falciform, curving upwards, the lower surface of each regularly curved and with seta?, the upper surface with three or four small spines near the base and one near the apex. The second uropod (fig. 28) is similar to the first, but shorter and bearing fewer setae. The third uropod (fig. 29) has the peduncle short, witli two spines on the lower margin at the extremity ; the inner ramus very small, rudimentary, with a small spine at the end ; outer ramus about three times as long as the peduncle, gradually tapering, the upper margin with eight seta? arranged in four jiairs in a longitudinal row, the extremity separated from the other portion and forming a small second joint. The telson (fig. 30) reaches about halfway to the end of the last uropod. It is more or less oblong, narrowing slightly towards the end, which bears a stout spine in a slight emargination at each corner ; the sides are slightly convex and the extremity between the two spines is either straight or slightly concave. There is no sign whatever of any cleft or division. Genus Gammakus, Fabricius, 1775. (See Stebbing's Report on the 'Challenger^ Ampbipoda, p. 1005.) Full information on this very old genus will be found in Stebbing's Keport as quoted above. In it he quotes the following generic diagnosis as having been given by Boeck in 1876 :— " Mandibles with the third joint of the palpi elongate, narrow. " First maxilla; with the inner plate broad, long, furnished on the inner margin with very many plumose seta?. " The body not carinate. The three hinder segments of the pleon furnished in the middle with fascicles of spines. The anterior side-plates of moderate size. CEFSTACEA OF NEW ZEALAND. 227 " Upper antemicB longer than the lower ; the peduncle moderately elongate. " Loiver antennce with a short flagellum. " First and second gnathopods with the hand smaU ; the second larger than the first. " The third uropods with long rami, furnished on the margin witli spines and plumose setae, extending beyond the rami of the two preceding pairs ; the inner ramus more or less shorter than the outer. " Telson long, cleft to the base." This definition answers very well to include Gammarus fragilis, which is the only species of the genus that I have had an ojijiortunity of closely examining. Gammarus fragilis, Chilton. (PI. XXI. figs. 1-25.) Gammarus fragilis, Chilton, New Zealand Journal of Science, vol. i. (January 1882) p. 14 ; id. Transactions New Zealand Institute, vol. xiv. p. 179, plate ix. figs. 11 to 18; id. New Zealand Joui'nal of Science, vol. ii. (March 1884j p. 89 ; Thomson & Chilton, Transactions New Zealand Institute, vol. xviii. p. 146; Moniez, " Faune des Eaux souterraines du Departemeut du Nord &c.," extrait de la Revue Biologique du Nord de la France, tome i. (1888-89) p. 50; Wrzesniowski, "O trzech kielzaeh podziemnych," De tribus Crustaceis Amphipodis subterraneis, pp. 16, 90 ; id. " Ueber drei unterirdische Gammariden," Zeitschrift fur wissenschaftliche Zoologie, L. 4, pp. 611, 698. Specific diagnosis. Eyes wanting. Body rather slender. Superior antenna? somewhat longer than the body ; flagellum much longer than peduncle, secondary containing from five to nine joints. Peduncle of lower antennae longer than peduncle of upjier ; flagellum longer than peduncle. Gnathopoda subequal, moderately large, each with the propodos ovate ; palm very oblique. Pirst and second perseopoda rather short, slender ; last three pairs of peroeopoda very long, the last (fifth) about as long as the body. Terminal uropoda with the rami subequal, about twice as long as the peduncle, cylindrical, not flattened or expanded. Colour. White, semi-transparent. Length of largest specimen 15 mm. Habitat. Eyreton, Xorth Canterbury {Chilton), Leeston (B. M. Laing), Winchester, South Canterbury (D. L. Inivood) : in wells. Remarks. It will be seen from the following detailed description that this species is a true Gammarus, and that in all generic characters it agrees very closely with Gammarus neglectus as described by Sars. I have not attempted to compare G. fragilis with the numerous other species of the genus already described. It appears to be well characterized by the very long peraeopoda. the want of eves, and the long cylindrical rami of the terminal uropoda. • Detailed Description. The hodtj (PI, XXI. fig. 1) is smooth, rather slender ; the appendages are also very long and somewhat slender. The coxae (side-plates) of the first four segments of the peraeon are rather deep, though not so deep as their respective segments. The segments of the SECOND SERIES. — ZOOLOGY, VOL. VI. 30 / 228 DR. C. CHILTON ON THE SUBTEEEANEAN perreon are all of about the same length and as long as the head ; the first three segments of the pleon are rather longer, then' inferior margins bear two or three stout setae towards the anterior end ; the fourth segment of the pleon has a strong spine on the inferior margin at the base of the uropod, and each of the last three segments bears four or five long spine-like setae on the dorsal surface. The upper antemice (fig. 2) appear to vary somewhat in length as compared with the body, but they are always very long, usually about as long as the body. The first joint of the podvmcle is stout, rather more than twice as long as broad ; the upper margin is straight, with a tuft of fine seta? at the extremity ; lower margin slightly curved and bearing two short transverse rows of spiniform setae, the second row being situated at the extremity. Second joint about as long as the first, but only about half the width ; upper margin with three or four fine setae ; lower margin with three or four tufts each containing a spiniform seta and one or more fine hairs, at the extremity there are tufts above and below and in the centre. Thii'd joint about one-third as long as the second, a few setae above and below at the extremity. Secondary ajjpendage slender, usually con- taining six or seven joints, though there may be as many as nine, each joint with minute setae at the extremity ; flagellum more than twice as long as the peduncle, consisting of a great number of joints, the setae on which are very short and fine, each joint bears a single small olfactory cylinder. The lower antennce (fig. 3) are more than half as long as the upper. The first joint of the peduncle is very short and bears a single seta at the extremity of the lower margin ; second joint very short, the gland-cone (the so-called "olfactory denticle") not reaching quite to the end of the succeeding joint ; the third joint more than twice as long as the second, upper margin curved, lower margin with a tuft of strong spiniform setae at the extremity; fourth joint very long, upper surface bearing five tufts of two stout setae each, the lower surface with numerous small tufts of stout setae and fine hau*s irregularly arranged ; the fifth joint slightly longer than the fourth and narrower, upper surface with about five small tufts, lower surface with five larger tufts of longer setae ; flagellum usually about as long as the peduncle, though the relative lengths vary somewhat; it usually contains about twenty joints, each bearing a few fine setae at the extremity. The dipper lip (fig. 4) is strongly chitinous and of the usual shape, being more or less semicircular, very broad ; the apex bears a thick fur of minute setae, mostly con- verging inwards. The mandibles (figs. 5, 6, 7, 8) appear to present a pretty close resemblance to those of Gammarus neglecttis as described and figured by Sars. The palp, which is the same in both mandibles, is large and strong. The first joint is the shortest; it widens slightly distally and bears four or five setae at the extremity. The second joint is about twice as long as the first; it is rather broad, and bears on the inner margin about a dozen long setae, those towards the end being the longest. The third joint is somewhat shorter than the second, and bears on the surface of the side four small tufts each containing two sette ; the outer margin is slightly curved and is free from setae ; the inner margin has along its whole length, except a little at trie base, a thick fringe of stiff setae about half CEUSTACEA OF NEW ZEALAIsT). 229 as long as the joint is wide ; at the extremity are three long setse nearly as long as the joint itself. The armature of the right mandible differs from that of the left, as is the case in this and many other genera of the Amphipoda. In the left mandible (fig. G) the outer cutting-edge consists of five strong teeth and the inner or secondary cutting-edge is similar in general form but contains only four teeth, one of which is considerably longer than the other three ; both outer and inner cutting-edges are curved so as to be concave on the inner side. In the right mandible (figs. 7, 8) the outer edge is not unlike that of the left, but contains only four teeth, and the imier cutting-edge is very different. When seen in profile, as in figure 8, it appears slender, dividing into two branches or forks, the upper one apparently tubercled, and the lower one bearing two or three denticulations at its base ; in this view it seems not very unlike that of Gmnmarus neglectns as figured by Sars [91, pi. iv. fig. 4]. When this inner cutting-edge is seen en face (fig. 7), however, it is found to be much more like that of Crangonyx com- ^ac^w* than would at first have been suspected; the upper portion jiroves to be broad and triangular in shape, with the edge dentate, and it is these denticulations which make the piece appear tubercled when seen in profile; the lower piece is narrow and bears one or two teeth on the surface at its base as already described. Next to the secondary cutting-edge in each mandible follow four or five strong denticulate or stiffly plumose setse. The molar tubercle docs not appear to present any remarkable featm-e. The lower Up (fig. 9) is of the usual form, deeply cleft, each lobe bearing on its rounded extremity a number of very fine irregular seta>, and on its inner margin a thick fringe of rather stouter setre. The first mmilla (figs. 10, 11, 12) has the inner lobe very delicate and fringed with nine or ten * delicate plumose seta?, each of which shows a transverse division at some distance from the base ; the surface of this plate is also covered with fine delicate scattered setae. The middle lobe ends in about ten strong setae, curving inwards ; most of them have two sharj) teeth on the inner edge, but the two innermost bear more numerous teeth. The palp has the first joint short, rectangular, and the second large, flat, and curved inwards. On the left side (fig. 11) the palp ends in about seven stout setae or spines, closely approximated together ; a single small simple seta is situated on the surface at a slight distance from the extremity. In the maxilla on the left side (hg. 12) the palp has the same general shape, but the setae at the end are much more slender and not so crowded, and there appear to be only six of them. The difference between the extremities of the two palps is reaUy rather greater than would appear to be the case from figs. 11, 12, for the right maxilla is here considerably compressed in order to show the spines more distinctly. The second maxilla (fig. 13) has the form usual in Gammariis. The inner lobe * The number of setse on the inner lobes of the first and second maxilla varies very greatly in different specimens. The numbers given in the text probably represent the average. I have another drawing showing 13 on the inner lobe of the first maxilla and 21 on that of the second maxilla. 30* 230 DR. C. CHILTON ON THE SUBTEEEANEAN bears a very oblique row of about twelve * finely plumose setae similar to those on the inner lobe of the first maxilla ; the inner margin of this lobe is fringed with many simple setse and the surface of the lobe bears a few very fine simple setse scattered over it. The outer lobe bears many long curved setse at the extremity as usual ; many, if not all, of these are finely serrate on the inner side. The maccillipedes (figs. 14, 15) are somewhat slender. When viewed from below (fig. 14) the first joint [coxa) is seen to bear three setiB on the outer margin. The next joint, the bases, is obliquely articulated with the coxa and bears near its base a short transverse row of short setoe, and at its extremity towards the inner margin a dense row of stout setae. The meros is rather longer than broad and bears a single seta on its inner margin at the extremity. The carpus is about as long as the three preceding joints together, and more than twice as long as broad ; its outer margin is regularly curved and bears no setae ; the inner margin is nearly straight and is thickly fringed with setae, which are chiefly arranged in irregular, short, transverse rows containing about two or three setae each. The propodos is rather more than half as long as the carpus ; on its outer margin at the extremity it bears two or three very long setae and its inner margin is thickly fringed with long setae irregularly arranged in tufts. The dactylos is very nearly as long as the propodos ; it is strongly curved and very acute ; the outer margin bears a fairly long seta near the base, and the inner margin bears three small setae, the third situated at the base of the terminal unguis, which is distinctly marked off from the rest of the dactylos. When seen from above (fig. 15) the carpus bears at the extremity an oblique row of four or five long setae and another similar row on the surface at some distance from the extremity ; the propodos has a longitudinal row of about twelve long setae along the centre of the upper surface (just like that which Humbert draws in Niphargus puteanus, var. iorelli [62, pi. vi. fig. 9]), and a small tuft of two setae near the outer margin. The inner lobe of the maxillipede— that is, the one attached to the basos — is rectangular, and bears at the end three stout spines and five or six longer stiffly-plumose setae ; the inner margin also bears three or four similar plumose setae. The outer lobe attached to the ischium bears on the inner margin about twelve stout spines, which, at the extremity, gradually merge into long denticulate setae ; a few simple setae are found along the inner margin, more particularly on the basal portion. The gnatliopoda are about equal in size and almost identical in structure and in the arrangernent of the setae on them, but the setae on the inner surface of each are more numerous than, and very different from, those on the outer surface and require separate description. T\\Q first gnathopod (fig. 16) has the coxa (side-plate) nearly square, the lower surface bearing a few fine setae. The basos is long, the front margin with a few irregular setae, the posterior margin with a tuft at the extremity. Iscliivim very short, with a tuft of setae on the posterior margin at the extremity, and this is extended into a short row along the inner surface of the joint. Meros narrow when seen from the outside, being partially overlapped by the carpus ; on the inner side it appears nearly rectangular, the * !^eo note on previous page. CRUSTACEA OF NEW ZEALAND. 231 end truncate and fringed with a dense double row of long sette, which also form a dense tuft on the posterior side. The carpus is triangular, widening distally, the short posterior margin being densely covered with long seta? arranged in five or six transverse rows ; there are no setae on the outer surface, but on the inner surface there is a transverse row of long setae along the end and another shorter row at a slight distance from the end; there are also two small tufts at the antero-distal angle and another situated more j)roximally. The j^i'opodos is lai-ge, fully as long as the bases, ovate, about twice as long as broad, and not much broader than the carpus ; the outer surface bears few setae, then a few very small ones along the anterior margin, a small tuft at the base of the dactylos, and a few along the palm ; on the inner surface near the anterior margin are five transverse rows each containing fx*om five to seven long setae : the palm is slightly convex and occupies almost all the lower margin ; it is defined by two large spines, a third large spine is situated on the inner surface a little nearer the base of the propodos, and near it are two or three small transverse rows of setae ; between the end of the palm and the base of the j)i'opodos are two other transverse rows on the posterior margin ; the palm is armed with a double row of short stout spines, and near the edge of the palm on the inner surface are about six small tufts of setae. The dactylos is long and curved, fitting closely ou to the palm ; the inner surface bears about six small tufts of setae ; the inner margin is minutely serrate, the serrations lying close to one another, and it bears about fifteen minute s^iinules placed at regular distances from one another along the inner edge ; the extremity is acute. The second gnathopod (fig. 17) differs from the first in having the extremities of the ischium and meros less densely fringed with setae; on the inner surface of the carpu.s the transverse row situated a little from the end is very short, containing only about six setae, and there is another small tuft near it ; in the propodos on the posterior margin are six transverse rows, instead of two, between the base and the end of the palm, and the tu.fts of setae near the palm are much smaller, containing only two or three setae each. The description of the gnathopoda, as given above, applies to the adult female. I am unable at present to say whether the male differs in any particulars or not. The first perceopod (fig. IS) is slender, of the same length as the second, and very much shorter than the third. The coxa (side-plate) is rounded below and beax's a few small setae irregularly placed along the margin. The bases is long, oblong in sliape ; the anterior margin with three or four rather long setae near the base, and three short spines towards the extremity ; the posterior margin is similarly supplied with setae, but the long setae are further from the base. The ischium is short, rectangular, with a single seta on the posterior margin at the extremity. The meros is slightly more than half as long as the basos, and is somewhat produced at the antero-distal angle ; the anterior margin is slightly convex, and bears three short spines, the last being at the extremity ; the posterior margin is straight, and bears three tufts, each containing two slender setae. The carpus is shorter than the meros, and bears on the posterior margin two spines and a few slender setae. The propodos is a little longer than the carpus, and bears on the posterior margin short spines arranged in four groups ; the anterior margin bears a few 232 DR. C. CHILTON ON THE SUBTERRANEAN fine hairs and a small tuft of setse at the base of the dactylos. The dactylos is rather short, and hears a single seta on the inner margin, imperfectly marking off the terminal unguis. The second percBopod is similar in all respects to the first. The tliird, fourth, and fifth perceopoda (see fig. 19) are all very long, and each is longer than the preceding ; the fifth is about as long as the whole body. The lengths of the perseopoda, as compared with the body, appear to vary, as is the ease also with the antenmB, and to increase with the age and size of the animal. The coxae of these peraeopoda are not easy to make out very distinctly ; that of the fifth is small, almost semicircular, regularly curved below, and bearing four setse on the posterior portion ; those of the third and fourth perseopoda appear similar, but flatter inferiorly, and with fewer seta; ; that of the third fits in front into an emargination on the posterior side of the coxa of the second pera?opod. It will be sufficient to describe the fourth perceopod (figs. 19, 20) as a mean between the third and fifth. The basos is not much expanded, and narrows distally; both margins bear small spines arranged in slight serrations ; the ischium bears one or two spines at the extremity of the anterior margin ; the meros, carpus, and propodos are all similar, but each is longer and narrower, and bears more numerous setse than the preceding. In all both margins bear numerous tufts of long spines arranged in slight serrations ; the dactylos is fairly long, of the same width throughout until near the end, where it narrows suddenly ; at this point on the inner margin are usually three setae, though in large specimens there may be as many as six. In the tuft of setae at the base of the dactylos are stout spines, fine setse, and one or two plumose setae similar to the " auditory setse " found on the antennae and elsewhere, but much curved or bent at the middle. Similar setse are found in most of the tufts on the posterior margin of the propodos. The plcopoda are of the usual shape, and the three pairs are almost identical. Fig. 21 represents the third pair ; in it the peduncle appears to consist of a short coxa and a long basos about three times as long as broad. The outer margin is somewhat convex, inner margin straight and bearing four fairly long setse, the longest being at the extremity near the two " coupliug-spiues." The latter seem to closely resemble those of Gammarus neglectus, as described and figured by Sars [91, p. 53], except that there are two only instead of three, as in that species ; each bears three or four teeth on each side. The outer ramus, which is somewhat shorter than the inner, is hollowed out on its inner side for the reception of the base of the inner ramus, and its margin, which is thinned out, bears four or five of the ordinary plumose hairs. The first joint of the inner ramus bears on its inner margin three "cleft-spines," like those described by Stebbing. The first and second pleopoda appear slightly larger than the third, and have the spines on the inner margin of the peduncle smaller and fewer, otherwise they precisely resemble the thu'd pleopoda. The first uropoda (fig. 22) extend as far backwards as the extremity of the second CEUSTACEA OF NEW ZEALAND. 233 tiropoda ; there is a strong spine on the body-segment just at their base. The peduncle is considerably longer than the rami ; its lo\yer margin straight or slightly curved, upper surface broad, concave ; both inner and outer margins supplied with about six small spines, a large spine nearly half as long as the inner ramus being situated at the extremity of the inner margin. The outer ramus is slightly longer than the inner ; upper margin with three small spines, a large one and two small ones at the extremity ; inner ramus similar, but with two large spines at the extremity. The second uropoda (fig. 23) are small, not reaching to the end of the peduncle of the third uropoda. Peduncle stout, about as long as the rami, concave above, both inner and outer upper margins with two or three spines ; outer ramus slightly shorter than the inner, upper margin with three small spines, a large one and two small ones at the extremity ; inner ramus with its upper margin supplied with about twelve small spines arranged closely in a row, two large ones and two or three short ones at the extremity. The third uropoda (fig. 24) are very long, nearly as long as the whole pleou. The peduncle, is rectangular, about three times as long as broad, two setae on the side near the lower margin ; upper surface slightly concave ; both inner and outer margins with spines, two or three at the extremity of the outer margin and one large one at the extremity of the inner margin. The two rami of equal length, nearly twice as long as the peduncle, each cylindrical, scarcely tapering towards the end ; outer surface of each with five groups, each containing three spines ; inner surface with five similar groups of stout spines, and in addition a number of long plumose hairs ; extremity of each with about six or seven spines of various lengths. In fig. 24' the last urojioda are represented as usually seen, the outer row of setse being shown on the outer ramus and the inner row with the plumose hairs being seen on the inner ramus, which is somewhat twisted round. The spines or setae on these uropoda arc shorter in proportion to the appendage in large specimens, and this is the case also with the spines on the legs and in other parts of the body. The telson (fig. 25) is short, reaching only slightly beyond the base of the pedimcle of the last uropod. It is cleft right to the base, each half being more or less rectangular ; the outer margin curved, extremity straight or slightly rounded, bearing on the inner half fovu- long spines about half as long as the telson, and towards the outer side two or three similar spines situated a slight distance from the extremity. The above description applies to fully developed females. I am not able to say whether the males differ from the females in the last pair of uropoda. as in Niphargus, but the numerous specimens that I have seen and closely examined all agree with the description given above. Genus Cai/Liopius, Leach. (Bate & Westwood, Brit. Sessile-eyed Crust, i. p. .259.) Of this genus Bate and Westwood give only the following as the generic character : — *' Like Pherusa, except that at least the second pair of gnathopoda have the propodos 234 DE. C. CHILTON OF THE SUBTEREAXEAN largely developed " [4, p. 259] ; and of Fherusa they merely say, " Like Atyliis, but telson not divided. Gnathopoda small " [4, p. 252]. According to Stebbing the genus Am2Mthopsis, Boeck, is most probably a synonym of Phcrusa, and of this genus he gives the following account in his notice of Bocck's work. The genus is, he states, instituted for those species which have " an elongate, compressed body with moderate epimera and long antennae ; the inner plate of the first maxillae furnished with four or five long, thick, plumose setae ; the inner plate of the second maxillae with many simple setae at the extremity, but several on the inner side very strong and plumose ; the maxillipeds large, with palps of moderate length ; the two first pairs of feet with hands of nearly the same size, small ; the third and fourth pairs of legs with the fifth joint very long, longer than the third joint ; the telson simple; the last uropods with the branches long, often unequal ; the marsupial plates much larger than the branchiae, closely margined with hairs " [108, p. 324]. It appears to me that all the genera mentioned, together with several other allied genera, require careful revision and systematic redescription ; and in the meantime I prefer to leave my species CalUopius suhterraneus under CalUopius, where I first placed it, although, if we consider only the female, it should no doubt be put in the same genus as Fherusa ccerulea, Gr. M. Thomson. It is evident, too, that due attention must be paid to the sexual diff'erences, for in CalUopius subterraneus the female is a Pherusa, while the male, which diflPers chiefly in the possession of larger gnathopoda, would be better placed under CalUopius. Calliopius subterraneus, Chilton. ( j , PI. XXII. figs. 1-15, PI. XXIll. figs. 1-9 ; 5 , PL XXIII. figs. 10-18.) Calliope subterranea, Chiltou, New Zealaud Joiu'ual of Science, vol. i. (January 1882) p. 14 ; id. Transactions New Zealaud Institute, vol. xiv. p. 177, plate ix. figs. 1-10; id. New Zealand Journal of Science, vol. ii. (March 1884) p. 89. Calliopius subterraneus, Thomson & Chilton, Transactions New Zealand Institute, vol. xviii. p. 148 ; Thomson, Transactions New Zealaud Institute, vol. xxi. p. 2G2. Calliope subterranea, Monicz, " Faune des Eaux souterraiues du Departement du Nord &c.," cxtrait de la Revue Biologique du Nord de la France, tome i. (1888-89) p. 50 ; Wrzesniowski, " O trzech kielzacb podziemnych," De tribiis Crustaceis Amphipodis subterraneis, pp. 16, 90 ; id. " Ueber drei unter- irdische Gammariden,'' Zeitschrift t'iir wissenschaftliche Zoologie, L. 4, pp. 611, 698. Specific description. — Male. Cephalon not produced into an appreciable rostrum. Eyes wanting. Upper antennae about two-thirds the length of the body; first joint of peduncle stout, second and third each much shorter than the preceding; secondary flagellum represented by a minute joint shorter than first joint of mam flagellum. Lower antennae stout, much shorter than the upper ; flagellum about as long as the peduncle. Calceoli are present on the second and third joints of the peduncle, and on the flagellum of the upper antenna, and on the flagellum of the lower antemia. First gnathopod very large and strong ; carpus very short ; propodos much longer than basos ; palm occupying nearly the whole of the posterior margin. Second gnathopod also large, but more slender than the first; carpus triangular, more than half as long as propodos; palm of propodos convex, occupying about half the posterior margin. Last three pairs CRUSTACEA OF NEW ZEALAND. 235 of peracopoda long and slender, each much longer than the preceding. Second uropods with the outer branch only about half as long as the inner. Telson rather short, sul)- reetangular ; postei'ior angles rounded and each furnished with a single fine seta; hinder margin slightly concave. Female. Differs from the male in the following points : the size is smaller, only about two-thirds as large ; the antennae are more slender and less strongly supplied with setae, and apparently do not bear calceoli ; the gnathopoda are much smaller and more slender, the first having the carpus triangular, as long as the propodos, which is elliptical, and has the palm only sHghtly oblique; the second guathopod is very long and slender, carpus and propodos similar, narrow oblong, carpus much longer than propodos, palm of latter quite transverse. Length. Largest male 12 mm. ; largest female about 6 mm. Colour. White, semitransparent. Habitat. Eyreton [Chiltoj/), Lincoln (i". Wilkinson), Ashbvu'tou (/?'. W. Smith and J. B. Ilayne), Winchester (_D. L. Iincood) : in wells. Remarks. The female of this species bears a very close general resemblance to Fhernsa ccerulea, G. M. Thomson [107, p. 2(;6j. I had judged this to be the case from the comparison of Stebbing's figures of the latter with my specimens, and an examination of specimens of Pherusa ccerulea, kindly supplied by Mr. Thomson, shows that the resemblance is even closer than I had imagined. Pherusa cceridea is stouter in body, has the side-2:)lates deeper, and of course diflers also in the possession of eyes and in its very distinct dark blue colour, but in the form of the antennae, the mouth-parts, and the gnathopods there is little difference of any importance. The upper antenna has a rudimentary secondary flagellum (not mentioned in Stebbing's description), as in Cal- liopins sithterraneus, but it is somewhat longer, being longer than the first joint of the main flagellum ; in the specimen I have dissected there are small calceoli on both antennae, just as in the specimens of Calliopias subterratieus that I have described below as " immature males." The gnathopods have the same general si i ape, but are not so long and slender, and, especially in the second, do not bear so many tufts of setae as in the female of Calliopius siihterranei(s ; the peiseopoda are shorter, the uropoda are similar and in like manner armed with spines, but the second has the branches less unequal in length, and the telson is rounder. The specimen of Pherusa ccerulea that I have examined is probably a young male, but none of the few specimens in my hands liave the gnathopoda so largely developed as in C'alliopius suhterraneus. On the whole it appears that the two species are very closely related, and eitlier Calliopius suhterraneus has been derived from Pherusa ccBrulea, or, what is more likely, both have been derived from a closely allied species once widely spread in New Zealand. Calliopius Jluviatilis, G. M. Thomson, is very common in freshwater streams in New Zealand, but is not so closely allied to the subterranean species as is Pherusa ccerulea. It differs considerably in the gnathopoda, and in the last pair of peraeopoda, which have the last joint simple, ending in a small pencil of long hairs, as in sr)ecies of the ffidiceroidae, and it seems scarcely necessary to compare it in detail with Calliopius subterraneiis. SKCOND SEKIES. — ZOOLOGY VOL. VI. HI 236 DR. C. CHILTON ON THE SUBTERKANEAN Detailed Description. In tliis species the male differs in a very marked manner from the female, being of considerably larger size, differing also in the antennae and particularly in the gnathopoda. The males are very much rarer than the females ; I have seen only about half a dozen males altogether, while I must have seen hundreds of specimens of the female. It ^vill be convenient to describe the male first, and afterwards to point out more in detail the characters in which the female differs from the male. The body (PI. XXII. fig. 1) is smooth, fairly stout. The head is longer than the first segment of the peraeon ; the segments of the peraeon subequal ; first three segments of the pleon considerably longer than the last segment of the peraeon. The side-plates of the first four segments of the peraeon are nearly as deep as their respective segments. The inferior margins of the first three segments of the pleon are regularly rounded and have no setae. Eyes. There is no external sign of the eyes. The tipper antennce (fig. 2) are more than two-thirds as long as the body. The peduncle has the first joint stout, about half as broad as long, with a few minute setae scattered over it, the lower surface with a row of about seven or eight short setae, and at the extremity three or four long auditory setae. Tlie second joint is about two-thirds as long as the first, but not much more than half the width ; the lower surface bears a few minute spinules and some longer setae at the extremity ; on the inner surface, towards the upper side, is a row of three or four " calceoli," at the base of each of which are two or three simple setae. Third joint about half as long as the second, similarly furnished with calceoli and setae. There is a minute secondary appendage on the inner surface, consisting of a single small joint tipped with two setae. The flageUum is more than twice as long as the jieduncle, and consists of a great number of joints, of which about the first third bear calceoli arranged in two rows, the first being situated on the inner surface towards the upper margin, the other also on the inner surface but lower down, and being on joints of the flagellum alternating with those that bear the first-mentioned row of calceoli, the part of each joint that bears a calceolus is somewhat produced into a small rounded prominence, which bears three or four simple setae as well as the calceolus. Towards the extremity of the flagellum the joints become much more elongated and cease to bear calceoli. Olfactory cylinders are found on the joints which do not bear calceoli, as well as on some, if not all, of those which do bear calceoli. The lower antennce (fig. 4) are al^out half as long as the upper, both the peduncle and the flagellum being rather stout. The " gland-cone " attached to the second joint is rather large and prominent, and bears two separate setae at some little distance from the apex. The short third joint is grooved below, and bears at the extremity of its lower margin two simple setae ; its articulation with the fourth joint is very oblique. The fourth joint is rather broad, neai"ly half as broad as long ; its upper margin bears thi-ee setae in slight serrations ; there is a tuft of four setae in the middle of the lower margin and another larger tuft at the extremity. The fifth joint is slightly longer than the fourth ; on the upper surface it bears four or five small tufts of setae, and on the lower margin CEUSTACEA OF NEW ZEALAND. 2;]7 four larger tufts ; aloug tlie extremity is a row of about seven auditory setse. The flagellum is rather longer than the peduncle, and is stout, especially toward the base, where each joint is much broader than long. It bears two rows of calceoli, arranged in the same way as in the upper antenna; the calceoli decrease in size towards the end of the flagellum, and cease entirely at about the seventh joint from the end. In addition to the calceoli each joint bears a few simple setse at the extremity. The general appearance of the calceoli is shown in fig. 3. These organs have been fully investigated by Blanc, as I learn from the abstract given by Stebbing. The general arrangement of the calceoli in the present species appears to resemble closely that in Eusiroides ccBsaris as described and figured by Stebbing [108, p. t)70]. When seen in profile, the outline of the calceolus is very different from that shown in fio-. 3, and is more like that shown by Stebbing in his figure of the calceoli of Tryphosa antennipotcns [108, pi. vi. fig. a. s. with enlargement]. In that species, too, the calceoli on both antennae are arranged in the same way as in the present species — " in both pairs so placed that, while the calceoli of alternate joints are seen full face, those of the other alternate joints will be seen in profile " [108, p. G18]. The iqjj^er lip (fig. 5) is rather large, oval in outline, widening distally ; the end is regularly rounded at the corners and nearly straight in the centre, and bears many short converging setse. Mandibles (figs. 6, 7, 8). The left mandible is shown in fig. 6, and differs consider- ably from the right in the details of the cutting-edges. The palp, which is the same in both mandibles, is large and rather broad. Its first joint is very short, not much longer than broad; it bears no sette. The second joint is the largest, being rather more than three times as long as the first ; it expands slightly towards the distal end, and bears at the extremity on the inner margin, which is there convex, a row of six or seven fiiirly long setiE. The third joint is about three-fourths as long as the second ; it is broadest near the base, narrows considerably toward the end, and is much curved, so that tbe extremity is almost at right angles to the plane in which the base of the joint lies (the double curving is not well shown in the figure). Along its concave margin it is thickly fringed with a dense row of short setse ; three longer ones are situated at the extremity. The surface on the concave side appears striated, the ajjpearance being probably due to rows of very minute setse. The molar tubercle is strong ; it has the extremity oblique, and covered, as usual, with rows of short spines. The sides of the tubercle bear numerous fine setae, and in connection with it is a long filament or seta, as described by Humbert in Niphargiia puteanus, by Sars in Gammariis neglectiis, and by other authors. The outer cutting-edge of the left mandible (fig. 7) consists of about six sharp teeth of varying shape, as shown in the figure ; the inner or secondary is edge somew hat similar, but contains only four main teeth. Both edges are very concave on the inside, and were a good deal compressed in the slide from which fig. 7 was drawn ; between the inner edge and the molar tubercle are five or six stout bristles. The right mandible differs principally from the left in the two cutting-edges. The outer edge is similar to that of the left, but appears to consist of five main teeth only, 31* 238 DE. C. CHILTON ON THE SUBTERRANEAN and usually presents tlie appearance shown in fig. 8. The inner edge is very different from that of the left ; it has a stout rounded base, and bifurcates towards the end ; each division tapers to a point, bears one or two teeth, and is more or less tubercled, as shown in the figure. Lower Up. Fig. 9 represents a portion of the lower lip of the large male from which this description is taken, the appendage having been torn in dissecting it out ; the whole of the lip is better shown in PL XXIII. fig. 10, which is taken from a female specimen. The two outer lobes are comparatively long and narrow towards the extremity ; their outer margins are fringed with very delicate setae, and the inner margins bear numerous short setae curving inward. The division between the two lobes does not appear to reach quite to the base of the lip. The inner lobes were not observed in the female ; a part which probably belongs to them is shown in the drawing taken from the male (PL XXII. fig. 9). The lateral backward processes are moderately long and narrow. The^y^r*^ maxilla (PL XXII. fig. 10, 11, 12, 13) in the male specimen dissected had the inner plate very small and delicate, oval, and with five plumose setae on the inner margin. The middle lobe is broad, rectangular, squarely truncate at the end, and bears about twelve strongly denticulated spines, as shown in fig. 11 ; the form and position of these spines will be more easily understood from the figure than from a verbal description. The palp has the first joint short, not much longer than broad, the end somewhat oblique ; the second joint is long and curved, rather broad, and terminates in the right (?) maxilla (fig. 12) in about seven stout, short setae or spines. The two outermost are the longest and narrowest and are bristled ; the others, which are short and stout, form very sharp teeth ; near the base of the second tooth from the outside arises a single shnple seta. In the other maxilla (fig. 13) the end of the jjalp is very different; it bears five setae, very much longer and narrower than those on the right (?) ; the single simj)le seta arises from the base of the second outermost one as on the right (?). The second maxilla is shown in fig. 14, and does not appear to present any remark- able feature. On the surface of the inner lobe is an oblique row containing seven plumose setae. The surface of this lobe towards the base is covered with very fine delicate setae, and similar setae are found on the outer margins of both lobes towards their extremities. The end of the outer lobe bears about seven or eight long setae, curved slightly inward ; the end of the inner lobe bears similar setae, which are, how- ever, much shorter, and some of them plumose. The setae extend some distance along the inner margin, but gradually become smaller as they recede from the extremity. The maxilUpedes, as seen from below, are shown in fig. 15. The bases hears at its extremity, towards the inner side, a group of nine or ten long setae ; the plate attached to it — the inner plate — extends only as far as the end of the inner margin of the meros; it bears at the end two stout sharp teeth and a third more slender, and numerous stiffly plumose bristles ; its inner margin bears five or six plumose hairs. The ischium bears at the extremity a group of setae as in the basos ; the plate attached to it — the outer plate — reaches as far as the extremity of the outer edge of the meros ; its inner edge is straight and bears about ten moderately stout spines, which gradually merge at the end into long, stiffly plumose, curved setae ; in addition to these spines the inner margin bears CEUSTACEA OF NEW ZEALAND. 239 numerous slender setae ; the convex outer margin of the plate is also supplied with many very fine seta? like those found on some parts of the maxillae. The meros bears about six setae on the outer margin towards the extremity and numerous setae on its inner margin. The carpus is similarly supplied with setae. The propodos is about two-thirds as long as the Ciirpus ; it bears three or four setae on the outer margin, and numerous long ones on the inner margin and on the surface near to it ; on the upper surface of the propodos (fig. 16) is a longitudinal row of about twelve set;e, extending right along the centre, with a few others more or less irregularly placed ; the outer extremity of the propodos at the base of the dactylos is produced into a small rounded lobe. The dactylos is long and slender, being about two-thirds the length of the propodos ; both margins bear five or six setae ; it narrows somewhat abruptly at the extremity, and bears a stout spine or nail. The normal form of the dactylos is shown in fig. 16 ; that shown in fig. 15 is evidently deformed, and was found on the right side of the same maxillipede. The foregoing descriptions of the mouth-parts have been taken from a large-sized male specimen. The mouth-parts of the female differ in several respects and are described belo^^, where some remarks on the probable changes that take place in the mouth-parts during the development of the male will also be found. The^rs^ gnathopod (PI. XXIII. fig. 1) is very large and strong, much larger than the second. The coxa (side-plate) is nearly as deep as its segments and is rhomboidal in outline, projecting strongly forward ; it bears a very minute seta at tlic anterior end of the lower margin, and one or two at the hinder end. The basos is long, somewhat curved at the base ; the anterior surface is grooved to receive the propodos when the limb is bent back at rest. The ischium is short and of the usual form. The meros is short, not much longer than the ischium ; the anterior surface is rounded and bears a number of setae more or less regularly arranged in three transverse rows. The carpus is very short, subtriangular, produced below on the outer side into a small rounded lobe, densely tipped with setae ; when seen from the inside (fig. 2) the carpus appears quite rect- angular. The propodos is very large, much longer than the basos ; the upper margin is regularly curved and without setae, except one or two very small ones at the base of the dactylos ; the basal part of the lower margin forms a rounded lobe densely covered with numerous setae arranged in five transverse rows ; the palm occupies the whole length of the lower margin with the exception of this lobe ; it appears rather broad, the outer edge bearing ten small tufts of rather long setae, each tuft containing from two to four setae. When seen from the inside (fig. 2) the end of the palm, against which the dactylos impinges, appeal's to be slightly concave ; the end is defined by three long spines ; roimd the edge of the hollow on the inside is a row of about seven shorter spines, and near them are some simple setae more or less regularly arranged in tufts. The inner edge of the palm is rather convex, and, except towards the proximal end of the palm, it extends beyond the inner edge ; it is minutely serrate and fringed with a few small setae, and near it is a longitudinal series of about twelve short oblique rows of long setae, each containing from five to ten setae. The dactylos is large and strong, slightly curved, and with a few very minute setae on the concave margin, but these do 240 DK. C. CHILTON ON THE SUBTEREANEAN not project beyond the margin of the dactylos ; the extremity is not distinctly marked off into a terminal unguis. The second gnutliopod (PI. XXIII. figs. 3, 4) is slightly longer than the first, but is much more slender. The coxa is rectangular, deeper than broad, the lower angles rounded, and with six minute seta? on the lower margiu ; arising from the coxa there appear to be two * gill-plates, one rather larger than the other. The basos is long, nearly straight, the posterior margin bearing seven or eight long setae on the proximal half, and a shorter one at the extremity. The ischium is rather long, one-third as long as the basos ; its j)osterior margin bears three or four small setae. The meros is about as long as the ischium ; its distal extremity bears a fringe of about eight or nine long setoe. The carpus is nearly as long as the ischium and meros together ; it is subtri angular, very narrow at the base, and rather loosely articulated to the meros, so that the distal jiart of the limb can readily turn upon this as a pivot, and hence often appears reversed, as shown in the figure of the whole animal (PL XXII. fig. 1). The anterior margin of the carpus is nearly straight, with a single minute seta at the extremity ; the posterior margin is strongly curved, and thickly fringed with long setae arranged in about twelve transverse rows, a small tuft of two or three being situated on the outer surface near the extremity. On the inner surface (PI. XXIII. fig. 4) the carpus bears towards the extremity a transverse row of four or five setae and three or four separate setae placed more proximally along the middle of the joint. The propodos is longer than the carpus and meros combined ; the anterior margin is straight, giving the limb a somewhat awkward appearance ; towards the end it bears three or four minute setae and two or three at the base of the dactylos ; the posterior margin is strongly convex, the palm occupying more than one-half the whole length ; it is defined by a stout spine and fringed on the outer surface with minute spinules, arranged singly, and a row of six separate long setae running parallel to the palm ; the basal part of the margin below the palm is thickly fringed with long- setae, arranged in about eleven transverse rows as in the carpus. When the propodos is viewed from the inside, the dactylos is seen to extend a little beyond the defining-spine and to fit into a slight depression bordered by four spines, one of which is much longer than the others ; running parallel to the palm is a longitudinal series of from twelve to fifteen obHque rows of long setae, each containing from two to four. The dactylos is similar to that of the first gnathopod, but is not so large and powerful. The first percBOpod. (fig. 5) has the coxa (side-plate) and basos entirely simikir to those of the second gnathopod, and, like it, appears to bear a double gill-plate. The ischium is short and of the usual form. The meros is oblong, rather more than half the length of the basos ; its posterior margin straight, with five or six separate setae, the anterior margin slightly convex and with the distal angle a little produced ; it bears a seta near the middle and another at the extremity. The carpus is more than half the length of * Though there are certainly two plates attached to the coxa, both in the second gnathopod and in the lirst and second perseopoda, in the male specimen dissected, I have not found them in female specimens, and am not sure that the second plate is a gill-plate. It differs in appearance from the true gill-plate, and might be considered a brood- plate, but it bears no setae on the margin, and I am practically certain that the specimen is a male. CRUSTACEA OF NEW ZEALAND. 241 the meros and is similarly furnished with setae, but those on the posterior margin are rather stouter than in the meros. The propodos is longer than the carpus and rather more slender; its anterior margin bears six liue setae and the posterior margin six groups, each containing one stout seta and usually one or two small ones. The dactylos is of average length, very acute, with the terminal unguis imperfectly defined ; on the outer margin, near the base, it bears a single seta, sparingly plumose at the end. The second fcrccopod is similar in all respects to the first. The third, fourth, and Jifth, permopoda are all similar to each other, but each is larger than the j^receding ; each appears to have only one gill-plate. Fig. 6 represents the third ferceopod and may be taken as a sample. The coxa is normally deep, distinctly bilobed, the posterior lobe being rather the larger. The basos is considerably expanded, oval in shape, about two-thirds as broad as long ; its anterior margin bears nine or ten stout setge ; the posterior margin minutely serrate and having a small seta in each serration. The ischium as usual. The meros is rather broad, the postero-distal angle somewhat produced, both margins with groups of long stout setae. The carpus is longer than the meros, but much narrower ; the propodos somewhat longer than the carpus ; both bear groups of long stout setre on both margins, those on the anterior margin being larger than those on the posterior margin. The dactylos is like that of the first peraeopod, but bears three small setse on the outer margin in addition to the plumose one near the base. li\\Q first pleopod is of the usual form ; the jieduncle is rather short and has both margins free from setae; there are two coupliug-spiues, each l)earing three or four teeth; the first joint of the inner ramus bears two cleft spines ; the inner ramus is slightly longer than the outer. The second and third pleopoda are similar to the first. The first vropod (fig. 7) has the peduncle long and slender, much longer than the rami; its upper surface is flat or slightly concave; both the upper margins supplied wdth spines. In the large male there were only three or four spines on each margin, but in females the spines are usually much more numerous (compare PI. XXIII. figs. 7, 16). The two rami are similar, with spines on both margins and longer spines at the ends ; the outer ramus is a little shorter than the inner. The second uropod (fig. 8) is shorter than the first and has the outer ramus not much more than half as long as the inner. It is supplied with setse in a similar manner to the first uropod. The third uropod (fig. 9) reaches further back than the others, the j)eduncle reaching as far as the ends of the first and second urojiods ; it bears spine-like setae ou both the upper margins. The rami are longer than the peduncle, somewhat broad, narrowing gradually to the ends, which are acute and bear no setse ; both margins of each bear thi'ee or four tufts of small spines. In the male specimen drawn the outer ramus is somewhat shorter than the inner, but in females the two rami are of about the same length and the whole uropod is rather longer and more slender (compare figs. 9, 11, PI. XXIII.). The telson (see fig. 17) is short, not reaching to the end of the peduncle of the third uropod ; it is nearly rectangular, rather broader than long ; the angles at the extremity 242 DR. C. CHILTON ON THE SUBTEREANEAN rounded, and eacli bearing a fine hair ; the hinder margin slightly concave. Fig. 17 is taken from a female ; in one male specimen examined the hinder margin was slightly more concave. Sexual differences. The female differs from the male as above described in many charac- teristic features, and especially in the gnathopoda, so that if they had not been taken together it is rather unlikely that the two forms would both have been assigned to the same species. With the facts before me, however, I have no doubt that we have to deal with the two sexes of the one species. The one form I consider the male from its largely developed gnathopoda, from the absence of brood-plates &c., although I have not actually found fully- developed spermatozoa in it. The other form is undoubtedly a female, for I have frequently taken it bearing eggs; it is found associated with the male both at Eyreton and Ashburton ; it is much smaller, the largest specimens being not more than two-thirds the size of the largest male, and it is very much more numerous. Although I have not yet obtained a complete series of transitional forms, still from the facts given below I feel convinced that in this species, as in many other Amphipoda, the young male at first resembles the female in the form of the gnathopoda &c., and that the peculiar characteristics of the male are not acquired until the animal has attained to sexual maturity. In the female the antennce are more slender than in the male ; in accordance with the smaller size of the animal, the setse on them are less prominent, especially in the lower antenna?, and the calceoli are wanting. I have found calceoli in some specimens which in other characters closely resembled females, but, as I have already said, these are more probably immature males. As the calceoli in these specimens are of very small size, extremely delicate and transparent, and hence easily overlooked, I thought at first that they were perhaps present also in the females, though I had failed to see them ; however, I have since looked for them very carefully in several mature females and can find no trace of them. In the upj)er lip, the mandibles, and the lower lip the female does not appear to differ from the male. In the first maxilla the inner lobe is larger and bears fully twice as many plumose setse as in the male specimen drawn in tig. 10, PI. XXII. It is quite possible that the number of plumose setse on the inner plate of this maxilla bears some relation to the size of the animal irrespective of its sex ; but all the female specimens examined have about twice the number found in the male, and I have not had sufficient male specimens of different sizes to be able to decide how many of these setae are usually present, or whether the one figured is exceptional or not. In full-grown females the setae on the middle lobe and at the end of the palp closely resemble those of the male as drawn, the two palps being different as in the male. In the second maxilla in tlie female the oblique row of plumose setse contains about twice as many setse as in the male figured in fig. VI, n, and the remarks made in con- nection with the first maxilla apply to the second maxilla also. In the maxilliiiedes (fig. 11, PI. XXIII.) we find a very considerable difference between the two sexes (compare fig. 15, PI. XXII., and fig. 11, PI. XXIII.) . In the female the two CRUSTACEA OF NEW ZEALAND. 243 lobes are cousiderahly larger than in the male, the inner lobe reaching nearly to the end of the ottter margin of the meros, and the outer lobe nearly to the end of the carpus ; the lobes are also broader, but the armature of each is practically the same in both sexes. The meros, carpus, and propodos bear fewer setse in the female, especially on the outer margins, and I cannot find the central row of setae along the upper surface of the propodos which was certainly present in the male specimen figured. Notwithstanding these differences, there is a very close agreement ia other respects, the resemblance being greater than would be imagined from a comparison of fig. 15, PI. XXII., and fig. 11, PI. XXIII. ; and I wish to repeat that I am not yet certain how far the differences observed are due to sex and how far to size alone. It is, however, in the gnathopoda that wc find the greatest difference between the sexes ; and it is, perhaps, worthy of note that each gnathopod is quite different in the two sexes, while in most cases in the Amphipoda one pair, at least, is the same, or ucai'ly the same, in both male and female. The first gnaihoiiod of the female (figs. 12, 13, PI. XXIII.) has the basos rather stout, widening distally, its posterior margin bearing a few setae. The ischiwii and raerOA' short, subequal, each witli a few setse at the extremity on the posterior mai-gin. The carpus triangular, a feAV setse on the anterior margin ; the posterior margin irregularly serrate and with small tufts or transverse rows of seta^, an oblique row of four or five seta; being situated on the svirfacc of the joint near the postero-distal corner. The i^ropodos is about as long as the carpus and not broader than the latter at its distal end, subelliptical in outline ; the anterior margin with three or four seta? and a small tuft at the base of the dactylos ; the posterior margin with four short transverse rows, an oblique row of seven or eight widely separated setae extending along the surface of the joint near the posterior margin ; the palm is a little oblique, defined by two stout setae, its edge somewhat creuate and fringed with a few small setae. The dactylos moderately stout, curved, with a few seta? on its inner margin. The second gnathopod (figs. 11, 15) is similar in general structure to the first, but is much longer and more slender. The basos, ischium, and meros are all similar to those of the first gnathopod, but more slender ; the carpus is very long, much longer than the propodos, narrow oblong, its posterior margin with about eight or nine tufts of setae in slight serrations ; the propjodos is also oblong in outline, of the same width as the carpus, both mai'gins with tufts of seta?, those on the posterior margin the longer, a very distinct transverse row being situated at the base of the dactylos ; the palm is transverse, defined by a small jirojection and a stout seta ; the dactylos very short. In the perceopoda, pleopoda, and uropoda the female does not differ from the male except in the few small points already mentioned, and it is quite probable that these are as much due to size as to difference of sex. I have, however, usually found the telson a Little more deejoly emarginate on the hinder margin in tlie male than in the female, but the difference is very slight. I have several times found small specimens otherwise like the ordinary female form but bearing calceoli on both antennae, the calceoli being much smaller and much less numerous than in the adult male, as above described, but similarly arranged. The SECOND SERIES. — ZOOLOGY, VOL. VI. 82 244 DR. C. CHILTON ON THE SUBTEREANEAN gnathopods of these forms, which I consider immature males, are usually quite like those of the ordinary female form ; but I have rough di'awings of one (made in 1883) in which the j)ropodos of the first gnathopod is more ovate, the palm oblique, occupying fully half the posterior margin, and the tufts of setae much reduced in number and containing shorter setae or spines ; the second gnathopod has the carpus as usual, but the propodos is shorter and differs in shape, being somewhat expanded distally, the posterior margin bears only three tufts of setse instead of about eight as usual, and the palm is rather oblique. It will be seen that in so far as this specimen differs from tlie female it approaches towards the male ; I have, however, not succeeded in finding any other forms intermediate between this and the fully-developed male. This particular specimen presented a peculiarity in the third pair of uropoda, having the two rami very unequal, one being as long as the peduncle and the other twice as long ; I have never seen any other specimen with this peculiarity in such a marked degree, though specimens are occasionally seen in which the two rami are a little unequal. In the first maxilla these " immature males " differ very considei*ably from the adult form ; the ends of the paljis of the right and left maxilljB are quite symmetrical, and the armature of the end of the outer lobe consists chiefly of broad comb-like setae like those shown in fig. 18, PI. XXIII., being thus about as different as can be from the adult form as shown in fig. 11, PI. XXII. In the former figure, only some of the setse are shown, those on one side ; the other curved denticulated seta? which are found on the other side and particularly towards the inner margin have been omitted in order to show clearly those that are represented. I have found the first maxilla to be similar to this in other small forms in which I could find no calceoli whatever, which were jn'obably either still younger males or young females, and I suppose that this form of the first maxilla is to be found only in immature individuals. Adult females have the first maxilla practically the same as that of the large male represented in figs. 18, 19, 20, 21, PL XXIII., so far as the two palps and the armatui'e of the middle lobe are concerned. I have not as yet found intermediate forms between the adult and the small specimens. Summary of the more important points in Part IV. It will be convenient here to summarize briefly the more important points that have been brought out in the examination of the six species now described, as some of them might otherwise be overlooked in the mass of technical description. (1) The genus Phreatoicus is shown to be a very peculiar one, requiring for its re- ception the creation of a new family, the Plireatoicidoe, which approaches in some respects to Asellidoe, differing, however, very much in the laterally-compressed body and the long six-jointed j)leon. (2) The pleopoda of Phreatoicits are well-developed and in some respects different from those of most other Isopoda. In the first pair there is a one-jointed endopodite and a one-jointed exopodite ; in all the other pairs the exopodite is two-jointed, Avhile in tlie third, fourth, and fifth pairs there is also a separate appendage arising from the protopodite and probably representing the epipodite. In the male the second pair of CRUSTACEA OF NEW ZEALAND. 245 pleopoda are specialh' modified, the penial filament being formed from a portion of the endopodite, a fact that will perhaps be useful to throw light on the more modified second pleopoda in the males of various Asellidse, &c. (3) A consideration of the eoxoe of Phreatoicns leads to a short discussion in support of Spence Bate's contention that the "epimera " or " side-plates " are in reality the coxa' of the appendages of the perseon. (4) In discussing the systematic position of Phreotoicus reference is made to the external characters by which the Amphipoda are separated from the Isopoda, and an additional difl"ei'ence is shown to exist in the ischia of the appendages of the perteon, as these are of moderate length in all Isopoda except the Apseudidai and Tanaidse, whih' they are almost always very short in the Amphipoda. (5) The genus Critregeifs, belonging to the Anthuridse, is described and compared with some allied genera. It has only six pairs of legs, and thus appears to perma- nently retain this larval character of the Isopoda, owing probably to an arrest of development. (6) The mouth-parts of Cruregens, which are very diificult to determine, are fully described, and it is shown that the mandibles are small and without any trace of a palp — a character very exceptional in the Anthuridae. (7) The terminal uropoda of Cruregens are shown to consist of an oblong peduncle, a long narrow exopodite arising from near the anterior end of the peduncle, and a one-jointed endopodite arising from its posterior end. Other authors, with the exception of Dohrn, have apparently wrongly described the uropoda of the Anthuridoe as having a two-jointed endopodite, the distal portion of the pedvmcle having been mistaken for a part of the endopodite. (8) The telson of Cruregens and of some other Anthurids is distinctly separated from the last segment of the pleon, though this is exceptional among the Isopoda. (9) The genus Crungomjx is discussed at some length, and the mouth-parts of Crangonyx compactus are described. The mouth-parts of Crangonyx do not appear to have been previously described. (10) The pleopoda of Crangonyx compactus have each only one ramus instead of two, as is almost universally the case in other Amphipoda. It appears to be the inner branch that is wanting. Nothing appears to be known of tlie pleopoda of most of the other species of Crangonyx. (11) The species Gammarus fragilis appears to correspond well with the characters usually assigned to tlie genus, but it is interesting to note tliat the present species has very long antennae, perieopoda, and terminal uropoda, thus showing some approach to the characters of Nlphurgus. 32* 216 DR. C. CHILTON ON THE SIJBTEEEANEAN (12) In CcMiopius svMerraneus there is very great dissimilarity between the two sexes, cliiefly in the gnathopoda, both of these in the male differing considerably from those of the female, while in other species one pair is usually almost or quite alike in the two sexes. There are also differences in some of the mouth-parts, viz. in characters which are often made use of for generic differentiation. Some remarks are made on the calceoli found in the males of this species ; they are also found in some specimens which otherwise resemble the females, but these are looked upon as immature males which have not yet acquired the peculiar gnathopoda of the fully-developed male. V. The General Pauna of the Subterranean Waters of Canterbury. In addition to the Crustacea described in the present paper there are doubtless many other forms to be found in the underground waters of the Canterbury Plains. In his paper on the fauna of the subterranean waters of the North of France, Dr. R. Moniez [78] gives a very long list, including Protozoa, Coelenterata, Turbellaria, Nematoda, Annelida, Rotifera, Gasteropoda, and various Crustacea, in addition to the Amphipoda and Isopoda, viz. Copepoda, Ostracoda, and Cladocera. In the various caves of North America, as described by Packard [83], and likewise in those of Europe, described by Joseph [67] and other writers, the fauna is a very extended one, and naturally includes many air-breathing forms that would be unable to exist in subterranean waters. I have made no extended search for other forms from the wells of Canterbury, but in collecting the Crustacea I have occasionally met with others, and it will perhaps be well to mention briefly here what is known on the subject, in the hope that greater attention will be directed to the matter in the future. Attached to tlie Amphipoda {Crangonyx compactns, Gammarus fragilis, CalUop'ms stiUerraneus) I have, on several occasions, noticed a small stalked Infusorian, probably a Vorticella, or something allied thereto. Various worms have been lirought up by the pump — one, an Oligochsete, is, Professor Haswell tells me, Phreoryctes Smiihii, Beddard ; another is a very remarkable Turbellarian, which is at present being investigated by Professor W. A. Haswell, of Sydney. Mr. W. W. Smith, who has examined the water brought up by pumps in the Ashburton district with great care and jjerseverance, has succeeded in detecting several forms that have not yet been observed from the Eyreton wells. Among these are some small Gasteropoda, a small Centipede, and a jieculiar worm, Phreodrilus subterraneus, Beddard [8]. The shells have been observed from several wells, but only very few specimens have as yet been obtained ; these were submitted to Mr. Suter of Christchurch, who states tliat they appear to be Potamopyrgus anti})odum, Gray, var. spelcBci, Prauenfeld. P. antipodnm is a freshwater species which is very widely distriliuted in New Zealand, and has probably received various names for its different varieties ; the type of P. spelcea was found in the Collingwood Caves near Nelson. There seems no doubt that the shells found at Ashburton really belong to the true subterranean fauna, as Mr. Suter states CRUSTACEA OF NEW ZEALAND. 247 that they were withovit pig-ment and of a dii'ty white colour, and the animals were still alive when got from the pump by Mr. Smith, who watched their movements for some hours before sending them off to Mr. Suter. The aquatic worm obtained by Mr. Smith Avas forwarded to Mr. F. E. Beddard, who has described it as " Phreodrilus suhterraneus, nov. gen. et n. sp.," making it the type of a new family of the Aquatic Oligochaita, viz. the Phreodrilidse [8]. The genus is, he considers, a very remarkable one, and, in addition to various peculiarities in the internal anatomy, the character of the seta? is alone sufficient for the creation of a new family. He regards the Phrcodrilidse as a very low form of Oligochteta, greatly specialized in certain directions. He adds : — " I should explain that in using the term ' low ' I do not mean that this genus is in any way near the ancestral form of the Oligochseta. The simplicity of structure in this and other aquatic genera is rather to be looked upon as evidence of degeneration." He places the PhreodrilidiB nearer the Naidomorpha than to any other group of the Oligoehseta, thougli admitting that the position of the genital organs suggests an atfinity with the Enchytraeidaj. There are also a few points in which Phreodrilus recalls the higher among the Ohgocha^ta, and Mr. Beddard comes to the conclusion that " it should be placed some way off the line leading from the more highly- developed Lumbriculida? to the lower Naidomorpha, but that its precise relationships require further study, and cannot be determined with any probability of success at the present time " [8, p. 292]. I have given the above account of Phreodrilus pretty fully because it appears in many respects to be parallel to the case of Phreotoicus, for which I have had to establish a new family. The two cases confirm each other, and show how exceedingly interesting the svibtcrranean fauna really is. No doubt other discoveries quite as interesting as these will yet repay careful and systematic search, for as yet the ground has been prospected merely, not thoroughly worked. Besides animals which, like the above-mentioned, undoubtedly belong to the true subterranean favma, it appears that surface animals from the neighlwurhood of the wells may sometimes be obtained through the pump, apparently from the well. Thus I have several times taken Cijdops novcB-zealandice, G. M. Thomson, from wells at Eyreton. The specimens were exactly like those found in surface pools in the neighbourhood and had the eye perfect, and had no doubt got into the well by accident — an accident that with this small creature might very easily happen. On one occasion Mr. Smith, after pumping for three quarters of an hour from a well at the Elgin Schoolhouse near Ashburton, 50 feet deep, and fitted with a cylinder-pump, obtained a spider and a small Gasteropod shell, and the seeds of some plants. The spider, which has perfect eyes, is, Mr. Goyen informs me, a species of Theridion frequently found in dark situations, such as crevices of rocks, &c. The seeds were submitted to Mr. D. Pctrie, who writes that one belongs to Chenopodimn, which is abundant everywhere in the district. The shell, deter- mined by Mr. Suter, is Amphij^eplea ampulla, Hutton, a species found everywhere in creeks, rivers, pools, &c. ; the animal had evidently been dead for some time, as the body was decayed ; the shell was of the normal horny colour, and, like the spider and the seeds, it must apparently have got into the pump by some accident, and forms no part of the true 248 DE. C. CHILTON ON THE SUBTEEEANEAN subterranean fauna. Mr. Suter points out that the shell of this specimen showed no approach to the dead-white colour of the Potamopyrgus, which is no doubt truly subterranean. At the same time and from the same pump Mr. Smith obtained one or two specimens of CalUopius subterraneus. VI. The Canterbury Plains and their Underground Waters. All the localities from which subterranean Crustacea have been as yet collected in New Zealand are situated on the Canterbury Plains, and in order to clear the way for the discussion of the probable origin of these forms it will be convenient to state first a few facts about the formation of the plains and as to their underground waters. Much of what follows is taken from the late Sir Julius von Haast's ' Geology of the Provinces of Canterbury and Westland, New Zealand ' [53]. In speaking of the plains formed on the eastern side of the Southern Alps he says : — " The most prominent amongst these are the Canterbury Plains, which, by their position, nature, and general characteristics, form a prominent feature of this island, and are already the centre of a rich, industrious, and large population. They begin at the dolerite plateau of Timaru, and stretch without interruijtion to Double Corner, iu a general direction from south-west to north-east, with a length of about 112 miles. Their breadtli from a few miles at both extremities, north and south, augments as Ave advance towards their centre, having their greatest lateral extension near Banks Peninsula, where, in a direction from east to west, they stretch a distance of nearly 50 miles to the base of the mountains. The Pacific Ocean is their boundary on the eastern side, where a long shore stretches in a line nearly from south-west to north-east — from Timaru to Double Corner — being only interrupted by the volcanic system of Banks Peninsula, which rises so conspicuously in the middle of that low shore, and to the existence of which so great a portion of the loose strata composing these plains owes its preservation from the destructive agencies of the waves and currents. The western boundary is formed by the outrunning spurs of the Southern Alps, having, as I have pointed out previously, by their disintegration, ofi'ered the material for the present configuration and other physical features of the plains. In their great bulk they consist of the accumulation of post- pliocene torrents. Having had their glacier-sources much nearer to Banks Peninsula than in present times, the latter were able to throw the boulders, shingle, sand, and ooze, carried along with them, not only in greater masses, but also on steej)er slopes than the present rivers crossing them can do, for reasons given in the geological portion. These post-pliocene deposits of large rivers have covered with an almost uniform gradient the palaeozoic, volcanic, or tertiary rocks composing here the sea-bottom " [53, p. 231]. The Canterbury Plains slope towards the sea at the rate of about 40 feet to the mile for the first fifteen or twenty miles from the mountains, and at an average of 24 feet to the mile for the remainder of the distance to the sea. This may be illustrated by the following figures taken from Sir Julius von Haast's ' Geology ' [53, p. 403], showing the fall of two of the rivers in the basins of which subterranean Crustacea have been found : — CEUSTACEA OF NEW ZEALAND. 249 Name of River. Difference between two Stations. Length of Plains. Fall of Plains per mile. Ashburtoii .... Waimakariri . . from Two Jirothers to sea mean From Two Brothers, 1500 feet, to Railway crossing. 305 feet feet. 1500 1195 255 15S0 228 827 322 33 miles. 351 25 101 44" 5 . 18| 131 feet. 421 48 29 36 41i 44 1* From Eailway crossing, 305 feet, to sea (50 feet above sea-level) From upj)er gorge to sea mean From junction of Kowhai, 1410 feet, to lagoon at gorge hill, 1 1S2 feet From lagoon, 11S2 feet, to the so-callcfl ISth- mile peg, 355 feet From 1 8th-mile peg, 355 feet, to last raised beach near North Road, 3-'> feet From last raised beach, 33 feet, to sea Some of the other rivers sliow rather more gradual falls than those quoted in the tahle ahove ; thus the River Selwyn from its entrance into the plains to its mouth at Lake Ellesmere has a total fall of 790 feet in a distance of 29 miles, or an average of 27 1 feet per mile. With regard to the origin of the plains Sir Julius von Haast says : — " All the levels, surveys, engineering works, together with Avell-sinking, have amply confirmed my views that the Canterbury Plains are of fluviatile origin, that, with the exception of some morainic accumulation in the upper portion and the drift sands round Banks Peninsula, and tlie partial laciistrine deposits filling the former extension of Lake Ellesmere, the whole of the plains were formed by huge rivers issuing from tlie frontal end of gigantic glaciers" [53, p. 396]. Consequently the Canterbury Plains consist of river shingle and sand, cemented more or less by a ferruginous matrix ; this has been proved by the sinking of wells in many directions on the Plains, some of them to con- siderable depths. In a well between the Ashburton and Rakaia, " where a supply of water was reached at a depth of 220 feet, the shingle at the bottom became much cleaner and incoherent, resembling the small shingle in the Rakaia river-bed " [53, p. 473]. All over the plains water is found at a greater or less depth below the surface, the depth varying according to the locality, the dryness of the season, the condition of neigh- bouring rivers, &c. In a great many places this water is found within about 30 feet of the surface, and can hence be brought up by suction-pumps ; in some cases, however, as in the one quoted above, water is not found until a depth of 200 feet or more is reached. These underground waters can percolate through the river-shingle of which the plains are composed with considerable freedom ; thus whenever a hole is dug to the water-bearing stratum, it is quickly filled by the water running in from the shingle all around : the various wells at Eyreton, again, are quickly aflfccted by the state of the river Eyre, which is from one to three or more miles distant from them ; thus if the water in these wells has sunk owing to drought when the river continues dry, it quickly rises again when the river is in flood. Evidently a considerable qviantity of the water of the Eyre and of other rivers flowing across the Canterbury Plains must leak away through the 250 DR. C. CHILTOJS ON THE SUBTEEEANEAN loose sand and shingle in their beds, and go to supply tlie subterranean waters. The Canterbury rivers are so rapid and so frequently in flood that they are continually washing^ away parts of their beds, and thus opening up a way for the water to escape through the loose shingle thus exposed, and there is no opportunity given for such openings to be permanently closed by the finer sediment brought down by the rivers. It frequently happens that in the bed of the river Eyre, some five or ten miles above East Eyreton, towards the source of the river, there is a considerable quantity of water, while the whole of this, except of coiu'se that lost by evaporation, sinks into the ground before Eyreton is reached, so tliat there the river-bed is quite dry. The subterranean Avatcrs, instead of being evenly spread over a whole district, often no doubt form more or less distinct streams, and probably different streams arising from diifei'ent sources may be found one below another ; thus Mr. Smith says that in the sections of the Canterbury Plains exposed at the mouths of the llangitata and Ashburton rivers, siibterraneau streams may be seen to flow out at various heights in considerable volume and force. These difl'erent streams are no doubt separated by harder and more impervious strata, and they will have different sources ; some of them will, perhaps, obtain their supply of water from the leakage that takes place at the foot of the hills owing to the break of the continuity of the strata of the plain. In his Presidential Address to Section E at the Christchurch Meeting of the Australasian Association, Mr. G. S. Griffiths [52] has given a number of facts about the subterranean waters of a part of Australia which it will be interesting to compare with what we know of those of Canterbury. Speaking of the artesian weUs which are being sunk on the back blocks from the centre of Queensland doT\Ti towards the mouth of the Murray, he says : — "The chief sources of these water-supplies must be looked for in the great eastern cordillera, which sheds the surface streams that also cross Riverina. Along its crests the rainfall is of course greatest, being from 20 in. to 10 in. per amium iu the Queensland portion ; and it is near to the long ribbon-shaped region of heaviest rainfall — that is, along the sides of the watershed — that the superficial deposits, being largely composed of gravel and rock debris, are most pervious. Further, the continuity of the strata of the plains is broken at the hill-foot, where they die out against the outcropping rocks of the main range, and this line of break affords to the water flowing down the hills a ready passage beneath the sediments of the plains. " Under these circumstances a large proportion of the rain caught on the ranges leaks under the subsoil directly it falls, and it flows to the sea slowly indeed, but with its volume undiminished either by the evaporation which lowers the surface waters of the Riverina G ft. per annum, or by the demands of vegetation, which are much greater upon river-water than the public has any idea of. " As these subterranean waters travel away from their sources they must thin out. . . . But it apjiears to me that in every district of any size there must be decider channels in that ancient land-surface which is now the bed-rock or reef of the miner " These underground watei'coiu'ses, or, as the miner would describe thein, these wet leads, will run out into the plains for greater distances than a hundred miles. Indeed, when we remember that the streams are undiminished by evaporation or the demands of CEUSTACEA OF NEW ZEALAND. 251 vegetation, and that they have been the recipients of all the leakage of the hills throughout all the ages that have passed since the sea retired, it appears to me that the deeper leads must be saturated with water right through from the mountain-foot to the Australian Bight. Eor, however slow the circulation of the system may be, as the water has never ceased to run in at the upper ends of the region, and as it does not rise to the surface as springs, it must run out at the lower end into the sea, escaping in the form of submarine springs. As a matter of fact, along the south coast of Australia, between Warrnambool and the Murray mouth, the sea literally bubbles up Avith fresh water which has leaked up through the sea-sands " [52, pp. 235, 236]. Doubtless a large portion of the deeper underground waters of the Canterbury Plains escapes into the sea in the same way by submarine springs, for in many cases they are known to be much below the sea-level. Thus the water-bearing stratum that suj)plies the ordinary artesians of Christchurch is, at the coast at New Brighton, 13G feet below the surface, and there is another stratum below at about twice that depth [03, p. 33]. Other portions of these underground waters in Canterbury rise to the surface, before reaching the sea, as springs, like those which form the source of the river Avon near Ckristchurcb. Facts like those quoted above from Mr. Griffith's address, and the Avidespread distri- bution of the subterranean genus Nipharyus in Europe, and of the closely-aUied genus Crangonyx in North America and elsewhere, remind us of what might otherwise be overlooked, viz. the universality and great extent of underground w^aters. An instructive example is given by Wallace in his ' Malay Arcliipelago ' : — "The little island of Kilwaru is a mere sandbank, just large enough to contain a small village, and situated lietween the islands of Ceram-laut and Kissa — straits about a tliii'd of a mile wdde separating it from each of them. It is surrounded by coral-reefs, and offers good anchorage in both monsoons. Though not more than fifty yards across, and not elevated more than three or four feet above the highest tides, it has wells of excellent drinking-water — a singular phenomenon, which would seem to imply deep- seated subterranean channels connecting it with other islands " [114, pp. 375-6]. Many similar facts have been brought to light in connection with the boring of artesian wells, and some of these will be found collected in Lyell's ' Principles of Geology ' [76, vol. i. p. 385 (fcc], where it is shown not only that the underground waters extend to great depths, often far below the level of the ocean, but that various distinct sheets of water may be met with, one below another, five distinct sheets having been intersected in a well at St. Ouen, in Prance [76, vol. i. ]). 3b9]. Lyell also gives some examples showing that there are often open passages by which the subterranean waters circulate. Thus, in a well at Tours, from a depth of 364 feet, there were brought up a freshwater shell, some land species, some seeds of plants and other vegetable matter, all of W'hich, it was supposed, had flowed from some valleys of Auvergne or Vivarais, distant about 150 miles, since the preceding autumn. After giving other examples of a similar kind, Lyell says, " we see evidence of the water not having been simiily filtered through porous rock, but having flowed through continuous underground channels. Such examples suggest the idea that the leaky beds of rivers are often the feeders of springs " [76, vol. i. p. 31)1]. SECOM) SERIES. — ZOOLOGY, VOL. VI. 33 252 DE. C. CHILTON ON THE SUBTEREANEAN Professor Porol, in considering the origin of the blind Niphargtis Forelii and AselUis -Fo?r^M, comes to the conclusion that they have originated, not in the lakes themselves, but in the underground waters, and he gives various interesting facts showing the commu- nication that must exist between these waters and the deep waters of the lakes [40, pp. 182-183 &c.]. The same thing is found in North America, for some of the blind cave-species, Ccecidotcea stygia for example, are obtained from wells in various districts, showing that they exist widely spread in the underground waters, and not merely in the caves themselves. It is possible that some of the species, perhaps Ccecklotcea stygia, may have originated in the underground waters, and not actually in the caves, thus forming an exact parallel to the case of Asellus Forelii in the Swiss lakes. It will not be necessary to bring forward any additional facts to show that there must be abundant opportunities by which specimens of the freshwater fauna of any country might be carried into the underground waters which almost everywhere exist, and thus have a chance of giving rise to subterranean species. In the case of the Canterbury Plains, the subterranean waters have almost everywhere sunk several feet further from the surface of the land during recent years, owins: to a succession of exceptionally dry seasons. Thus at Eyreton the level of the water has sunk on an average about 10 or 12 feet ; Miss Young tells me that it has sunk also at Winchester, and that the well there, from which subterranean Crustacea have been obtained, has had to be deepened, and it will be seen from the following interesting account, prepared by Mr. W. W. Smith, that the lowering of the water has been very marked at Ashburton : — " Previous to the years 1890 and 1891 no lowering or discoloration of the subterranean water was observed on the plains, at least there are no records of such existing. The water in the pipe-wells and in the outflowing streams at the base of the terraces of the Ashburton river, and also in the surface springs on the plains, remained constant at all seasons and perfectly pure. As the drought increased, the Avater in the pipe-wells lowered, and left tliem all, with one exception, dry. Near one house a large surface spring rose in a small gully, and discharged a heavy flow of cool pure water. It began to diminish in volume in October 1890, and by the December following it had ceased to flow. The terrace springs, situated 25 feet lower, held out several m onths longer, and they in turn gradu.ally became dry. Half a mile below Ashburton a large strong-flowing spring exists right in the river-bed ; it is distant about a quarter of a mile from the nearest terrace, and situated 12 feet below it. It flows out of a partially conglomerated bed of small stones and clay, and unquestionably belongs to a lower stratum or stream of water than those supplying the pipe-wells in tlie town. The water in this spring is never affected in volume or colour by the flooding of the river, but retains its purity at all seasons. The nearest terrace is 12 feet above it, and is composed chiefly of clay. It is only a few feet above the stratum of water which supplies the wells in the town. Before the drought several springs arose at the base of the terrace, none of which, nor any of the surface-springs, have at present recommenced to flow. " I may mention that Mr. W. P. Dolman, a practical well-sinker in business here, informed me that there is no question about the water flowing between the various strata CEUSTACEA OF NEW ZEALAND. 253 or irregular beds of shingle and sand composing tlie plains, at least in the Asliburtoa district. Some of the beds are intensely hard and extremely difficult to pierce with the steel-pointed pipes. After the lowering of the water, Mr. Dolman ascertained when driving the pipes to unusual depths that the pipe frequently entered ' dry-beds,' and he had either to draw up or lower the pipe to tap the water. The deepest well he has driven is 65 feet, and it has continued to give a good flow ever since it was driven. Mr. Dolman states that there is no limit, so far as he knows, to the depth the vrater is found in the plains, although it flows in thinner or shallower streams the lower he sinks. Eeferring to the discoloration of some streams, he informed me that he has found small round particles of clay in the water, and he attributes its discoloration to these floating particles. When sinking open w'ells, Mr. Dolman has occasionally observed the direction and rate at which the subterranean water flows. He estimates its motion at from one- quarter to one-half a mile an hour. One important fact he has several times ascertained, when driving the pipes through the lower and harder beds, is the rising of the w^ater in the pipe to variovis heights from the newly-taj^ped stream. He has known it to rise from 2 fett to 14 feet, and afterwards to remain permanent. There is considerable difference in the work of sinking the various wells — some are put dow^n in a few hours, the pipes driving freely, and others require as many days, and this sometimes with a heavier 'monkey ' at work. These facts can be better studied by an examination of the high sections of the plains at the mouths of the Kangitata and the Ashburton Elvers. " The exceptional well I have mentioned, which did not become dry, is driven 27 feet, and is in a low-lying part of the town. Nearly all the pipe-wells originally driven were sunk to various depths, ranging from 15 feet to 22 feet. These, without any exception, became di"y." VII. Origin of the Subtekranean Crustacea. In considering the source from which the subterranean Crustacea have been derived, it will be well to state first what little is known of the freshwater forms of the Amphipoda and Isopoda found in New Zealand and Austraha. In New Zealand only one freshwater Isopod is known, Idotea lacustris, G. M. Thomson [21, p. 263], and this one has no connection whatever with the subterranean fauna. In Australia, however, a species of Fhreutoicm is known, P. mistralis [26], as yet found only on the top of Mt. Kosciusko, about 6000 feet above the sea. In the Amphipoda we have two freshwater species recorded from New Zealand. One, Callioinus fluviatiUs, is very common in almost all running streams of the South Island ; but is also found in various places in Otago Harbour, in water that is quite salt. This species is very abun- dant in the surface-streams of the Canterbury Plains, in the localities wdiere the subter- ranean forms also abound ; but, as I have already pointed out, although it approaches Calliopius subterraneus, it is dissimilar in several respects, and it does not seem at all likely that C. subterraneus is directly descended from it. The other species is Pherusa ccerulea, G. M. Thomson [107, p. 206], found by Mr. Thomson on the top of the Old Man Range, 3000 feet, in Otago, and as yet known from this locality only. I have compared this S2)ecies in some detail with Calliojnus subterraneus (see above, p. 235), and have 33* 254 DE. C. CHILTON ON THE SUBTEERANEAN shown that in many points the resemhlance is very great, and that most prohably Pherusa ccernlea and Calliopms suhterraneus are both descended from a species formerly A\ddely sj)read in New Zealand. This is all that is as yet knoAvn of the freshwater Amphipoda and Isopoda ; but it must be remembered that our knowledge of the subject is very imperfect, and that careful search of other streams, especially in the mountainous parts, will probably reveal other forms. As an example, I may mention that until lately Idotea lacustris was known only from the Tomahawk Lagoon near Dunedin, a lagoon situated very close to the sea ; I have, however, since collected a variety of the same species in great abundance in the streams, up to a height of about 1000 feet, around Mt. Mihiwaka, between Port Chalmers and Blueskin, as well as in streams some five or six miles distant, and on the other side of the Waitati valley [21, p. 263]. In the same situations I have also taken another Ampliipod, at present undescribed ; this, however, appears to belong to the genus Mycdella, and throws no light on the origin of any of the subterranean forms. No freshwater Amphipoda have been described from Australia, but in January 1892 Mr. Thomson collected two species on Mt. Wellington, near Hobart, Tasmania, and examples of both species have since been kindly supplied to me by Mr. Alex. Morton, of the Tasmanian Museum. They are being examined by Mr. Thomson and have not yet been fully worked out. One is a rather large species, and seems to belong to NipJmrgus in its general structure and in the uropoda, though the terminal uropoda are not very long. The other species, which is smaller, and comes from the top of Mt. Wellington, about 4000 feet high, also seems to aj)proach very closely to Niphargus, though very different from the preceding species in general appearance ; it closely resembles that species in the antennse, the mouth-parts, and the gnathopoda, which are subequal, and have the propodos subquadrate, as in most species of Niphargus ; the telson also is deeplj cleft, not double, and bears stout spines on the hinder margin of each lobe, as in Niphargus ; the body, however, is not slender, but rather compact, and the third uropods, though consisting of a very small inner branch and a longer two-jointed outer branch, are not elongated, and the second joint of the outer branch is very small, so that in these respects the animal resembles Crangonyx rather than Niphargus. It is, however, very different from Crangonyx compactus in the gnathopoda, the side-plates, the base of the perseopoda and the pleopoda, and of course also in the telson. However, the species presents a nearer approach to both Niphargus and Crangonyx than any form at present found in the surface-streams of Europe, and it is interesting, because it shows the wide distribution of forms similar to those from which Niphargus and Crangonyx must have been derived *. The question of the origin of the subterranean Crustacea has from the first given rise to much discussion and to the most diverse opinions. Unfortunately, too, the question has been obscured by some of the conclusions being based on insufficient facts, and by some of the facts themselves being at first incorrectly stated, as, for example, the affinities of CcBcidotcea. The explanation that most readily offers itself is that the subterranean Crustacea are * This species Mr. Thomson has named NijiJiai-gus montanus, sp. nov. ; the one previously mentioned he calls Nipliargus Morioni, sp. nov., though he tells me he does not feel satisfied about placing it in the genus Nipharr/ics. CRUSTACEA OF NEW ZEALAND. 255 direct descendants from those now living in fresh waters on the surface of the earth. This view has hcen strongly upheld hy some — by Fries, among others — and appeared to receive some support from the fact that specimens of Gammarus fossa rum, kept in darkness during the winter, lost to some extent the pigment of the eyes, thus showing some approach to the blind Niphargl. I shall refer to this again later on. Others, again, confining their attention more particularly to the special affinities of one or two genera of the subterranean Crustacea, have pointed out that, in place of being- allied to freshwater forms, they more closely resemble marine forms, some of which are inhabitants of deep water. Thus Spence Bate states that Niphargus resembles the marine Eriopis much more than the freshwater Gammarus [i, p. 311], and that Crau- gonyx appears to have its nearest ally in the marine Gammarella [4, p. 326]. This resemblance of the subterranean forms to members of the marine fauna appeared at first to receive some confirmation from the unfortunate name Ccecklotcea [81] given to the blind Isopods from the North-American caves, and from the mistaken ideas as to its affinities ; and, misled by this and by the very impei-fect kno\^'- ledge of the freshwater Crustacea of New Zealand, I have also stated that the subter- ranean Crustacea of New Zealand appeared to have been derived from a marine source [23, p. 88]. No doubt the subterranean Crustacea, as well as the freshwater forms, have originally sprung from forms inhabiting the sea, but from the fuller array of facts now before us there can be no doubt that they have not been derived directly from these, but from a freshwater fauna. Niphargus and Crangonyx may, perhaps, show affinities to marine forms, and there certainly does not appear to be any closely-allied form now inhabiting the surface fresh waters of Europe ; but in North America various species of Crangonyx are found in surface-streams, &c., and the fact that a closely-allied form is found in the fresh waters of Tasmania seems to show that the genus has probably been at one time widely spread in the freshwaters of the globe. Ccpcidotcea is really a very close ally of the freshwater Asellus, species of which are found in the streams of both Europe and North America, Avith representative subterranean forms in both places. Professor S. I. Smith, in view of the fact that the Crustaceans have several times been referred to as indicating the partially marine origin of the cave-fauna of the Western States of North America, has considered their affinities in detail, and points out that, looking at the Crustaceans alone, there is " no reason for supposing that the fauna of the caves of Kentucky and Indiana has been derived from any other source than the recent fauna of the surface of the neighbouring region" [104]. The fuller knowledge that we now possess forces us to a somewhat similar conclusion with regard to the subterranean fauna of New Zealand, though here our knowledge is not so complcite. The New- Zealand forms at present known are six in number — Gammarus fragilis, Crangonyx compactus, CalUop'ms suhterraneus, Cruregens fontanus, Phreatoicus typicus, and Ph7-eatoicus assimllis ; and if we consider in turn the freshwater allies of tliese, we find the following facts : — No freshwater species of Gammarzis is known from New Zealand or Australia as yet, l)ut the genus is one very widely distributed and has freshwater species in other parts of the world ; Crangonyx, as has been already pointed out, appears to be exclusively confined to fresh water, species are known either from surface-streams 25(5 DE. C. CHILTON ON THE SUBTEEEANEAN or from caves and wells in England {C.subterraneus), Italy {C. imngens). North America {C. gracilis, C. viireus, &c.), Kamtschatka {C. Evmanni), New Zealand (C. compactus), and a form more or less closely allied still inhabits the fresh waters of Tasmania ; Callioplus subterraneus appears to have its nearest ally in Pherusa ccsrulea, found in a stream ou the top of mountains 3000 feet high in Otago, New Zealand, while another species {CalUopius fluviatilis), which perhaps belongs to the same genus, is very abundant in the freshwater streams of the South Island of New Zealand ; no freshwater form at all approaching Cruregens is as yet known ; besides the two subterranean species, the only other known ^T^eciQs, oi Phreatoicus is found on the top of the Mt. Kosciusko Plateau in Australia, living in pools and streams. It will thus be seen that there is no difficulty in supposing that the subterranean fauna of New Zealand has been derived directly from a freshwater fauna, and when we consider the affinities of the general fauna of the North-American caves as given by Packard [83], or of the various Euroi^ean caves, there can no longer be any doubt that the cave- and well-fauna has been derived from the surface-fauna of the neiohbourhood. While this conclusion thus appears to be well founded, it by no means foUows that the subterranean fauna is necessarily derived from the freshwater fauna at present inhabiting the surface-streams and lakes ; indeed there are several facts which seem to show that some species at any rate are derived from a more ancient surface-fauna. Thus, while the subterranean species Asellus cavaticus may perhaps be the direct descendant of the surface-species A. aquaticus, there is no doubt that Niphargus is not a mere modified form of any of the surface-inhabiting Gammari at present found in Europe. Wrze^niowski has clearly pointed out that experiments like those made by Eries and observations on pale forms of Gammarus found in mines, &c., like the one described by Schneider, do not bear on the question, for the specimens approach Niphargus only in the pale body and in the partial loss of the eyes while still retaining the general build and characteristic mouth-parts, &c., of Gammarus. As to the actual origin of Gammarus and Niphargus we are, he says, quite in the dark ; but he is of opinion that neither is derived from the other, but both from a common ancestor. Humbert had previously come to much the same conclusion and is of opinion that Nlpjhargus is an ancient genus derived from a form now extinct. The Crayfish inhabiting the caves of North America also appear to be more ancient than those at pi'esent found in the surface-water of the neighbourhood. Speaking of Cambarus pelluciihis. Professor Eaxon says it " is a very aberrant species, with no very closely related form outside the cave. The simple form of the male appendages, and the combination of characters belonging to different groups, seen in C. pellucidtis, indicate, to my mind, that it is a very ancient form, which has been preserved in the seclusion of the cave, whilst its nearest kin supcumbed in the sharper struggle incident to life outside, or were replaced by modified descendants evolved to meet the changeable con- ditions which obtain witliout the caverns " [37, p. •^"1]. This view is, he says, confirmed by the fact that the same form, C. pellucidus, is found in caves on both sides of that ancient river, the Ohio, and by the discovery by Gustav Joseph of a species of Cambarus in the caves of Carniola in Southern Austria. As the CEUSTACEA OF NEW ZEALAND. 257 present Crayfish of Europe belong to a different genus, Astucus, Professor Faxon looks upon the existence of a Cambarus in the Carniolan eaves (if the species really belongs to that genus) as evidence of the former existence of the genus Cambarus in the rivers of Europe [37, p. 42]. In connection witli the latter point it is as well to mention that Packard has stated that Joseph's species, Cambarus sf/jgius, is based only on a single di'y specimen from one cave and remains of the forceps of another specimen from another cave, and that " it seems premature to draw conclusions from such limited facts " [83, p. 119, footnote]. Passing on to the NcAv-Zealand forms we find that although six species are known from the underground waters of the Canterbury Plains, only one, Calliopius ■fluviatills, G. M. Thomson, is found in the surface-waters of the neighbourhood, and that this species, though allied to some extent to Calliopius subterraueus, is dissimilar in several points, and certainly not so close to it as is Thernsa ccerulea*. It would there- fore seem that the subterranean forms are more ancient than the present surface-fauna of the Canterbury Plains ; and this is confirmed by the fact that their nearest allies are found in remote situations. Thus Fherusa ccerulea, the nearest ally of Calliopius sub- terraneus, is known only from one situation on the top of a mountain between 200 and 300 miles distant ; no allies of Gammarus fragilis nor of Cruregens fontanus are known from the fresh waters of the southern hemispliere ; Crangonyx compaetus has its nearest allies in Europe and North America; while Phreatoicus, Avhich is proved to be an ancient form by the possession of characters common to several ftimilies, appears to have been preserved only in the subterranean waters of New Zealand and on the top of Mt. Kosciusko in Australia. Although it is thus probably true that some species of the subterranean fauna are ancient forms that have long since taken up their abode in the vmderground waters, we should naturally expect to find others, especially in the fauna of caves, that have much more lately adopted a cave life and are the direct descendants of surface-species still in- habiting the neighbourhood. Such specimens we undoubtedly do find, and they appear also to show several stages or transitions from surface-forms accidentally carried into the caves up to true cave-inhabiting forms. Thus in the caves of America among others the surface-forms Cambarus Bartonil [83, p. 40] and Asellns communis [83, p. 33] have been found, the specimens of these being more or less bleached and much jialer in colour than the ordinary surface-forms ; again, the cave Myriopod Pseudotremia cavernarum is, Packard says, only a modified form of the widely diffused Lysiopetalmn lactarium, Say, and various other examples of the same kind are also to be found in Packard's work. In the same way Schneider has described a subterranean variety of Gammarus pulex, found in mines at Clausthal, which diff'ers from the normal forms of that genus in its pale colour, the partial degeneration of the eye, and the lengthening of the anterior antennae [96]. Mouiez also has found in the reservoir at Emmerin in the north of France a single specimen of a Gammarus which has been modified in much the same way as the * I have already pointed out, p. 234, that CalUophis sahterranem should 'perhaps be transferred to Pherusa, but that for the present I have left it in the genus in which it was originally placed, as the limits of these two and other allied genera appear to me to need fre^li and careful definition. 258 DE. C. CHILTON ON THE SUBTEKEANEAN variety described by Sckneider, forming to some extent a link between this variety and the surface-type, though approaching again towards Gammarus fluviatiUs, while Schneider's variety seems to come from Gaiimiarus pulex [78, p. 40]. These examples are sufficient to make it clear that the subterranean fauna of any country is not always to he looked upon as a whole, but that the different species have in many cases adopted the subter- ranean life at different times, and that under favourable cii-cumstances the subterranean forms may even at the present time be reinforced by immigrants from the surface. It is, however, obvious that transitional forms of the kind spoken of above will be much more common in caves than in underground waters, for the means of entrance will usually be greater, and immigrants from the surface will have to struggle with the forms that have already become adapted to a subterranean life, and will hence find it difficult to establish themselves unless they should happen to be carried into regions not already ])eopled. This is probably the reason why the subterranean Amphipod fauna of Europe is so fixed in character and uniform as it is, and why the subterranean species sometimes belong to such ancient forms. In the case of the New-Zealand forms it is rather rash to speculate, but, considering the similarity of conditions all over the Canterbury Plains and the fact that aU the known species, with the exception of Phreatoicus assimtUs, are found together in the same stratum of water at Eyreton, it seems probable that all the forms adopted the sub- terranean life at about the same time, and that they are not now being reinforced by fi*esh immigrants from the surface. This is not for want of opportunities (for I have shown above, on p. 249 et seq., that there are doubtless many ways by which the surface- forms can gain access to the underground waters), but because the surface-fauna from which the subterranean forms were derived no longer exists in its entirety. If it stiU exists at all it will doubtless be found preserved in mountainous situations in the same way as Pherusa ccsrulea and Phreatoicus cmstralis. The deep-water fauna of the sea and especially of freshwater lakes presents many resemblances to the subterranean fauna. The deep-water fauna of the Swiss Lakes, as described by Professor E(3rel [40], is particularly interesting in this connection, as it contains two species at least which also belong to the subterranean fauna, viz. Niphargus Forelii (= N. putemius, Koch, var. Forelii, Humbert) and Aselhis Forelii, Blanc. In considering the origin of this deep-water fauna Professor Porel comes to the conclusion that the greater part of it is derived from the littoral fauna of the lakes themselves, the animals having descended to greater or less depths, and having become more or less modified accordingly, and he also points out that every year new immigrants come to renew the deep-water fauna, just as ^ve saw probably happens with the cave-fauna. With regard to the two species mentioned above, however, the case is difi'ereut, and after a very long and full discussion of the whole problem [40, pp. 170-183] he decides that these come, not from the littoral fauna, but from the subterranean fauna that is so wide- spread throughout Europe. This confirms the conclusion of Humbert, WrzesnioAVski, and others, that Niphargus is not the direct descendant of Gammarus pulex of the surface. The latter species is found in the littoral fauna of the lakes and sometimes extends to deep water; but though it may Jbe somewhat modified as regards colour, eyes, &c., CEUSTACEA OF NEW ZEALAND. 259 it still preserves the distinguisliing marks of Gammarus and shows no approach in structure to ]Sij)liargtis. Professor Forel points out that there mvist be means of com- munication— not necessarily permanent — between the subterranean waters and the deep waters of the lakes and also between the subterranean waters of different localities, thus fully confirming what I had already -wTitten above pn p. 258 before I had read Professor Porel's remarks on the subject. VIII. The Special Characteristics of the Subterranean Fauna. The special conditions of cave- and well-life and the peculiarities of the subterranean fauna have been discussed more or less elaborately by many authors, and a complete dissertation on the subject would require a volume to itself. All that can be done here is to mention a few j)oints upon which information is supplied by the six subterranean Crustacea described in this paper. The subject has been fully discussed by Schiodte, Joseph, and Packard; and Forel has considered the conditions of life in the deep waters of the Swiss Lakes, the fauna of which presents many analogies to that of the under- ground waters. Colour. The effect of the absence of light on the colour of all animals living in caves and in underground waters seems to be very uniform, all such permanent residents being bleached and colourless. Speaking of the inhabitants of caves, Packard says : — " As regards change of colour, we do not recall an exception to the general law, that all cave-animals are either colourless or nearly white, or, as in the case of Arachnida and insects, much paler than their out-of-door relatives " [83, p. 117]. The same statement might be made concerning the inhabitants of underground waters, different authors speaking of them as " colourless," "snow-white," " translucent," &c. The Crustacea are usually more or less translucent, vitreous, and pellucid, though by no means so much so as pelagic members of the same group. The six species dealt with in this paper may be described as white or colourless, more or less translucent. I have sometimes noticed a slight pink or rosy tint on the body of CaUlopins subterraneus, which is most apparent in female specimens bearing eggs, and then appears to arise chiefly from the yolk of the eggs themselves ; the " liver "-tubes of Cruregens fonkmus, which can easily be seen through the transparent integument, are of a very pale yellow colour, and the tip of the dactylos of the first pair of appendages of the peraeou (gnathopoda) is of a very distinct but light bro^\Ti. The subterninean worm Phreodrilus subterraneus, Beddard, is stated by Mr. Smith (quoted by Beddard [8, \}. 273]) to be " fleshy red " during life. This is chiefly due to the red colour of the fluid in the various vessels of the vascular system, the integument and the greater part of the body being colourless ; this was plainly seen in a very fine specimen that Mr. Smith kindly sent alive to me in September 1892. Professor S. I. Smith has pointed out that the deep-sea Crustacea present a marked contrast to cave Crustacea in colour. In a general account of the Crustacea of the SECOND series. — ZOOLOGY, VOL. VI. 31 260 DE. C. CHILTON ON THE SUBTEREANEAN ' Albatross ' dredgings in 1883 [105] lie points out that the colour of these deep-sea forms is very striking. A few are nearly colourless, hut the majority are some shade of red or orange. A few species (100 to 300 fathoms) are conspicuously marked with scarlet or vermilion, but such markings were not noticed in any species from below 1000 fathoms. Below this, orange-red of varying intensity is apparently the most common colour. He also shows that some of the species ranging down to 2000 fathoms possess eyes, some of them as well developed as in corresponding shallow-water forms. Summing up these facts he says : — " However strong may be the arguments of the physicists against the possibility of light penetrating the depths from which these animals come, the colour and the structure of their eyes, as compared with blind cave-dwelling species, show conclusively that the darkness beneath 2000 fathoms of water is very different from that of ordinary caverns. While it may be possible that this modification of the darkness of the ocean abysses is due to phosphorescence of the animals themselves, it does not seem probable that it is ■wholly due to this cause " [105, p. 56]. I wished to test this conclusion by studying the colour of animals found in the deep waters of lakes, such as tliose of Switzerland, but, unfortunately, the facts that I find ready to hand are not very conclusive either way. In considering the modifications undergone by the deep-water species, Forel says under the head " Pigmentation " : — " La couleur est generalement plus claire dans les especes littorales " [40, p. 167]. He also states that Du Plessis has noticed a rosy colour in some Turbellarians from the deep waters, which is not found in those of the littoral region. There does not, however, appear to be a prevailing red or orange tint at all comparable to that which has been noticed by Smith in deep-water marine Crustacea, or special attention would have been drawn to it by Porel ; but, again, the species of Crustacea found in the deep waters of the Swiss Lakes are very few in number compared with those in the deep waters of the sea, and there are none of the larger forms like those examined by Smith, so that there is scarcely a sufficient basis for a comparison of any value. Porel describes Niphargus Forelii as " blanchatre avec des teintes rosees," and Asellus Forelii as " d'un blanc grisatre, sale" [40, pp. 112, 113]. On the whole, however, the colour of the animals in the deep waters of the Swiss Lakes appears to resemble that of the animals in caves and underground waters rather than that of the inhabitants of the deep waters of the ocean ; and this would incline us to imagine that the difference in colour between the two last-mentioned is due to some differences of chemical composition rather than to the presence or absence of light. Loss of Eyes. In all animals inhabiting caves and underground waters the eyes appear to undergo more or less degeneration. Schneider has described the commencement of such degeneration in Gammarus pulex, var. suhterraneus [96], and in Asellus aquaticus, var. freihergensis [97], and Moniez in Gammarus fluviatilis, var. d'Emmerin [78, p. 39]. Packard, who has considered the subject very fully in connection with the inhabitants CEUSTACEA OF NEW ZEALAND. 261 of the North-American ca\ es, in which all stages of degeneration are met with, thus sums up the effects of the loss of sight on the eyes and optic lohes : — "1. Total atrophy of optic lobes and optic nerves, with or without the persistence in part of the pigment or retina and the crystalline lens {Ccecidotcea, Cmngonyx, Chthonius, Adelops, Pseudotremia). " 2. Persistence of the optic lohes and optic nerves, but total atrophy of the rods and cones, retina (pigment), and facets {Ovonectes). "3. Total atrophy of the optic lobes, optic nerves, and all the optic elements, including rods and cones, retina (pigment), and facets {Anophthalmus, Scoterpes, and ? AntJirobia) " [83, p. 118]. He also points out that Ave never find any rudiments of the optic lobes and optic nerves ; if they are wanting at all they are totally abolished ; while, " on the other hand, we have series, as in CcBcldolcea or Chthonius, where there is but a single, or two or three, or several crystalline lenses, partially enveloped in pigment " [83, p. 118]. He lays stress on these facts as opposed to what he calls the " invariably slow action involved in pure Darwinism." Many conflicting statements have been made by different authors as to the presence or absence of the eyes of the European species Niphargiis puteanus, and in consequence it was fully investigated by Leydig, who found " that the optic ganglion is present, but not the eye, though j)igment-spots mimicking the eye have led some observers to believe that an eye existed in fact " [quoted from Stebbing, 108, p. 481]. While this may no doubt be quite true of the specimens observed by Leydig, it appears from Packard's results that the external eye may be represented in varying degrees of completeness in different specimens of the same sj)L'cies ; and that being so, there is no ground for refusing to believe that it may be altogether absent in some, though present (more or less imperfectly) in others. Porel, too, has pointed out that the blindness of Asellus Forelii, Blanc, is not without exception ; two specimens taken near Merges and Ouchy, at depths of 200 m. and 300 m., presented rudiments of eyes, whilst all other specimens taken up to that time — even young taken from the brood-pouch of the female — were absolutely devoid of eyes [40, p. 114]. We can hardly suppose that Forel was deceived by mimicking pigment-spots in these two specimens only. In the New Zealand subterranean Crustacea I have not been able to find any external trace of eyes except in the one species Crangonyx compactus, in which the eye is repre- sented by two or three imperfect lenses apparently quite v/ithout pigment. In all the other species all trace of external eyes appears to be wanting. I regret that as yet I have had no opportunity of making sections to study the condition of the optic lobes and nerves. Compensation for Loss of Eyesight. Several authors have pointed out that in many species inhabiting the dark regions of caves or underground waters the loss of eyesight has been more or less compensated for by increased powers in the other senses — especially those of touch and smeU. Many of the species are more slender and possess longer antennae, legs, and other appendages 34* 262 DR- C. CHILTON ON THE SUBTERRANEAN than their surface-dwelling allies. In some cases the increased length of the antennae, &c., would no doubt give greater tactile power ; but it also appears probable that, in the case of species living in underground waters, the greater slenderness of the body has been acquired in order to adapt the animal for its life in the restricted spaces betw een the stones and shingle in which it has to live. This explanation is strongly suggested by a comparison of the two subterranean species of Phreatoicm with the surface-species P. australis. The whole subject of the compensation for the loss of eyesight has been fully discussed by Packard [83, pp. 123-130], who has supplemented the anatomical descrip- tions with an account of what is known of the habits of some of the species. To this account I must refer the reader, and I shall only add here the few facts bearing on the same question that I have observed in the New-Zealand specie s. In the two species of Phreatoiciis, P. typicus and P. assimUis, the body is more slender and the antennae and legs longer, especially in P. typicus, than in the surface-species P. ausiralis, but I have not observed any marked increase in the number or size of the olfactory rods, nor have I observed any other sensory setae like those found in some of the other species. In Cruregens fontanus the antennae are well supplied with olfactory rods, which appear to be more numerous and of greater length than in allied eyed species ; besides these, other sensory setae, like the " soies auditives" described by Sars, are found in considerable abundance on the antennae, the various joints of the legs, and the urojioda. Similar setae are found in the same places in eyed species of AntJiura, Paranthura, &c., and Sars has figured them also in Asellus aquaticus, but they are rather more numerous and are longer in Cruregens than in the other species . In Crangonyx compacfns I have not noticed any increase in the number of sensory setae beyond what we usually find in similar Amphipods ; in this species, too, the body is compact and not elongated as in some other species, and the legs are only of the usual length. In Gammarus fragilis the body is slender, and the antennae, peraeopoda, and terminal uropoda are much elongated. On the peraeopoda, the last three pairs of which are of great length, setae somewhat like the " soies auditives " occur in most of the tufts of setae fovmd on the various joints, but with this exception there does not appear to be any increase of sensory setae beyond what we usually find in species of Gammarus. In Calliopms suhterraneus the body is rather more slender and the various limbs rather more elongated than in the closely allied species Plierusa ccerulea. Numerous " soies auditives " are found at various places on the antennae, which, in the male, are also abundantly suj)plied with " calceoli," which are no doubt also sensory in function. These, however, are also found in Plierusa cmrulea and in CalUoplus JiiwiatiUs, and in some species described by Stebbing, such as Eusiroicles Ccesaris, &c., the calceoli are quite as numerous as in Calliopius suhterraneus. On the whole the New-Zealand subterranean Crustacea give only a modified support to the conclusion that subterranean species are more abundantly supplied with sense- organs (other than eyes) than allied surface-animals. Probably the former have been CRUSTACEA OF NEW ZEALAND. 263 more carefully examined than the majority of surface or marine species, and a fuller ^examination of the latter will perhaps show that many of them are as well supplied with sensory setse as the suhterranean sjiecies. The Food of Suhterranean Animals. The source of the food-supply for the animals living in caves and underground waters is a question of much interest and of considerable difl&culty. Almost all writers on the subject speak of the food-supply being very scanty, and yet the animals, though of course few in numbers compared with those living on the surface of the earth, are yet numerous, and when captvired do not look particularly ill-fed. According to Packard [83, p. 2i] the blind fish of the caves of North America probably live on the blind crayfish and the Crangonyx, and perhaps the Ccecidotcea, and the crayfish also lives on CiBcklotcea ; so that, confining our attention to the Crustacea, the question is narrowed down to the food of Crangonyx and Ccecidotcea, viz. animals similar to those found in undergroimd waters of the Canterbury Plains. As Packax'd points out : — " It goes without saying that there are no truly vegetable-eating animals living permanently in the caves ; no plant-life exists (except in rare cases a very few fungi, and most of these probably carried in by man) in the caves on account of the total darkness " [83, p. 25]. Crangonyx and Ccecidotcea are hence probably mainly carnivorous, but what they find to eat is a great puzzle. Packard suggests that they may devour their own young ; but what the young find to live on he considers still more difficult to conjecture, as rotifers, infusoria, and copepods are so very scarce. Cope, writing of the fauna of the "Wyandotte Cave [30, p. 13], states : — " As to the small Crustaceans, little food is necessary to support theii' small economy, but even that little might be thought to be wanting, as we observe the clearness and limpidity of the water in which they dwell. Nevertheless, the fact that some cave-waters communicate with outside streams is a sufficient indication of the presence of vegetable life and vegetable debris in variable quantities at different times. Minute freshwater alga3 no doubt occur there, the spores being brought in by external communication, while remains of larger forms, as confervse &c., would occur plentifully after floods." Still the supply imported in this way must be very scanty, and as an illustration of the general poverty of the food-supply in the caves Packard mentions that in the Wyandotte Cave the common Myriopod was found gathered around the hardened drops of tallow which strew the pathways of the cave *. Concerning the food of the Niplwrgus found in the Avell at Ringwood, Hogan, quoted by Stebbing [108, p. 316], remarks : — " Some water drawn from the pump at Ringwood has been proved by microscopical examination to contain numerous animalcules; and this will probably turn out to be the case with all the waters in which Niphargi are found." The facts bearing on this subject that I have observed in connection with the New- * "The Cave-Beetles of Kentucky," American Naturalist, x. (1876) p. 285. 264 DB. C. CHILTON ON THE SUBTEEEANEAN Zealand subterranean forms do not, I am afraid, help much toward a solution. The \\ater in which they are found is very clear and pure, with very little sediment, and in almost all cases is used for drinking without being filtered. Some years ago Mr. George Gray, of the School of Agriculture, Lincoln, was kind enough to analyse some of the water from the Eyreton pump for me, and he found that the amount of organic matter in it Avas considerably below that allowed for a healthy drinking-water. Mr. Mayne, speaking of the Ashburton water, informs me that " it stands the permanganate of potash test." There appear to be very few Infusoria or Rotifera in it ; certainly it could not be said to contain " numerous animalcules," as stated by Hogan of the water at Ringwood. The intestinal canal of the various species is frequently full of a dark blackish or brownish material, but though I have frequently examined this I have not found any- thing in it that I could recognize except grains of sand and earth. I have frequently kept specimens of some of the species in small freshwater aquaria, and in this have seen them apparently eating small filamentous algae. In April, 1890, I put three specimens of Crurecjens fontanms into a small bottle containing water taken from the Brighton Creek, near the sea ; the water in this creek is often brackish, and has Rnppia mm^itima &c. growing in it, but at the time when I filled my bottle the water was quite fresh to the taste. In the bottle I had a small piece of Ruppia maritima growing, also various filamentous algae, and no doubt plenty of Infusoria &c. In this the three specimens of Cruregens lived till the beginning of June, when one was lost sight of, a second one died at the beginning of August, and the third about the end of that month, having thus lived for about five months. During this time I frequently saw them seize pieces of the algse with their gnathopoda, but I could never make quite certain whether they ate them or not. The mouth of Cruregens, like that of the other Antburidae, appears to be suctorial, but I can form no idea as to what the tinderground Cruregens sucks, unless it merely sucks up a great quantity of water, retaining any organic materials that it may contain ; the maxillae form lancet-organs, but I have never seen the animals using them for piercing the stems of the Rnppia maritima or for any similar purpose. So far as I am aware, we are equally ignorant of the use that the marine Antburidae make of their suctorial apparatus : from the structure of their mouths we should almost expect them to suck nutritive fluids from the bodies of other animals ; but I have never heard of them doing this, and if they did we might reasonably expect some species at least to have permanently adopted a parasitic manner of life ; the only parasitic species, however, known to me is Eisothistos vermi- fonnis, Haswell [54, p. 1], which lives in the tubes of Serpulae ( Vermilia). Haswell says nothing about the structure of its mouth, and it is uncertain whether it actually derives its nourishment from the Vetvnilia or not. The other species are usually taken creeping freely on the surface of various sea-weeds, but whether they live upon these sea-weed& or not does not appear to be known. Summing up, we are forced to admit that very little is as yet known as to the source of the food-supply of the subterranean Crustacea, and further observations on this point are very desirable. It must also be remembered that these animals may live for a long CBU8TACEA OF NEW ZEALAND, 205 i time with very little food ; thus Dr. John Stoan states that a blind fish (Ambli/oj]s/s spelcBus) lived for twenty months " without having taken any visible food " (see Packard [83, p. 127]). Arrested Development. The fauna of caves and underground regions presents us with several examples of what appears to be an arrest of development. Packard has drawn attention to one example. Writing of the cave-dwelling Myriopod Pseudotremia cavernarum, and comparing it with the widely diffused Li/siopetalum lactarium, Say, he remarks : — " It differs in having only about half as many segments as in its out-of-door parent form (this diminution in the number of segments being due to arrest of development) . . ." [83, p. 120]. In our New-Zealand forms we have a good example of the same thing in Cruregens fontanus, which has the seventh segment of the peraeon small and without appendages, as is the case in the young forms of many Isopods. It seems tolerably clear that we have here simply a case of arrested growth, and not a reversion to a true ancestral form, for while in the process of development of the embryo of the Isopoda the seventh pair of the appendages of the perseon are the last to be developed, I am not aware of any reason for supposing that the ancestors of the Isopoda ever j^ossessed only six pairs of appendages to the perseon. In remarking on this example, Alois Humbert quotes other cases observed by Heller. He states (Archives des Sciences naturelles, viii. [Sept. 1882] p. 267) :— " Nous rapj)ellerons a ce sujet que le Dr. Camil Heller a d^crit un genre cavernieole de Glomeride (Trachysplicera), se distinguant des Glomerls en ce qu'il ne possede que 11 segments au lieu de 12, et 15 paires de pattes au lieu de 17 ; le menie auteur a fait connaitre un autre Myriapode [Brachi/desmus) provenant, comme le precedent, des grottes de la Carniole et ne differant des Polydesmus que parce qu'il n'a que 19 segments au lieu de 20, nombre normal cliez les Polydesmides adultes. Si les TrachyspJuera Schmidt'd et Brachydesnms subterraneus ont 6te etablis d'apres des individus reellement adultes, ce qvie nous avons certaines raisons de croire, il y aurait chez ces deux Myriapodes un arret de developpement tout-a-fait semblable a celui que M. Cliilton vient d'observer aux antipodes chez son Crustace souterrain." M. Humbert attributes this ai'rest of development in cave-animals to the influence of darkness, the lack of sufficient food, and the other necessary conditions of their environ- ment. I have given above merely the examples of arrested development that are known to me ; probably a full examination of the literature of the subject would show that many others have been recorded. Habits. In their habits in confinement the subterranean Crustacea seem to differ ])ut little from their surface allies. Observations on their habits have been made by Hogan [59 and 60], Stebbing [108], Packard [83, pp. 123-130, &c.], and others. According to Hogan, 266 DR. C. CHILTON ON THE SUBTERRANEAN quoted by Sjience Bate [1, i. p. 321], Nipliargus fontanus " soon dies if exposed to the light." This is certainly not my experience with the New-Zealand forms : I have kept all the species, except Phreatoicus, for longer or shorter periods in glass bottles, in which they could get no shelter, exposed to the full light of day ; and if the water was properly aerated, they appeared to live without inconvenience. As stated above, species of Cruregens fontanus have thus lived for five months. In the same bottle I afterwards kept a specimen of Gammarus fragilis, wliich appeared quite at home, but then un- fortunately died during an unsuccessful attempt to moult its exoskeleton. It had no shelter from the ordinary light of day, and made no attemj)t to hide itself ; if placed so that the strong light of a lamp was focussed on to it by the convex surface of the bottle it, however, moved away. I did not notice anything peculiar in its habits ; it usually crawled around at the bottom of the jar or along the stems of the plants in the bottle, but at times swam freely like ordinary Amphipods. There is very little more to record concerning the habits of the Cruregens. The animals usually crawled about on the bottom or along the stems and leaves of the Ruppia mariUma ; they could not, however, crawl up the vertical sides of the bottle, the glass being too smooth for them ; they ran backward and forward with equal rapidity, and did not seem particular which way they went ; they did not swim, but if they dropped off the plant wriggled helplessly till they reached the bottom. I did not notice any- thing that would indicate any power of vision, but, on the other hand, often saw them running against objects in a way which seemed to indicate that they were totally blind ; occasionally I have seen two approach very near each other, apparently without being aware of it, and then suddenly jump apart when one touched the other. IX. The Bearings of the Phenomena of Subterranean Life on the Theory of Descent. It has been early recognized that the phenomena of cave and subterranean life have an important bearing on the Theory of Descent. Here the conditions of life are so peculiar, so abnormal, the fauna so scanty, and its environment so simple and so i-estricted that we may naturally expect to find the problems that are to be solved presented to us in their simplest forms. Thus we have no vegetable life of any kind except a few fungi, only a comparatively small number of animals of various groups, and these surrounded by con- tinual night and exposed to a temperature probably pretty uniform from year to year ; in many cases we can tell, with at any rate a fair approach to accuracy, from what surface-species the underground species has descended ; and knowing also, within certain limits, the age of the latter, we can estimate the changes undergone and consequently the rate at which these have been made in this jiarticular instance. The importance of Isolation in securing permanence of type in the case of cave- dwelling animals has been dwelt upon by Packard [83, pp. 14jO-14<1]. Similar remarks would apply with perhaps even greater force to the subterranean fauna, such as that of the underground waters of the Canterbury Plains, for it is probably even more com- pletely isolated from the surface-fauna than is that of caves. CEUSTACEA OF NEW ZEALAND. 267 It is, however, with regard to the effects of the disuse of organs that the cave and subterranean fauna has been studied with the greatest interest, and here we closely approach the controversy between the Neo-Darwinians and the Neo-Lamarckians. While it would be utter presumption on the part of the writer to enter upon a discussion of this question, it will be interesting to review a few of the opinions expressed by various writers on the subject in so far as it is exemplified by the phenomena of subterranean life. Darwin, in his ' Origin of Species ' [35, pp. 110-112], after pointing out that in the case of the mole and similar burrowing animals natural selection will probably aid the effects of disuse in producing blindness, refers to the blind inhabitants of caves, and remarks : — " As it is difficult to imagine that eyes, though useless, could be in any way injurious to animals living in darkness, their total loss may be attributed to disuse " [35, p. 110]. Further on, after quoting Schiodte's observations as to animals, some of which are adapted to the twilight and others to the perfect darkness of caves, he observes : — «' By the time that an animal had reached, after numberless generations, the deepest recesses, disuse will on this view have more or less perfectly obliterated its eyes, and natural selection will often have effected other changes, such as in increase in the length of the antenna? or palpi, as a compensation for blindness " [35, p. 111]. That animals living in darkness do as a general rule gradually lose their eyes is now a very familiar fact, and it no doubt appears at first sight simplest to explain this as an example of the effects of disuse ; but there are numerous instances known of animals living in darkness that yet possess more or less perfect eyes, and unless these can be accounted for in some way they would appear to prove that the effect of darkness, per se, does not necessarily produce degeneration of the eyes. Semper, in his ' Animal Life ' [99, pp. 76-87], after giving a number of examples of the loss of eyesight apparently through disuse, adds that " it would nevertheless be wholly false to assume that lack of light must necessarily lead to total or partial blindness " [99, p. 81] ; he then proceeds to give examples of animals living in darkness with more or less perfect eyes, and on the contrary, of animals blind or half-blind, which yet " live in w^ell-illuminated situations, where the moderate intensity of the light would allow them the full use of eyes." The examples given by Semper have been considered in detail by Packard [83, pp. 130-132], who points out that some, at any rate, of the first group are " twilight animals," living near the entrance of the caves as well as in the total darkness of the innermost recesses, and that those animals which live in total darkness may perhaps cross with those living near the entrance, and the eyes thus remain unimpaired. Other cases in which our knowledge is not so complete, may, he considers, perhaps be explained in the same way; and with regard to the second group, i. e. blind or half-blind animals living in weU-lighted situations, many may spend the greater part of their lives burrowino- in the mud or in dark places where eyes would be of little or no service to them ; in this way he explains the blind Cymothou mentioned by Semper [99, p. 83] which he found in the full light of day. Whilst some cases may perhaps be accounted for in this way, it does not seem to me that SECOND SERIES. — ZOOLOGY, VOL. VI. 35 2f!R DE. C. CHILTON ON THE SUBTEERANEAN all, even of those mentioned by Semper, can be thus explained. Thus Packard appears to make no reference to the Pinnotheres mentioned by Semper [99, p. 80], the zogeaof which has well-developed eyes of the typical character, while the full-grown animals which live in the " water-lungs " of Holothurians " gradually become blind or half-blind ; the brow grows forward over the eyes, and finally covers them so completely that, in the oldest individuals, not the slightest trace of them, or of the pigment, is to be seen through the thick skin ; while at the same time the eyes seem to undergo a more or less extensive retrogressive metamorphosis " [99, p. 81]. Cases like this certainly seem to indicate, as Semper observes, " that the influence of darkness is proved to be direct in each individual, and not hereditary." Here we see that the eyes are preserved in the free swimming zosea, where they are of service to the animal, but are gradually lost in the adult, where they are no longer required ; and while this shows the powerful effects of disuse in the individual, it does not show that these effects are inherited without the intervention of Natural Selection, as appears to be assumed by Packard and others, who account for the blindness of cave animals by the direct effect of the darkness and the consequent disuse of the organs. If the characters thus acquired through disuse were necessarily inherited, we should expect to find the eyes of the zosea of the Pinnotheres more or less imperfect. Packard, who discusses the bearing of cave life on the Theory of Descent at con- siderable length, is thoroughly Neo-Lamarckian in his views, and sees little or no room for the operation of Natural Selection. Thus, on p. 121, he remarks : — " Given great changes in the physical surroundings, inducing loss of eyes through disuse, the abolition in some cases of the optic ganglia and optic nerves, the elongation of the appendages, isolation from out-of-door allies, and the transmission by heredity owing to close in-and-in breeding within the narrow fixed limits of the cave, are not these collectively verce causae ? Do they not fully account for the original variations and their fixation ? In short, can we not clearly understand the mode of origin of cave species and genera ? What room is there in a case like this, or in that of parasitic animals, for the operation of natural selection ? The latter principle only plays, it has seemed to us, a very subordinate and final part in the set of causes inducing the origin of these forms " [83, p. 121]. If these modifications, however, were the direct inherited eff'ect of the environment, i. e. darkness &c., should we not expect to find them similar in all animals subjected to the same conditions ? The modifications might be greater in some instances than in others, in accordance with the varying lengths of time that the animals had lived under these conditions, but we should certainly expect that the development in all cases would be proceeding uniformly and in the same direction. Now it seems to me that we do not find this process demonstrated even in the facts adduced by Packard himself, but that there is a certain apparent capriciousness which is inconsistent with the constant and uniformly acting causes that he sets forth. Thus, in the case of the eyes, instead of the degeneration proceeding on similar lines in all individuals, we may have — : (1) Total atrophy of optic lobes and optic nerves, with or without the persistence in part of the pigment or retina and the crystalline lens ; CEUSTACEA OF NEW ZEALAND. 269 (2) Persistence of the optic lobes and optic nerves, but total atrophy of the rods and cones, retina (pigment), and facets ; or (3) Total atrophy of the optic lobes, optic nerves, and all the optic elements. [See 83, p. 118.] If we consider the other modifications of the body, legs, antennae, &c., which Packard also accounts for as " evidently the result of loss of sight " [83, p. 120], Ave still find the same capriciousness, and even in a more marked degree. Thus, taking our New Zealand forms, we find that Cruregens fontanus and Culliopius subterraneus have developed additional sensory setae beyond what are usiially to be found in their surface relatives, while apparently Gammariis fragilis and Crangonyx compactus, and certainly the two species of Phreatoicus, have not. Again, in the species of Phreatoicus, in Gammarus fragilis, and to a less degree in Callioplm subterraneus and Cruregens fontanus, the body, antennae, and appendages are slender and elongated, while there is no sign of a similar modification in Crangonyx compactus, which has the body normally stout, the antennae and legs of only moderate length, and the uropoda even somewhat short and stumpy. Many similar examples could doubtless be adduced from a review of the underoround fauna of other covmtries. Thus Boruta tenebrarum [124, pp. 677-G87] does not appear to have the body particularly slender or the appendages elongated, while the species of Niphargus usually do possess these peculiarities ; in Niphurgus the outer branch of the third uropoda is greatly elongated, in Gammarus fragilis the peduncle and both branches of the third uropoda are similarly elongated, while again in Cranqonyx mucronatus, Forbes, the elongation takes place, not in the third uropoda at all, but in the telson ! These examples, showing a development apparently capricious and varying in its direction in animals all subjected to the same or similar environment, appear to jjoint rather to the action of Natural Selection seizing here upon one variation useful to the animal and there upon another, and fixing and maintaining these variations just as we find it doino- in the more complicated phenomena of surface life. Packard refers to the cave Crustaceans as living " in a sphere where there is little, if any, occasion for struffo-liuo- for existence between these organisms " [83, p. 110]. But surely here, as elsewhere, the animals tend to increase in a geometrical ratio, and since all cannot live, must necessarily struggle among themselves for food, which is as Packard points out, very scanty. The Ccecidotea and Crangonyx of the North-American caves are, Packard states, eaten by the blind crayfish, and must therefore " struggle," in the sense in wliich the word is used by Darwin, with their destroyer, and in this struo-o'le they appear to have developed those additional olfactory sette, &c., mentioned by Packard, which enable them more readily to escape their enemy. If they had no occasion for struggling for existence, w^hy should these additional sense-organs be developed at all ? Packard does not appear to have considered the action of Natural Selection on the individuals of the same species, an action which results in the perfecting and maintainiu"- in a state of perfection any organ that is of importance to the animal. It is, however, 35* 270 Dll. C. CHILTON ON THE SUBTERRANEAN this action of Natural Selection which is of the most importance when we consider the case of the blind inhabitants of caves, &c., as has been clearly pointed out by AVallace [115, p. 413, &c.], Weismann [119, p. 90, &c.], &c. My former teacher, Professor Hutton, put it very clearly and impressively in his lectures when he said that Natural Selection consists not so much in the " Survival of the Fittest " as in the " Non-survival of the Upfittest" ; and, as he proceeded to demonstrate, the difference between the two points of view is a real one, and not a mere question of words. Thus, in the case of any animal living in the full light, a certain degree of perfection of eyesight will be required by the animal in order to enable it to escape its enemies, obtain food, &c., and all individuals falling below this standard will perish ; so that by the action of Natural Selection the eyesight of the animal will be kept in perfect adaptation to its environment. Now in the case of animals that have taken to living in dark caverns, &c., the eyesight, being no longer of use to the animal, will no longer be maintained in its state of perfection by Natural Selection (although of course Natural Selection will still act on other organs that are of use in the darkness) ; consequently all degrees of eyesight will stand an equal chance of preservation, and by the intercrossing of individuals of varying degrees of perfection there will result a degeneration of the eyesight — a " regression towards mediocrity," as Galton has called it. The explanation of the gradual loss of the eyes in cave animals is the one adopted by Wallace, in his ' Darwinism ' [115, p. 416], who also adds that besides becoming useless, the eyes might also become injurious on account of their delicacy of organization and liability to accidents and disease ; so that in addition to the " regression towards mediocrity," owing to the withdrawal of the action of Natural Selection in maintaining perfection. Natural Selection would also actively reduce and finally abort them. It is important to observe that this " regression towards mediocrity " is a general law of heredity, and produces its effect quite irrespective of any use or disuse of the organ in question [Wallace, 115, p. 414]. A similar explanation has been given by Weismann [119, pp. 90 and 292], who has introduced the term '■'Panmixia" for the suspension of the preserving influence of Natural Selection, and the consequent inter- crossing of animals of all standards of perfection. Of course, if we accept his dogma of the non-heredity of acquired characters, that at once excludes the effects of disuse as an explanation of the blindness of cave animals ; but even without going to this length the principle of panmixia, combined with the other active effect of Natural Selection adduced by Wallace, will be sufficient to account for much of the degeneration of eyesight, and to these must be added another equally important consideration advanced by Lankester [70, p. 818-819]. After pointing out that the eyesight of different individuals varies, owing to congenital fortuitous variations, he remarks : — " Suppose that a number of some species of Arthropod or Fish be swept into a cavern or be carried from less to greater depths in the sea, those individuals with perfect eyes would follow the glimmer of light, and eventually escape to the outer air or the shallower depths, leaving behind those with imperfect eyes to breed in the dark place. A natural selection would thus be effected." This explanation is no doubt a true statement of fact, for caverns and underground CRUSTACEA OF NEW ZEALAND. 271 waters have in all probability Ijeen gradually peopled by animals from the surrounding neighboiu-hood, and as they advanced further and further into the darkness a selection of this kind would go on in each geueration, and, as Poulton has observed, " such a sifting process would certainly greatly quicken the rate of degeneration due to panmixia alone" [119, p. 292, footnote]. The same explanation is quoted with approval by W. P. Ball, who considers, however, that ixinmixla "would probably be the most important factor in causing blindness" [3, pp. 17, 72]. To the various causes mentioned above we must add the effects of disuse in the individual, which are undovibtedly very considerable in amount, and in cave animals breeding in the darkness would commence in all cases from birth. I may add here one or two notes on the age of the blind fauna of caves and wells, and on the rate at which development has consequently taken place in these animals. Although, as I have pointed out elsewhere (pp. 2.o3-25S), there is reason to believe that some, at any rate, of the blind species are older than the surface fauna at present inhabiting the same neighbourhood, there seems little reason to doubt that the whole underground fauna is of comparatively recent origin. Packard [82, p. 25], after con- sidering the facts on the question adduced by Cope, came to the conclusion that " the subterranean fauna of this country does not date back of the Quaternary Period." In his later paper he repeats this opinion, and, after considering the different classes of caves more fully, adds : — " It seems, then, fair to assume that the final completion of the caverns, when they became ready for occupancy by their present fauna, may not date back more than, to put it into concrete figures, from 7000 to 10,000 years, the time generally held by geologists to be sufficient for the cutting of the present river gorge of the Niagara and the Palls of St. Anthony. We may, then, put the age of our cave fauna as not much over from .5000 to 10,000 years before the dawn of history, which itself extends back some 5000 to 6000 years" [83, p. 23J. He concludes, therefore, that the greatest part of the cave fauna of North America was directly derived from the present fauna, and that consequently the changes under- gone have been brought about in at most a few thousands of years. The fauna of the European caves descrilied by Schiodte, &c., also seems to date from the " close of the Tertiary, or more probably the beginning of the Quaternary Period " (Packard [82, p. 25]). In New Zealand, too, the subterranean fauna must be very recent, geologically speaking. All the places where subterranean forms are found are marked on Professor Haast's geological map of Canterbury and Westland [53] as either " post-pliocene alluvium " or " recent alluvium," most of them being in the latter. Phreatoicus, by its generalized character and by its occurrence in Australia as well as in New Zealand, is shown to be an ancient form, probably once widely spread in fresh waters, but of course it does not foUow that its subterranean species are more ancient than the other subterranean forms. If t'lorough search were made it is quite possible that some species of the genus would still be found inhabiting freshwater streams among the Southern Alps. 272 DE. C. CHILTON OF THE SUBTERKANEAN In speaking of the variety freihergensis, Schneider, of Asellus aquaticus, Moniez says : — " Differents auteurs (Schneider, Chilton, etc.) attachent beaucoup d'importance a la date a laquelle ont ete fores les puits dont ils ont etudie les eaux, admettant volontiers, mais bien gratuitement, a notre avis, que c'est a cette epoque que les animaux y sont arrives et ont commence a se modifier. Nous avons deja fait entendre, a propos du Cyclofs fulchellus (p. 34), que cette facon naive de j)roceder a I'etude de la variation des especes ne pent se soutenir, car elle ne tient pas compte d'un facteur important dans la question, celle des eaux sowterraines, dans lesquelles les animaux observes pou- vaient vivre avant le forage, et par lesquelles, grace anx infiltrations, de nouveaux in- dividus a I'etat d'oeufs, ou meme a I'^tat parfait, peuvent arriver a tout instant, comme nous I'avons fait remarquer plus haut (pp. 37, 38) " [78, p. 52, footnote]. It is true that in my first jDaper on the Subterranean Crustacea of New Zealand I did mention the age of the well from which they were obtained, because I wished to give all the facts that might have a bearing ou the question, and though the age of the well has, of course, nothing to do with the development of the Subterranean Crustacea, it may have had some effect on numbers occurring at that particular place ; but there is nothing in my paper that can be interpreted to mean that I imagined that the Crustacea — all true subterranean forms — had begun to modify only after the well was bored ; and in my second paper [23, p. 87, &c.] I made it quite clear that the Crustacea are inhabitants of the underground waters and not merely of the wells. The cases brought forward by Schneider, i. e. Gammarus pulex, var. siMerraueus, and Asellus aquaticus, var. freihergensis, seem to me to be quite different. Here, as in the case of Gammarus fluviaiiUs, var. d' Emmerin, mentioned by Moniez himself, we have subterranean varieties which differ from the parent species still found on the surface only in a few small points, such as colovir, slight degeneration of the eyes, &c., and though 1 do not know what age is to be assigned to the mines in which Schneider found his examples, I see no reason for doubting that these slight differences have been acquired in a very few generations. Other similar examples are given by Packard ; one is that of some examples of an isopod found in subterranean regions, which, although of the normal form and size of Asellus communis (the surface species), were bleached as white as Ccecidotca stygia, and of this variety, which he calls pallida, Packard remarks : — " It is interesting to note the occurrence of this bleached variety, which may have become thus modified after but a few generations, perhaps but one or two " [83, p. 32]. Other examples given appear to confirm this view, and all go to show that slight modifications, such as in the cases mentioned above, may be produced within very short periods. X. Conclusion. In the foregoing pages I have endeavoured to give as full and accurate an account of the Subterranean Crustacea of New Zealand as the material and the time at my disposal would allow. But although the work has gradually grown under my hands until the present memoir has far exceeded the limits I originally anticipated, its CRUSTACEA OF NEW ZEALAND. 273 increase in size has, I fear, only multiplied its imperfections, and given rise to more questions than have been solved. It has, indeed, shown that no single animal can be profitably studied by itself, but that in attempting to explain one we must study all, and that the one can be thoroughly known only when all are known. In concluding his work on the fauna of the Swiss Lakes, Porel has pointed out that the phenomena connected therewith, which at first appeared strange, anomalous, and altogether unaccountable, were gradually interpreted witla increasing knowledge until they harmonized with what we learn of the Avorkings of nature in other places less far removed from man's curious gaze. The same statement applies to the consideration of subterranean life, and we can exclaim mth Forel — " La nature est grande et belle, parce qu'elle est harmonieuse en tout et partout." But one fact that has been impressed upon me more than any other by the very existence of subterranean life is the keenness of the struggle for existence that goes on in the world of animals and plants. I am not aware that he ever did so, but from tiie tendency of animals to increase in a geometrical ratio, and the consequent struggle for life, Darwin might have deduced the conclusion that every spot on earth capable of supporting life at all would be occupied by its apjn'opriate denizen ; and certainly such a conclusion would have been amply verified by the facts now known. Even if we take a single group like the Crustacea, and of these only the small and apparently help- less Amphipoda and Isopoda, we find that they have spread until scarcely any place can be named from which they are absent. They are found on land and in the sea ; in running streams and in stagnant ponds ; in hot springs and in frozen pools ; hio-h on mountain-tops and deep in mines ; on the seashore and far out in the ocean ; burrowino- in mud and boring into wood and stone ; on the surface of the sea and in its lowest depths ; in the waters on the earth and in the dark recesses of caverns and of the waters under the earth, where no storm ruffles the everlasting stillness, no light illumines the thick darkness, and no sound breaks the eternal silence. XL Bibliography. List of Works referred to. [The originals of many of the works quoted below have been inaccessible to the writer, the contents being, however, known to him through abstracts and notices in other works. The chief source from which such information has been gained is given in each case but in many cases the contents of a paper have been known through abstracts in several other works. Though the list is far from complete, it is hoped that the chief works bearino- on the Subterranean Amphipoda and Isopoda will be found mentioned below.] 1. AsPER, G. — " Beit rage zur Keimtniss der Tiefseefauua der Schweizersecu/' Zoologischer Anzeiger Band iii. Jahrg. 1880, pp. 130-134., 200-207. 2. AsPER, G. — " tlber die Lichtverliiiltnisse in grossen Wassertiefen." Kosmos, Zeitsehrift fvir die gesammte Entwicklungslehre, Band i. Stuttgart, 1885. Quoted from Wrzesniowski [124, p. 715]. 274 DE. C. CHILTON ON THE SUBTERRANEAN 3. Ball, W. P. — ' Are the Effects of Use and Disuse inherited ? An examination of the view held hj Spencer and Darwin.' Nature Series. London, 1890. 4. Bate, C. Spence, and Westwood, J. O. — 'A History of the British Sessile-eyed Crustacea.' 2 vols. London, 1863-1868. 5. Bate, C. Spence. — 'Catalogue of the Specimens of Amphipodous Crustacea in the Collection of the British Museum.' London, 1862. 6. Bate, C. Spence. — " On the Genus Niphargus, Schiodte." Dublin Univ. Zool. and Bot. Assoc. Proc. vol. i. 1859, pp. 237-240, figs. 1-4. Quoted from Stebbing [108, p. 311.] 7. Bate, C. Spence. — " On the British Edriophthalma." Report of the Glasgow Meeting of the British Association for the Advancement of Science. 1855. London, 1856, pp. 18-62, pis. xii.-xxii. 8. Beddard, Frank E. — "Anatomical Description of two new Genera of Aquatic OligocJneta." Trans. Royal Society of Edinburgh, vol. xxxvi., part ii., no. 11, pp. 273-305, plates i.-iii. Edinburgh, 1891. 9. Beddard, Frank E. — " Report on the Isopoda collected by H.M.S. 'Challenger'.'' — Part II. Report on the Scientific Results of the Voyage of H.M.S. 'Challenger' during the years 1873-76. Zoology, vol. xvii., part xlviii. London, &c., 1886. 10. Beneden, Edouard von. — " Sur la presence k Li^ge du Niphargus puteanus, Sch." Bulletin de 1' Academic royale des Sciences, des Lettres et des Beaux-Arts de Belgique, 3 serie, tome viii. no. 12. Bruxelles, 1884, pp. 650-652. Quoted from Wrzesniowski [124, p. 715] . 11. Blanc, Henri. — "Isopode aveugle de la region profonde du Leman, etc." Bulletin de la Societe Vaudoise des Sciences naturelles, ser. 2, vol. 16, p. 377, pi. 13. Quoted from Bovallius [15, p. 10]. 12. Blanc, Henri. — " Contribution a I'histoire naturelle des Asellotes heteropodes. Observations faites sur la Tanais Oerstedii, Kroyer." Avec les planches x., xi., et xii. Recueil zoologique suisse (Dr. Herman Fol), tome premier, no. 2, pp. 189-258. Geneve-B^le, 1884. Quoted from Stebbing [108, p. 549] . 13. Boas, J. E. V. — " Studien iiber die V'erwandtschaftsbeziehungen der Malakostraken." Morpholog. Jahrbuch, Band viii., pp. 485-579, plates xxi.-xxiv. 14. BoECK, Axel. — " Crustacea Amphipoda borealia et arctica." Vidensk-Selsk. Forhandlinger, 1870. 15. Bovallius, Karl. — " Notes on the Family Asellidse." Bihaiig till k. Svenska Vet.-Akad. Hand- lingar. Band ii., no. 15, pp. 1-54. Stockholm, 1880. 16. Bovallius, Karl. — " lanthe, a new genus of Isopoda." Loc. cit. Band vi. no. 4, p. 4. 17. Bruzelius, Raynar M. — " Bid rag till kannedomen om Skandinaviens Amphipoda Gammaridea." K. Svenska Vetenskaps-Akademieiis Handliugar, vol. 3, no. 1, 1859, pp. 1-104, pis. i.-iv. Quoted from Stebbing [108, p. 312]. 18. Budde-Lund, G. — " Crustacea Isopoda Terrestria." Copenhagen, 1885. 19. Caspary, Robert. — " Gammarus jjvteanus." Verhandlungen des naturhistorischen Vereins der preussischen Rheinlande uid VVestfalen, 6. Jahrg. pp. 39-48, Taf. ii. (Bonn, 1849). Quoted from Wrzesniowski [124, p. 708]. 20. Catta, J. D. — " Sur uu Amphipode nouveau, le Gammarus rhipidiophorus ." Actes de la Societe Helvetique des Sciences naturelles reunie k Bex, les 20, 21, et 22 aout 1877. GO' session. Compte-rendu, 1876 & 1877, pp. 257-263. Lausanne, 1878. Quoted from Stebbing [108, p. 475]. 21. Chilton, Chas.--" Notes on son.c New-Zealand Amphipoda and Isopoda." Transactions New Zealand Institute, vol. xxiv. pp. 2.")8-269. Wellington, N. Z., 1882. 22. Chilton, Chas. — "On some Subterranean Crustacea." Loc. cit. vol. xiv. pp. 174-180, pis. ix. & x. CEUSTACEA OF ]SEW ZEALAND. 275 (Abstract iu the ' New Zealand Journal of Science,' vol. i. (March 1882) p. 44, also in ' Nature/ Sept. 28, 1882. Review by Alois Humbert in 'Archives des Sciences naturelles/ Sept. 1882, viii. pp. 265-267.) 23. Chilto.v, CiiAs. — "Notes on, and a new Species of, Subterranean Crustacea." Loc. cit. vol. xv. pp. 87-92, plate iv. 24. Chilton, Chas. — "Revision of the New Zealand IdoteidiE." Loc. cit. vol. xxii. pp. 189-204. 25. Chilton, Chas. — "Subterranean Crustacea." New Zealand Journal of Science, vol. ii., March 1884, p. 89. (The writer's name was accidentally omitted from this article.) 26. Chilton, Chas. — " On a new and peculiar Freshwater Isopod from Mt. Kosciusko." Records of the Australian Museum, vol. i. part 8, pp. 149-171, plates xxiii.-xxvi. Sydney, 1891. 27. Chilton, Chas. — "A new Species of Munna from New Zealand." Annals & Magazine Natural History, ser. 6, vol. ix., Jan. 1892, pp. 1-12, pis. i. & ii. 27*. Chilton, Chas. (and Thomson, G. M.).— See Thomson, G. M. [HI]. 28. Chyzer, C. — " ijber die Crustaceenfauna Ungarns." Verhaudl. der k.-k. zoologisch-botanischen Gesellschaft in Wien. Wien, 1858. Quoted from Wrzcsniowski [124, p. 710]. 29. Cope, E. D.— " Life in the Wyandotte Cave." Ann, & Mag. Nat. Hist. ser. 4, vol. viii., Nov. 1871, pp. 368-370. 30. Cope, E. D. — " On the Wyandotte Cave and its Fauna." American Naturalist, vol. vi., July 1872, pp. 1-17. 31. Cope, E. D., and Packard, A. S., Jun. — " The Fauna of the Nickajack Cave." Loc. cit. Nov. 1881, p. 877. 32. Costa, Achille. — " Rieerche sui Crostacei Amphipodi del regno di Napoli." Memorie della Reale Accademia delle Scienze, vol. i. fasc. 2. Napoli, 1857. Quoted from Stebbing [108, p. 295]. 33. CzERNiAVSKi (Tschernjafski), Woldemak. — " Materialia ad Zoographiam Ponticam comparatam." Studiosi Universitatis Charcoviensis Voldemari Czerniavski. Quoted from Stebbing [108, p. 378]. 34. Daday, Eugene. — ' Catalogus Crustaceoruni fauu;e Transylvaniae e collectione Musei Transylvanici, coUegit et determinavit. . . . Kolosvart (Klausenburg).^ 1884. Quoted from Wrzesniowski [124, p. 715]. 35. Darwin, Charles. — ' The Origin of Species by means of Natural Selection.' Sixtii edition (Twenty- second thousand). London, 1880. 36. Dohrn, Anton. — " Zur Kenntniss dcs Baues von Paranthura costana." Untersuchungen iilier Bau und Entwicklung der Arthropodeu, Erstes Heft, no. v. pp. 91-103, plate ix. Leipzig, 1870. 37. Faxon, Walter. — " A Revision of the Astacidpe. — Part I. The genera Cambarus and Astacus." Memoirs of the Museum of Comparative Zoology at Harvard College, vol. x. no. 4. 38. Forel, F. a. — " Introduction k I'etude de la Faune profonde du Lac Leman." Bulletin de la Societe Yaudoise des Sciences naturelles, vol. x. no. G2, December 1869, p. 221. Quoted from Humbert [62, p. 288]. 39. FoREL, F. A. — " Faunistische Studicn in den Siisswasserseen der Sehweiz." Zeitschrift fiir wissen- schaftliche Zoologie, Dreissigster Band, Supplement (Leipzig, 1878), pp. 383-391. Quoted from Stebbing [108, p. 476]. 40. FoREL, F. A. — " La Faune profonde des Lacs suisses." Memoires de la Societe Helvetique des Sciences naturelles, vol. xxix. 2'-' livraison, August 1885. 41. Forbes, S. A. — "List of Illinois Crustacea." Bulletin Illinois Museum of Natural History, I. 6", Dec. 1876, figs. 1-7. Quoted from Packard [83, p. 37]. SECOND SERIES. — ZOOLOGY, VOL. VI. 36 276 DE. C. CHILTON ON THE SUBTEREANEAN 42. Fric a. "Die Krustenthiere Bolimens." Archiv fiir die naturwissenschaftliclie Laudesdurch- forsclmng Bohmeus, ii. Tlieil. Prag. (Also published in Bohemian.) Quoted from Wrzesniowski [124, p. 712]. 43. Fries, S. — " Mittheilungen aus dem Gebiete der Dunkelfauna. — I. Gammarus {Niphargus) pute- anus)." Zoolog. Auzeiger, 1879, pp. 33-38, 56-60, 129-134, 309. 44. Fries, S. — " Die Falkensteiuer Holile, ihre Fauna und Flora." Jahreshefte des Vereius fiir vaterltindische Naturkunde in Wiirttemberg, 30 Jahrg. Stuttgart, 1874. Quoted from Wrzesniowski [124, p. 712]. 45. Gerstaecker, A. — ' Dr. H. G. Bronn's Klassen uud Ordnungen des Tliierreichs, wissenschaftlich dargesellt in Wort und Bild. Fortgesetzt von Dr. A. Gerstaecker.' Fiinfter Band, ii. Abtheil- ung. Gliederfiissler : Arthropoda. 46. Gervais, Paul. — " Note sur deux especes de Crevettes qui vivent aux environs de Paris." Annales des Sciences naturelles. Zoologie. Second surie. Tome quatrieme. Paris, 1835. 47. Gervais, Paul, et Beneden, P. J. van.— ■' Zoologie Medicale.' Tome premier. Paris, 1859. Quoted from Stebbing [108, p. 316]. 48. 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Aus den Verhandlungen d. k.-k. zoologisch-botanischen Gesellschaft in Wicn (Jahrgang 1865) besonders abgedruckt. Quoted from Stebbing [108, p. 359]. 59. Hogan, Arthur R. — "On the habits of Nipharyiis foiUunus (n. s.). A'. Kochianus (n. s.), and Crariffonyx subterraneus (n. g. & s.), Speuce Bate." The Natural History Review and Quarterly Journal of Science, vol. vi., 1859, pp. 166-169. 60. Hogan, Arthur R. — "Notice of British Well-Shrimps." Report of the 30th Meeting of the British Association for the Advancement of Science, pp. 116-117. London, 1861. CEUSTACEA OF NEW ZEALAND. 277 61. Hosius, August. — " Uber die Gamma)-ns-\rtcn der Gegend von Bonn." Archiv fiir Natur- geschichtc, ]5. Jalirg., 1850, Bd. i. pp. 233-248, Taf. i.-ii. Quoted from Wrzesniowski [124, p. 708]. 62. Humbert, Alo'js. — " Desoription du Niphargus puteanus, var. Forelii." Bulletin de la Societe Vaudoisc dcs Sciences naturellcs, tome xiv., 1876, pp. 278-398, pis. 6 & 7. (Abstract in the ' Bibliotheque Universelle : Archives des Sciences,' 15th Jan. 1877, pp. 58-75, a translation of which, by W. S. Dallas, F.L.S., appeared in the 'Annals & Magazine of Natural Historj',' ser. 4, vol. xix. 1877, pp. 243-254. 63. HuTTON, F. W.- — ' Handbook of Christchnrch. For the use of the Members of the Australasian Association for the Advancement of Science.' Edited by F. W. Hutton. Christchnrch, N.Z., 1891. 64. Imhof, O. E. — " Die pelagisehe Fauna und die Tiefseefauna der zwei Savoyer Seen, lac du Bourgct und lac Annecy." Zoologischer Anzeiger, G. Jahrg., 1883, no. 154, pp. 655-657. Quoted from Wrzesniowski [124, p. 715]. 65. Joseph, Gustav. — " Uber die Grotten in den Krainer Gebirgen und deren Thierwelt." Jahresbcrich der schlesischen Gesellschaft f. vaterl. Cultur, Jahrg. 1868, p. 48. Breslau, 1SG9. ' Quoted from Humbert [62, p. 287]. 66. Joseph, Gustav. — '' Zur geographischen Verbreitnng von Niphargus puteanus." Zoologischer Anzeiger, 1879, pp. 380-381. 67. 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"Notice of the Invcrtebrata dredged in Lake Superior in 1871 by the U.S. Lake Survey." By S. I. Smith and A. E. Verrill. Number xii. pp. 418-454. The American Journal of Science and Arts. New Haven, 1871. 103. Smith, S. I.— "The Crustacea of the Freshwaters of the United States," &c. Extract from the Report of Prof. S. F. Baird, Commissioner of Fish and Fisheries. Part ii. Report for 1872- 1873. Washington, 1874. Quoted from Stebbing [108, p. 34]. 104. Smith, S. I. — "The Crustaceans of the Caves of Kentucky and Indiana." American Journal ot Science and Arts, vol. i.x. June 1875. 105. Smith, S. I. — " Crustacea of the ' Albatross ' Dredgings in 1883." American Journal of Science, vol. xxviii. pp. 53-56. July 1884. 106. Stebbing, T. R. R., and Nokman, .\. M. — " On the Crustacea Isopoda of the ' Lightning,' ' Por- cupine,' and ' Valorous ' Expeditions." Transactions of the Zoological Society, vol. xii. part iv. pp. 77-141, plates xvi.-xxvii. London, 1886. 107. SteBbixg, T. R. R. — " On some new Exotic Amphipoda from Singapore and from New Zealand." Loc. cit. vol. xii. part vi. 1887, pp. 199-210, plates xxxviii., xxxix. 108. Stebbing, T. R. R. — "Report on tlie Amphipoda collected by H. M.S. ' Challenger ' during the years 1873-1876." Report on the Scientific Results of the Voyage of H. M.S. ' Challenger • 280 DE. C. CHILTON ON THE SUBTEEEANEAN during the years 1873-1876 : Zoology, vol. xxiv. Two volumes of Text and one volume of 212 Plates and a Map. Loudon, &c., 1888. 109. Tellkampf, Theodor G. — " Beschreibung einigcr neuer in der Mammuth-Holile in Kentucky aufgefundener Gattungen von Gliederthieren." Arcliiv fiir Naturgeschiclite, Zelinter Jahrgang, Erster Band. Berlin, 1844. Quoted from Stebbing [108, p. 208]. 110. Thomson, G. M. — "Notes on, and recent additions to, the New Zealand Crustacean Fauna." Transactions of the New Zealand Institute, vol. xxi. pp. 259-268. Wellington, N.Z., 1889. 111. Thomson, G. M., and Chilton, Chas. — "Critical List of the Crustacea Malacostraca of New Zealand. Part I." Transactions of the New Zealand Institute, vol. xviii. pp. 141-159. Wellington, N.Z., 1886. 112. Valette St. George, Adolphe de la. — 'De Gammaro puteano.' Dissertatio inauguralis (Berolini, 1857), pp. 5-16, with 2 plates. Quoted from Stebbing [108, p. 304]. 113. Vejdovsky, Fr. — ' Thierische Organismen der Bruunenwasser von Prag.' Prague, 1882, pp. 66, 8 plates. Quoted from Wrzesniowski [124, p. 715]. 114. Wallace, A. R. — 'The Malay Archipelago.' Seventh edition. London, 1880. 115. Wallace, A. R. — 'Darwinism : an Exposition of the Theory of Natural Selection, with some of its Applications.' London, 1889. 116. Weber. Max. — " Uber Asellus cavaticus, Schiodte." Zoologischer Anzeiger, vol. ii. p. 253. 117. Weber, Max. — "Uber einige neue Isopoden der Niederlandischen Fauna." Tijdschrift der Nederlandsche Dierkundige Vereeniging, Deel 5, p. 17J. Quoted from Bovallius [15, p. 11]. 118. Weber, Max. — "Uber den Bau und die Thatigkeit der sogenannten Leber der Crustaceen." Archiv fiir mikroskopische Anatomic, xvii. (Bonn, 1880 ?), pp. 385-457, pis. xxxvi.- xxxviii. Quoted from Stebbing [108, p. 525]. 119. Weismann, August. — 'Essays upon Heredity and kindred Biological Problems.' Authorized translation. Oxford (Clarendon Press), 1889. 119*. Westwood, J. O. (and Bate, C. Spence). — See Bate [4]. 120. Westwood, J. O. — 'Annals and Magazine of Natural History,' vol. xii., 2nd series, London, 1853, p. 44. 'Also Proceedings Linnean Society,' no. 51, p. 218, London, 19tli April, 1853 121. White, Adam. — 'A Popular History of British Crustacea; comprising a familiar Account of their Classification and Habits.' London, 1857. Quoted from Stebbing [108, p. 304]. 122. Wiedersheim, R. — "Beitriige zur Keuntniss der Wiirttemberg. Hohlenfauna." Verhandl. d. Wiirzburger physik.-med. Gesellsehaft, Neue Folge, Bd. iv. Wiirzburg, 1873. Quoted from Humbert [62, p. 289]. 123. Wrzesniowski, August. — " O trzech kielzacli podziemnych." De tribus Crustaceis Amphipodis subterraneis. Pamietnik Physiographische Deukschriftcn, Bd. viii., 3. Abtheilung (M^arschau, 1888), pp. 221-830, Taf. vi.-xvi. 124. Wrzesniowski, August. — "Uber drei unterirdische Gammariden." Zeitschrift fiir wissenschaft- liche Zoologie, L. 4, pp. 600-725, plates xxviii.-xxxii. Leipzig, 1890. (A translation, with some additions and alterations, of the previous work.) 125. Zenkeii, J. C. — "De Gammari pulicis, Fabr., historia naturali atque sanguinis cii'cnitu com- mentatio." Jeuce, 1832. Quoted from Wrzesniowski [124, p. 707]. CRUSTACEA OF NEW ZEALAND. 281 EXPLANATION OF THE PLATES. Plate XVI. Phreatoicus assimilis. Fig. 1. Side view of the whole animal, a female, x 12. 3. Upper antenna. 3. Lower antenna. 4. Upper lip. x 58. 5. Outer convex surface of mandible with palp attached. 6. Left mandible. 7. Lower lip. x 58. 8. Fii-st maxilla. x 58. 9. Second maxilla. x 58. 10& 11. MaxiUipedes. Plate XVII. Phreatoicus assimilis. Fig. 1-3. First appendage of the perseon. 4. Second ditto. 5. Propodos produced along the base of dactylos. 6. Fourth appendage of the peroeou. 7. The same, distal extremity enlarged. 8-9. Fifth and sixth appendages of the person. 10. First pleopod. X 19. 11. Second pleopod, of male. X 19. 12. Third pleopod. X 19. 13. Side view of end of pleon, sliowing the telson ana uropoda. x 19. Plate XVIII. Phreatoicus Ujpicus. Fig. 1. Side view of the whole animal, a female. X 6. 2. The antennie, side view, showing the upper antenna and the peduncle of the lower antenna. X 35. 3. Extremity of the left mandible, much compressed. x 180. 4. Lower lip. X 58. 5. First maxilla. X 58. 6. Second maxilla. X 58. 7. Leg of the first pair, of female. X 19. 8. Extremity of the same. X 45. 9. Leg of the second pair, x 19. 10. Leg of the si.xth pair. X 19. 11. Lower margins of the first five segments of pleon. x 19. 12. Side view of end of the pleon, showing the telson and uropoda. x 19. 282 DE. C. CHILTON ON THE SUBTEERANEAN Plate XIX. Cruregens font anus. Fig. ]. Side view of the whole animal. X 12. 2. Antennae, from above. X 45. 3. End of upper antenna. X 1 80. 4. Portion of lower antenna. X 180. 5. Basal portion of lower antenna, from below. X 45. 6. Upper lip. X 120. 7. Mandibles. X 120. 8. Mandibles and end of masillipedes, seen from below and partly from the side, x 120. 9. First maxilla. X 56. 10. Portion of same. X 120. 11. Second maxilla and lower lip. X 120. 12. Lower lip. X 120. 13. Second maxilla. X 120. 14. Maxillipedes, distal portion, from below, x 120. 15. Leg of first pair, outside view. X 30. 16. Portion of the same, inside view, x 30. 17. Leg of second pair, x 30. 18. Palm of same. X 83. 19. Leg of fourth pair. X 30. 20. Pleon, with telson and uropoda, from above. X 30. 21. First pleopod, from below, x 30. 22. One of the posterior pleopoda. X 45. 23. Uropoda, from above. X 30. Plate XX. Crangonyx compactus. Fig. 1. Side view of the whole animal. X 12. 2. Upper antenna. X 45. 3. Portion of flagellum of same. X 120. 4. Lower antenna. X 45. 5. Upper lip. X 120. 6. Right mandible. X 70. 7. Extremity of same. X 240. 8. Extremity of right mandible of another specimen. X 240. 9. Extremity of left mandible (figure inverted) . X 240. 10. Lower lip. x 120. 11. First maxilla. X 120. 12. Extremity of middle lobe of same. X 350. 13. Extremity of palp of same. X 210. 14. Second maxilla. X 120. 15. Extremity of inner lobe of same. X 350 16. Maxillipedes, from below. X 70. 17. Extremity of same, from above. X 120. 18. Inner lobe of same, x 120. CRUSTACEA OF NEW ZEALAND 283 Fig. 19. Outer lobe of same, x 120. 20. First griathopod. X 30. 21. Second gnathopod. X 30. 22. First ])erfeo])0(l. X 30. 23. Fourth perseopod. X 30. 24. First pleopod. X 30, with " coupliug-spines " more enlarged. 25. Second pleopod. x 30. 26. Third pleopod. X 30. 27. First uropod. x 30. 28. Second uropod. x 30. 29. Third uropod. X 30. 30. Telsou. X 30. Plate XXI. Gammarus fragilis. Fig. 1. Side view of whole animal, x 12. 2. Upper antenna, x 30. 3. Lower antenna. x 30. i. Upper lip. X 70. 5. Left mandible, showing palp and cutting-edges only, x 70. G. E.\tremity of same. X 120. 7. Extremity of right mandible, from above, compressed. x 70. 8. The same seen in profile from below. X 70. 9. Lower lip. x 70. 10. First maxilla of right side. x 70. 11. Extremity of palp of same, x 120. 12. Extremity of palp of first maxilla of left side. x 120. 13. Second maxilhi. x 70. 14. ^laxillipedes, from below. X 45. 15. The same, from above. X 45. 16. First gnathopod, inner side, from a large specimen. x 30. 17. Second gnathopod, outer side, from smaller speeiiiien. x 30. 18. First perseopod. x 30. 19. Fourth perseopod, basal joints and extremity, x 30. 20. Extremity of same. X 70, with " auditory seta'' more magnified. 21. Third pleopod. x 30, with '■ coupling-spines " more magnified. 22. First uropod. x 30. 23. Second uropod. x 30. 24. Third uropod. x 30. 25. Telson. x 30. Plate XXII. ('uUiopius subterraneun, c^ . Y\g. 1. Side view of male. x 12. 2. Peduncle of upper antenna, x 30. 3. Calceolus from the same, highly magnified. 4. Lower antenna, x 30. SECOND SERIES. — ZOOLOGY, VOL. VI. 37 284 ON THE SUBTEREANEAN CEUSTACEA OF NEW ZEALAND. Fig. 5. Upper lip. x 58. G. Left mandible. X 58. 7. Extremity of same. X 1'20. 8. Extremity of right maudiljle. X 120 9. Portion of lower lip. X 58. 10. First maxilla, x 45. 11. Extremity of middle lobe of same, x 180. 12. Extremity of palp of same, right (?) side. X 180. 13. Extremity of palp of first maxilla of other (? left) side. X 180. (These two drawings, 12 and 13, were aecidentally made one from above and one from below, hence they both face in the same direction.) 14. Second maxilla. x 120. 15. Maxillipedc, from below, x 45. 16. Extremity of the same, from above. X 45. Plate XXIII. Calliopius subterruneus, (^ . Fig. 1. First gnathopod, outer side. X 19. 2. Extremity of the same, inner side, x 19. 3. Second gnathopod, outer side. X 19. 4. Extremity of the same, inner side, x 19. 5. First perseopod. x 19. 6. Third perseopod. X 19. 7. First uropod. x 19. 8. Second uropod. X 19. 9. Third uropod. x 19. Calliopius suhterraneus, 9 . 10. Lower lip. x 120. 11. Maxillipedc, from above, x 120. 12. First gnathopod. X 45. 13. Extremity of the same. X 120. 14. Second gnathopod. X 19. 15. Extremity of same. X 120. 16. Side view of posterior end of pleon, showing the uropoda and telson. x 45. 17. Third uropod and telson, from above. X 45. 18. Extremity of middle lobe of first maxilla of a small specimen (an immature male?), showing some of the setse only, x 445. I Trans Linn Soc Zool, 5i:R.2.Voi..Vl.PL,16. C Chilton del HarJiirt imp PHREATOICUS A&^m[U^,ChiUon, sprno^ .JOL CiKR ^ ' ^^'/rM^rftf^' C, Chilton, liel PHREATOIGUS ASSIMILIS , C/z../^,;, , Sp. I-U)V CChilfco-n Tr.^ns.L™k, Soc Zool , Ser.2 -Yol.YI.Pl.IS, PHREATOICUS TYPICUS , 6%jZro ro CChiloon rp.AMS.LiNN Soc.ZooL Skr 2 Vo: , VI Pl/19. C Ohilcon . Trails. Linn, Soc Zool.Ser 2. Vol .VI ?l 20. '1 \ , '^:y]W CCKilfaon. del . CR^.NGONYX COMPACTUS, ^A^Z-6o Hantiiir;- .itnio rv T-RANs Linn Soc Zool Ser 2-V'ol VI Pl, 21 C OiuLon del Hai\V.ar& imp GAMMARUS J'RAOJIA 6 .C/i, Clv.lbi IhjViss Lin"n Soc Zool [ver.2Vol. .Vi Pl,22 C Chilton del CALLIOPIUS SUBTEREAKEUS ,GhvlLorv : a til". AT-, •."■i^ C C'hilbo:'. dsi CALLIOPIUS SUBTERRAI^EU^ "v Har.Kart- :n\ji LINNEAN SOCIETY OF LONDON. MEMORANDA CONCERNING TRANSACTIONS. The First Series of the Transactions, containing hoth Botanical and Zoological contributions, has been completed in 30 Vols., and a few entire sets are still for sale. 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Part I. 1894 2 0 0 . . . . Part II. 1894 1 11 0 .... Price to Fellows. 1 5 6 1 4 0 1 2 6 0 0 0 0 0 0 0 4 6 0 18 0 1 1 0 0 12 0 0 9 0 0 3 9 1 0 0 0 9 0 0 4 6 0 9 0 0 4 6 0 6 0 0 9 0 1 1 0 0 2 0 1 10 0 1 3 3 2nd Ser. ZOOLOGY.] [VOL. VI. PART 3. ^"T' ~ THE TRANSACTIONS OF THE LINNEAN SOCIETY OF LONDON. ON A FEESHWATEK SCHIZOPOD FROM TASMANIA. BY GEOUGE M. THOMSON, F.L.S. L O N D O N PllINTED FOR THE LINNEAN SOCIETY BY TAYLOR AND FBANCIS, RED LION COURT, FLEET STREET. SOLB AT THE SOCIETY'S APARTMENTS, BURLINGTON-HOUSE, PICCADILLY, W., AND BY LONGMANS, GREEN, AND CO., PATERNOSTER-ROW. Aiffjii^t 1894. [ 285 ] III. On a Freshwater ScUzopod from Tasmania. By George M. Thomson, F.L.S. Eead 2nd ?\"ovember, 1893. (Plates XXIV.-XXVI.) In a paper read before the Royal Society of Tasmania on November 14th, 1892, I have given a brief account of the discovery of this interesting Crustacean, Anaspides tasmanke*, and have described it as the type, not only of a new genus, but of a new family of Schizopoda. In some respects, indeed, the structure of this animal is so unique as to entitle it to even higher specific rank ; but in many of its characters it is found to be allied, though somewhat remotely, to the Euphausiidce of Sars {Thysanopodidce of Bronn's ' Thierreich ' ). Owing to long isolation it has undergone very profound modification. I found this species in a pool near the summit of Mt. Wellington, Tasmania — that is, at a height of over iOOO feet. The pool was in a small crevice only two or three feet deep, but seemed to have somewhat extensive ramifications among the rocky masses of which the upper part of the mountain is composed. The shrimps which came into the more open part were mostly small ; the larger ones appeared to hide in the deeper crevices of the j)Ool and would not come out while anyone was near. I obtained only a few specimens at the time of my visit (January, 1892), but Mr. L. Rodway, of Hol^art, was kind enough to make an expedition to the top of the mountain at my request on May 24th, and obtained a further supply from under the thick coat of ice which then covered the pool. He secured them by setting a small baited muslin net, but found the larger specimens very shy, as they tried to get the bait through the meshes of the net without venturing inside. Still he was enabled to obtain both males and females, the former of which were not included in my own collection. Unfortunately, none of the specimens in my possession are well preserved, so that it has been very diflicult to make out their anatomical structure, and impossible to arrive at several important details. In the pools and swampy ground round the spot where these were taken, Mr. Rodway, and subsequently Mr. Morton, F.L.S. , of Hobart, obtained specimens of a small Amphipod which I have described in the paper referred to as Niphargus montanus. This species, like Anaspides, is evidently a very old type, belonging, apparently, to a genus hitherto described only from Europe and composed chiefly of underground * This form, was originally described by me under the name of Aaaspis, but as my friend the Rev. T. E. E. Stebbing informs me that this name is pre-occupied, I have altered it to Anaspides, at his suggestion, so that the name of the new order may not have to be changed. SECOND SERIES. — ZOOLOGY, VOL. VI. 38 286 ME. GEOEGE M. THOMSOIS' ON A FEESHWATEE species. Among these was also found a single specimen of Phreatoicus australis, Chilton, previously only obtained from water springs and marshy ground on Mt. Kosciusko in New South Wales at a height of 5700 feet. The type species, P. typlcus, Chilton, is eyeless, and occurs in the subterranean waters of Canterbury, New Zealand. The genus FJireatoicus, as Dr. Chilton has shown *, is an archaic one ; it is, indeed, a remarkably generalized form of Isopod. I have given the new shrimp the following systematic position in the above paper, the name Anaspides being suggested by the total absence of carapace. Tribe SCEIZOPODA. Eamily ANASPID^. Carapace wanting ; the cephalon and all the segments of the body distinct. Maxilli- peds and succeeding seven pairs of limbs uniform in general structure, adapted for walking, furnished with external lamellar branchise. No egg-pouch (?). Pleopoda with well-developed natatory exopodites; endopodites of first and second pleopoda specially modified in the males as copulatory appendages. Uropoda normal. Auditory organ in the base of first pair of antennae f. Peveloj)ment ? Genus Anaspides. Anaspis, mihi. Trans. Roy. Soc. of Tasmania for 1892, p. 51. Integument thin and flexible. Whole body divided into 15 distinct (subequal) segments, viz. one cephalic, eight thoracic, and six, abdominal. Eyes well developed. First antennpB with 3-jointed peduncle and two flagella ; second antennfe with well-developed scale on the second joint. Mandibles with 3-jointed palps. First maxillae 2-branched ; second pair 4-branched. Maxillipeds pediform, with two rudimentary branchiae projecting externally from the coxa ; exopodite small and rudimentary. Legs generally uniform in structure, 7- or 8-jointed, each furnished with a claw-like dactylos. The coxa of each leg (except those of the last pair) bears two external lamellar branchiae which project forward, and the basos bears a well-developed natatory exopodite. Pleopoda with a rudimentary endopodite in the females and in the 3rd-5th pairs in the males. First pair in the males with the endopodite developed into a lamelliform organ (penis ?) ; second pair with the same organ produced into a clasping-process. Telson short, rounded. Uropoda with both plates subequal ; inner wdth a slight longitudinal median ridge ; outer with an imperfect transverse articulation near the middle. External Form. The most remarkable and characteristic features of the body (PI. XXIV. fig. 1) are (1) its separation into 15 distinct segments without any trace of a carapace, thus recalling * " On a new and peculiar Preshwater Isopod from Mount Kosciusko,'' by Chas. Chilton, M.A., D.Sc. Eeeords of the Australian Museum, vol. i. no. 8, p. 149, t This character is not in the original diagnosis. SCHIZOPOD FROM TASMANIA. 287 tlie appearance of an Ampliij)Ocl, and (2) the external lamellate brancliite of the thoracic appendages. The cephalic segment is short and is produced into a triangular subacute rostrum (PI. XXIV. fig. 2) ; the front margin, which is slightly hollowed out for the eye-sockets, is entire and rounded ; the sides are not produced far downward, but leave the tumid basal joint of the mandibles exposed. The eight thoracic and the six abdominal somites are distinctly articulated one to another, but there is much room for overlapping between them, so that a considerable power of flexion on the dorsal line is provided. In many specimens the posterior margin has its overlapi)ing portion distinctly marked out from the rest of the segmeat by its much paler colour. The first thoracic segment is only about half as long as the cephalon ; its lateral portion, which extends further down than the sides of the preceding segment, is separated ofi" l)y an oblique line into a distinct cpimeron, which is widest anteriorly. The other thoracic segments are rather short, so that the thorax and cephalon together only equal in length the whole of the abdominal portion. The sides of all the segments are rounded and do not extend far down ; there is no trace of epimeral marking, but the margins are thicker and more strongly chitinized than the remainder of the segment. Viewed externally, the lateral margins of the thoracic segments are nearly hidden by the branchiae, which project almost to the bases of the second antennae, and by the plumose exopodites of the 2nd to 6th pairs of pera;opoda, which are produced upward and backward on the sides of the body. The colour of these animals is a brownish grey, ajoproximating closely to the sides and bottom of the pool in which they were found. The iutegument is very thin and some- what tough, thinner indeed than that of any other free-swimming Crustacean with which I am acquainted. This is no douljt due in part to the semi-subterranean abode in which the animals occur. The external layer of the integument is transparent, and underneath it are cells containing the pigment to whicli the colour is due. There is no calcareous matter in the integument, neither nitric nor glacial acetic acid producing any trace of effervescence, or indeed appearing to alter it in any way. Strong nitric acid alters the pigment to a yellowish colour and rapidly dissolves it. The pigment-cells are somewhat hexagonal in form, and can be removed in a thin layer, presenting a tesselated appearance. Appendages. The eye-peduncles are short and stout, and are directed obliquely outward ; they reach beyond the extremity of the basal joint of the second antennae, Imt not so far as the extremity of the basal joint of the first pair. Each peduncle is 1-jointed, cylindrical in form, and very slightly enlarged toward the extremity; its length is about twice its diameter. The ocelli, which are very numerous, occupy about the upper third of the stalk ; just below them, particularly on the outer side of the peduncle, are a very few short stiff hairs. Anterior antennce (PI. XXIV figs. 3 and 4). — These organs are normally formed. The 38* 288 ME. GEORGE M. THOMSON ON A FEESHWATER peduncle is 3-jointecl, with the joints broad and somewhat flattened ; the first and second joints are subequal in length, the basal slightly the largest and widest, and having a longitudinal suture tending somewhat obliquely outward along its upper surface ; the second joint also bears a slight longitudinal groove on its upper surface, and is fringed on its outer margin with plumose setae. The third joint, w^hich is also similarly fringed on its outer margin, is broader at its distal than its proximal end, and carries two whip-like flagella. The outer flagellum is from two-thirds to three-fouvths the length of the body, and is divided into very numerous articulations. In the yovmgest specimen examined, the body of which was only about 9 mm. long, there were 36 articulations on the outer and only 8 on the inner flagellum; but in adult specimens the number varies from 70 up to 92, Avhich was the largest number observed. The articulations are furnished with a few short spinose setse on both sides. On the ten or twelve joints nearest the peduncle the setse are long and plumose, but they tend to become shorter and more simple on the joints nearer the extremity. On all the joints but those few setose ones nearest the peduncle there are blunt hairs or cilia of a very characteristic appearance, which are probably sensory organs. The inner flagellum is about one-fourth the length of the outer, and usually consists of about one-fourth the number of articulations ; the joints nearest the base have more or less plumose setse, those further out have the setse simple. But in the male this inner flagellum is modified in a curious manner (PI. XXVI. fig. 12). The fifth and sixth joints are much dilated ; the former bears a large tuft of slightly phimose setse, while the latter cai'ries two large stout setse, w^hich are rugose in their distal half; each is also apparently furnished with a nerve-fibre. The first seven joints also bear a number of short, curved, finger-like setse, all more or less covered with rugosities, so as to resemble a round rasp or file ; these rugosities are arranged in an annular manner and appear to consist of minute stiff hairs. These thickened processes are scattered somewhat irregularly, there being a tuft of about six or seven on the basal joint, then isolated ones or in twos or threes on the succeeding joints, about seven on the sixth joint, and three on the seventh; they are directed toward the upper surface of the flagellum, w^hile the long setse of the proximal joints are all on the lower surface. The remaining joints are simple, and carry short simple setse as in the corresponding organ in the female. These peculiar processes in the male are probably sensory in their function ; they certainly form a very distinct sexual modification. The auditory cavity is placed in the basal joint of the jieduncle of the first antennae, its roof being formed by the flattened upper surface. It communicates with the water outside by a duct which opens at the extremity of the joint under a fringe of setse. Second antennce (PI. XXIV. fig. 5). — The peduncle consists of four (perhaps five) joints, and bears a long flexible flagellum ; all the joints are more or less flattened out laterally, but the upperside of the first and second joints is produced into a longitudinal crest or ridge, which gives the base a somewhat triangular section. The first and second joints are short and subequal in length ; both bear on their outer extremities a crovm of short spines, and the second joint has also a tuft of fine setse on its inner extremity. This joint also bears an oval plate (the scaphocerite of Spence Bate) fringed with long plumose setse. SCHIZOPOD FEOM TASMANIA. 289 This appencla^^e lias a uniformly smooth margin, but it is slightly raised into a median ridge, especially in its basal portion. The third joint, which is subequal with and nearly covered by the scaphocerite, is slightly longer than broad, flattened and thickened on each margin, where it bears a fringe of plumose setse, those on the inside being the longest. The fourth joint is shorter and narrower than the third, and is also similarly furnished with plumose setae ; at its exti-emity it bears a very short joint, which, though somcAvhat narrower than the one bearing it, is considerably broader than the joint of the flagellum which succeeds it. It is probably the fifth joint of the peduncle Avhich is thus almost merged in the fourth. The flagellum is not quite tAvo-thirds as long as the body of the animal, and is composed of very numerous (45 to 60) joints. Each joint bears at its extremity on both sides a number of seta3, those at the proximal end being long and plumose, hut dimin- ishing in size and becoming smootli on the more remote joints ; the last joint is blunt and bears numerous short simple setoe. The oral aperture (PI. XXV. fig. 10) as seen from below is well defined. The dipper lip is a thick fleshy appendage, rounded in front and widening out below. It seems to have very considerable flexibility and power of movement, and is strongly supplied with muscular bands. Close behind it lie the cutting-edges of the mandibles (PL XXIV. figs. 10, 11, and 12), which are similar on both sides. These organs are strongly developed, and are so placed as to close the mouth-opening with their exposed side. The cutting-edge is furnished with a double row of strongly indurated teeth, while placed nearly at right angles and interior to it is a ridge fringed with short bristles, culminating in a strongly-produced grinding tubercle with an oval finely-toothed margin. Tlie palp is 3-jointed, and when at rest projects forward between the bases of the first pair of antennae : the basal joint is broader than long, and furnished with a few short plumose setsB on each side ; the second joint is much the longest, is three or four times as long as broad, and bears a tuft of setse at its upper distal extremity ; near its base on the lower side it is produced into a short triangular tooth, while on the distal two-thirds of the same side it hears numerous short setse arranged in two rows and leaving a long narrow groove, into which apparently the third joint can be folded and so completely protected ; the third joint is short, slightly broadened towards the outer end, and densely fringed with short seta?. All the setse on this organ are furnished with very short hairs, which almost make them appear serrated. The base of the mandible is widely dilated for the reception of the powerful muscles by which it is moved. The under-lip (PL XXIV. fig. 9), placed immediately behind the mandibles, is a deeply 2-cleft fleshy plate, rounded on the outer margins, and finely fringed on the upper and inner with minute close-set hairs. The two sides appear to be capable of opening widely apart. First maxilUe (PL XXIV. fig. 6). — These organs are 2-branched; the external branch, which is strongly chitinous, bears on its inner oblique margin a double row of serrated spinose teeth, which are brown-coloured and strongly chitinized ; the inner branch is Heshy, smaller, more rounded, fringed Avith sliort plumose setse, and seems to have but little power of movement. 290 ME. GEOEGE M. THOMSON ON A FEESHWATER Second maxillce (PL XXIV. figs. 7 and 8).— These are thick, fleshy, and 4-branched, each branch being 1-jointed. The broad basal portion which bears these branches is rounded on its outer edge, which bears a few small spines ; at its upper and outer extremity it has a small crown of setse at the articulation of the outer branch. This basal portion is longitudinally a little bent on itself, so that while the two outer branches on each side work against each other, the two inner lie more in the same plane and move obliquely one against another. The first (outer) branch is short and rounded, and, as is the case with the second branch, ends in a great number of setse, which are somewhat curved inwards and are toothed along their inner margins. The third branch resembles the narrow second one in form, but the setae are not toothed. The fourth (innermost) branch is setose along its inner margin, and is expanded on its outer into a thin rounded lamella which partly covers the third branch. These four setose plates are evidently for the purpose of preventing particles of food from escaping from the oral aperture. 3IaxilU])eds (PL XXIV. figs. 13, 14, and 15).— These organs are distinctly pediform, differing from the succeeding pairs of legs only in the degree of their development. They are 7-jointed. The coxal joint bears on its outer side two lamellar bi-anchite, each of which is obliquely crossed near its base by a tine line of articulation ; the upper of these is more than twice as broad as the lower, which is long and very narrow. On its inner side the coxa bears two small lameUar organs fringed all round with setae, the inner and narrower of which stands alongside, but at right angles to, the outer. These setose plates serve to close the oral aperture behind. The upper portion of this joint bears at its outer extremity a slender appendage which is subequal in length to the rest of the joint. This exopodite appears at first sight to be unjointed, but is seen to bear a minute articulation at its apex. The basos is Ions, and is rounded on the anterior or outer side, while the keeled inner side bears a double row of plumose setae. The ischium, which is similarly shaped in section, is about half as long, and the meros is as long, as the basos. The two succeeding joints form a distinct — and in spirit-specimens a sharp — geniculation with the meros, being bent in towards the middle line of the body ; they are both somewhat shorter than the meros, and are rather densely setose. The propodos is more flattened than the carpos, and is fringed with numerous curved hairs on both margins, while the dactylos ends in three powerful hooked claws, which are almost hidden among setae. These organs I have termed maxillipeds, as in position they correspond to those appendages in other Crustacea; but they might more appropriately be called the first pair of loalk'mg legs. The next seven pairs of legs resemble the preceding pair in general structure, but differ considerably in detail ; they all want the setose lamellae on the inside of the coxal joint, which indeed appear to act partly as oral organs, but several of them have a small pointed lobe which may be a homologous development. The exopodites and branchiae are differently developed in all the limbs, while the basal joint is shorter than in the first pair. In the second to the sixth pairs, the long plumose exopodites apparently serve as natatory organs and facilitate progression though the water. In the second pair of legs (PL XXIV. fig. 16) the joints are similar in number, shape, and relative length, as well as in distribution of setae, to those of the first pair. The SCHIZOPOD FEOM TASJIANIA. , 291 lamellar branchiae are, however, much broader and are subequal in size, the lower one being more oval and pointed than the upper. The exopodite is developed into a long peduncular joint, bearing a stout multi-articulate fiagellum, fringed on the posterior side of the articulations witli long plumose sette. The third j^air closely resemble the preceding, but are in every way larger. The lower of the two branchiae is slightly larger than the upper. The fourth pair of legs are the longest of all. The lower branchia is half as large again cis the upper. The fifth pair are similar to the fourth in most respects, but the sette are more tufted and scattered. On the coxal plate there projects downward and alongside the basos a small lobe, tufted — especially at the end — with setse. The sixth pair (PI. XXV. fig. 1) are shorter, slighter, and less setose than the preceding. The exopodite is, however, relatively strongly developed and is nearly as long as the whole limb, while in the much larger third pair of legs it does not reach the extremity of the meros. The setose lobe on the coxal plate is half as long as the basos. The seventh pair of legs (PI. XXV. fig. 2) show a sudden diminution in the size of the branchiae, which are not half so large as in the preceding pair. The exopodite also is reduced to a small branchia-like projection, not reaching the extremity of the ischium and quite destitute of segmentation. The joints of the leg are more slender and the setae fewer than in the preceding pair, but the coxal appendage — at least in the females — is much more strongly developed. In the eighth ixiir (PL XXV. fig. 3) the diminution is most pronounced; the joints are slender and nearly destitute of setae, while the branchial plates and exopodite are totally wanting. The exact relation of the joints of the legs near their point of attachment to the body is somewhat difficult to make out. In the first pair — the maxillipeds — there appear to be eight joints, and if we count back from the dactylos it would seem that the coxal joint is separated into two articulations, the proximal part bearing the branchiae and the internal processes, and the distal part the exopodite. The same arrangement is seen in the second pair of legs. The eighth pair is also segmented into eight very distinct joints, none of which bear appendages. But in the sixth pair the coxa appears to be reduced to a plate passing on the inner side into the sternum and carrying the branchiae on its outer side, while the exopodite is borne on a special lobe or process. In the seventh pair the coxa appears to be cleft longitudinally, the imier part bearing the ciliated lobe, while the outer carries the branchiae and the exopodite. The latter is not on a distinctly sej)arated process, but has a constriction at its base as if indicating a rudimentary joint. The joints of all the eight pairs of legs from the dactylos to the basos appear to be easily homologized ; the difficulty of identification seems to lie in the development of the coxa. In the females the genital opening (PI. XXV. fig. 3) is a transverse slit on the apex of a rounded tubercle which is placed just anterior to the last i)air of legs. It stands between, and a little in front of, the coxal joints, and almost on the sternal divisions. The setose processes on the inside of the fifth, sixth, and seventh pairs of legs have probably some relation to this organ. 292 ME. GEOEGE M. THOMSON ON A FEESHWATEE The five pairs of pleopocla (PI. XXV. fig. 4) on the first to the fifth abdominal segments are all of a similar form in the females. Each consists of a subquadrate basal joint, the outer portion of which appears almost as if articulated on to the rest. Near the outer angle is the large multi-articulate exopodite, which forms an apparently more perfect oar than the corresponding organ on the thoracic legs. Each is formed of numerous short joints carrying several long plumose setse. On the inner side of the base is a small oblong plate like a rudimentary branchia — the endopodite. In going back from the first to the fifth segment, this endopodite diminishes in size. In the males the first pair of pleopoda (PI. XXV. fig. 5) have the exopodite normal, but the endopodite developed into a lamelliform plate which projects inward (figs. 6 and 6 a). This plate appears to be furnished with a duct which opens near its extremity. The whole organ is somewhat dilated toward the end, and is furnished with a row of minute spines down the sides of the duct. In the second pair (PL XXV. fig. 7, 8, and 9) the endopodites are each produced into an elongated peduncle, which is deeply grooved on its inner face, and bears a double row of stout, slightly-curved spines near its extremity, and a scoop-like terminal process having smooth edges and with the hollow faces meeting in the middle line. Both pairs evidently act as copulatory organs ; but I have not been able to trace the passage of the vasa deferentia into the first pair, which I think represent the openings of the male generative organs. The second pair appear to act only as clasping-organs. The succeeding 3rd-5th pairs of pleopoda arc similar to the corre- sponding limbs in the females. The uropoda form with the telson a large tail-fin (PL XXV. fig. 9), as in most shrimps. In each the basal portion is relatively smaU, while the exopodites and endopodites are produced into large plates or swimmerets ; these are subequal in length, oblong in form, and bluntly pointed : the distal halves of all four plates are densely fringed with long comb-like setaj or spines ; the proximal halves of the inner plates are quite smooth on the outer margin, while those of the outer pltites have a very few short spines. The telson is short and almost transversely truncate, its length hardly exceeding the breadth at its base. The blunted end is furnished with a fringe of comb-like teeth. The shortness of this telson is a characteristic feature, as in the majority of Schizopods it exceeds the uropoda in length. It is only in certain genera of Mysidse (e. g. Euchceto77iera) that the latter reach far beyond the end of the telson. The relative width of the uropoda in .4 ??«spV/^6- causes this tail-fin to act as a very powerful swimming-organ, and this enables the animal to retreat very rapidly from any danger menacing it in front. The largest specimen of Anaspides examined by me was 38 mm. or 1^ inch long, but the length in smaller specimens hardly exceeds 25 mm. I found ova in the oviducts. Anatomical Structure. I have met with very considerable difficulty in working out the structure of Anaspides, owing to the imperfect state of preservation of my specimens. These when caught were merely put into alcohol of unknown strength, and even this was not changed for two or three weeks. The result was that all the internal organs were more or less disintegrated. SCHIZOPOD PKOM TASMANIA. 293 and it was a matter of difficulty — and in some cases of impossibility — to separate them one from another or from the adjacent tissues. In not a single specimen could I isolate the heart throughout its length or trace the course of the principal blood-vessels. The same remark applies to the hepatic tubes, which were completely disintegrated except at tlieir extremities. This has necessarily led to an incomplete and imperfect resolution of many details of structure. The best results in regard to the soft parts were obtained by means of sections. Alimeittury system. — The oesophagus is very short and passes vertically into the stomach (PL XXVI. figs. 1 and 6). The latter is an o^ien sac. curving over nearly at right angles to the gullet and passing directly back into the intestine ; it is of very simple structure as compared with the usual structure of this organ in the higher Crustacea. In front, and just where it widens from the oesophagus, the median line is chitinized into a stout ridge which thickens upAvard into a club-shaped process, covered at its extremity with tine tooth-like rugosities, and projects into the cavity of the stomach (fig. 7). Above this process the median ridge bends over to form the dorsal ridge of the stomach, and this thickening is continued back as far as the fourth thoracic segment. On each side of the base of this line the chitinous thickening is expanded into a t\vo-lol)ed pro- cess, ending in sharp and somewhat widely separated points. At the posterior side of the mouth-opening there arise two stout chitinous ridges densely covered, especially at their base, with setiu or curved bristles, all pointing inwai'd. Thus the opening of the stomach is guarded by so many projecting processes that it must be almost impossible for food to be again ejected at tlie gullet. On each side of the frontal median ridge the stomach is produced into two curved concavities occupying the front portion of the cephalic segment almost to the bases of the antennae aad the ocular peduncles. The base of the stomach, reaching back from the oesophagus to n ear the fourth segment of fue body, is chitinized, and the bands on each side of it are thickly ciliated (tig. y). Tvvo other ciliated bauds pass up the sides and converge towards the median band, forming along with it the roof of the cavity. The side-wails of the stomach between the chitinous bands are very thin and membranous, and are protected by tlie dense mass of muscles of the mandibles. The whole of the stomach and part of the fore-gut appear to be covered by a longitudinal sheath of muscular tissue. Except the clu]>-shaped projection in the front of the stomach, there seems to be no special masticatory apparatus, and trituration of the food appears to depend on the up-and-down movement of the whole upper part of the sac. Maceration of the food is certainly very imperfectly effected, as I have investigated the contents of the intestine and found that so far back as the seventh thoracic segment fragments of Copepoda, &c., occurred, in which the integuments and portions of the limbs were still intact. I think it probable that the hepatic tubes open into the alimentary canal just at the posterior end of the stomach or at the very com- mencement of the intestine ; but neither by dissection nor by longitudinal and transverse sections could I detect the opening, although the tubes themselves were in several cases followed up to this part of the canal. Erom the stomach the intestine proceeds back as a straight, simple, and rather wide tube ; for about the posterior half of its length the wall is wrinkled into small folds, as SECOND SERIES. — ZOOLOGY, VOL. VI. 39 294 MK. GEOEGE M. THOjMSON ON A FEESHWATEK if capable of very considerable backward and forward movement. At about t\^ o-tbirds of its lengtb, or just about tbe first abdominal seg-ment, it bears on its upper surface a sbort oval csecum — in large specimens about 2 mm. long, — directed forward (PI. III. fig. 2). Tliis organ is evidently an excretory gland. Its cavity is densely lined with tube-sliaped cells placed vertically to tbe walls, leaving a hollow space in tbe interior, which is partly tilled with loosely-interwoven elongated and pointed cells, and communicates by means of a sbort duct Avith the intestine. At about tbe extremity of the antepenulti- mate segment of the abdomen the intestine bears on its upper surface another csecum, shorter than the first and directed backward (fig. 3). This is also lined with glandular tissue arranged in the same manner as in the anterior one, and has a central duct. Tlie function of both these organs is probably urinary. In tbe last abdominal segment the intestine contracts sharply to less tban half its previous diameter, and, entering the telson, bends abruptly upward and backward, and then passes out nearly straight to the anus, which is in the form of a longitudinal slit. Where it contracts the wall is surrounded by a coat of muscles arranged in an annular manner. The liver is quite difi"erent in its structure from the corresjionding organ in any other Crustacean with wdiich I am acquainted. Ow ing to tbe very soft tissue of which it is com- posed, especially in its anterior portion, and its consequ.ent state of disintegration in all my specimens, I have been able to make out only a portion of its structure. It consists of a number of slender cylindrical tubes, lying horizontally, but slightly interwoven in the body-cavity, above and on both sides of tbe alimentary canal, and reaching back to half- way betw een the intestinal caeca. In one specimen I traced as many as eighteen of these tubes forward to about tbe posterior end of the stomach, but failed in every instance to find any duct or opening into the alimentary canal. These tubes are of a yellowish straw-colour in ordinary spirit-specimens. Their posterior portions, when considerably magnified, exhibit at the extremity a mass of slightly elongated pointed cells, thickly charged with granular contents (PL XXVI. fig. 9). At a short distance from tbe end a duct arises, the cells all round it, winch line the w'alls of the tube, being arranged in a more or less vertical direction. Excretory organs. — My identification of the so-called " green gland " or renal organ characteristic of all tbe higher Crustacea is not satisfactory, if indeed it exists at all. I have not identified it in dissected specimens, but in one or two sections I have observed ■what appears to be a small mass of glandular tissue lying in front of and partly below the anterior lobes of the stomach and close up to the bases of the lower antennae. At the same time I have not found any duct by -which its excretions are liberated. It is just possible that I have mistaken for this the somewhat disintegrated tissue of the pre- oral ganglion ; but if so, its connexion with the large nerves supplying the eyes has not been traced. It is perfectly possible that the organ is wanting or only exists in a rudimentary state, especially if the intestinal caeca usurp its functions, as I have surmised. Circulatory apparatus. — My observations on this part of the anatomy are A'ery frag- mentary, but they are suflicient to attest the primitive character of Ana.spides. The heart consists of a long simple tube, apparently little dilated in each body- SCHIZOPOD TROM TASMANIA. 295 segment, lying close to the dorsal surface and tapering gradually at both ends into a more slender cylindrical vessel. I have traced the whole tube from about the third thoracic segment back jxxst the posterior intestinal cfecum. Of the arteries passing from the heart, exclusive of its anterior and posterior prolongations, which may be considered respectively as the cej)halic and upper abdominal arteries, I have succeeded in tracing only one prominent artery passiiig almost vertically downward between the seventh and eighth thoracic segments, which probably su^jplies the greater portion of the sternal region. But I have failed to find any trace of the valvular openings into the pericar- dial sinus, by which the blood returning from the branchite and other portions of the body is again fed back to the heart. This is of course due to the very imperfect condition of the tissues examined. The branchiie, as already mentioned, are all lamelliform and are carried externally. Morphologically there are seven pairs on each side, but those of the first pair of legs (maxillipeds) are very much reduced in size, and probably more or less in function also. The branchia-like cndopodites of the abdomiual appendages are no doubt f unctionless as breathing-organs. Reproductive organs. — I have not succeeded in definitely making out tiu; structure of the testes and vasa deferentia in the very few male specimens at my disposal. The male organ, so far as it was identified, consists of two thin, whitish tubes, lying nearly parallel one to another, above and slightly on each side of the intestine (PL XXVI. fig. 5). These extend from the third segment of the thorax, where they are smaller and very mu.ch twisted, as far Ijack as the telson. The densely-twisted part of the organ lies in the penultimate segment of the thorax. The vasa deferentia pass outward from the body- cavity by two rather wide tul:)es, which come down near the outer side of the body to the first pair of abdominal legs. Tlie ovaries form a somewhat flattened pinkish mass on each side of the body above the alimentary canal, having rounded lobes projecting upward and downward so as almost to meet in the median line. The supra-abdominal artery lies along the margins of these lobes, which extend from the last segment of the thorax to the region of the posterior intestinal caecum. In more sexually mature specimens in w liich the ova were found lying in the oviducts, the latter were seen to lie lower down in the body-cavit}^ at the sides or even below the intestine. In the most advanced specimen examined the ova were nearly one millimetre long and were oblong in form. Even in such relatively well-developed ova there was no commencement of differentiation into definite structures. The whole interior appeared to be composed of more or less spherical cells, which were especially densely packed and were smaller in size towards the centre. Even at this stage, the ovum had a strong, homogeneous, well-defined wall, and appeared as if nearly ready to be extruded. In one specimen I found ova ranging from an early morula (?) stage up to the form described, but all the tissues were in bad preservation. I have not succeeded in tracing the ovaries down to the genital opening, which is on the sternum, between the last two pairs of thoracic legs. 39^ 296 MR. GEORGE M. THOMSON ON A FRESHWATER NercoMS System and Sense-Organs. The nerve cord (PI. XXVI. fig. 4) was easily traced along the whole ventral surface of the hody from the extremity of the ahdomen to the mouth, but the organization of its anterior end was not made out satisfactorily either by dissection or by means of sections. In the abdomen there are six quite distinct paired ganglia, the cords being almost united at the very base of the telson to form the largest of these. From each pair of ganglia at its anterior and outer side there proceeds a dense jjlexus of nerves to the surrounding masses of muscular tissue, while from its posterior outer side there passes one rather stout nerve obliquely backwards and downwards to enter the appendage. Each pair of ganglia is separated by two very distinct and somewhat widely separated commissures. In the thorax the ganglia lie much closer together, the commissures, though quite distinct, being parallel and touching throughout their length. The ganglionic portion of the cord is not sharply defined as in the abdomen, the position of the different centres bemg made out most readily by the nerves which pass into the appendages. There appear to be seven (or eight) fairly well-defined ganglia in the thorax, but imme- diately behind the gullet is a mass of ganglionic tissue which appears to supply all the mouth-orsans, but which I was not able to resolve into its constituent elements; nor could I trace the passage of the commissures round the mouth to the anterior ganglionic mass from which proceed the powerful nerves which supply the eyes and the antennoe. The etjes are well-developed as in the higher forms of Crustacea. I have not examined their minute structure. The organ ofhearing (PI. XXVI. fig. 10) is situated in the basal joint of the first pair of antenna?. It consists of an oblong cavity, occupying about two-thirds of the length of the joint, and communicating with the outside by a duct which opens at the end of the joint under a tuft of terminal sette. The roof of the cavity is formed by the flattened upper surface of the joint. This roof is lined by a colourless tissue formed of two (or three ■?) layers of somewhat elongated hyaline cells, standing obliquely or nearly vertically to the surface. The internal layer which forms the lining of the upper part of the cavity appears to form a series of trumpet- or cup-shaped sockets, into which the auditory hairs are jointed. Each of these hairs consists of a club-shaped stalk or pedicel, bearing an elongated bell-shaped cell or capsule (fig. 11). I cannot make out Avithout fresh material whether these cells are open or not ; I am inclined to think that they are closed sacs. I have not been able to trace the se2iarate nerve-fibres passing into these auditory tubes, except near their base, but a very considerable nerve enters the antenna, and has been followed by me nearly up to the auditory cavity. I could not detect any trace of sand-particles such as are common in most of the higher Crustacea, in which the auditory sac communicates with the outside water by a canal, nor of an otolith such as occurs in those forms Avhich have a closed sac. Each auditory tube or hair appears to possess a somewhat complicated structure in its capsular portion. These sense-organs are quite unlike any others hitherto recorded among the SCHIZOPOD 1«'E0M TASMANIA. 297 Artlii'opoda, and will evidently repay close investigation. I tliink each cavity contains a single row of these auditory hairs. I have already referred to the tactile and olfactory hairs of the antennas. Fragmentary and imperfect as this sketch of the anatomy is, it is sufficient to show that in several respects the structure of Anaspldes is unique among Crustacea. The abdominal caeca, the numerous isolated hepatic tubes, the simple tube-like heart, and the curious structure of the auditory hairs are features peculiar to this Crustacean, differen- tiating it not only from other members of the family Sehizopoda (from which Amspides is also separated by its want of a carapace and external lamellate gills), but, I think, from all other described Malacostraca. Affinities and Systematic Position. Anaspides is manifestly a schizopod shrimp, but its greatly generalized characters as well as its remarkalile habitat point it out as a survival of a very old type. The most conspicuous external features are the want of a carapace and the plate-like character of the branchiae. Both are no doubt associated with its habitat among the clefts of rocky pools, where its enemies were probably few and far between, and in which its body was greatly protected, but the former feature especially seems to me indicative of the great antiquity of the type. Until the full development has been worked out — and we know absolutely nothing about it yet — it is impossible to arrive at any conclusions as to how far the carapace is developed in the embryonic stages ; but, with this solitary exception, 1 know of no Crustacean belonging to the Thoracostraca in which there is absolutely no trace of a carapace in the adult forms. In general appearance Anaspiides apjjroaches nearest among Sehizopoda to the family Euphausiidse, with which it agrees in the following external features : — (1) the 7-jointed pediform maxillipeds ; (2) the general uniform structure of the walking-legs ; and (3) the well-developed natatory abdominal limbs, the first two pairs of which are modified in the males as copulative organs. The points of dissimilarity are numerous enough, but they are features in which it differs from all Schizopods, and not from the Euphausiidie alone. Sars has shown* that in the Euphausiidge there are six principal stages of development. After the young animal has passed through the Nauplius and Meta- naiiplius stages, it enters on the Culijptopis stage, so-called by him after one of Dana's spurious genera. In this stage, in which only the cephalic appendages are jiresent, the carapace is attached to the anterior part of the body of the larva, and though it pvojects backward to cover the portion which afterwards develops into the thoracic segments, it is not anywhere joined to these segments, but only to the cepbalon. Even at this early stage, however, it covers and comes to be attached to the somite which bears the maxillipeds. Thus early in the development of a typical Schizopod has the carapace come to be a prominent feature. It may here be pointed out that the resemblance of the body of A// asp ides to that of a sessile-eyed Crustacean is not confined to the want of a carapace and the occurrence of lamellate branchiae ; it is also suggested * Report on the Sehizopoda of the 'Challenger' Expedition, p. 150. 298 ME. GEOiiGE M. THOMSON OX A EEESHWATEK by the presence of a well-marked lateral suture on the tirst thoracic segment, recalling the epimeron of most Isopoda, which, however, is in some instances not developed on the first, though prominent on the succeeding segments. The plate-like character of the branchiae is a feature which does not exhibit nearly so radical a digression as the loss of the carapace. In the development of Ewphaiisia pellucida, Sars has shown * that after the Cahjptopis stage the larva passes through a Furcilia stage, in which the anterior legs and the pleopoda begin to develop. The legs first ajipear as simple processes or lobes, giving rise on their outer side to a minute knob, which is the rudimentary exopodite. As the endopodite develops and gradually becomes articulated, a simple; knob-like protuberance arises at its base, below the exopodite, which as development proceeds bifurcates into two rudimentary plates. This stage appears to cori'cspond with tliat reached by Anaspkles, only in the Furcilia larva the branchiae continue to subdivide imtil they ultimately become arborescent in the adult, because they are sheltered under a carapace and so must expose the largest surface possible to the somewhat limited sujjply of water with which they are surrounded. In most of the Schizojioda the gills become arborescent. The archaic character of Anaspides is more fully revealed by a study of its anatomy. The alimentary canal sho\\s a much simpler structure than prevails in any other described Schizopod. In Ilysis t, which may l)e looked on as one of the least highly developed forms of the suborder, the stomach is distinctly divided into an anterior (cardiac) and a posterior (pyloric) })ortion ; the latter is much the smaller, is of very complicated structure, and is the j^art in which the food is chietiy triturated. Opening- just behind it and placed dorsally is a small caecum, which acts probably as a sort of salivary gland. The liver is composed of ten jjouch-likc masses, five on each side, which unite their contents into a hepatic duct entering the intestiiie just where it leaves the stomach. The intestine is a nearly straiglit tube, passing directly to the anus, and having no caeca or diverticula communicating with it anywhere behind the opening of the hepatic duct. In Ettphausia % the structure of the alimentary canal is essentially similar, but above the pyloric portion of the stomach are two small incurving caeca (not one as in Ml/sis), while the liver consists of a mass of minute hepatic tubes on each side of the intestine and not reaching to the posterior portion of the thorax. These masses of tubes are quite distinct in appearance and aggregation from the long isolated tubes of Anaspides. Ca^ca of the mid-gut are found in all orders of Crustacea as paired or unpaired organs. Their position appears to vary a good deal. Eor example, in some Bracliyura (e. g. Carcimis) a pyloric ca3cuni or diverticulum arises on each side of the stomach in front of the hepatic ducts, which when uncoiled exceeds the intestine in length, Avhile at about one-third of the distance from the stomach to the anus a solitary caecal appendage arises, also in the form of a long tube. In others (e. g. Maia) the latter caecum is placed at the extreme anterior extremity of the intestine. In the Macroura there is always the usual pyloric caecum, but in some genera (e. g. Astacus) * L.c. p. 10:?, pi. XXX. figs. 23-27. t G. 0. Sars, ' Hist. Nat. des Urustaces d"eau douce de Norvi'go/ p. 2G. X ' Challenger ' Report, p. T-j. SCHIZOPOD FEOM TASMANIA. 299 there is uo appendage of the intestine, though this is present in others. In all the Tlioracostraca the liver is in the form of a moi'e or less compact mass composed of numerous small caeca. In Amphipoda (e. g. Gammarus '*) a single pyloric caecum opens just beliind the stomach, and this is also jirobably salivary in its function; while at the posterior end of the mid-gut two slender cylindrical processes open into the intestine. These caeca are placed along the dorsal surface of the intestine, antl reach as far forward as the last thoracic segment. Their function is probably nrinary. In CaprcUa deutafaf a single pyloric ctccum is placed dorsally to the posterior part of the stomach and opens in the front part of tlie intestine, while near its posterior extremity the intestine carries a small simple caecum very similar to the posterior one in Anaspk/e.s. In the Schizopod under consideration tlie stomach is hardly separable into a cardiac and pyloric portion, nor is the separation between the hind part of the stomach and the intestine at all well marked. The liver is unique in its structure. There is no trace of a pyloric caecum J, the first organ of the kind being placed as far back as the first abdominal segment. Prom the imperfectly triturated condition of the food in the part of the intestine which passes through the thorax, I am inclined to believe, as said before, that the gastric function is only imperfectly performed by the stomach, and that the anterior part of the intestine acts as part of the pyloric stomach. If this be so, the anterior cfecum may still function 2iartly as a salivary organ (though this is hardly probable), and the posterior one, Avhich is placed far back in the alimentary canal, may be excretory only and may act as a urinary gland. It is clear, however, that the whole structure of the alimentary canal bears a closer resemblance to the lower Amphipoda (Caprellidaj) than to any of the higher forms of Crustacea, and this is probably to be looked on as another survival of a primitive type of structure. The circulatory apparatus has been shown to be very elementary in its structure. In the Brachyura the heart reaches its maximum development, occurring in most crabs as a short polygonal vessel placed in such a central position as to readily control by its rhythmic action the blood-supply of the body. In Macroui-a it is also a well-developed saccular organ, from which the passage of the various arteries can readily be traced. In Schizopods, though not so well developed, it still preserves its saccular character. But in Anaspides it is apparently reduced to a simple tube. Only in the Stomatopoda, among the higher Crustacea, is there any approach to such a primitive form. It is premature, with the imperfect knowledge of this animal still at our disjjosal and our absolute ignorance of its development, to attempt to frame any genealogical scheme showing its position among the Schizopoda, but from the points referred to I thmk it probable that the Ajiaspidae and the Euphausiidte were somewhat closely allied in their origin. *^Sars, Crustacc's rl'eau douce, p. 5-5. t 1*. Mayer, ' Die Caprelliden des Golt'es von jS'capcl,' p. 147, Taf. 9. figs. 2, '■'>, and 4. % This statement must be accepted with the reservation due to tlie fact that 1 could not make out this feature clearl}', but it appeared to me as if the upper part of the pyloric portion of the stomach was enveloped in an easily disintegrated tissue of which I could not trace the close connection with the alimentary eanal which certainly existed. "Whether this tissue represents an imperfectly developed pyloric caecum, or an anterior process of the liver, I have not succeeded in demonstrating. 300 ME. GEOEGE M. THOMSON ON A FEESHWATEE In trying to arrive at some conclusions as to the lengtli of time during wliicli Anaspides has heen isolated, the following facts are of interest. I am indebted for this information on the geology of the district to my friend and former pupil, Mr. A. Mont gomery, M.A., Government Geologist of Tasmania. The top of Mt. Wellington, as well as the central plateau of Tasmania, consists of a mass of greenstone (diabase) of about Permo-Carboniferous age. According to Mr. R. M. Johnston, the greenstone existed prior to the deposition of the shell-beds and sandstones which flank its base, while Messrs. Stephens and Montgomery consider it to be younger. Mr. Johnston admits, how^ever, that there was a " newer greenstone " eruption which broke through these marine deposits, so that it is agreed that the Permo-Carboniferous beds were penetrated by greenstones subsequent to their formation, and it is probable that the eruption of these greenstones and the elevation of the marine beds were contemporaneous. The green- stones break through and cover the Upper Coal-measures, W'hich have been referred to the Mesozoic period on account of the plant-fossils contained in them, though no strati- graphical break has yet been discovered between them and the Permo-Carboniferous marine beds at a horizon very little below them. If Mesozoic at all, they must probably be referred to the beginning of that period, and the greenstone eruptions were probably little later. They were certainly older than the oldest Tertiary beds, which may be Eocene. There are no Secondary marine beds, and the Tertiaries are quite littoral, so it appears certain that Tasmania has never been under water to any great extent since some time in the Mesozoic, and possibly since the close of the Palaeozoic period. It seems probable that the basaltic eruption, of which the diabase greenstones are the remains, took place early in the Mesozoic period, and that it was of immense extent, the whole of the eastern half of the island being covered with lavas. Sub-aerial erosion has since carved out these, leaving the central plateau and the top of Ben Lomond as remains of the great covering sheet, and exposing the dykes and bosses through which tlie molten matter was ejected, in the numerous small greenstone hills in the loAver country. Mt. Wellington was probably one of the large centres of eruption, as a deep bore at the Cascades near Hobart shows the greenstone to underlie the Permo-Carboniferous beds. The fact that Tasmania has been dry land since Mesozoic times Avill probably not be disputed by any one conversant wdth the geology of the country. It seems to me probable that Auasjndes has been isolated from some marine form since a period shortly after the eruption of the greenstones referred to. The occurrence of freshwater Crustacea belonging to marine types may be variously accounted for. It is alw ays possible that the animals themselves or their eggs may have been carried by aquatic birds ; but I know of no recorded case of such a mode of distribution, nor do I know of any marine form which would survive in fresh water. I have often plunged various littoral species belonging to different families (Palinurus, Atylus, Dexamme, Sphceroma, &c.) into fresh water and found that they died in a very short period of time, usually in the course of a few minutes. On the other hand, the adaptability of various marine Crustacea to a freshwater habitat by gradual stages is a well-ascertained fact. The following examples are of interest. In New Zealand I originally described Idotea laeiis- tris from brackish water at the mouth of a lagoon which communicates with the sea at SCHIZOPOD FROM TASMANIA. 301 spring tides or after heavy rains, and afterwards found the same species further up the lagoon where the water was quite fresh. My co-worker and friend, Dr. Chilton, has since found the species in a mountain stream in the same neighbourhood at an elevation of 1200 feet. It is clear that in this instance this Isopod has within very recent times made its way up the stream, where it is now thoroughly estabhshed. The same species has been taken in the Straits of Magellan, and all the other numerous species of the genus and family are marine with the exception of the Scandinavian Gbjptonotus entomon. Leander fluviatilis, St/menosoma lacustris, and CalUophis fluviatilis occur in New Zealand streams and lakes, and, though not found in the sea, are not uncommon in tidal waters. Crangonyx compactus, Calliojmis siibteivaneus, ami Gammarusfrayills, found by Dr. Chilton in the subterranean waters of Canterbury, and Pherusa cccrulea, found by myself in a stream in the Old Man Range in Otago at an elevation of 3000 feet, are species belonging to marine genera, which have most probably migrated from the sea by gradual stages. I have myself taken Coroph'mm excavatum, Allorchestes recens, and a species of Schizopod which I identify as Iltisldopsis incisa, Sars (origuially described from a specimen obtained at the entrance of Port Phillip from a depth of 33 fathoms), from the mouths of streams or lagoons where the water is frequently quite fresh. These are a few examples, taken from instances occurring in New Zealand, of a gradual transi- tion of marine into freshwater species, and of which similar examples could no doubt be recorded from all other jmrts of the world. In such a manner most probably the ancestral forms of Anasjildes found their way from the sea in Mesozoic times into the streams and lakes then occurring in Tasmania, in which, to judge from its remarkable specialization, it has been isolated for a great period of time. Its association with Phreatoicus australis and Niphargns montanus points in the same direction. The former, as already stated, is an Isopod of a very old and greatly generalized type. Its occurrence in two such isolated localities as Mt. Kosciusko in New South Wales, a granitic mass of great antiquity, and Mt. Wellington in Tasmania, and at a very considerable elevation m both, would appear to show that it has survived thi'ough long periods of time ; coupled Avith which is the fact of the only allied species being an eyeless form from the underground Avaters of Canterbury in the South Island of New Zealand. The very vegetation on the summit of Mt. Wellington suggests the antiquity of the region. Surrounding the locality in which Anaspides was found grow numerous forms of plant-life characteristic of the Antarctic Plora of Tasmania, the Australian Alps, and Isew Zealand, such as Abrotanellu, Doimtm, Carpha, Oreobolns, Uncinia, &c., so that could one shut one's eyes to the Australian element which is so abundantly present, it would not be difficult to imagine one's self on a mountain in the south portion of New Zealand or on one of the peaty swamps of Stewart Island. These facts certainly give no direct testimony to the age of Anaspides, but they are suggestive, and may enable us, when its development has been worked out and its own distribution and that of its associated forms are better known, to arrive at some more defluite conclusions on the subject. SECOND SERIES. — ZOOLOGY, VOL. YI. iO 302 ME. GEORGE M. THOMSON ON A FRESHWATER EXPLANATION OF THE PLATES. Plate XXIV. Figs. 1-16. AnaspUles tasmanice. 1. Body of animal, ? . x 4. 2. Dorsal view of ceplialoii : (e) 1st antennae; (6) 2nd antennae, x 30. 3. Basal portion of 1st antenna. x 26. 4. Portion of tLe external tlagellum of same, showing setse and sensory haiis. x 56. 5. Basal portion of 2nd antenna, x 26. 6. First maxilla, x 26. 7. Second maxilla, x 26. 8. One of the comb-like setse from the outer lobe of the second maxilla. X 56. 9. Under-lip. X 26. 10. Mandible, with palp, x 26. 11. Cutting-edge of same, showing the double row of teeth. x 84. 12. Grinding tubercle of same. x 84. 13. Leg of the 1st pair (maxilliped). X 13. 14. Section of basis of same, x 26. 15. Extremity of propodos, and dactylos of same, underside, x 56. 16. Leg of the 2nd pair. X 13. Plate XXV. Figs. 1-10. Anaspides tasmania. 1. Leg of the 6th pair. x 13. 2. Leg of the 7th pair, female, x 13. 3. Leg of the 8th pair, female : ^.o. = tubercle with genital opening. x 13. 4. Second pleopod, female, x 13. 5. First pleopod, male, x 13. 6. Eadopodite of same, x 26. 6 a. Endopodite of same, seen from the inside, young male, x 56. 7. Second pair of pleopoda in male, without the exopodites. x 13. 8. Endopodite of 2nd pleopod in male. x 26. 8«. Extremity of same turned inward. x 26. 9. Telson and uropods from above. x 13. 10. Oral aperture seen from the underside. X 10. i.a., 1st antennae; o.a., 2nd antennae; m./., under lip ormetastoma; ware., mandibles ; mp., maxillipeds. Plate XXVI. Figs. 1-12. Anaspides iasmania. — Anatomy. 1. Longitudinal (diagrammatic) section through the body of a female specimen (the heart is represented as too near the dorsal surface, the large dorsal muscles not being shown) : o.a., mouth-orifice; in., intestine; h.t., liver; n.c, nerve-cord; c, heart; ov., ovaries; co., anterior intestinal ctecum ; co.j, posterior intestinal caecum ; an., anus. SCHIZOPOD FEOM TASMANIA. 303 Pig. 2. Longitudinal section through portion of intestine and anterior caecum. 3. Corresponding section through intestine and posterior caecum. 4. Nerve-cord. 5. Testes and vasa deferentia. 6. Outline representing longitudinal section of stomach : «., gullet ; in., intesthie. 7. Club-shaped process in front of stomach. 8. Chitinous hairs from the lining of the stomach. Highly magniiied. 9. Posterior extremity of a hepatic tube. Highly magnified. 10. Section through base of first antenna showing the auditory cavity. 11. Auditory capsules or setae. Highly magnified. ] 2. Basal joints of inner flagellum of first antennae, showing the remarkable tactile hairs, &c. / ^i^||i^.., Tp^jfK.LjHjff.Soc . Zool,.Ser.2 .Yc- «;. ^^ , i ,* -. '.>^' LINNEAN SOCIETY OF LONDON. MEMOKANDA CONCEllNING TEANSACTIONS. The First Series of the Transactions, containing both Botanical and Zoological contributions, has been completed in 30 Vols., and a few entire sets are still for sale. Only certain single volumes, or parts to complete sets, may be obtained at the original prices. The price of the Index to Vols. 1-25 is 8s. to the public, and 6s. to Fellows ; to Vols. 26-30, 4s. to the public, and 3s. to Fellows. The Second Series of the Transactions is divided into Zoological and Botanical sections. The prices of the Zoological parts of these which have been published are as undermentioned (for the Botanical parts see Botanical wrapper) ; — Wlien Price to the Volume. Publisht-a. Public. £ s. d. Second Series. — Zoology. I. Part I. 1875 1 4 0 . 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LONDON: PRINTED FOR THE LINNEAN SOCIETY BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. SOLD AT THE SOCIETY'S APARTMENTS, BURLINGTON-HOUSE, PICCADILLY, W., AND BY LONGMANS, GREEN, AND CO., PATERNOSTER-ROW. iV/ ''Februorn 1896. SEP 9 1898 [ 305 ] IV. The Comparative Ilorphologij of the Galeodidae. By H. M. Bernard, 3LA. Cantab.^ F.L.S., F.Z.S. {From the Huxley Research Laboratory, Royal College of Science.) (Plates XXVII.-XXXIV.) Bead 7th February, 1895. Contents, _ Page Introduction 305 Historical , 307 I. The External Form and Segmentation 308 II. The Internal Apodematous Skeletal System 319 III. The Limbs 321 IV. The Cuticle and its Derivatives, and the Hypodermis 330 V. The Muscular System 335 VI. The Nervous System 341 VII. The Sense Organs 345 VIII. The Alimentary Canal 355 IX. The Heart and Circulation 365 X. The Kespiratory System 371 XI. Excretory Organs 377 XII. Reproductive Organs 384 XIII. Summary, an attempt to elucidate the Phylogeny of the Arachnida 387 XIV. Bibliography 404 XV. Explanation of the Plat«s 407 Introduction. A COMPARATIVE study of the Arachnidan family, the Galeodidge *, has long been a desideratum. The chief sources of our knowledge of this family date back to times before the all-absorbing questions of ancestry had made morphology the fascinating study it now is. The Artbrojiods, for many reasons, have long been recognized as presenting a rich field for investigation in this direction, and most modern works deaUng with the mor^ihology of any Arthropod form contain discussions as to the probable affinity of the family described with other members of the group, and its bearing on the ancestry of the Arthropods in general. Of such discussions, none have been carried on so vigorously as that on the affinities of the Arachnida. This controversy, for such it is, arose out of an attempt to connect the Arachnids with the ancient aquatic Merostomata, one form of which, Limulns, is still extant. This suggested relationship, though widely accepted, has been also strenuously opposed. Some opponents confine themselves to a purely negative attitude, others prefer to see distant affinities with the lusecta. The Galeodidae are largely responsible for this suggested * This name was given by Ohvier, 1791, and, according to Dufour, referred to the resemblance of the cephalic lobes to a helmet {galea). Others, however, would deduce it from the Greek yaXeri, a weasel-like animal, in refer- ence, no doubt, to the light colour and rapid movements of the commoner species. The name Soljiuga was given later by Herbst, 1797. SECOND SERIES. — ZOOLOGY, VOL. VI. 41 306 ME. H, M. BEENAED ON THE Hexapodan affinity, chiefly because tliey appear to have a head separated from a thorax of three segments ; this, taken together with the presence of Malpighian vessels, unknown in the Crustacea but characteristic of the Hexapods, was brought forward as evidence. The Galeodidce, therefore, might be expected to be valuable witnesses one way or the other. The present attempt to gather the evidence to be gained from the Galeodidse began in the following way: — In 1892* I endeavoured to show that the morphology of the Crustacean A^nis (and of the Merostomata) could be explained by deducing them from a Chsetopod Annelid, which, in adaptation to a new manner of feeding, bent the first segment, with mouth and prostomium, ventrally, so as to push the food iuto the mouth by means of the parapodia. The necessary conclusion, that Liniulns was a primitive Crustacean, brought me involuntarily into the question of the origin of the Arachnida, inasmuch as the supporters of the Arachnidan affinities of Limulus separated the Merostomata from the Crustacea. I therefore set myself the following problem : — Is it possible, by comparing the known Arachnids one with another, to find out, as I claim to have done in the case of the Crustacea, what modifications of the primitive Annelidan segmentation, in adaptation, probably, to some special manner of feeding, gave I'ise to the Arachnidan phylum ? Por I assumed, at the outset, that modifications for better acquiring the materials for growth were the most far-reaching and fundamental in initiating new departures in animal morphology. The Arachnids might still be derivatives of the Merostomata, in spite of the fact that the latter were, as I believe, primitive Crustacea. The only way to settle the question was to ascertain, if possible, how the arrangement of their anterior segments had been derived from a jirimitive ■undifferentiated condition. Here, again, Galeodes promised to yield valuable evidence, on account of its claim to have a head and three thoracic segments. The results here recorded were not obtained at once. I had already drafted the description of the anatomy of the Galeodidse iu extenso, and had worked over the draft at least twice without discovering any satisfactory explanation of the morphology of the anterior segments of the Arachnida. The difficulties seemed insuperable, in spite of the apparent simplicity of the results. One clue, however, led to another, each one in turn necessitating considerable recasting of the MS. It is, indeed, with reluctance, under the pressure of other engagements, that I now let it go forth ; for, though I believe that I have solved the problem I set myself, the paper covers so much ground and deals with so many points that I am painfully conscious not only of blanks which I wished to have filled, but of very uncertain handling of many subjects, where I have neither done justice to my own accumulated material nor to the existing literature. I need hardly apologize for errors which, in a work of this extent, are almost unavoidable, except where I have unconsciously overlooked or misunderstood the views and statements of others. I have at the outset to fulfil a pleasant duty in thanking the authorities at the Royal College of Science for having placed a table in the Huxley Research Laboratory at my * "Tho Apodidae." ' Nature' Series : London, 1892. COMPAEATIVE MOEPHOLOGY OF THE GALEODID^. SOT disposal for three consecutive sessions, during one of wliich I was granted tlie Marshall Scholarship. Por material I am indehted to Professor Howes, who kindly obtained for me specimens of two genera, Galeodes and Rliax [I further take this opportunity of acknowledging my great indebtedness to Professor Howes for much invaluable and sympathetic advice] ; to Pi'ofessor Mobius, director of the Berlin Museum, who kindly sent me four large specimens labelled " Galeodes cjrrecus (Koch)," but which, according to Mr. Pocock, are G. arabs (Koch) ; to Professor Tichomirotf, of Moscow, who generously sent me some fine specimens of Galeodes and Rhux ; and, lastly, to Miss Hay, formerly of Tashkeud, for two specimens of Galeodes and one of Rhax. Some of these specimens were cut into sections, a difficult process, owing to the enormous thickness of the cuticle in various parts of the ce2)halothorax, and others were dissected. I have further examined the collection of Galeodidae, containing five genera {Galeodes^ Solpuga, Rhax, Clcobis, and Glncia), in the Eritisli Museum, and owe my best thanks to my friend Mr. E.. I. Pocock, who has charge of them, not only for his courtesy in placing them at my disposal, but also for much friendly advice and criticism *. I have followed Mr. Pocock's classification throughout. Owing to the necessarily limited supply of these rare animals, there are many points left entirely untouched. And, further, owing to the indifferent state of j)reservation in which the specimens come from the collectors, many important histological questions can only be provisionally answered. Nevertheless, the positive results obtained are of sufficient interest and importance to justify tliis publication in the hoj)e that, at some future time, if my efforts to obtain material are successful, it will be followed by a supplement supplying at least some of the deficiencies. HiSTOPaCAL. In 1797 Lichtenstein and Herbst published an intei'esting historical account of the Galeodidae +. All the references to the group to be found in the works of previous writers, ancient and modern, are quoted, and the manner of life of some of the commoner forms is described. The first compreliensive account of the anatomy of the Galeodidae, by Modest Kittary, appeared in 18^8 (41). It deals with two species called by the author G. aranoides and G. intrepklus. The description is on the whole very accurate, and many of the results obtained seem not to have received the attention they deserve. Blanchard's * 1 have also serial sections of Pseudoscorpions, Phalangidaj, Araneae, Scorpions, Thelj-phonidte, and Phrynidaj, for most of which I am indebted to my wife. My thanks are also due to my friend Mr. Martin Woodward for some beautiful sections of Scorpio and Spiders. I further dissected I'hri/nus, large .Spiders, and Scorpions for tlio purpose of comparison. t " Natnrgeschichte der Insekten-Gattungen Solpuga und Phalangiam " : Uerlin, 1797. The authors adduce reasons for believing that the " mice " which plagued the Philistines [I. Samuel, 5 and 6J were " Wind-scorpions," as the Arabs call Galeodes. They record the evil reputation of this animal, which is said to have forced the inhabitants of flourishing regions to desert their habitations, and to be particularly dangerous to sleepers, man and beast. The fact of its having the same name among the ancients as mouse and shrew-mouse suggests an explanation of some of the superstitious about shrew-mice and cattle which still sur\-ive among us. 41* 308 ME. H. M. BERNAED ON THE great Avork on the Arachnids in ' L'Organisation clu Regne animal ' contains heantiful drawings of the anatomy of Galeodes, but vmfortnnately, beyond the explanation of the plates, the text is wanting. The most exhaustive account of the Galeodidae is from the pen of the illustrious French naturalist Dufour. His " Anatomie, Physiologic, et Histoire naturelle des Galeodes " (31) has the special advantage that the author's previous studies on Scorpio enabled him to handle the subject comparatively. In addition to these three works, there have been several small articles dealing with special points. Systematic papers have naturally not been taken into account, the object of this paper being purely anatomical and morphological. I. The External Form and Segmentation*. Fusion of Segments. — The general form of the Galeodidae (PI. XXVII. figs. 1, 11, 15 ; PI. XXIX. figs. 3, 4, 6) is so well known that we need discuss only the points of mor- phological interest. The Galeodidae show the primitive metamerism of the body more markedly than any other Arachnid, the first three segments of the cephalothorax being the only fused segments in the body. The three posterior segments remain movable. The abdominal region consists of ten segments, all of which are free. This limitation of the fusion of ■segments to the first three is a very important point in endeavouring to fix the systematic position of the family. In the Scorpionidse, Thelyphonidse, and Psoudoscorpionidse, while the segments of the abdominal regions are free, the segments of the cephalothorax have been fused together. In the Araneidse, all the segments both of the cephalothorax and of the abdomen are fused into two groups, the first six forming the cephalothorax and the last ten forming the abdomen. Scldzonotus is the only other Arachnid which, like Galeodes, has retained free cephalothoracic segments, but it is not easy to make out the segmentation 'exactly. There are certainly two free segments, and I should not be surprised if there ultimately prove, on examination of favourable specimens, to be three, as in Galeodes. Segmentation of the Dorsal Surface : Cephalothorax. — Behind the large plates of the cephalic lobes {cl.), we can trace three clear segments, /. e. the 4th, 5th, and Gth, and the remains of the 3rd not quite obliterated by the cephalic lobes. The details can be gathered from figs. 1-7 (PI. XXVII.). The terga of segments 5 and 6 have remained practically unmodified, and are the direct forward continuation of the series of abdominal terga (fig. 1). The tergum of segment 4 has undergone a striking change. The Galeodidae can bend the body not only between the Gth and 7th segments (at the waist), but also between the 4th and 5th. To facilitate this anterior bending, the greater part of the tergum of the 4th segment is soft and flexible, while what I assume to be its anterior edge has given rise to two spring-like rods, the tips of which fuse anteriorly with the posterior border of a rim * Since, in the Arachnida, the limbs are typically arranged as foUows : — two pairs grouped round the mouth, viz., the chelicera3 and the pedipalps, and four pairs as ambulatory legs — it is a matter of indifference whether we speak of them as chelicerie, pedipalps, and Ist, 2nd, 3rd, and -Ith pairs of legs, or as appendages 1-6. In what follows, both designations are used, the 1st leg meaning the 3rd appendage, and so on. COMPAKATIVE MORPHOLOGY OF THE GALEODID^. 309 of cliitin projecting from under the cephalic lobes. Laterally, these rods {>', PI. XXVII. figs. 5, 0, 7) are continued downward to the skeletal framework of the ventral surface posterior to the bend (PI. XXVIII. fig. 15, r). These rods, which are supports for the so-called " head," vary slightly in their points of fusion with the chitinous plate or pair of plates just mentioned, which project from under the cephalic lobes (cf. PI. XXVII. figs. 1, 3, 4, 6). These projecting plates (marked 3 in the figures) are, in all the Galeodidie, separated by a suture from tiie posterior border of the cephalic lobes themselves ; and in transverse and longitudinal sections they are seen to run under the posterior blind ends of the lobes (PI. XXVII. figs. 11, 12). In some genera, e.g., Bhax, the single piece is but a narrow strip (figs. G, 7). In Galeodes the strip is wider and bent upward at an angle from the cephalic lobes (fig. 5). It is sometimes wddest in the median line (fig. 3) ; at others, at the sides, where it may form a pair of triangular plates (fig. 1). These are, it seems to me, the remains of the tergum of the 3rd segment, the anterior portion of which, together wath the terga of the 1st and 2nd segments, has been obliterated by the cephalic lobes. The Cephalic Lobes. — These two plates, joined by a suture along the middle line, form one of the most striking features of the Galeodidte. Their anterior edges, which vary in outline in different genera, are generally sharp, and pass at once into the flexible membrane round the bases of the chelicerse. In the genera Biton and Cleobis, the anterior edge tends to bend over to form a slight " forehead " (fig. 2). From the anterior end of the median suture, the ocular tubercle protrudes. Where there is a slight " forehead," the eyes project forward from it (fig. 2). The median suture is sometimes, comparatively speaking, indistinct, the plate formed by the two lobes being posteriorly rounded off {Rhax, fig. 6). On the other hand, the suture may be very marked, even dividing the posterior margin of the double plate into two lobes [Soljpuga, fig. 3). In all the Galeodidae there is a curious area [a in the figures) on each side of the cephalic lobes, which is not easy to explain. Pocock sviggests (6o) that these are the remains of the proximal joints of the cheliceraj. In this interpretation I was at first inclined to agree, but now think that they have arisen secondarily from an infolding of the cuticle to form the strong buttresses upon Avhich the chelicerse rotate (see further, infra, p. 321). Origin of the Cephalic Lobes. — In endeavouring to answer the question, " what are these remarkable plates Avhich so disturb the segmentation at the anterior end of the body ? " I have been led to refer them to the translocation of the chelicerse from a postoral to a preoral and dorsal position. I would suggest the following explanation of the changes which have taken place in the arrangement of the segments : — In order to carry the enormous chelicerae, lateral processes of the first segment have been thrown backward on to the dorsal surface, where they meet in the middle line, giving rise to the so-called " head," which Dufour attributed to these animals. A close examination of this " head " shows that it consists of a pair of chitinous lobes carrying the muscles of the chelicerae ; no other muscles run into them, and, moreover, the muscles of the chelicerae are almost, if not entirely, confined to them. Fig. 12 (PI. XXVII.), 310 ME. H. M. BERNAED ON THE which is a transverse section, shows that posteriorly they are a pair of blind pockets restino- on the dorsal surface. These cephalic lobes may then be explained as the lateral re^-ions of the first segment which, for tlie attachment of the muscles, have travelled upward and backward in the process of tilting forward the powerful chelicerae (as shown in the diagram, PI. XXVII. fig. 8) into the striking position which they occupy dorsally to the mouth and labrum. The position of the chelicerge is one of the features which distinguish the Arachnids from all other Arthropods. If the above explanation of the origin of these lobes is correct, we ought, then, to find them, or traces of them, in all other Arachnids. I have already pointed out (9) the marked likeness between these lobes in Galeodes and the cephalic lobes which appear in the embryos of Spiders. Further, by taking account of yolk-displacement, the embryonic procephalic lobes of the Scorpionidse may be referred to the same structures. We have, then, to explain the embryonic cephalic lobes of Arachnids as recording the movement of the basal regions of the chelicerse (which, from being postoral limbs, became preoral) laterally round and above the mouth till they met in the dorsal middle line behind the labrum and the eyes. The only other Arachuid with the cephalic lobes as pronounced as they are in Galeodes is Schizonotus, which, as we have seen, resembles Galeodes in the non-fusion of the last two (V three) cepbalothoracic segments. In the majority of Arachnids, the cephalic lobes have been more or less secondarily obscured. The two chief causes of this gradual obscuration of the cephalic lobes in the Arachnida are (1) their complete fusion with the terga of the 4th, 5th, and 6tb cepbalothoracic segments, so that the dorsal surface is covered by a single piece ; (2) the secondarily acquired enormous development of the pedipalps as compared with the chelicerae, so that the cephalic lobes, which were primarily the carriers of the originally powerful chelicerse, are no longer so pronounced as to be immediately recognizable [cf. fig. 9). Many Arachnids still, however, show unmistakable traces of the paired lobes divided by the median suture. In some Scorpions, the formation of the carapace out of a pair of median anterior plates with the triangular remains of the tergum of the 3rd segment, followed by three distinct terga, can still be made out. In Thelyphonus the lobes can still be recognized. In the Araneaj, except in the Aviculariidse, which are in other respects also primitive, they are bent down anteriorly to form a " forehead,"' and are still here and there traceable on the carapace, e. g. of the Drassidse. The Ocular Tubercle. — If this view of the secondary origin of the anterior dorsal surface is correct, il is clear that, if the eyes were primitive structures belonging to the primitive dorsal surface, the cuticle immediately round such eyes must be part of that original dorsal surface, and not primarily continuous with that of the new dorsal surface, formed by the meeting of the cephalic lobes in the dorsal middle line. We find some evidence that this is indeed the case. The ocular tubercle in very many Galeodidse obviously protrudes from between the median suture, and in some species of RJiax it often differs markedly in colour, being bright green, while the surrounding surface is red or reddish brown, and in sections there are signs that the eye-tubercle is a discontinuous element in the cuticle {ot, PI. XXXI. fig. 1). In some other existing Arachnids, the median eyes show signs of not belonging to the surrounding cuticle. In Scorpio they appear to be protruding through a median suture, an impression which is some- what increased on dissection. We have, however, only to look at the drawing of the Silurian Patau- COMPAEATIVE MORPHOLOGY OF THE GALEODID^. 311 phonus nuncivs (65) (reproduced in PI. XXVII. fig. 10) to see that this conjecture is correct. The animal had apparently lost its eyes, but the region where the eyes normally are in Scorpions is seen to be an island of the original dorsal surface, gradually being grown over by the cephalic lobes which, in all modem Arachnids, have closed together in the middle line. The ocular tubercle must then be considered to be a primitive feature. And it is worth recording that, of the Aranese, the Aviculariidse, which alone retain an optic tubercle, have also retained other primitive features, e. r/. the coxal glands. Segmentation of the Dorsal Surface : Abdomen. — The tergites of the abdomen continue without change, except in the matter of size, the series begun by those of segments 5 and G of the cephalothorax (PI. XXVII. fig. 1). As a rule, the tergites gradually decrease in size towards the anal segment. Ithax, however, is a remarkable exception, the terga towards the posterior end of the hody gradually widening until the large anal segment is completely encircled {cf. fig. 13). It is, however, not certain here whether this great encircling plate of the anal segment is really morphologically a tergum. The tergites are, functionally, only more rigid areas of the cuticle for the protection of the circulatory mechanism. The lateral extensions of these areas at the posterior eud of the body in Ehas may be for the protection of the defenceless end of the body from eaemies. The ventral position of the anus in this genus is in keeping with this suggestion. Segmentation of the Ventral Surface. — Although there are no structures like the cephaHc lobes to disturb the segmentation ventrally, it requires a considerable amount of ektcidation. The first segment has practically disappeared from the ventral surface, while the limbs which belong to it have been shifted up dorsally above the mouth. Consequently the 2nd pair of a2)pendages become the most anterior pair of limbs ventrally, and have moved forward to the anterior end of the ventral surface. This forward shifting of the pedipalps has apparently forced the ventral portion of the 1st segment still iurther forward, to form the " labium," or lower half of the beak, which will be described presently. In the majority of Galeodidse, this " labium " or sternal surface of the 1st segment is no longer visible from the ventral surface, but in the genus Solpuga the relations can still be made out (PI. XXVII. fig. 14). The second segment is the first obvious component of the ventral surface (figs. 14 and 15), and this is followed by a complete series to the end of the body. The most remark- able feature in these ventral surfaces of the segments is the almost complete absence of the sternites. This obliteration of the sternites along the thorax is due to the coxae of the legs meeting in the middle line, and there is evidence to show that, along the abdomen, the areas which appear to be sternites are really the remains of limbs, also meeting in the middle line, which have now flattened down to form part of the body-wall {cf. section on tlie abdominal limbs, p. 328). The remains of sternites in the Galeodidse are very slight. We can make out the remains of three sternites, which are visible in Solpuga (fig. 14); i. e. of the fii'st three segments. These together form a long plate, which, anteriorly, supports the labium, and ends posteriorly between the coxse of the third pair of appendages. This posterior butt- end of the plate is often the only part of it visible from below. The only other remains ^f a sternite in Galeodes is perhaps the triangular piece which occurs in front of the genital operculum, between the coxae of the last pair of legs. These coxae, sloping forward, would perhaps allow the sternite to persist in the angle between them. 312 ME. H. M. BERNAED ON THE The obliteration of the sternal plates by approximation of the basal joints of the limbs along the ventral middle line, which is thus a characteristic of the Galeodidfe, is found more or less marked in all Ai'achnids, at least for certain segments. The causes of it are not easy to see. Figs. 15-18 (PI. XXVII.) and 1, 2 (PI. XXVIII.) show, in series, the ventral surfaces of Galeodes, Scorpio, Thelyphonm, Phrynus, a Spider and a Chernetid, the true sternal areas being in all cases shaded. In Phrynus [Taratitula tessellata, fig. 18) sternites are found along the whole length of the body, except in segments 7 and 8, where they are covered by the large genital operculum. In Thelyphonus (17) the sternites of the 1st and 2nd segments forming the labium ai'C now enclosed between the coxse of the pedipalps. The sternum of the third segment is a fold beneath the solid plate which represents the sternite of segment four, having been displaced by the pedipalp. A very small plate is all that remains of the sternite of segment five. A large triangular plate is sternite six. In Scorpio (fig. 16), the first and second sternites are no longer visible externally. The short pointed labium found in sections is all that now remains of them. The sternites of segments three and four have quite disappeared. Sterna five and six are present as a triangular plate in some genera. In others, even this plate has been almost obliterated secondarily, not by the approximation of the coxse, but by the forward movement of the genital aperture and opercula. The sternite of the 7th segment is covered by the opercula, while the sternites of the eighth and following four segments are clear. With regard to the abdominal sternites in Scorpio, Thelyphunus, and Phrynus, I believe the lateral boundary of the sternite to be the attachment of the dorso-ventral muscles ; outside these are the areas which I refer to vanished limbs [cf. PI. XXVII. figs. 16, 17, 18 Za). In the Pseudoscorpions (PI. XXVIII. fig. 2, ? sp.) the sternites have vanished from the cephalothorax, persisting perhaps only in the labium, and in a triangular plate between the last pair of legs which is visible in some genera. On the abdomen, the conditions appear to resemble those in Galeodes; we have the sternal plates, at least, very frequently, in pairs divided by a median line continuous with that separating the coxse of the cephalothorax. On the other hand, the dorso-ventral muscles do not always meet in the ventral middle line, but their points of attachment may have shifted. In the Araneae, the sterna of the cephalothoracic segments are fused to form a solid plate, but in young Epeirids just hatched (when cleared) this plate is found marked as in the figure (PI. XXVIII. fig. 1) We here see that sterna 1 and 2 are fused to form the labium, while sterna 3, 4, 5, 6 are well marked. The condition of the abdomen in the Spiders is not quite clear. From the approximation of the spinning-glands in the median line, I should be inclined to think that the sternites in this group, as in Galeodes, had disappeared from the abdominal segments. In the Phalangidse, the sterna of the cephalothorax have disappeared, either by the approximation of the coxse, or by the forward thrust of the genital aperture. In the Acari all conditions are found : the sterna, in some genera, seem to be well developed on all the segments except perhaps the 1st and 2nd. I have, however, made no study of the group. We thus have, in the Arachnida, almost every possible variation in this matter. The sterna have almost completely vanished from the cephalothorax of some Scorpions, of the Phalangidse, and of the Pseudoscorpions. In the Spiders they have been apj)arently obliterated from the abdomen. In the Pedipalpi, traces of them persist along the whole body, having completely vanished only in the anterior end of the abdomen, where they are covered over by the large genital operculum*. Lastly, in the Galcodidic the sternites have vanished along the whole length of the body, the only persistent traces being the supporting plate of the labium and the triangular piece between the last pair- of legs. These diff"erent departures from the primitive conditions of the segments are so very distinct that it is impossible to deduce the existing Arachnids one from another : they can only be different speciali- zations of some common racial form in which the sternites were distinct along the whole length of the * Laurie (47) describes a plate roofing the genital vestibule to which a pair of dorso-ventral muscles are attached ; this is almost certainly the sternite of the 2nd abdominal segment. COMPARATIVE MOBPHOLOGT OF THE GALEODID.E. 313 body. They were, perhaps, at first obliterated at the anterior end of the body, or rather converted into the labium by the grouping of the two first pairs of limbs round the mouth (see p. 311), and then secondarily, in the genital segment, by the change of a pair of limbs into genital appendages (see p. 328, and PI. XXIX. fig. 14). The Numhev couJ Character of the Abdominal Segments. — The abdomeu in the Galeodidse consists of ten segments, which, as above stated, are distinct. They are fairly iiiiifonn, i. e. they ta^oer away in a typical manner, showing no specialization into a tail of any kind. The last segment is little more than an anal jjapilhx except in Ilhax. The cuticle is adapted for the great extensions to which the abdomen is liable. After a full meal the abdominal region may be nearly twice as thick and twice as long as at ordinary times. While the ventral and dorsal surfaces are protected by more solid chitinous plates (tergites and " sternites " *), the intersegmental and lateral integuments are very thin and flexible. Fig. 6, PI. XXXIV., shows the remarkable folding of the integument between two segments of a contracted abdomen ; this is even more pronounced in the more anterior segments. The fine structure of this flexible integument will be described elsewhere. Great variations are found in the hairiness of the abdomen. Swollen abdomens often look smooth, owing to the drawing apart of the hairs, which in the contracted state would be crowded together. For this reason, contracted specimens are often very hairy. This, however, does not explain the whole facts. In some, the lateral membranes are smooth, in others hairy. The " sternites " are smooth, in others again hairy. The hairiness of the lateral membrane is often felt-like ; that of the " sternites " repeats that of the cox0e of the legs. The number of segments in the abdomen of Arachnids varies considerably. The greatest number, twelve, occurs in Thelyphonus, Phrynus, and Scorpio, and, according to Mr. Pocock, in Schizonotus. The abdominal segmentation of the Pseudoscorpiouidte is very difficult to unravel. The anal papilla may perhaps represent a segment, but there are reasons for believing that it does not. But whether the first free tergite, in those cases in which there are undoubtedly eleven tergites, belongs to the abdomen or to the cephalothoras I have been unable to determine. In view of the free cephalothoracic segments of Galeodes and Schi-onoiiis, and the absence of a marked waist, either interpretation is possible. I suggest that the point may be settled by a careful examination of the dorso-ventral muscles. I do not agree with Hansen (33) in claiming the ti'iangular piece sometimes seen behind the coxae of the last pair of legs as belonging to the first abdominal segment, but think that it belongs to the last cephalo- thoracic segment, and, as in Thelyphonus and Galeodes, has been left bare by the inner anterior slope of the coxse. But the Chernetidse show great and puzzling variations. In some there is a clear triangular piece in front of the genital plate ; in others the last pair of coxae seem to reach back so as to cover, ventrally, the anterior segments of the abdomen (lO; compare figs. 1 & 2). In the Spiders there are, as a rule, tea se^^ments, while in the Phalangidae and in some Acariuae the number is still further reduced. This difference in the number of abdominal segments is not a matter of any great morphological importance. The specialization of the Arachnids has clearly taken place at the anterior end of the body, in the grouping of the first two pairs of limbs round the mouth and in the development of the limbs of the four following segments as walking-legs. This cephalothoracic region, specialized for loco- * As above stated, I do not consider them to be morphologically sternites, but rather limb-areas, i. e. areas where limbs have vanished by flattening down. SECOND SERIES. — ZOOLOGY. VOL. VI. 42 314 ME. H. M. BERNAED ON THE motion and prehension, is followed by a well-demarcated abdominal region specialized as a distensible sac-like receptacle for digestion and reproduction. This specialization comprises all the abdominal segments in Galeodidse, Pseudoscorpionidse, Araneidse, Phalangidae, Acaridse, while in the Scorpionidse, Thelyphonidse, and Schizonotidje a few of the most posterior segments form together a kind of caudal appendage secondarily specialized for different purposes. In all discussions as to the primitive segmen- tation of the abdomen, we have to bear in mind that its swollen condition is a secondary specialization. In Scorpio and Thehjphomis, although the posterior segments of the abdomen take no part in the formation of the visceral sac, they are greatly specialized for other functions. Moreover, these tail- formations difPer too greatly to be considered primitive structures. The lengthening of the tail- segments of Scorpio was most probably a secondary and compensatory specialization to allow of the use of the terminal sting, as the anterior abdominal segments were becoming sac-like and thus no longer capable of bending backward. We may, I think, safely conclude from the varied conditions of the abdominal segmentation of existing Arachnids that the abdominal segments of the ancestral form were quite unspecialized. The differences in the number of the segments specialized for distension shows clearly that neither this nor the " tail " is primitive. In Scorpio, seven form the distensible sac and five the tail. In Thelyphonus, nine form the distensible sac and three a totally different tail ; while in Galeodes ten, in Cliernes jierhaps eleven, form the distensible sac, no segments at all being specialized into a tail. It is impossible to deduce these forms from any specialized ancestor. The reduction in the number of segments in some Arachnids is doubtless in some way due to the excessive weight of the distended sac. We have thus tolerably clear evidence that the original and most important specialization of the Arachnidan abdomen was into a digestive and reproductive sac, while the anterior region was specialized for locomotion. Diaphragm or Waist. — Between the 6th and 7th segments, i. e. between the cephalo- thorax and abdomen, there is, in the Galeodidae, no true specialized waist, although there is a strong intersegmental constriction, the abdomen being able to bend up almost at right angles to the cephalothorax at this point. Internally, this constriction has given rise to a very striking " diaphragm," which has already been described and figured by Kittary (41). It forms a very complete wall between the interior of the cephalothorax and that of the abdomen, and is pierced by the dorsal vessel, the alimentary canal, the nerve- cords, and the tracheae. Close examination shows that this diaphragm is due, as stated, to a strong indrawing of the intersegmental membrane between the above- mentioned segments, so that it is composed partly of a chitinous infolding and partly of muscle-bands. It is clear that if the opposite two internal faces of such a deep segmental constriction fuse together, they form a diaphragm : if they remain unfused, they form a waist. In the Galeodidse we seem to have an unsj)ecialized ai'rangement, the intersegmental infolding being fused only in its deeper parts, forming the diaphragm, while the outer parts of the fold remain open, making some approach to a waist. Waists or diaphragms appear to be characteristic of the Arachnids. The Pedipalpi and the Aranese have highly specialized waists. Scorpio has secondarily lost all traces of its waist and has only a diaphragm. The Pseudoscorpions show very deep constrictions laterally and ventrally, but not dor- sally ; these constrictions thus do not form a true waist. The Phalangidie and Acari are the only forms which appear to have lost all traces of the former waist. This is perhaps to be correlated with the diminution of the abdominal region characteristic of the former and of many of the latter. COMPAEATIVE MOEPHOLOGY OF THE GALEODID^. 315 The origin of the waist or diaphragm in the Arachnida is not far to seek. It divides the body into the two well-defined regions above described, the anterior knit together by muscles to form a specialized locomotory mechanism, the posterior a distensible bag for the digestive and the reproductive apparatus. It seems to me that the development of the former region would necessarily draw in the intersegmental constriction between the two regions. The function of the diaphragm will be better explained in the section on the alimentary system. It supplies, as we shall see, a kind of neck to the digestive bag, which serves to protect the organs of the cephalothorax from undue pressure on the part of the contents of the abdomen when it is greatly distended. The Segments — Special Structures. Having thus reviewed the general segmentation of the body, we have to describe certain special structures connected with the segments, such as the beak, the eyes,, and the limbs. First Segment: the Beak. — The beak* is a marked feature in the Galeodidse. It projects anteriorly from between the basal joints of the pedipalps, ventrally to the chelicerai. The mouth being at its tip, we may safely assume that it is composed of a labrum and of a ventral labium fused together along their edges. It is represented in PI. XXVII. figs. 11, 14, and in sections in PL XXVIII. figs. 3, 4, 5, 6. The labrum, which is in all Arachnids a structure sui generis, is keeled dorsally and very firm ; the keel may originally have been due to the jn'essure of the chelicerse on each side. It is, moreover, quite immovably fixed to the coxal joints of the pedipalps (PI. XXVIII. fig. 3), W'hich are themselves rigidly attached to the ventral skeleton. Anteriorly, an arrangement of feathered setse projects from the labrum in such a way as to form a sieve for the straining of the animal- juices, which form the characteristic food of the Arachnids. The setae are arranged in a vertical row on each side of the mouth, the two rows lying very close to each other (PI. XXVII. fig. li). The setae of the same side are joined together by cross-pieces, so that the sieve has regular rectangular meshes (PI. XXVIII. fig. 6). The labium, w'hich is applied all along to the base of the labrum, so as, with it, to form a beak, ends anteriorly in two fleshy lobes (PI. XXVII. fig. 14), each provided with a long, feathered, tactile hair. The tip of the labium seems to be movable by means of muscles, but the exact mechanism is difficult to make out. In the ventral middle line, the labium is strengthened by a chitinous plate folded along the median line. This is a prolongation of the sternal plate betw^een the coxae of the pedipalps ; the whole plate may be considered to be the fused sternites of the 1st, 2nd, and 3rd segments {cf. PI. XXVII. fig. 14 with PI. XXVIII. fig. 3, and p. 311). I have not hesitated to call the parts composing the beak the labrum and labium, because I can see no reason why they should not be so. They form the upper and lower maro-ins of an anterior mouth ; the labrum has the typical position of a labrum or prostomium (i. e. if we take into account the shifting forward of the chelicerse), and the labium is the protruded anterior margin to the sternal surface bounding the mouth posteriorly. As ah'cady suggested, this protrusion is no doubt due to the distortion of * " Eostre buccule,"' " labium haustelhforme,'' " languette sternale," &c. of authors. 42* 316 MK. H. M. BEEXARD ON THE the first segment, by the shifting forward of the pedipalps, when tlie chelicerse left the ventral surface. I therefore cannot follow Croneberg (28) in his endeavour to deduce these parts from fused limbs. Such a derivation brings hopeless confusion into tbe segmentation, where none really exists. The solid chitinous framework round the posterior portion of the beak is necessary to counteract the action of the muscles which expand the CBSophagus for the pumping-in of the food (PI. XXVIII. figs. 3, i, 5). The significance of this position of the pumping-apparatus in the Galeodidse, viz. Avitliin the beak, will be referred to later, in the section on the alimentary canal. From the description above given of the origin of the beak of Galeodes, it is clear that it raust be considered to be a primitive Arachnidan characteristic, since it arose as a natural consequence of the shifting of the chelicerse and of the pedipalps to positions above and at the sides of the prostomium. We have abundant evidence among the Arachnida that the beak was, as contended, a primitive structure. In Thelyphonus, where the fusion of the basal joints of the pedipalps has rendered a beak, as such, unnecessary, it nevertheless persists : that is, it is in a position where it could not well have been ■secondarily developed. Examination further shows that here also its floor contains, like that of Galeodes. a chitinous plate somewhat folded anteriorly, which can be traced in sections to the transverse infolding of the cuticle at the anterior end of the large sternite of the 4th segment {cf. p. 312). This infolding is apparently the sternal surface of the 3rd segment, crushed in by the enormous backward growth of the coxse of the pedipalps (PI. XXVTII. figs. 11, 12, 13, 14). This beak, like that of Galeodes, •contains the sucking-apparatus. The Pseudoscorpions * and the Gamasidce t are the only other Arachnids known to me which possess well-developed beaks, but the mouth-parts of all the other Arachnids can be best deduced from a primitive beak which has been variously modified. Starting from Galeodes (PI. XXVIII. fig. 5), with the mouth at the tip of the beak, we have a complete series which shows the gradual reduction of that organ. In the Chernetid;e (fig. 10) the mouth lies ventrally, in a labrum with a dorsal keel, the pointed labium fitting into the oral aperture; the lining of the mouth is finely striated transversely. The next stage is that of Scorpio (fig. 9), in ■which the dorsally-keeled labrum, though of considerable length above, is shortened ventrally, the mouth having travelled back towards the body, so that it is impossible longer to speak of a beak. The shortened labium is, however, still a pointed median process, as in the Chernetidse. In Phrynus (fig. 7) we have a process almost the opposite of that in Scorpio, viz. a great reduction of the labrum, while the long pointed chitinous support of the labium remains as an anterior prolongation of the first clear sternite. This labium has two divergent set;e at its tip, as in Galeodes. In marked contrast to Thelyphunus, where the beak has been enclosed between the pedipalps, in Phrynus the labrum and labium seem to have been forced apart by these same limbs. The mouth, which is immediately under the labrum, is thus no longer bounded ventrally by the labium, but by the pedipalps, which meet in the middle line. The labrum, though greatly reduced, is quite distinct and shows the dorsal keel ; it ran best be seen by removing the dorsal shield and bending back the chelicerse. * It is worth recording also that the larval Pseudoscorpions are provided with au enormous sucking-beak ; cf. Metschnikofi' (55). t Judging from Winkler's figure (76, Taf. iii. 15), this is a typical beak comparable with that of Galeodes, and contains the sucking-apparatus along the greater part of its length. Winkler, however, calls the labium the maxillae. The long pointed process which he calls the under-lip must be some specialized structure, although its superficial resemblance to the process in Phryiws, which I believe is a true under-lip, is certainly suggestive of an interpretation of the mouth-parts of Phrynus differing from that given in the text. COMPAEATIYE MOEPHOLOGY OF THE GALEODID.T:. 317 The Spiders (fig. 8) show still further modifications : the labnim is round and fleshy and directed downward ; it is opposed by a distinct labium also bent downward and formed by the anterior edge of the sternal plate. The opposed inner oral surfaces are finely striated transversely, as in the Pseudo- scorpions and Thclyphonidffi. The cosal joints of the pedipalps function as maxilhe on each side of the mouth. We thus have, in the Arauese, the mouth placed more vcntrally than in any other Arachnid *. Asa concomitant change, we have the chelicerae bent downwards from the almost directly forward position which they occupy in most other Arachnids. The Aviculariidic, however, which have retained other primitive features [cf. p. 311), still have the ehelieer2 :— " Der scharfe Geruch, der seinen Sitz hauptsiichlich in dem hoUen Knopf an der ISpitze der Vorderfiihlor hat, locket sie dahin," et seq. See also the description of the action of the pedipalps quoted by Murray (57). COMPAEATIVE MORPHOLOGY OF THE GALEODID.E. 325 The only other Araclinids with fixed coxal joints to the pedipalps are, I tliink, Theh/phomts and Schizonotus, and (?) some Pseudoscorpious. In Thelyphonus the beak is enclosed between the enormous coxal joints of the pedipalps, ■which thus form on their upper and inner sides a sort of channel in which the beak lies. In Phrymis, we have the coxal joints movable, but the beak as such has aborted in such a way (PI. XXVIII. fig. 7) that the inner opposite faces of the coxie can meet in the middle line. In the Spiders, the coxal joints function on each side of the mouth as accessory mouth-parts*. In the Chernetidse, it is difficult to say for certain whether the coxal joints of the pedipalps are movable, but their lamellate sensory processes (above described) are certainly, in some cases, movable, and serve to hold and crush prey in front of the beak. In Scorpio, the coxfe are movable, but do not appear to be able to close together, owing to the retention of the large labrum between them. These various arrangements will be referred to again in the section on the alimentary system, inasmuch as they are different adaptations to the special manner of feeding of the Arachnids. The Belat'tve Developments of Chelicerce and Pedipaljis. — In the Galeodidse, the cheli- cerae have certainly been secondarily developed into their present enormous proportions. In the primitive form, there is no reason to believe that there was any great difference between the development of the cbelicerae and that of the pedipalps, except, perhaps, in length ; sections through their basal regions would probably have agreed in size. We can best explain the conditions in Galeodes by assuming that the chelicerse have greatly developed, while the pedipalps have retained more nearly their relative importance with regard to the remaining limbs. In the Araneffi and the Phalangidfe, the same relations subsist as in Galeodes ; the chelicerfe are the principal seizing organs, and are correspondingly developed. In those forms, however, iu which the pedipalps have become the seizing organs, they have, from their greater initial length, more or less monopolized this function, and have been correspondinglj^ specialized. We have thus a series in which the pedipalps progressively increase, while the chelicene recede in importance, having henceforth to fulfil only the quite subordinate function of squeezing juices out of prey already killed or maimed by the pedipalps. In Schizonotns the pedipalps are in the upright, clawing position, and in this animal and in the related Thehjphomis the distal joints have formed a simple kind of nipper. In Phrynns no such pincer is formed at all ; the pedipalps are clawing limbs. In these three we find the pedipalps highly developed, while the cheliccrae are probably in process of reduction, and tending to flatten out in the median plane (PI. XXV^III. fig. 9). Lastly, in Scorpio, the pedipalps are enormously developed, the original clawing action having developed powerful pincers t, while the chelicerse have greatly diminished in size (PI. XXVILfig. 9 6). The series of figures 9 a, 9 b, 9 c (PI. XXVII. ), and 9 (PL XXVIII.) represent cross-sections of Galeodes, Scorpio, Obisium, and Thelyphonus (drawn with camera lucida). The great diminution of the chelicerae in Scorpio and Thelyphonus is seen to be a secondary specialization. Both Galeodes and Scorpio depart in opposite directions from the Obisimn type, in which the bases of the limbs are shown of nearly equal importance in cross-section, such being in all probability the primitive condition. The great modifications of the anterior segments brought about by the original translocation of the chelicerae are still further complicated by the development and specialization of the pedipalps as a 2nd * These are not biting jaws, working within or at the sides of the oral aperture ; such jaws (except, according to my friend Mr. Michael, in some Acari) are unknown among the Arachnids. t If the pedipalps of a Scorpion are turned upwards into the sagittal plane, the distal joint will, in closing, be found to move in a clawing direction, /. t'. towards the body. 326 ME. H. M. BERNARD ON THE pair of seizing limbs. Sucli limbs must have powerful bases from which to work. The method in which the bases of the great seizing pedipalps have developed in adaptation to their new requirements varies greatly in different Arachnids. This fact leaves little doubt that the specialization is a secondary one. In Schizonotus, the enlarged basal joints of the pedipalps have grown out anteriorly far in front of the chelicerfe. They, however, still lie ventrally to the cephalic lobes — that is, meet in the middle line. In the Pseudoscorpionidffi the arrangement differs from that in Schizonotus, in that the coxal joints of the large pedipalps do not project beyond the front of the body, but posteriorly, thrusting back the four following or ambulatory limbs, which are pushed further from the mouth than in any other Arachnid (PI. XXVIII. fig. 2 does not show this so markedly as it is seen in some genera). In Thehjphonus, the large coxal joints of the pedipalps have found room for development backward, by displacing the 3rd pair of limbs, the coxal joints of which no longer appear on the ventral surface (PI. XXVII. fig. 17). And in Phrynus, the enlarged coxee of the pedipalps have partially displaced the coxie of the 3rd pair of limbs,, though they are still visible from the ventral surface. In both these cases, the comparatively small chelicerae have sunk in between the coxal joints of the pedipalps. But in all these cases the bases of the pedipalps meet ventrally in the middle line. In the Scorpions we reach an extreme of specialization. The basal regions of the enormous pedipalps are thrust out anteriorly and laterally. The crowding forward of the walking-legs to the anterior end of the body not only prevents any backward development of the coxae of the pedipalps, but has even forced them apart so that they no longer meet ventrally in the middle line, nor take any part in the formation of the ventral surface of the cephalothorax. These changes in the relative development of the chelicerae and the pedipalps have naturally led to great modification in the cephalic lobes, which owe their origin to the translocation of the former. In my preliminary notice of these cephalic lobes, I thought that, as the chelicerae became subordinated to the pedipalps, the cephalic lobes carrying them became wedged in completely between the shoulders of the pedipalps, but that is not the case ; the cephalic lobes still form the whole of the anterior dorsal surface. The relations can be made out by comparing the sections (PL XXVII. figs. 9 a, 9 6, 9 c, and PI. XXVIII. fig. 9). Thus, starting with the condition found in Galeodes, the Spiders and Phalaugids, in which the chelicerae are the only true seizing organs, we have every stage in the gradual specialization of the originally simple leg-like pedipalps into complicated seizing and crushing limbs. The oi'd Pair of Limbs. 1st Pew- of Legs. — The 3rd pair of limbs, like the pedipalps, are leg-like, but have apparently lost their locomotor functions, and are specialized into a second pair of sensoiy limbs. Like the pedij)alps, they are long in Galeodes, but short in MJuix. In Galeodes, they are also very thin (PL XXIX. fig. 3). The presence of a pair of reduced claws at their tips shows that they were at one time ambulatory legs. Their specialization into feelers in addition to the existing pedipalps must be due to the great activity of these hunting animals *. The special sensory cells at their tips will be described in the section on the sensory organs. No other Arachnid has two pairs of feelers. In the Scorpions, Araneae, Pseudoscorpions, and Phalangidae, the 3rd pair of limbs are true ambulatory legs, while in the Phryuidae and Thelyphonidae the tendency shown in Galeodes to become sensory feelers has reached an extreme of specialization. This is doubtless a compensating modification, owing to the secondary transformation of the pedipalps into seizing organs. In these animals, the first pair of legs become long, filiform, many-jointed feelers. It is not immediately apparent why, in the * The auimal kingdom presents other examples of a high development of sensory organs with rapidity of motion in the pursuit of prey. COMPAEATIVE MOEPHOLOGT OF THE GALEODID.-E. 327 Scorpions and the PscudoscorpionSj in which the pedipalps are seizing organs, the 1st pair of legs have retained their original loconiotory functions unmodified. The comparatively slow, deliberate manner of hunting prey may account for the fact that they require no more specialized feelers than the pedipalps themselves, which are, as everyone who watches them alive knows, highly sensitive. The Remaining Liinhs. — The i-emaining three pairs of legs are long and powerful, the last two having the femur divided by an extra joint, as Gaubert (32) has pointed out, hut whether the reasons he has given for this are correct I am unable to judge, having never seen the animals alive. The last of the three pairs of legs carries the remarkable racquet-shaped sensory processes which will he described in detail in the section on the sensory organs. General Eemarks on the Cephalothoracic Appendages. — These six pairs of limbs are the appendages of the first six segments, i. e. of that region of the Araehnidan body which is specialized for locotnotory, sensory, and predatory functions, while the region immediately following is typically developed into a nutritive and generative sac, and, as such, loses its limbs. These six pairs of limbs are characteristic of all adult Arachnids, although the possession of six pairs of appendages on a specialized anterior region of the body would not constitute an animal an Arachnid. The arrangement of these limbs, and especially of those nearest the mouth, supplies the most important diagnosis of the class. In no case does the first pair of limbs form feelers; in no case [? certain specialized Acaridse] do the limbs form biting jaws projecting into, or arranged close to, a mouth-aperture. In all cases, the first pair of limbs are jointed, seizing and crushing limbs, transposed from behind to a position in front of and above the mouth, which is typically a beak. Special feelers are sometimes dispensed with, at other times developed out of the 2ud, at others out of the 3rd, at others, again, out of the 2nd and 3rd pairs of limbs; while, in most cases, the 2nd pair of limbs assists the 1st in the capture and crushing of prey, the juices of which alone are sucked in by a mouth which is typically provided with a straining apparatus. These characters constitute the Arachnids a class removed entirely from all other Arthropods, in which, typically, the first pair of limbs are sensory feelers, while a certain number of those which follow form true jaws, not only to crush food but to push it into the mouth, round which they are ranged. Certain Acari, in which the mouth-limbs (perhaps fusing with a primitive beak) form a piercing sucking apparatus, distantly approach, hy secondary specialization, those Arthropods of other groups (Crustacea and Hexapoda) whose mandibles and maxillae are also secondarily specialized into a sucking proboscis. These six pairs of cephalothoracic appendages, constant in the (adult) Arachnida, show certain interesting variations in their arrangement on the body. These can be gathered at a glance from the diagrams (PI. XXVII. figs. 15-18 and Pl.XXVlII. figs. 1, 2). None of the arrangements can be con- sidered primitive. That represented by certain Acari and Arancffi, inasmuch as the sterna are preserved and the limbs regularly arranged, must be considered as nearest to the original. The circular arrange- ment in the Spiders is certainly secondary. The regular arrangement of the legs in two straight series in Galeodes is primitive, but the disappearance of the sterna is a secondary specialization. Another point of interest is the fixation of the coxa; which occurs to some extent in most Arachnids. In Galeodes all are fixed, as is also the case in Thehjphonus and the Phalangidae. In Scorpio the coxae of the first pair of legs are alone movable, those of the other three are fixed. In the Spiders, Phrynidse, and (?) some Pseudoscorpions all are movable *. * In fig. 2 (PI. XXVIII.) the coxk certainly appear to be fixed ; hut there is great variation in the arrangements of the coxai in this order. 328 - MR. H. M. BEEXAED ON THE Takino- the limbs as a wholCj the variations are considerable, and no single Arachnid can claim to have retained the primitive conditions. It seems only possible to deduce them separately from a primitive ancestral form in which the limbs were evenly developed and evenly arranged along the two sides of the body, separated by a median row of sternal plates, as shown in the diagram (PI. XXIX. fig. 14). The character of the limbs, suggested in this diagram and in figure 5, PI. XXIX., is not unlike that of the ambulatory limbs of the Silurian Scorpion Paheophonus (PI. XXVII. fig. 10), whose semiaquatic, i. e. littoral, existence makes its retention of the primitive type of ambulatory leg not improbable. Vestiges of Abdominal Appendages. — CareM study of the ventral surfaces of Galeodiclae has led me to the conclusion that the " sterna " along the ahdominal segments represent rudimentary limbs which have simply flattened down. Figs. 6, 7, 8, 9, 10, PL XXIX., show a continuous series of plate-like structures on the abdominal segments bearing all the characters of vestigial appendages. That these are the vestiges of limbs which formed at one time a continuous series with those on the cephalothorax we gather from the following facts : — (a) Fig. 7, PI. XXIX., shows a chitinous fold across the genital operculum, repeating the interarticular fold of the preceding appendage (d). In the Pseudoscorpions the same ganglionic centres are discoverable. The enormous backward deve- lopment of the coxae of the pedipalps, driving back the coxae of the remaining legs, finds some reflection in the brain. The ganglionic centres of the six limbs all seem to radiate from the proximal end of the root of the pedipalpar nerves (fig. 3 e) . The cheliceral nerves seem to rise from the upper ends of the oesophageal commissures without being quite supra-oesophageal. The supra-oesophageal portion lies forward over the anterior half of the ventral portion. The central nervous system of Gamasus, according to Winkler's description (76), is of great morphological interest. While the concentration of the limbs at the anterior end of the body has condensed the infra-cesophageal portion, the cheliceral ganglia are said to have retained their positions at the lower ends of the ossophageal commissures. Inasmuch, however, as the muscles moving the powerful chelicerre are inserted far back on the dorsal wall, the cheliceral nerve, in order to reach them, has to traverse the supra-oesophageal portion. This, if correct, has been brought about by the secondary shifting of the cheliceral muscles carrying the nerves, which originally pointed forward, backward over the brain until they have become surrounded by brain-substance. This is a very high specialization of a primitive condition, jjointing back to a time when the cheliceral ganglia were infra-oesophageal. The nervous centres of the Pedipalpi at my disposal were not well enough preserved for the purpose of making trustworthy comparisons. If, then, we start from the primitive arrangement in which all the segmental ganglia were ventral in position, the nerve-centres of the Arachnids can be deduced from it by progressive forward concentration. The first movement was doubtless made by the cheliceral ganglia, following the tilting forward of the COMPAliATIVE MOEPHOLOGY OF THE GALEODID^. 313 limbs tliey innervate, which, as we have explained, was probable the original specialization of the Arachnids as a class. The Spiders show but little advance on this. The Galeodidae, in spite of the comparative freedom of the three posterior segments, show greater concentration of the ventral segmental ganglia than do the Aranese with their moi-e uniform fusion of the cephalothoracic segments. Scorpio shows still greater specialization, the ganglia are pushed forward so as to form an almost cubical mass sur- rounding the (Esophagus. Lastly, iu Phalangiuin, the forward movement of the limbs and genital aperture has thrust the segmental ganglia of the cephaiothorax forward and upward till they lie almost in the transverse plane. Pt'iiicipcd Nerves. — Thenervos leaving the central nerve-mass of Galeodes are : — (1) The optic nerves, which run forward from behind, I'emaining in contact with the hrain before bending upward to the eyes (PL XXXI. figs. 2, 5, on). (2) The cheliceral nerves (figs. 4, 5, ch), which rise just in front of the optic nerves, and soon give off a branch [ch!) to the cheliceral muscles. (3) The powerful nerves to the pedipalps, wliich are double, dividing into smaller dorsal and larger ventral branches soon after leaving the brain (fig. 6, pp). (4, 5, 6, 7) The nerves to the other limbs, all of which are double, a fact which was recognized by Kittaiy, but only noticed for the two posterior legs by Blanchard. Iu each of the last two limbs the smaller branch accompanies the mid-gut diverticulum. (8, 9) Three long nerves, which run straight backward from the posterior ventral end of the nerve-mass, one in the median line and the other two on each side of it. They run through the neural aperture of the diaphragm (i)). The lateral nerves {g) supply the genital glands : while the median {ah) is the main abdominal nerve, which, after passing through the neural arch of the diajihragm, swells into a large ganglion, the abdominal ganglion ; it then runs backward immediately under the central canal of the mid-gut, innervating it and the stercoral pocket, and also apparently sending up nerves among the digestive tubules. (10) Nerves which appear to leave the posterior end of the dorsal (supra-oesophageal) portion of the mass to supply the mid-gut. So far as I can make out, these do not leave the brain in compact bundles of fibres, but spring from the whole posterior surface of the brain wherever the alimentary canal is in contact with it. I have assumed that the centre is the mass which lies behind the optic ganglia, but I failed to find any very clear connections. (11) The paired (or unpaired) nerves which leave the brain between the cheliceral nerves and supply the labruni (PI. XXXI. fig. 6, L). (12) Paired nerves leaving the anterior end of the ventral portion of the nerve-mass, supplying the labium. (13) Two small nerves leave the brain on each side between those running into the 2nd and 3rd legs (or else branch from these in some way), and run to the stigmatic apertures (fig. 6, stig.). Peripheral Nerves. — Of the peripheral nervous system I have been able to fi.nd only traces. A network of fibres runs in close contact with the hypodermis, supplying the cuticle and hairs. These nerves are sometimes marked out in white in parts of the dorsal sm-face where pigment has collected. I have not succeeded in tracing these integumental nerves to their sources. 344 ME. H. M. BERNAED ON THE The heart is very richly supplied with nerves. In portions of that organ dissected out, cleared, and examined in toto, it seems to be enveloped in a network of nerve-fibres which is especially developed in its dorsal wall. Pig. 7, PI. XXXIV., is a small portion of the heart (ventral aspect) showing a layer of nerve-fibres (w) running longitudinally. The exact source of these heart-nerves I have been unable to discover. A not very close network also surrounds the digestive tubules of the mid-gut, the main canal of which is very richly supplied anteriorly, apparently direct from the brain, but posteriorly also from the great abdominal nerve (PI. XXXI. fig. 6, ah). The Abdominal Ganglion. — The abdominal ganglion lies just above the genital aperture, and in all probability supplies it with nerves, although the genital glands themselves have their own independent nerves coming direct from the central nerve-mass. It is possible that this position of the abdominal ganglion may be due to the abdominal musculature, which is only developed to any great extent in the first two or three abdominal segments {cf. p. 336). The nerve which in other Arachnids is of importance for comparison is the abdominal nerve, as its ganglionic svpellings may be primitive ganglia of the ventral nerve-chord which have persisted as separate centres, and have not beeu incorporated in the cephalothoracic nerve-centre. In the Aranese there are no large swellings on the abdominal nerve. In this group, as we have seen, the posterior median component of the central nerve-mass appears to consist of five or six fused segmental ganglia, i. e. if the connective-tissue strands which penetrate it dorso-ventrally represent primitive divisions. In Phrynus, also, there are apparently no ganglionic swellings in the abdominal nerve. The same is true of the Pseudoscorpions. In Thehjphoims there is a large svpelling at the posterior end of the abdomen, apparently in associa- tion with the muscles for elevating the three tail-segments and for moving the caudal appendage. In Phalangium a ganglionic swelling is figured by Blanchard. This may be in association with the highly specialized ovipositors and penes, with tbeir own musculature, which characterize tliis group. In Scorpio, in which animal alone the musculature of the abdomen is highly developed, there are seven ganglionic swellings of the abdominal nerve *, which may again be associated with the developed musculature for the movement of the tail-segments. The "Sympathetic." — The only other nerves to which I should like to refer are the "sympathetic." Both St. Remy t and A. Schneider J describe a stomatogastric nerve as branching off laterally from the brains of Spiders. Schimkevitch also describes a pair of nerves proceeding backwards from the brain, but, like myself, failed to establish their places of origin. Blanchard figures nerves running backward from the brain on to the mid-gut of Galeodes, and scattered nerves running backward on to the mid-gut from the brain of Mygale. I have myself, as above stated, failed to find any clear connection between the brain and mid-gut in either Galeodes, the Spiders, the Scorpions, Pseudoscorpions, or Opiliouidse. Although the brain is, in all or nearly all cases, in contact with the mid-gut and its lobes, until I read the works of St. Remy and Schneider I had concluded that the nerves leave the posterior surface of the brain and spread out over the mid-gut, not in definite bundles, but as single fibres, which easily * Cy. Newport (58), "On the Nervous System, &e., of Macrourous Arachnids," Phil. Trans, vol. cxxxiii. 1843^ and Blanchard (24), ' Les Arachnides.' t St. Eemy (61), ' Contributions u I'Etude du Cerveau chez les Arthropodes tracheates,' Poitiers, 1890. J Schneider (64), '> Systiime stomatogastrique des Aranoides,'" Tab. Zool. ii. 1891. COMPAEATIVE MOEPHOLOGY OF THE GALEODID.^. 345 escape observation among the connective tissue. Further research is much needed. In the meantime, perhaps, we are not wrong in assuming that the great nerve-mass in the brain, behind the optic ganglia (which shows as a crescent in horizontal sections of Spiders, behind and half encircling the optic lobes), would be the "sympathetic" ganglionic centre. The nerves of Galeodes are always in very close association with tracheae, a fact which is interesting in connection with the close association of the nerves with the blood-jmssages in Scorpio. Histology. — One observation seems to be worth recording. The cross-sections of the large nerve-trunks show the usual fine network which represents so many tubes cut across. But, in other parts of the body, where nerve-fibres can be seen isolated, they are exquisitely fine fibrils with fusiform nuclei (PI. XXXII. fig. 7). These are most easily seen in the racquet-organs (fig. 1, nf), but can be found also in other parts of the body. What, then, are the tubes ? I would like to suggest the following explanation. In order to protect the nerve-fibrils from mechanical stimuli along their courses, they run in a delicate connective-tissue framework (comparable to that which envelops the muscle-fibrils, PI. XXX. fig. 12). The hollow tubes are filled with fluid, and the fibrils run along closely applied to their walls, the whole arrangement being an adaptation to protect the nerve from mechanical stimulus of any kind along its course. In the racquet-organs the fibrils are in no such danger ; they are enclosed, at least in the shaft, in a stout cylinder of chitin, and run singly to their destinations. An examination of the points of departure of large nerve-trunks from the brain leaves little doubt that the tubes, which are at this point very large and irregular, are not the nerves themselves. The fibrils themselves are, as a rule, too fine to be distinguished in the walls of the tube, but their fusiform nuclei are often quite distinct. I have found the same nerve-fibrils in Scorpio., but have been unable to demonstrate the individual nerve-fibrils in Spiders. An examination of the general structure of the nerve-strands as they leave tlie brain, however, leaves little doubt in my mind that the irregular tubes are but fluid-channels in the walls of which the — as a ru.le invisible — nerve-fibrils run. The absolute necessity of isolating the fibrils in their courses from the periphery to the brain seems certainly to require some such arrangement. VII. The Sense Organs. The Galeodidae, which are for the most part great hunters, are well provided with sense organs. We have to describe (1) the large median eyes, (2) the vestigial lateral eyes, (3) the protrusible organ at the tij)s of the pedij^alps, (4) the racquet-organs on the last pair of legs, (5) sensory setae, (6) certain specialized areas containing organs of unknown significance, presumed to be sensory. (1) The Median Eyes. — The large pair of median eyes stand on a tubercle anteriorly in the dorsal suture, between the cephalic lobes. This tubercle, as we have seen, is probably the remains of the original dorsal surface {cf. p. 310). The lenses are round glassy prominences. In the genus Galeodes they are very large SECOND SERIES. — ZOOLOGY, VOL. VI. 46 346 ME. H. M. BERNARD ON THE compared with the size of the ocular tubercle, and somewhat tilted so as to look side- •oays, their axes making together an angle of 90". In the genus Bhax (PI. XXVII. fig. 6) the lenses are small and lie rather wide apart, looking almost directly upward. The lens is formed by the sudden thickening of the cliitinous lamina? of the cuticle, and is thus itself laminate *. As it stains deeply, it is probable that these layers are largely protoplasmic or permeated with fluid in the interest of transparency. The outermost layer of the chitin is generally wrinkled (fig. 9), as if it had shrunk by the al)straction of such a fluid. The whole eye, indeed {I. e. the soft parts), is abun- dantly provided with canals for the free circulation of fluids through all the tissues {fig. 8, Ic). In the angle between the globular lens and the cuticle from which it is developed a thick fold of pigmented hypodermis forms a kind of iris. It is apparently rather more pro- noimced than Leydig's ' iris-artige Giirtel ' in the eyes of Spiders, which was only a ring of pigmented hypodermis. In Galeodes it is a thick and very definite fold arranged right round the retina (PL XXXI. figs. 7, 8, 9). Its apparent function will be presently described. The general character of the eye can be obtained from the figures. The most remarkable featui^e is the thinning away of the retina in the axis of the eye, and its great development roimd the periphery. The i-elative measttrements were as follows : — greatest depth of lens 25, depth of retina in the axis of the eye 3, at the periphery (posterior) 20, (anterior) 12. The whole of the soft parts of the eye are enclosed in a well-developed connective-tissue membrane, which stretches across below the ocular tubercle (PI. XXXI. figs. 7, 8, m). The optic nerve enters the postero-median region of this ocular chamber, and immediately swells into a ganglionic mass. From the dorsal surface of this ganglion the fibres bend sharply to right and left to run in all directions to the retina-cells. Pitrment-cells, with rather large round granules, begin to accompany them almost immediately they leave the ganglion, like single or double strings of beads. The space aroimd this ganglion, and for some way up at the sides of the retina, i. e. between it and the chitinous walls of the ocular tubercle, is filled with blood-cells and traversed by connective-tissue fibres. High tip round the lens the circular iris-like fold of the hypodermis is filled by a close reticulum of coarse threads like a sponge {sp). This spongy cushion, which completely surrounds the lens in the angle between it and the chitinous body-wall, may perhaps have something to do in effecting or regulating, by means of fluid pressure, slight movements of the eye. Prom the flexibility of the cuticle, close round the lens (fig. l,fl), some slight movements seem possible, and I have found no other mechanism for the purpose. From the fluid space beneath the retina and around the ganglion an enormous number of channels, anastomosing freely with each other (fig. 8, Ic), run up between the retinal cells as far as the hypodermal cells which secrete the lens. These, no doubt, * Bertkau(i8) says that in Spiders there are more laminae in the lens than in the cuticle. This is not the case in Galeodes ; so far as it is possible to count the lamina? accurately, the numbers agree. COMPAEATIVE MOEPHOLOGY OF THE GALEODID.E. 347 supply nourishment to the retinal cells and to the hypodcrmis, and fluid to the lens. The ahstraction of the fluid from these canals causes the collapse of the retina and its shrinking from the lens and from the circular iris-like fold of tlie hypodermis, in the way shown in figs. 7, 8 (PI. XXXI.). Owing to the uusatisfactory state of preservation of the tissues, I have not succeeded in making out the histology of the retina. The collapse of the fluid-channels above mentioned, which perhaps kept the retinal elements distinct, in all cases confused the field. Certain important points were, however, clear : 1. There was no developed vitreous body, the hypodermis-cells (%) l)cing confined to a single thin layer of closely-packed cells with large nuclei, separated from the distal ends of the retinal cells by a very fine membrane. 2. The clear ends of the retinal cells, which were very short in the axis of the eye, but longer round its j^eriphery, showed no difi'erentiation into rods. 3. A short way below the commencement of the pigment-layer is found a zone of large nuclei, wliich are apparently the nuclei of the retinal cells. I could make out no retinulation or grouping of retinal cells round a rhabdom. I could indeed find no traces of rhabdoms, and from the very crooked courses of the retinal elements in the axial portion of tlie eye I doubt whether any such could have been present. It appeared to me as if the retinal cells ran singly, closely entwined by strings of pigment-granules, which, liere and there, were clumped together. These pigment-clumps may, in some cases, indicate the presence of the nuclei of the pigment-cells, in the pseudopodia of which the strings of smaU pigment-granules are probably enclosed. 4. While the hypodermis-cells secreting the lens are naturally clear and free from pigment, those which form the iris-like fold, and which from thence line the rest of the ocular tubercle, are closely packed with very large round pigment-granules. A comparison of the eye of Galeodcs with the homologous eyes in Scorpio on the one hand (Lan- kester and Bourne, 45), and of the Spiders on the other (Bertkau, 18), shows how little reliance can be placed on eyes in establishing points of relationship. It is not too much to say that, according to the descriptions given, the median eyes of these thi'ce Arachnids, the Scorpions, Spiders, and Galeodidse, are built on entirely different plans. A similarly complete difference between the lateral eyes of the Pseudoscorpions and those of the Scoi'pions has also been pointed out (10). (2) T//e Vestigial Lateral Ei/es. — The most interesting point about these eyes is their extreme irregularity. These lateral eyes occiu-red in all specimens of Galeodidse which I have examined, sometimes in two pairs. They lie under the remarkable area at the sides of the cephalic lobes, and thus look forward and downward. Tliis fact again suggests that these areas are quite secondary modifications developed for the purpose above described (jj. 321) since the lateral eyes left the ocular tubercles. These lateral eyes vary in size and shape, the anterior being sometimes long and elliptical, while the posterior is small and round ; sometimes they have run together to form a long narrow single eye (PI. XXIX. fig. I, le, Rhax melaiia). The lees has eutu-ely atrophied, and the eyes are inserted into j)its on the inner side of the thick cuticle (14). It is on this account that I call the eyes vestigial, although, from the develojiment 46* 348 ME. H. M. BEENARD ON THE of their nerves and the masses of pigment enveloping the retinal cells, they seem, at least in some cnses, to be functional. I have not been able to make out any more of the finer details of these eyes than those which are given in the paper referred to. The great diversity in number, arrangement, and structure of the lateral eyes of Arachnids lends some support to the view that they are secondary developments. A review of their positions and numbers throughout the Arachnida inclines one to the belief that we have in the Aviculariidse the most primitive condition. There we find an ocular tubercle with two large round median eyes, one on each side of the median line. These median eyes are of the typical appearance of the median eyes of the Arachnida, which generally seem to have a blue-greenish colour. On each side of the median line, symmetrically an-auged, on the base of the tubercle, are three eyes differing in size, shape, and appearance, as well from the median eyes as from one another. These are generally red or yellow, and often very lustrous. Whether these accessory eyes of the tubercle are later developments than the median eyes or not it is impossible to say, but I am inclined to think that, whenever they arose, they belong in their place of origin to the ocular tubercle. In no other Arachnid are they now found on the tubercle, having, it appears, wandered off laterally on to the cephalic lobes. In the Spiders they have not wandered far from the principal eyes, but are grouped in various ways in front of and at tiie sides of the principal eyes, which, as a rule, retain their positions close to the median line. This arrangement might clearly have been brought about by tlie obliteration of the optic tubercle. In Phrynus the little groups of three lateral eyes on each side appear to have wandered ofiF from the tubercle a short way outward and backward, leaving the median eyes in the original position, i. e. as in Galeodes, on a tubercle anteriorly in the suture between the cej^halic lobes. In Thelyphonus the optic tubercle is obscured, but the median eyes retain their position upon the somewhat modified anterior edge of the cephalothorax. The brilliant lateral eyes are in groups (three in each in my specimens, as in Phrynus), but each group has travelled further back than in Phrynus, and is at the edge of the dorsal surface, and far behind the median eyes. In Scorpio the median eyes frequently occur on an ocular tubercle, arranged at very different points along the suture between the cephalic lobes. The lateral eyes appear to have wandered off when the tubercle was in its original (anterior) position, inasmuch as, while the median eyes have wandered backward, the lateral eyes are arranged near the anterior corners of the dorsal surface. They are in groups of from five to two. The Phalangidae have retained the ocular tubercle, which is very prominent, owing to the tilting of the eyes so as to look out sideways from the median line. As in many Scorpionidae, it has shifted back along the cephalic suture. Lateral eyes occur in rare cases [Cyphophthalmus) , but it is a question whether, in these cases, the lateral eyes are not the median eyes wandered apart. In the Chernetidse the median eyes have degenerated. The lateral eyes, arranged singly or in pairs, are alone present at the lateral edges of the dorsal surface. It is, perhaps, possible that the lateral eyes here, as in Cyphophthalmus, are the homologues of the median eyes, and that these median eyes wandered apart, ou the obliteration of the ocular tubercle *. It is simpler, perhaps, to believe that the eyes spread out from the tubercle, those in the middle line having degenerated. When the Acari have eyes they appear to be always laterally placed, and the same remarks apply to them as to Chelifer. These lateral eyes are generally, if not in all cases, innervated from branches of the median optic nerve, which supports the hypothesis that they wandered off the ocular tubercle. * MetBchnikoff (" Entwickelungsgeschichte des Chelifer," Z. w. Z. xxi. p. 71) makes no observations on the origin ot the eyes. COMPAKATIVE JIOEPHOLOGY OF THE GALEODID.^. 349 (3) The Pi'otntsible Organ at the T'q)s of the Pedifalps. — The invagination at the tips of the pedipalps, the sensory nature of Avhich is evident directly its structure is taken into account, requires to he described in detail. The chitinous mechanism is as follows : — A pair of soft-skinned lips (PI. XXXI. fig. 10) open transversely across the tip of the limb. The ventral lip has no hard framework, but the dorsal is only soft where it is in contact with the ventral ; it soon becomes a solid chitinous arch or lid, which moves on hinges at its ends (fig. 11). This lid is opened by a muscle in the next proximal joint (tig. 12, m^\ a long tendon from the muscle being attached to the lid on that side of the line passing through the hinges which is opposite to that on which the lips occur. The aperture leads into a deep conical invagination, running through the whole length of the joint, which is free in Galeodes (PI, XXIX. fig. 3, and PI. XXXI. fig. 12), but fused with the next proximal joint in Rhax (PI. XXIX. fig. 4). The folded walls of the invagination gradually converge, and run down the tibia as a long tendon. This tendon is attached to a very powerful muscle (Wo)' which almost fills up the proximal end of the tibia. The contraction of this muscle draws down the invagination and tightly closes the lips. The whole of this chitinous invagination is covered by an epithelium continued down the tendon as far as the muscle, where it becomes lost to sight. The green pigment- cells {cf. p. 331) gravitate towards the tendon as towards the outer cuticle. The epithelium covering the inner ventral face of the flattened conical invagination is deep, contains several layers of smaU nuclei (Pi. XXXI. figs. 13, 13 a), and is sensory. The sensory cells send fine hair-like processes through the cuticle, which project into the invagination, clothing its ventral wall like a fine velvet. These hairs are about 1 n thick and 75 ^i long ; the sm-face formed by their tips is wavy, perhaps for the purpose of increase (PI. XXXI. figs. 13 and 14). The cuticle, traversed by these hair-like processes, is regularly channelled through by rows of pores close together, so that it has, at times, a net- or lattice-like appearance. It is considerably thickened, perhaps to keep the sensory area spread out. It is, neverthe- less, liable to be folded longitudinally, the longitudinal bars of the latticework being thicker than the transverse (fig. 14). The dorsal sm"face of this sensory invagination is entirely free from such hairs, and is extremely thin and delicate. When the lips are closed the tips of the sensory hairs rest against this membrane. When the Ups are open the up2)ermost sensory haii-s jn-oject through the gape. They :are not, however, confined to this part, but continue right down to near the extreme base of the pit, where it runs into the tendon {cf. fig. 12). Pigs. 15, 16, 17 show the organ fully protruded, this protrusion probably being effected by blood-pressure *. In this condition the sensory haii-s deej) down in the base of the invagination are brought into closer contact with the outer air. As to the function of these organs there has been some difference of opinion. In * lu its evagioated condition the outer skin is very smooth and glistens like satin, wliich fact would account for the following description of an eye-witness : — '• When the palpi arc applied to any object, a sort of phosphorescent flame seems to be emittted from them." — Murray's ' Economic Entomology,' p. 42. 350 ME. H. M. BEENA.ED ON THE describing the sbavp sense of smell of these animals, Lichtenstein and Herbst (48, p. 52) state that it is eliiefly localized in the hollow knob at the tip of the feeler. Dufour, however, who discovered the retractile organ itself, interpreted it as being a sucker. Koch had adopted the earlier view, which, from the above description, seems almost certainly the correct one. That it is not an organ " pour s'accrocher ou grimper " (Dufour, and recently re-stated by Bertkau, 20, and Gaubert, 32) follows from the fact that it has no teeth and no circular or radial muscles, and is lined with fine hairs on. only one side, which hairs extend right down into its base, where they could take no part in any external action. Turther, Avhen fully distended (PI. XXXI. figs. 15, 16, 17) it does not make a complete circle as a sucker must do, and is not conveniently placed, opening not downward but outward. All the observations on living animals show that the pedipalps are organs of fine sensation *. So far as is at present known, the only other Arachnids with invaginations at the tips of the pedipalps are the male Spiders. In these they are specialized as sexual organs ; the transition between a sensory invagination and a spermatophore carrier is not difficult to imagine when we remember that the Spiders have lost the highly sensory organs which, presumably, were at one time present on the limbs, either in front of or behind the genital aperture (compare the pectines of Scorpio and the racquets of Galeodes). In other Arachnids there is no doubt that the pedipalps, as occupying the foremost position of all the limbs, are the seat of fine sensation. The Scorpions and Pseudoscorpions use their pincers with great caution, as if feeling with them. Hansen has described and figured fine tactile hairs on the pincers of Scorpio. Long delicate hairs a])pear to rise from the bottom of cup-like pits on the pincers of some Pseudoscorpions. In Phrynus, within the most distal joint or claw of the pedipalps, there is a sensory area surrounded by hairs of different shapes |. (4) The Racquet-organs. — Five of these, as is well known, are found, in most, if not in all, genera, on each of the last walking-legs, two on the coxa, two on the trochanter, and one on the femur. On comparing this with the pectines of Scorpio we find a striking parallel, inasmuch as the pectines in many genera show clearly that they consist of the same thiee joints, i. e. of the coxa, the trochanter, and a small portion of the femur of a pair of legs behind the genital aperture. We may perhaps conclude from this that, in the original Arachnid, the limbs both in front of and behind the aperture were provided with sensory organs on these joints. The racquet-organs stand sti-aight out ventrally from the cuticle of the leg as tubular outgrowths, slightly folded round their bases for the sake of flexibility. This tubular shaft varies greatly in length, being long in Galeodes, which runs high off the ground on its long and jiowertul legs, but very short in Rhax, wliich has comparatively short * " Les palpes s'agitent alors commc pour interrogcr I'espace " (Dufour). See, further, the account in Murray's- ' Economic Eutomology,' quoted in the preceding note. t In the Ann. & Mag. N. H. ser. 6, vol. xi. 1S93, I stated that this area sloped away sideways under the cuticle into a pocket which ran down into the next joint, and was provided, as in (laleodcs, with sensory hairs. I have been unable to find any trace of this pocket in sections, and have re-examined the cleared specimen in which it seemed so apparent. It was some time before I found the clue to the discrepancy ; the cleared specimen is apparently preparing to shed its skin, and the sensory area is repeated beneath the cuticle and reaches into the next joint, thereby giving the appearance which deceived me. COMPAEATIVE MOEPHOLOGr OF THE GALEODID^.. 351 legs. There may also he some difference in the length of the shaft in males and females. In sagittal sections the sensory processes of the pectincs of Scorpio are seen to belong to the ventral, if not to the anterior, face of the limb, which is folded backward. They are not on the posterior face, where they ought to be if they were the derivatives of gills like those of Limulus. The shaft suddenly expands into a fan, which is apparently capahle of hcnding on the former. The more median fans are symmetrical with the shaft ; those lying externally are asymmetrical, the inner or median edge heing almost on a line with the shaft. The distal edge of the fan has a fold rvmning along its wliole length. The investiga- tion of the exact natui'C of this fold has heen a task of some difficnltv. The foUowinsr description differs from that given hy Gauhert (32), whose account seems to me rather too simple and diagrammatic. It is true that his drawings refer to the racquet-organs of Odleodes barbarus, whereas mine refer to those of Galeodes arabs and Rhax fsp.). Compared w'ith the depth of the whole fan (excluding the shaft) the fold is very shallow, -2^0- to -0-5-, and not ,V, as in Gauhert's drawing *. The fold appears to he very similar in Mhax and Galeodes ; the form in section can he gathered from PI. XXXII. fig. 2. We have a sharp, stiff ridge (in cross-section a digitiform process), bordering the furrow anteriorly, while the posterior hoimdary is holster-shaped (in section a knoh-like process), which either stands straight up or hends over towards the stiff digitiform process (PI. XXXII. fig. 3). The nerve-endings in the specimens examined by me are not whei-e Gauhert figiu^es them, ^. e. in the base of the fvuTow, but on the bolster-shaped ridge, in such a position that when it stands up so that the fiu-row is open the nerve-endings are along the most distal edge of the ridge ; when, however, the bolster rolls inward against the sharp, stiff ridge, the nerve-endings would be protected by this latter ridge {of. the figures). The chitin of the whole racquet-organ is very thick and tough, and my attempts to make thin sections almost completely failed. The lateral edges of the fans are specially thickened (PI. XXXII. fig. 4, ch). On the flat surfaces the ordinary staining layers of the cuticle can be made out, and an outermost refractive layer which has a very wavy external surface. The waviness is very pronounced near the furrow-edge of the fan, and may be due to the movement of the two ridges bordering the furrow in opening out and closing one against another. An irregular row of markings occurs on each face of the fan ; these are apparently apertures for the passage of fine sensory hairs, which are, as a rule, destroyed. I have, how^evcr, found one or two m situ (cf. fig. 4, sh). Internally the racquets show the following arrangement of tissue : — The powerful nerve, whose fibres are closely mingled with fine tracheal tubes, spreads out like a fan on leaving the shaft. The nerve-fibrils appear to run distinct, bathed in blood-fluid, for, between the fibrils, blood-ceUs are freely scattered. The fibrils themselves have long fusiform nuclei in their course ; whether more than one to a fibril, and if so at what distance apart, I have been imable to make out (PI. XXXII. fig. 1, nf.). After traversing about halfway through the depth of tlie fan, the nerve-fibres no longer * Plate 3. fig. 5. It is necessary to refer to Gauhert's details, as his account is, so far as I know, the first attempt to describe the minute anatomy of these organs. 352 ME. H. M. BEENAED ON THE radiate so regularly outwaixl, but have to bend about among a great network of blood- lacimse wMcb are limited by connective tissue (PL XXXII. figs. 1, 5, ret). This irregular arrangement gradually becomes regular again. It appears to be as follows, my description being based upon racquets cleared in cedar oil and studied by the liighest oil-immersion lens applicable (3 mm. apochromatic of Zeiss) : — A thick epithelium runs in wavy folds, as shown in the diagrammatic cross-section, fig. 8. The nerve-fibres all rixn. on the posterior side of this epithelium, largely within the posterior folds themselves. In the anterior folds, i. e. between the epithelium and the cuticle, the space is apparently filled with blood-fluid, in which are a few blood-cells. Still nearer the outer edge of the fan (figs. 1 & 6) the folded epithelium flattens out again, and the nerve-fibres radiate again freely outward. They terminate in a long row of minute pores through the chitin of the outermost face of the bolster, but do not appear to project. As above described, when the bolster rolls inward towards the furrow these nerve-endings are bent down under protection of the stiff ridge. In one of my mounted specimens the bolster is standing up throughout a part of its course, aj)parently unable to roll round, owing to the presence of a foreign body ; on each side of this tract, however, the bolster is rolled round and the nerve-endings are bent backward. Eig. 9 (PI. XXXII.) is the surface view of the edge of a racquet-organ of a Bhax, which shows the nerve-endings bent sharply round, perhaps abnormally so, owing to the pressure of the cover-glass. The protecting ridge {j)r) has also in this case been flattened out. I could find no trace of any muscular fibres which could effect the movements in the ridges. I therefore think that the erection of the bolster-ridge is due to fluid pressure. It seems also not improbable that the folded epithelium effects this erection by means of the fluids contained in the folds. There is uo histological resemblance between tiie racquet-organs of Galeodes and the pectines of Scorpio (cf. Gaubert). The "teeth" of the latter, however, in sagittal sections, look as if they were erectile by means of fluid pressure. (5) Sensor?/ SetcB. — The Galeodidae are very richly provided with setse, of which there are several specialized forms — specialized, that is, as sense-organs. I must confine myself to two, having made no special study of these structures. 1. We have the plumose bail's, which appear to be sensory, but arc not necessarily so ; they are generally found grouped on the inner sides of the chelicerse, and serve, perhaps, as a felt-like barrier to prevent the escape of nourisliing fluids. The elaborate sieve in front of the mouth is probably due to the concrescence of plumose hairs. On the other hand, the two long plumose hairs, one on each tip of the under-lip, look like sensory organs. In all these plumose haii's fine staining channels can be seen running out laterally from the central axis of the hair into each barb. 2. While it is probable that all the longer hairs are to some slight extent sense-organs, there are some which are highly specialized as such, notably the long fine hairs on the pedipalps and on the first pair of legs, which, as above stated, is in process of becoming a second pair of feelers. PI. XXXII. fig. 12 is a drawing of the tip of the first pair of legs (3rd appendage) of a COMPAEATIVE MOEPHOLOGT OF THE GALEODID.E. 353 small Galeodes, cleared in cedar oil. It shows the base of each haii- suiTounded by a si^ecialized arrangement of cells. Eig. 18 is an enlarged drawing of a few of these, as seen in the cleared specimen, while figs. 14 and 15 rejiresent others in section. We find the base of the hair- slung, in a chamber in the solid cuticle, by the hard refractive outermost layer, as above described (p. 333). Its innermost end is attached by elastic (?) fibres to the waU of the chamber. These radiating fibres thus form tos-ether a septum across the chamber, dividing it into an upper and a lower portion. The uj)per portion is kept supplied Avith body-fluid by means of a seimrate channel (fig. 14, c). which I have already mentioned. The hair itself owes its origin to a group of cells which are attached to it only by protoplasmic processes, apjiarently to avoid overcrowding round its small base. One, two, thi-ee, or more nerves run from the base of the hair and swell into large ganglion-cells proximally to the group of the secreting-cells. These two groups together (the secreting- and the ganglion-cells) are protected under a dome-like arrangement of cells (fig. 14, ro) wliich projects into the hollow of the liml), and is closed on all sides except proximally, where the nerves run out to join the nerve-trunks in the limb. Eig. 15 represents a small terminal hair where the protecting roof is not reqrured. The exact innervation of the hair I have not succeeded in making out. I am disposed to think that the nerves terminate in the septum of radiating fibres, and for the follo-vving reasons : — (a) I can find nothing like a nerve running up the axis of the hair ; (6) the radiating fibres would natm-ally be the first to be strained or relaxed — strained on the side towards which the hah- is bent by contact with an object, and relaxed on the opposite side ; ((?) the development of a special channel between the portion above the septum and the cavity of the limb may perhaps imply great physiological activity of this fibrous septum, (6) Other Organs of unknown significance. — At the tips of the pedij^alps and of the pair of legs, which, in the Galeodidse, are gradually losing their claws and becoming feelers [cf. the Pedipalpi), remarkable sensory organs have apparently been discovered simultaneously by Bertkau (20) and Gaubert (32). In each case they occru* on the upper, or dorsal, and slightly on the outer sides of the limbs. They occiu" in con- siderable nimibers, but not in regular arrangement nor in any well-defined areas. Gaubert has given a description of these organs, mth a figiu-e showing their distribution on the first leg of Galeodes harharus, and Bertkau has given drawings of the appearance of the organs in section on the j)edipalps of Solpuga flavescens. The observations I have been able to make on these organs are, unfortunately, very far from complete, especially in reference to their soft parts. I have found three kinds : — 1, (PL XXXII. figs. 11 a, 11 b.) A sort of barrel-like pit in the cuticle, which appears to open externally, and from the base of which a fine pointed process rises, but does not quite reach the external apertiu^e. Passing through the lower boundary of the barrel, the fine process is continued downward into a large bag-like cell, apparently full of fluid. At the base of this cell lies a mass of dense granidar protoplasm with a large nucleus. These bag- like cells are of all lengths, and are supported in a framework of connective tissue, the cells of which often appear to belong to the bags, and indeed I cannot be sure whether SECOND SERIES. — ZOOLOGT, VOL. VI. 47 354 MR. H. M. BERNARD ON THE some of the nuclei in close proximity to the large nuclens just mentioned do or do not belong to the organ under discussion or to the connective-tissue cells. Owing to the large size of the hag-cells compared with the size of the external openings, the former are greatly- crowded together, and at the edges of the sensory area the necks of the bags are very long, and bend away at right angles under the cuticle (fig. 11 b). These appear to be the commoner form in a small species (or ? young specimen) of Rhax from Tashkend. (Figs. 11 a, 11 h, are enlarged from fig. 10.) 2. (PI. XXXII. figs. 16 a, 16 b.) A small conical pit with the base of the cone outermost, passes at its slit-like apex into a larger conical passage, the base being in this case innermost. I have foxind it almost impossible to decide whether the outer pits open at the surface of the cuticle ; I am inclined to think not, but that an exquisitely fine membrane spreads over the mouth. I have found, for instance, small bodies apparently suspended over the mouths of the pits in a manner which is difficult to explain, except on the assumption that they are resting on a fine membrane ; but I am not at all certain of this. Prom the narrow slit-like apex, where the cones pass into one another, a short chitinous tube depends, from which the soft parts are often torn away. When the soft parts are in situ, the appearance of the whole is as shown in the figures, and perhaps corresponds with organs described by Bertkau. The outer apertures (?) of these organs measure about 12 n across, and are found on slight eminences, comparatively speaking, rather far apart. They seem to be always present in limited numbers, generally along the outer edges of the sensory areas under discussion. In fig. 12 a row" of them occurred along the left edge of the dotted area, and on the right a few w^ere found even among the hairs. They occurred also in the section fig. 10. 3. Smaller conical pits (whether with or without membranous covers I have again failed to decide) which pass very rapidly into a slit-like canal within the cuticle ; this again rapidly changes into a tube of varying length which runs down freely among the soft tissues subjacent to the cuticle. These pits seldom aj)pear circular when they reach the outer surface of the cuticle ; they look, on siu'face view, heart-shajied, leaf-shaj)ed, sometimes oval. They occur in great numbers (fig. 12), and, according to Bertkau, are occasionally so numerous that their apertures (?) seem to run together to form small common depressions. The exact details of the proximal ends of these organs I have been unable to make out. The appearance is as if the soft parts had been crowded away from the cuticle, with which, therefore, they remain connected by means of long tubes. These tubes show remarkable modifications just before reaching their proximal oi'gans. Some of Bertkau's figures appear to refer to the same, and give fairly well the general appearance of the whole structure. Pigs. VI a & VI h give their appearance (seen by an oil immersion in optical section on the limb, fig. 12), but I am as uncertain whether I have interpreted the details correctly as I am as to what the functions of these organs may be. In these figures (17 a, 17 b) it seems as if the jirotoplasmic process running from the large bag-like terminal cell had been ruptured before it reached the tube to the cuticle. I failed here also to make out for certain the position and character of the nuclei of the bog-cells. COMPAEATIVE MOEPHOLOGT OF THE GALEODID.E. 355 These last-described organs, which ajipear to be the commonest forms, were not found on the first leg of the small llhax above referred to (PI. XXXII. fig. 10). Lyriform Organs. — I have been able to confirm Hansen's description (33) of the group of slit-like markings at the ventral edges of the chelicerse. These were the only organs of the kind Hansen succeeded in finding in the Galeodida?. I have also accidentally found an isolated lyriform organ among the hairs on the ventral side of the first leg of a Galeudes. I have made no special search for them. What these organs are, morphologically and physiologically, is at present imknown. I would suggest their probable derivation from setal pores. As evidence iu favour of this explanation of tlie lyriform organs, the following points deserve attention : — 1. These lyriform organs, when simple, not only agree in size with the setal pores, but also show the same variations in this respect as do the setal pores. 2. They occur singly or iu scattei'ed groups, the individual members of which either vary or agree in size, or, lastly, in closely-arranged groups. 3. They occur in jjlaces where hairs generally occur or might be expected to occur, and often among the hairs. In the latter case their size agrees well with that of the adjacent setal pores. 4. They sometimes appear to run iu rows parallel with rows of hairs, and where they occur it looks as if a row of hairs was wanting. Iu addition to these arguments, I would point to the pores which appear to open at and round the tips of the mandibles of Gal codes. These seem to be open, owing, perhaps, to the wearing away of the hard outer layer of the cuticle ; and if so they may account for the poisonous character attributed by many persons to their bite. These pores are certainly setal. There is no inherent difficulty iu this suggestion ; as a seta aborts, the pore with the nerve which once ran to the seta might jjersist and be adapted for other purposes. On the other hand, however, I have found " lyriform organs ■" which have not so arisen. On the coxa of the last leg of a small Tliehjphonus , zigzag cracks occur iu the thick chitin, many in the shape of an open W. Setfe often occurred near them. Close examination showed that iu the angles of the zigzag came the corners of the polygonal cells of the tesselated hypodermis. These organs, then, were merely slits iu the chitin between the seereting-cells. I could see the nerve-fibres running among the hypodermis cells, but the chitin of these slits was so dense and refractive that it was impossible to see whether a nerve came to the surface between them or not. I think it is almost certain that they are sensory organs of some, perhaps very simple, kind. These organs, which certainly do not rise from setal pores, do not alter my view that the ordinary lyriform organ with a cylindrical channel through the chitinous cuticle, as occurring on the underside of the chelieer?e of Galeodes, did arise in the way above suggested. VIII. The Alimentary Canal. The Mouth and Q^sojjhagus. — The mouth, as has already been described, is situated at the end of a beak, and is guarded by an elaborate sieve-like arrangement of bristles (PI. XXVII. fig. 11, PI. XXVIII. figs. 5, 6). It opens into a long oesophagus, which runs through the beak and passes through the ganglionic mass to enter the mid-gut. Within the beak the oesophagus, which in transverse section is triangular with the apex pointed downwards (PI. XXVIII. fig. 3), can be alternately expanded and contracted, by means of a system of radiating and circular muscles, making thereby a sucking-apparatus 47* 356 ME. H. M. BEENAED ON THE of considerable length. This sucking-apparatus is therefore anterior to the brain. On reaching the central nervous mass, the oesophagus narrows, and its musculature is apparently confined to a layer of circular fibres, which are continued along the whole length. After passing through the nervous mass, it widens again, to end posteriorly in a blind corner (PI. XXXI. fig. 5). The opening into the mid-gut is situated on the dorsal surface of the oesophagus (PL XXXI. tig. 1). No salivary glands enter this oesophagus. The specialization of a portion of the CEsophagus into a sucking-apparatus is common to all Arachnids, but a comparison of its position in the different forms leaves little doubt that in Galeodes we find the primitive condition. We find, for instance, the pumping-apparatus contained in a beak in such widely different groups as Galeodes, Thelyphonus *, and Gamasus among the Acarids. The Pseudoscorpions also have a beak, but the sucking-apparatus is condensed at its posterior end, although still anterior to the brain (PL XXVIII. fig. 10). In the Scorpions, in which the beak is much modified, and in the Phalangidse, the sucking-apparatus or its homologue is also in front of the brain. But in these cases the shifting backward of the mouth and the shortening of the beak have also shortened the sucking- aiDparatus. In Phrynus the beak is aborted, and part of the sucking-apparatus is in front of, and part behind, the braia (PI. XXVIII. fig. 7) The Spiders have the sucking-apparatus posterior to the brain, although a few expanding muscle-fibres still remain in front of the brain (fig. 8) . In this case, that portion of the oesophagus which projects backward beyond the central nerve-mass is very considerable. The shifting back of the poi'tion specialized for sucking is no doubt to be traced to the shifting backward of the mouth, which goes furthest in the Spiders t- Specialization of the oesophagus itself seems to have gone furthest in some Phalangids, in which the portion of it posterior to the brain is developed into an enormous " crop.'' I know of no salivary glands in the Arachnids. The single pair of mid-gut diverticula in front of the diaphragm in Scorpio have been usually taken for such glands, but this is incorrect, the epithelium of this first pair of diverticula not differing in any essential from that lining the following (so-called " liver ") diverticula. This absence of salivary glands in the Arachnids is perhaps to be explained in the following way : — In the Insecta, where the mandibles and maxillifi have been much reduced and highly specialized as organs of mastication, grouped closely round the mouth, the acicular glands (from which I would deduce the salivary glands as well as the spinning-glands and tracheae) might easily be specialized as secreting- glands opening within the oral aperture. But in the Arachnids, where the first pair of limbs, and later the second also, are primarily highly-developed seizing-organs (the cheliceree being typically 3-jointed, the pedipalps 6-jointed), and where there is typically no attempt to group them closely around and within the oral aperture as masticatory organs, the absence of salivary glands is what we might expect. It is true, the basal joints of the pedipalps of the Spiders have been secondarily developed as a pair of mouth-organs ; but they are not chewing-jaws. In this case, it is of great interest to find that groups of glands which are probably derivatives of setiparous glands J have been modified to form the so- called " maxillary " glands, whose function, however, is not yet clear. This complete absence of chewing-jaws round the mouth in Arachnids (except, according to Mr. Michael, in some Acari) is closely associated with their method of feeding. The Arachnids suck in liquid food by means of their pumping-apparatus. The chelicerse and pedipalps are variously specialized in order to crush the juices out of prey close in front of the mouth. This method of feeding has had * Galeodes and TJieh/pJioiiiis are, however, connected by Sc7iho)wtus, t Stecker, in his paper on Gihhocellum, figures the mouth behind the basal joints of the pedipalps. This is such an obvious error that one can hardly help taking it for a misprint. X Cf. figs, in Schimkevitch, ' Anatomie de I'Epeire' (62), COMPARATIVE MORPHOLOGY OF THE GALEODID^. 357 far-reaching consequcuces, and^ indeed, we owe to it the special morjjliology of the group, viz. : the character and position of the anterior seizing-limbs, and the division of the body into an anterior loco- motory region and a posterior highly distensible food-bag. In adaptation to this liquid food we have apparatus (1) for preventing the escape of the juices crushed out in front of the mouth, and (2) for straining them so that no solid matter finds its way into the alimentary system. Special Apparatus for conducting and straining juices. — The juices flowing from the wound made by the chelicerte are conducted towards the tip of the beak by bushy rows of jilumose hairs Avhich run along the digits of the chelicerge on their inner sides. The juices are strained by the sieve-like arrangement at the tip of the beak already described (PI. XXVIII. fig. 6). In one of my series of sections, the outside of this sieve is thickly covered witli moth's feathers and scales. A few of these were also found in the digestive tubules, and in each case embedded in small masses of blood- plasma, which, apparently on account of their presence, had not been taken in and turned into food-globules by the digesting-cells (i i). Thelyphonus also has a beak, but it is enclosed between the basal joints of the pedipalps, which are fused below it, but are open above it (PI. XXVIII. fig. 12) . The ehelicerte crush the prey into the channel thus formed by the coxse of the pedipalps, and the juices are drawn in by the powerful pumping- apparatus. They are strained by transverse rows of fine hairs, which line the aperture (figs. 12, 13, st). In Phrynus the pedipalps are not fused below, but their inner faces are covered with fine hairs and they can be apposed. Their upper inner faces are provided with specialized " gutters," i. e. one on each side, for conducting the juices to the mouth, as Gaubert (32) has already pointed out. The Phalangidse are also said (McLeod) to have similar gutters, or, as they have been somewhat inappropriately called, " pseudotrachese." In Scorpio, the coxse of the pedipalps, which are generally adapted among the Arachnids to prevent the escape of fluids, have been forced apart by the squeezing forward of the two following coxie, which, again, may have been forced forward by the anterior translocation of the genital aperture. To prevent the escajje of juices, therefore, processes of the coxae of the first and second pairs of legs have developed forward, and together form a sort of spoon-like structure under the mouth (PI. XXVIII. fig. 9, /j) . Fine hairs prevent the juices from escaping between these coxal processes, and a pair of "gutters" [Euscorpw] conduct back any which happen to be escaping in that way (PI. XXVII. fig. 9 6,^). The Spiders apparently apply the oral aperture to the wound in the prey, the dense tufts of hairs on the parts bordering the mouth and on the coxai of the pedipalps hindering the escape of the juices. The sti-aining-apparatus is very highly developed. The entrance to the oesophagus between the labrum and labium is a long transverse slit provided with transverse rows of fine straining-hairs ; between these rows of hairs are gutters sloping upward and inward to open, in some cases, through windows into a central gutter which itself gradually widens into the cesophagus proper. The latter is prevented from collapsing under the powerful sucking-action by its solid chitinous dorsal wall. The only exception I know to this order of things is the case of an unknown Phalangid (already mentioned), which I cut in sections for some special purpose, and found, to my astonishment, that behind the brain the oesophagus formed a large muscular ' crop ' which was full of solid particles. As there were none in the stercoral pocket, I presume that this is some special arrangement of the sucking-apparatus, and that the solid matter is again ejected through the mouth. The Mid-gut. — The oesophagus, in Galeodes, is not in a continuous straight line with the mid-gut, but doubles back slightly on itself, so that, with the mid-gut, it form.s an S-shaped bend (PI. XXXI. fig. 5), the lower loop of which gives rise to the blind pocket 358 ME. H. M. BERNAED ON THE above described. This bend in tbe oesopbagais may perhaps be an indication of the compression of the first three segments. The mid-gvit itself pursues a straight course backward to the commencement of the hind-gut. It is lined, apparently throughout, by an epithelium of cylindrical cells, which vary in depth in different parts (PI. XXXIII. figs. 10, 11) ; they are specially long just before reaching the hind-gut. In nearing the diaphragm, the canal narrows considerably, and in passing through it, its lumen is very small (PI. XXXIII. fig. 1, and also figs. 2, 3, 4, Avhich are drawn to scale). After passing the diaphragm, the lumen increases greatly in size, and then gradually narrows again in the 4th abdominal segment, remaining narrow until it joins the hind- gut (PI. XXXIII. figs. 1 & 5). The mid-gut of Galeodes, as of all Arachnids, is supplied with diverticula for the reception of the liquid food. These originally segmental diverticula were, in their simplest condition, probably inherited structures. It is not impossible that there is some relation between their present enormous development in the abdomen, where they fill up every available space, and the pumping-apparatus — that is, the latter may have helped to sjiecialize the former by its force-pump action. Por convenience, we divide these diverticula into two groups, the cephalothoracic and the abdominal, although, morphologically, they belong to one and the same series. But, while the diverticula in the muscular cephalothorax show signs of degeneration, those in the abdomen, which is specialized into a distensible sac, are, as stated, developed to an astonishing extent {cf. PI. XXXII. fig. 18 with PI. XXXIII. fig. 5). The Cephalothoracic Diverticula. — In the cephalothorax, the mid-gut of Galeodes gives off four pairs of thin diverticula towards the four pairs of legs : the two anterior pairs do not run into the legs themselves, and are apparently atrophying ; they are often found folded back upon the gut (PL XXXII. fig. 18). The two posterior pairs penetrate into the limbs as far as into the trochanter. These two usually have a branch about halfway down their lengths. This tendency to branch in the posterior cephalothoracic diverticula is interesting as leading on to the highly-branched diverticula in the abdomen. The anterior segments of the body were here again clearly those first specialized. These cephalothoracic diverticula are provided with powerful circular (cm) and longitudinal fibres (PI. XXXII. fig. 19, Im). These four pairs of diverticula, running towards or into the four legs, seem very typical of Arachnids, being found in Galeodes, the Spiders, Phrynus, Thehjphonits (Laurie), and Phcdanyium (Blanchard), and lead us to conclude that in the primitive form the CES0j)hagus ran through two segments, while in the 3rd segment the mid-gut commenced, sending out lateral diverticula in this and in the following three segments, omitting for the moment all mention of tlie abdominal diverticula. That these diverticula were originally separated one from another by dorso-ventral muscles we have sufficient evidence. Although, in Galeodes, these muscles in the cephalothorax are no longer, with certainty, recognizable {cf. supra, p. 336), in the Spiders we have the dorsal suspensors of the endo- sternite regularly separating the diverticula ; the same is apparently the case in Phrynus and Thehjjihonus. In those Arachnids in which there are no longer the four typical cephalothoracic diverticula, as Scorpio and Chernes, this is due to secondary reduction. In the former case [Scorpio) it must be accounted for by the extraordinary longitudinal compression of the cephalothorax. Instead of the COMPARATIVE MORPHOLOGY OF THE GALEODID^. 359 typical four pairs of diverticula, we find in Scorpio only one pair, which have often been taken for salivary glands. In the Pscudoscorpions also there is only one pair of diverticula in the cephalothorax, but m these animals the diverticula are not so specialized ; they are only shallow lateral outpushings of the mid-gut, which might easily run into one another, so that the segmental divisions may have become obliterated. Passing on from tliese four pairs of diverticula, the last two, as above stated, shomng a tendency to branch, we find in Galeodes, immediately in front of the diaphragm, numerous small branched accessory diverticula (PI. XXXII. fig. 18, ad), resembling those behind the diaphragm. These are interesting, as they seem to show the action of the pumping- apparatus in causing diverticula to appear irregularly, w^herever, in fact, there is room among the tissues for their development. Behind the diaphragm, the whole cavity of the abdomen which is not occupied by the genital glands, the stercoral pocket, tracheae, &c. is filled to distension witli diverticula. The Abdommal Diverticnia. — The abdominal diverticula are hooped by fine circular muscles, like those of the cephalothorax. These circular fibres are 4-5 ju apart in the contracted normal condition of the diverticulum, -with the epithelium in situ, but 8-15 ^ apart in distended diverticula, with the epithelium disorganized by food {of. ii). The distinction often drawn between the mid-gut diverticula in the cephalothorax and the " liver " diverticula in the al)domen is erroneous. As I have shown elsewhere (il), the epithelium of these diverticula throughout the w'hole mid-gut from the posterior end of the oesophagus to the commencement of the hind-gut is essentially similar, and is throughout digestive in its function. The differences which appear in the epithelia of the cephalothoracic portions of the mid-gut and of the abdominal are not differences in kind ; they are due to the fact that the latter have far more food pumped into them to digest. The diverticula throughout the Arachnida are typically mere extensions of the digestive surface, and are nowhere converted into hepatic or pancreatic glands. This uniformity of the epithelium in the diverticula throughout the whole alimentary canal is true of Galeodes, the Spiders *, Scorpio, and Cherries. Lavirie ('47) claims a difference between the epithelium of the cephalothoracic and abdominal diverticula in Thelyphonus. I would suggest that the difference noticed by him is accidental, and due chiefly, as above suggested, to the state of the contents and consequent activity of the cells. 1 can see no essential difference between the two in my own sections of Thelyphonus. It is a difficult and tedious oj)eration to dissect out the connections of the diverticula with the central canal in the abdomen. I do not believe that any clear idea of the arrangement of the diverticula can be obtained in this way. It was only after carefully reconstructing serial sections of the abdomen tliat the foUoAving remarkable arrangement was discovered. As shown in PI. XXXIII. fig. 1 {cf. also the section fig. 4), close behind the diaphragm, a large group of diverticula open into the alimentary canal on each side somewhat dorsally. There is no difficulty in finding the apertures of these diverticula in sections, on accoimt of their size and importance. * In the Spiders there appear to bo a few highly-specialized cells scattered irregularly in the epithelium of the .abdominal diverticula, which are not simply digesting-cells. 300 ME. H. M. BEENAED ON THE There is no other opening into the central canal. For a long time I was convinced that a second pair of apertures existed in the 7th segment. A great accumulation of faeces (PI. XXXIII. fig. l,f) is frequently found ovitside the central canal, far hack, near the stercoral pocket, hut in adjacent diverticula. This, I concluded, must pass into the hind-gut ^^itliout having to travel forward again all the way to the 1st segment. But fresh series of sections have shown that there is no entrance here into the mid-gut. Behind this anterior pair of openings the tuhules which fill up the ahdomen open into two lateral canals, which run backward more or less symmetrically from the anterior pair of openings to nearly the end of the body (PI. XXXIII. fig. 1). The tubular diverticula opening into these lateral canals show no regular arrangement, but branch out dorsally and ventrally, /. e. above and below the great tracheal trunks which run along outside the lateral canals (PI. XXXIII. fig. 5). They are arranged in irregular groups, alternating with tufts of branches from the main tracheal trunks. In distended animals, the diverticula hang down on each side of the great medio-ventral blood-sinus, which is continuous with the neural aperture through the diaphragm (PL XXXIII. figs. 3, 4, n, and PI. XXXIV. fig. 8, vs). This blood-space is especially large under the stercoral pocket in such cases, and is here often found filled with a sohd mass of coagulum. The lateral canals run outside the series of dorso-ventral muscles. Posteriorly, they are applied in a remarkable manner to the end of the mid-gut, being bound together over it and under it by muscle-bands. The arrangement is seen in PI. XXXIII. figs. 1 & 7. "Where the lateral canal at this place is in contact with the mid-gut, its epithelium is modified into a kind of supporting tissue (fig. 7, inep). It appears as if each cell had become vacuolated, while its wall stiffened. Between this curious supporting epithelium, and the actual wall of the mid-gut is a layer of fine blood-lacunae with coagulum, granules (? digested matter), trachese, and {V) cells. It is in this part of the lateral canal that the accumulations of faeces above mentioned are found (/), which led me at first to believe that there must be an opening here into the mid-gut {mg). These lateral canals, therefore, supply a means of constricting the mid-gut just anterior to its entrance into the hind-gut. The muscle-bands {tm) binding the two above and below the mid-gut are connected by means of the rigid-looking, highly modified epithelial cells of the inner walls of the lateral canals. The muscles with these epithelia form a hoop round the end of the mid-gut. Some power of constricting the mid-gut at this place is, as we shall sec, a necessary adaptation to the Arachnidan method of feeding. The number and arrangement of the abdominal diverticula ia other Arachnids are of great interest, inasmuch as they were originally segmentally arranged. Scorpio. — We find^ in serial sections as well as in dissection, five pairs of primary diverticula leaving the central canal at regular intervals in the first five segments of the abdomen. As with the first pair in Galeodes, these diverticula open into the mid-gut latero-dorsally. From their openings into the mid-gut, the diverticula immediately branch out in all directions, forming the compact lobes of the so-called liver. These lobes are strictly segmental, and are separated from each other by the dorso- ventral muscles (PL XXXIV, fig. 1, dvm). The fifth pair of lobes run backward, filling up the rest of the distensible portion of the abdomen. In this regular serial alternation of the diverticula with the dorso-ventral muscles, Scorpio has COMPAEATIVE MORPHOLOGY OF THE GALEODID^. 361 undoubtedly retained a primitive feature which has been lost in Galeodes. Before connecting the two forms, we will describe the coTiditioii in the Thelyphonidie and Pseudoscorpions. Thelyphonidce. — As Laurie has described (47), there are four pairs of diverticula from the central canal, alternating regularly with the dorso-ventral muscles. The fourth pair stretches back on each side inside the rows of dorso-ventral muscles, and is itself constricted by them, while the central canal becomes transformed into what is functionally a hind-gut (PL XXXIV. fig. 2). Pseudoscorpions. — The canal gives off one median ventral and two lateral diverticula in the first segment ; the latter run backward on each side of the central canal and are regularly constricted by the dorso-ventral muscles (PI. XXXIV. fig. 3). I have placed these four types of the alimentaiy canal side by side in PI. XXXIV. : Scorpio fig. 1, Thehjphonus 2, Galeodes 4, and Chernes 3. From the segmental character of the diverticula separated from each other by dorso-ventral muscles, we are, I think, justified in assuming that in the primitive form there were originally at least seven pairs in the abdomen before reaching the chitin-lincd hind-gut, which appears to have begun between the 7th and 8th segments. We should then have the primitive arrangement, consisting of seven pairs of diverticula separated from one another by six pairs of dorso-ventral muscles. I have shown this hypo- thetical primitive condition in fig. 5 and also, slightly altered, in PI. XXXIII. fig. 12. To what are we to attribute these various modifications of the primitive segmental arrangement ? It is at once apparent that in all cases the posterior diverticula degenerate, while the few anterior diverticula which persist are of increased size and importance. We shall not be far wrong if we see in them various adaptations to the method of feeding. I would throw out the following suggestion. The forcing of the liquid food into the alimentary system has to be regulated, otherwise it would be driven straight out through the hind-gut and anus. W^e accordingly find the central canal so narrowed in its course that masses of fseces could easily be utilized to stop the passage. Thus the food would tend to be pumped chiefly into the anterior diverticula, which would become highly developed, while the posterior would degenerate. The longer the liind-gut is, the further back would such stoppage occur, and the greater the number of the diverticula which could develop. Hence the great number in Scorpio. In Galeodes, where the dorso-ventral muscles, meeting ventrally in the middle line, are near together, the greatly enlarged antci'ior diverticula grew backward outside them ; but in Thelyphonus and Chernes these muscles are wide enough apart to allow the anterior diverticula to grow backward between them alongside of the central canal. Phrynus is said to have four pairs of abdominal diverticula. I can find only three pairs ; the arrange- ment in other respects closely resembles that of Thelyphonus, the smaller number of diverticula being perhaps connected with the shortening of the hind-gut by the loss of the tail. There seems to be great difference of opinion as to the number of abdominal diverticula in the Spiders. Wasmann (74 a) figures two pairs in Myyale. Bertkau, who studied this subject with great care, concluded that, in addition to certain small diverticula, entering irregularly into the central canal immediately behind the waist, there are five primary diverticula — a median ventral, which may compare with the median ventral diverticulum in the Chernetidse, and two pairs of lateral. These median ventral diverticula may perhaps be treated as accessory outgrowths of the mid-gut due to the action of the force-pump arrangement of the oesophagus *. In the Phalangidse and Acari we have altogether different conditions. In the former we have a reduction to six abdominal segments, and in the Acari very variable reduction — in some cases the abdomen consists of only three segments t- We should therefore hardly expect abdomiual diverticula to be developed in such cases. * Bertkau (16) caUs these diverticula " glands," under the influence of the old name, the " liver." t Ixodes, which has carried the distensibility of the abdomen to an extreme, develops 10 segments, which, as in the Spiders, early become obscured : Wagner (73). SECOND SERIES. — ZOOLOGY, VOL. VI. 48 362 ME. H. M. BEENARD O^' THE For a comparative account of tlie epithelium lining these digestive diverticula and of the " peritoneal " cells covering them externally, which latter are generally ahseut in Galeodes, occurring only here and there, hut are common to all other Arachnids, cf. " Notes on some of the Digestive Processes in the Arachnids," Journ. Royal Microsc. Society, 1893. The Malpig-hian tubules open into the mid-gut in the 4th segment, where the gut narrows (see PL XXXIII. fig. 1, and the section on excretion, p. 380). T/ie Hind-gut and Stercorcd Pocket. — The passage from the mid- to the hind-gut takes place in the region of the 7th segment ; it can easily be made out in sagittal sections of distended specimens. The long club-shaped cells suddenly cease, and the chitin-lined hind-gut commences (PL XXXIII. figs. 8, 11). The posterior portion of this hind-gut is specialized into Avhat is called a stercoral pocket, which is simply a great enlargement of its dorsal wall. In the contracted condition of the abdomen it reaches far forward, but much less so when the abdomen is distended. In order to increase the surface of the stercoral pocket in Galeodes, its wall is thrown into elaborate folds, between which the faecal masses are pressed, having, as I have shown elsewhere (ii), digestible material absorbed out of them. Great masses of faeces are retained in this pocket for such final absor2:»tion. I have only seen traces of an extremely thin tesselated epithelium on the outer side (i. e. on the side tow^ards the body-cavity) of the thin chitinous membrane, with minute, rather closely arranged nuclei. In addition to this epithelium, there is a thin layer of muscle-fibres, but their exact distribution round tlie jiocket is very difficult to make out ; I could find no such regular basket arrangement as that figured by Dufour (31). Purther, when we remember that many of these animals live on scorching sands, where an economy of fluid matter is a necessary condition of existence, Ave may well believe that one function of this hind-gut is to dehydrate the faeces *. The anus is a large median slit, sometimes placed ventrally {Mhaa;), but, as a rule, posteriorly, in the anal segment. The great variation in the hind-gut of Arachnids is a point of no small interest. The Spiders have the posterior abdominal segments much shortened; hence \ie find the stercoral pocket developed dorsally, as in Galeodes, as a receptacle for the fseces f. In Scorjj'/o the hind- gut, commencing in the region of the 7th segment, runs through the long specialized tail-segments as a straight tube, showing no enlargement as a stercoral pocket. In Chernes we seem to have a long coiled hind-gut, showing further a slight enlargement anterior to the anal aperture. In Tliehjphonus, the hind-gut runs through the three tail-segments as a thin tube, while an anterior enlargement functions as stercoral pocket. The greater part of this enlargement appears to me to be chitin-lined, the chitin commencing a little behind the entrance of the Malpighian tubules * It has long been recognized that this is a conspicuous function of the mammalian hind-gut {cf. Edkins, Journ. of Physiol, vol. i, p. 459). t Kischinouye (40) claims that the stercoral pocket of the Spiders is of mesodermal origin, and Laurie (47) that that of Phrynvs is cndodermal. In view of the presence of a chitin-lined hind-gut in Oalcodes, Scorpio, and Thehjiihonus reaching, at least in the two former, to the 7th abdominal segment, I think there must have been some error in interpreting the phenomena {cf. note, p. 380). COMPARATIVE MORPHOLOGY OF THE GALEODID.E. 363 (PI. XXXIV. fig. 2). As in the hind-gut of Galeodts, tlie chitinous wall is thrown into countless folds, which are found caked with coagulum, and thus much obscured. Laurie attributes tlie whole of this stercoral pocket to the mid-gut. In Phryniis, my sections (not very well preserved) seem to show a similarly sudden change in the 7th segment, from mid-gut to hind-gut, as is seen in Galeodes. The relative lengths (measured iu segments) of the different portions of the alimentary canal in the ancestral Arachnid may be stated as follows : — The oesophagus ran through two segments. The mid-gut had originally four pairs of segmental diverticula in the cephalothorax (reduced to one pair in Scorpio and C/iernes), and presumably seven pairs in the abdomen. It thu.s ran through eleven segments. We shall see further (footnote, p. 307) that there is reason to believe that there were originally 12 pairs of diverticula. The hind-gut, therefore, ran from the 14th or 15th segment to the end of the body^ and has been variously specialized in adaptation to the progressive shortening of the abdomen. Eevii'w of the Alimentary System. — In endeavouring to understand these variations in the morphology of the alimentary canal in the Arachnids, we have to ajjpeal to its physiology. The typical food of the Arachnids is essentially fluid, i. e. the body-juices sucked from prey seized, held, and crushed in front of the beak or mouth. These juices are, in nearly all cases, carefully strained by special apparatus in front of or in the mouth. By means of a special puniping-apparatus (developed primarily iu the beak) this liquid food is forced into the mid-gut and its diverticula, giving rise even to accessory diverticula where space among the tissiies could be found for them. This method of filling the mid-gut with fluid requires regulation. We find, for instance, that but a small quantity of this food runs into the ceplialotboracic diverticula, whose serious distension would interfere with the highly-developed musculature of this region of the body. Undue distension of the cephalothoracic diverticula is perhaps prevented by their muscular tissue (PI. XXXII. fig. 19), which appeal's to be much more powerful than that of the abdominal diverticula. After simply filling the cephalothoracic diverticula, the food flows on into the abdomen, where the highly specialized diverticula are filled to their fullest capacity. Galeodidae are often found with enormous abdomens, reminding one of females distended by eggs ; on dissection, the distension is found to be due to food. The abdomen of Spiders can even be seen to swell while they drink ; and carmine particles mixed in the water are found at the tips of the diverticula (Bcrtkau). Most remarkable of all, the ticks, when once attached to a host, having practically an unlimited supply of food, distend so enormously that their skins are specially strengthened, as much, perhaps^ to prevent them from bursting themselves as from being easily burst by the scratching action of the host. With regard to the mechanical movements of the distensible bag-like receptacle for the liquid food, when there are rigid tergitcs aiul steniites, the segments telescope into each other, while latcrallv there is a strong flexible membrane {Galeodes, Scorpio, Chernes, Pedipalpi). In the Spiders, many Acari and Phalangids, the whole abdominal integument seems to be equally extensible. In Scorpio only seven, and in Thelyphonus nine, segments are capable of distension [cf. PI. XXIX. fig. 14). The constriction of the mid-gut by means of the diaphragm takes place in Galeodes [cf. PI. XXXIII. figs. 2, 3) J Scorpio, and Spiders (PI. XXXIII. fig. 6), and very probably in all Arachnids which have diaphragms or waists. This is an arrangement quite in keeping with the distension of the abdomen by forcing liquid food into it by means of the pumping-apparatus. The constriction serves to prevent the food from flowing back into the cephalothorax. In Galeodes and the other Arachnids with the sucking- apparatus in front of the nerve-mass, the long, narrow oesophagus, as it passes through the brain, is supplied with circular muscles which would prevent the fluid from returning into the pumping-apparatus. In the Spider Lycosa, and, according to Schimkevitch, in Epeira, there is a W'Cll-developed sphincter 364 MR. H. M. BERNAED ON THE for constricting the passage immediately behind the sucking-apparatus. In the Spiders the constriction by the muscles in the waist must therefore be primarily to relieve the cephalothoracic diverticula from pressure when the abdomen is fully distended. We can thus understand the progressive rudiraentatiou of the cephalothoracic diverticula seen in many Arachnids. Their presence is more or less a hindi'ance to the musculature, which is as highly specialized in the thorax as the mid-gut is in the abdomen. Further, the comparatively feeble develop- ment of the epithelia of the cephalothoracic diverticula is, as above suggested, referable to the limited amount of food which they receive. One further arrangement is necessary, and this is to prevent the liquids being forced through the central canal of the mid-gut into the hind-gut or stercoral pocket. As the pressure must be very great to drive the food to the tips of the innumerable diverticula, distending them to their utmost, there must be some arrangement to keep it from escaping into the hind-gut. In Galeodes, we find (PL XXXIII. fig. 1) that the central canal narrows greatly in the fourth abdominal segment. Here, then, the canal might be constricted, perhaps by its own circular muscles, especially if fsecal masses were present and helped to choke up the passage (in fig. 5 two masses of fseces are seen in the passage). In this way, it is obvious that the food would be driven most easily into the anterior pair of openings, and from these, along the lateral canals, into the diverticula. We find a similar narrowing of the canal in Thelyphonus , sufficient, if faeces were present, to force the fiuid to the end of the persistent lateral diverticula. Further, the singular arrangement above described, and shown in PI. XXXIII. fig. 7, is clearly for constricting the extreme end of the mid-gut. In hungering and contracted specimens we find the end of the mid-gut closed by folds of the hind-gut (fig. 9) . In Scorpio, the fresh liquid food is probably prevented from escaping posteriorly by muscular constriction of the hind-gut, assisted by the presence of faecal masses in the central canal. In a small, contracted specimen of Euscorpio, I found that the canal, at the junction of the mid- and hind-guts, made a loop which would assist in arresting the progress of fluid. In the Pseudoscorpions, the fluid would be readily pumped into the large primary diverticula. The long narrow hind-gut is generally filled with faeces. The Fceces. — The waste products of digestion, the fsecal " crystals," which, as I have shown (it), are substantially identical in all Arachnids, would find their way back from the anterior diverticula straight into the central canal, in which faecal masses are found in considerable quantities. Posteriorly to this first and only pair of apertures, however, the fgeces must travel forward along the lateral canal to the anterior opening. The raising of the abdomen at right angles to the body might perhaps assist in bringing the faeces forward towards these apertures ; but how the fseces themselves travel up those diverticula which depend on each side of the body (PI. XXXIII. fig. 5) is a problem which I have been entirely unable to solve. The difficulty becomes still greater when the epithelial cells leave the walls of the diverticula, the tips of which become mere bag-like receptacles for fsecal crystals. The circular muscles, which are easily demonstrable, may perhaps bring about some kind of peristaltic action. If longitudinal muscles are also present on the abdominal diverticula, as they are on the cephalothoracic, the process would be facilitated. This problem presents itself in all Arachnids : How do the faeces find their way from the tips of the diverticula back into the central canal? The Spiders appear partly to have given up the attempt, and some pi'oportiou of the fscal " crystals " appear to pass out through the walls of the diverticula (especially at their tips), and are apparently carried away by the Malpighian vessels (i i). COMPARATIVE MORPHOLOGY OF THE GALEODID^,. 365 IX. The Heart and the Circulation. The Dorsal Vessel. — The dorsal vessel, or heart, of Galeodes is a long tube extending; from about the 4th or 5th segment anteriorly to the 13th posteriorly. It is extremely delicate, and, for the size of the animal, unimportant, this fact being attributed, according to the well-known principle, to the great development of the tracheal respiratory system. In spite, however, of tliis feeble development of the dorsal vessel in Galeodes, it has retained certain primitive featui-es, viz., great length and a great number of ostia, viz. eiglit pairs — two in the cephalothorax and six in the abdomen. These ostia, in the abdomen at least, are strictly segmental and occur under the posterior third of each tergite (PI. XXX. fig, 15), just in front of the dorso-ventral muscles. The longitudinal section of the last chamber of a heart of a Bhax whose alimentary canal was empty, and the abdomen consequently somewhat telescoped together, is given on PI. XXXIV. fig. G. In addition to these eight pairs, there appear also to be indications, viz., a swelling of the aorta, of an extra chamber anteriorly (PI. XXXI. fig. 5, h), which would imply that there were originally at least three pairs of ostia in the cephalothorax. The ostia are on the dorso-lateral surface of the heart, and the valves are formed by fine membranes attached posteriorly to the lips of the ostia and floating forwards on the blood-stream. The lower membrane (or edge of the valve-tube) is attached anteriorly to the floor of the chamber (PL XXXIV. fig. 6). On contraction of the heart, these membranes would be forced up against the dorsal surface of the lumen and the aperture would be closed. The anterior end of the heart is produced into an aorta, which rims through the mass of tubules developed at certain times (? or in diff'erent S2:)ecies) by the proximal ends of the coxal glands, and apiiears to discharge the blood direct on to the central nerve-mass (PI. XXXI. fig. 5). The posterior opening of the heart, Avhich is valvular, the valve being formed by a simple membranous infolding of the walls (PI. XXXIV. fig. 6), is immediately in front of the stercoral pocket. The heart is continued into a vein, which appears to end just behind the stercoral pocket. In transverse sections, the heart is seen to be suspended by strands of connective tissue which, dorsally and dorso-laterally, are attached to the body-wall, 1)ut ventrally radiate outwards on each side into i-egular wing-like arrangements of strands, Avhich lose themselves among the digestive tubules (PI. XXXIV. fig. 8). These wing-like strands may act as elastic expanders of the chambers of the heart ; their chief function is, however, almost certainly to keep the heart from being too compressed when the abdomen is tightly distended with food. Suspended on these strands and scattered about all around the heart large cells are fomid, the function of which I have not ascertained; they may be connective-tissue cells specialized as reserve cells, and suggest an incipient fat body, such as is found on each side of the heart in many Hexapoda. The heart itself is very delicate, and consists of but a single layer (ca. 6/* thick) of striated muscles lined on the inner side by a fine 366 MR. H. M. BERNAED ON THE refractive membrane (PI. XXXIV. fig. 6). Outside tlie heart ventrally tliere is a single layer of nerve-fibres closely applied to it and running longitudinally (PI. XXXIV. fig. 7, n). Thelyphonus has nine pairs of ostia, two in tlie ceplialothorax and seven ia the abdomen, with distinct traces of an extra chamber in front. Scorpio has seven pairs of ostia, all in the abdomen, with traces of a chamber (Newport) in the cephalothorax. The heart of Scorpio is thus more specialized than that of either Galeodes or Thelyphonus, i. e. it has lost more of its primitive segmental pairs of ostia. It is fui'ther, owing probably to the localization of the respiratory organs, much more strongly developed than that of Galeodes. In a specimen of Euscorpio the dorso-veutral diameter of the heart was to that of the abdomen as 1 to 7; in a small Thelyjihonus the proportion is 1 to 9, wliereas in a specimen of Rhaw it is 1 to 21. These measurements were taken between the successive pairs of ostia where the heart is a simple tube. Further, the Rhax was fasting, so that this difference is not due to any great distension of the abdomen on the part of the last-named. The ostia of the heart in both Thelyphonus and Scorpio are situated, as in that of Galeodes, on its dorsal surface ; but their valves have a more special mechanism, being apparently muscular. As in Galeodes, the heart is prolonged anteriorly into an aorta running towards the brain and posteriorly into a vein (? or artery) which runs into the tail. The asj)ect of the heart, suspended by the connective-tissue strands, is very similar in the two cases. In addition to the dorsal and lateral suspenders from the body-wall, tlie heart is powerfully expanded by means of bundles of connective-tissue fibres, no doubt homologous with the wing-like bundles in Galeodes. In the cases of Thelyphonus and Scorpio, however, these bundles are continued into muscle- fibres (the veno-pericardial muscles of Lankester and Miss Beck), which run through the mass of alimentary diverticula to be attached to the connective-tissue enveloping the lung-books. This is a specialized mechanism to save the heart from being compressed when the abdomen is distended with food. In view of the great specialization of the abdomen as a distensible vegetative sac, this mechanism deserves further description. The heart, in both Thelyphonus and Scorpio, appears to be contained in a pericardium. But the pericardium, of Scorpio at least, is really a connective-tissue membrane embracing and binding together the distensible diverticula of the alimentary canal in the interest of the circulation. It runs laterally down the sides of the alimentary masses and keeps the passage open between them and the outer bodv- wall (PI. XXXIV. fig. 9, ?w), and originally it ran also between the segmental diverticula of the mid-gut. These latter segmental infoldings have now, however, practically disappeared, leaving interesting traces behind. Dorsally, they still persist as deep conical pockets, into which the wing-like expanders of the heart run to be attached by means of muscle-fibres to the ventral portion of the membrane which arches over a blood-space. The muscle-fibres connecting these two infoldings are probably the remains of the infolding of the mcmbi'aue between the diverticula. Into these segmentally arranged blood-spaces, which are the ventral i-emains of the infoldings between the diverticula, the respiratory organs project. The veno-perieardial muscles, as those muscles are called whicli mark the original inter-diverticular blood-passages, therefore perform three functions : (1) they hold down the membrane which covers the alimentary system and thus prevent that system, which, as we have seen, is liable at any moment to enormous distension, from pressing on the heart ; (2) they raise the same membrane ventrally, and thus prevent the alimentary system from pressing upon the lung-books and hindering the free circulation of the blood along the floor of the body; and (3), being attached by means of the numerous radiating fibres above mentioned to the heart itself, they may be active muscular expanders of the same. A pair of these veno-pericardial muscles accompanies each pair of ostia. They run down through the mass of digestive diverticula, close to the dorso-vcntral muscles, whicli agrees with the suggestion that COMPAEATIVE MORPHOLOGY OF THE GALEODID.'E. 367 they run where there once was an inter-diverticular infolding of the membrane. I was at first inclined to believe that they had borrowed these fibres from the dorso-ventral muscles, but now think that they are developed out of the remains of the membrane. I am led to this belief by noticing that, in Thelyphonus, while the dorso-ventral muscles run outside the long fourth pair of diverticula (PI. XXXIV. fig. 2), the " veno-pericardial " muscles run iuside between these diverticula and the hind-gut, but where segmental diverticula once existed but have now disappeared. The veno-pericardial muscles persist as their last vestiges. In Tfiefi/jjhoims we have two pairs of these muscles in the cephalothorax, attached ventrally to the eudosteruite, and in the abdomen seven pairs *, raising up the membrane ventrally in each segment to form a pair of blood-spaces. Further, in Scorpio, we also have seven pairs in the abdomen. The morphological importance of these series of ventral blood-spaces connected by fibrous and muscular strands with the heart, and alwnys accompanying the ostia, will be discussed in the section on rcsjiiration. In both Scorpio and Tiiehjphonus the circulation is further specialized by the presence of short connections between the heart and the membrane surrounding the diverticula. They are short muscular (valvular?) funnels liy which the blood can be pumped directly under the membrane, where it can circulate through a system of blood-spaces with thin membranous walls among the diverticula (PL XXXIV. fig. y). There are nine pairs of these iu TheltjphoHUS. Lankester describes seven pairs ("arteries") in Androctonus -. I have only succeeded in finding five pairs in a small Euscorpio ; there may, however, be seven, as in Androctonua, although five is the number of alimentary diverticula which they have to supply. In the Pseudoscorpions the heart seems to vary, according to the observations recorded, as to the number of ostia. According to Croueberg (27), there are three jiairs ; according to Winkler, one pair j and according to Daday (29), there are four pairs and a certain number (4) rouud a rosette-like terminal portion. In a series of cross- sections of Obisiiim, in which the heart was well distended, it was found to commence (from behind forward) iu about the same trausverse plane with the hind-gut (PL XXXIV. fig. 3). The posterior aperture was very wide (36yti), and, being dorso-ventrally flattened, would, seen from above, have a fan shape, which may be Daday's rosette. The posterior lips were irregular, which maybe due to valvular infoldings. From the posterioi opening, the heart, suspended in the typical way, rapidly narrowed to J- (IS/"') of its posterior width, and then widened again (20 yu.) to form one chamber. This chamber has the typical appearance, and is fastened by the wing-like groups of fibres converging downward towards the dorso-ventral muscle, apparently to lose themselves among the diverticula. From this point the heart narrows to form an aorta. The whole structure is thus very minute, with, as Winkler stated, only one pair of ostia. As in Guleudes, its insignificance peiliaps has some connection with respiration by means of tracheiie. In Fhrynus we have six pairs of ostia, which correspond with six pairs of abdominal ostia in Galeodes. We find the same mechanism as in Thcli/phomis and Scorpio to protect the circulatory system from undue pressure when the abdomen is distended, viz., the veno-pericardial muscle- strands. The heart of the Spiders is fairly well known ; it is entirely confined to the abdomen. From it, as iu the last three families mentioned, an anterior aorta runs into the cephalothorax. There is a highly- developed pericardium, no doubt specialized from a membrane enveloping the alimentary system, surrounding and protecting the heart from undue pressure when the alimentary tubules are distended by a full meal. In some Spiders, e. g. Epcira, these tubules may eveu grow up on each side of the pericardium so as to force it, with the heart, away from the dorsal wall f- Foi" the protection of the heart, the pericardium is fastened back by a system of strands, which appear to lose themselves among the alimentary tubules. There are three [Epeira) or four {Mijgale %) pairs of ostia, * This implies that there were once at least twelve pairs of primary alimentary diverticula (see the diagram PL XXXIII. fig. 12). t Cf. Schimkevitch (62), pi. ii. fig. 9. t Wasmuiin (74 rr). 368 ME. H. M. BERNARD ON THE The small one-chambered heart of some Acari can be deduced, as I have shown elsewhere, from that of a Spider which failed to develop the full number of abdominal segments (6). From a comparison of these hearts, we learn then that there were originally at least ten paii's of ostia in the ancestor of the group, at least three in the cephalothorax (two persisting as functional only in Galeodes and Thelyphunus), and seven in the abdomen (retained in full only in Thelyphonus and Scorpio) . In the other Arachnids, varying numbers of ostia have been suppressed and the muscular heart itself correspondingly shortened, although in all cases the aortic prolongation of the heart towards the central nerve-mass persists. In all cases, except in Galeodes and Thelyphonus, the muscular heart is confined to the abdomen. This connection between Thelyphonus and Galeodes is especially interesting. The two forms are further connected, as no two other Arachnids are connected, by a transition form, Schhonotus — at least in so far that the latter appears to have retained distinct cephalic lobes and free cephalothoracic segments. The Circulation. — The various developments of the heart in the Arachnids are only understood when the circulation is taken into account. Tt is only then that we can appreciate the intimate connection between the circulatory, the respiratory, and the alimentary systems. None of these systems can be properly studied alone. In Galeodes the blood, after bathing the brain and circulating in the anterior end of the body and anterior appendages, has to pass back on its return from the anterior end of the body towards the abdomen through an array of mviscles, large tracheal tubes, and excretory tubules of the coxal glands. The proximal end of the last of these is sometimes developed into a great spongy mass of tubules wiiich stretches right across the cavity of the body behind and above the brain. PI. XXXIII. fig. o, eg, represents only a portion of this spongy mass. Through this all the blood must filter on its retiu'n from the anterior end of the body. It is necessary to assume that subsidiary streams are diverted into the limbs. On reaching the diaj^hragm, some of the blood probably rises to the dorsal surface in front of the diaphragm, to re-enter the heart by the two pairs of cephalothoracic ostia. The rest passes through the neural arch (PI. XXXIII. figs. 3, 4, n), bathing the large abdominal ganglion on its way, to flow backward through the great ventral sinus (PL XXXIV. fig. 8, vs) which stretches through the al)domen under the alimentary canal. This sinus is bordered on each side by depending diverticula. As the anterior part of the abdomen is much crowded with the genital organs, tracheae, and ahmeutary diverticula, the sinus is protected by a membrane {cf. PL XXXIII. fig. 4, n), which is not found more posteriorly. It ceases, in fact, in the 2nd segment, and the blood escapes from the sinus in all directions between the alimentary tubules, to find its way itji dorsally, and posteriorly round by the stercoral jjocket to the heart. In its passage through the diverticula, it is often confined here and there to special vessels of irregular shape and thin membranous walls, which serve probably to guide it towards parts which would otherwise be out of the regular stream {cf. PL XXXIV. fig. 8). The most important point which w^e notice here is the complete disorganization of the regular segmental alimentary diverticula, with the accompanying complete obliteration of the original inter-diverticular blood-spaces, there being no veuo-j)ericardial strands. The atro^jhy of all the primary diverticula except the first, and its development into a mass of branching tubules, naturally necessitated a change in the original circulation. COMPAEATIVE MOEPHOLOGY OF THE GALEODID.^. 369' On reaching the median ventral blood-sinus, instead of flowing u]i between the original inter-diverticular blood-passages, it was now required to flow through the maze of branched tubules. Such a change as this necessarily affected the respiratory invaginations, which originally j)rojected into these inter-diverticular blood-passages (PI. XXXIII. tig. 12). The dispersal of these regular streams into a (Uffuse streaming among the tubules no doubt played some part in causing the respiratory invaginations to develop into long tubules branching freely among the tissues. The same principle applies to the cephalothorax, where the blood-streams are much divided by the tissues and had therefore to be sought out by the respiratory invaginations. In Scorpio, though a certain number (5) of the primary abdominal diverticula persist, they are no longer simple, but consist of a mass of branching tubules. This change necessarily affected both the circulatory and the respiratory systems, in a manner, however, strikingly different from what we have described in Gakodes, although both are but modifications of the same original system. The blood is propelled forwards into a series of membranous sinuses closely surrounding and pene- trating the brain. On leaving the brain anteriorly, it is conducted along apparently membranous channels accompanying the principal nerves, both the nerves to the limbs and the long ventral ganglionic chord. These channels are not ordinary blood-vessels, but appear to be rather guiding-membranes ; that which accouijianies the ventral chord, however, presents remarkable histological features which show it to be an organ of some unknown physiological significance which deserves investigation. This remarkable channel runs dorsally to the nerve-chord, here and there sending a branch between the chords, which opens into the ventral lacunar system. The physiological connection between this vessel and the nerve-chords is seen at the ganglia. Over these latter the vessel spreads out and sends branches mto their interior. The vessel then runs on above the chords to the next ganglion. The object of this and of the other vessels accompanying nerves is apparently to pi'ovide them and the ganglia with a stream of oxygenated blood. In Gakodes we find the nerves invariably accompanied by large trachere. From this system of nerve blood-channels, the blood escapes into the general lacunar system of the body, either directly or, as in the case of that accompanying the nerve to the third leg, after first passing through the coils of the coxal glands (12), As in Galeodes, the blood passes through the neural arch of the diaphragm and then runs along a median ventral blood-sinus (PL XXXIV. fig. 9, vs). From this sinus it no doubt originally ran up between the primary segmental diverticula along the dorso-veutral muscles (PL XXXIII. fig. 12) to the heart, being aerated by the respiratory invaginations. The present segmental divisions of the abdominal alimentary system and the persistence of the veno- pericardial strands (PI. XXXIV. figs. 1 and 9, on the left) show clearly that this primitive arrangement persisted long enough to allow the respiratory invaginations to become highly speciaHzed. With the increasing specialization of the distensible abdominal alimentary system, the inter-diverticular passages became squeezed up and the blood hud to flow out laterally from the median sinus, passing across and not along the respiratory invaginations, on their way. In adaptation to this change, the respiratory invaginations developed in process of time a system of laminated air-chambers (the '' lung-books "). Between these laminje (PL XXXi\. fig. 9, right) the blood, on its way up to the pericardium, would in future have to pass. The inter-diverticular blood-passages gradually closed up, and the infolded membrane degenerated into the strands above described, the veno-pericardial muscles (PL XXXIV. fig. 9, left) . This system, however, would no longer suffice when the primary diverticula broke up into branched tubules, a change which in Scurpio proijably took place much more recently than in Galeodes. Each of these alimentary tubules must be supplied with blood. It is obvious that they cannot receive it, as they do in Galeodes, from the stream flowing along the ventral median sinus, for in Scorpio all this blood is SECOND SEllIES. — ZOOLOGY, VOL. VI. 49 370 MR. H. M. BERNARD ON THE required to flow laterally through the specialized luugs. The blood for the digestive tubules is received direct fi-om the heart. On each contraction of the heart the blood is forced, through several pairs of latero-ventral openings (Lankester, "arteries" in Anclroctonus) , among the alimentary tubules. At these vents the heart is in contact with the " pericardium," so that the blood is discharged under the latter and can only find its way back to the heart after circulating (1) through the mass of digestive tubules, and (2) (PI. XXXIV. fig. 9, cf. arrows on the right) through the upper laminae of the lung-books, whence it escapes into the lateral blood-passages, which convey the blood, close under the skin, to the "pericardium." Among the digestive tubules the blood circulates freely, with, however, membranous vessels here and there (as in Galeodes) for the purpose of guiding it to all parts. This cannot be considered as a primitive arrangement, inasmuch as the breaking up of the primary simple alimentary diverticula into the branching tubules must have itself been a secondary modification. These specializations have clearly necessitated the formation of the continuous membrane round the ■whole alimentary system, which keeps the complicated streamings apart. It is this membrane which, ■where it passes under the heart, functions as a pericardium. In the Pseudoscorpions we have an entirely different specialization ; the heart, as in all Arachnids, propels the blood on to the brain, and after flowing among the tissues, coxal glands, spinning-glands, &e., in the cej^halothorax, finds its way back along the floor of the body to the abdomen. On its way it is apparently divided into two latero-ventral streams by the development of a large median ventral diver- ticulum of the mid-gut. Each of these streams has to pass through a felt-work of extremely fine tracheal tubules (27 and 10), which have developed at the tips of the original simple tracheal invagination of the 2nd and 3rd abdominal segments. The blood is thus aerated, as it flows into the abdomen, by two pairs of specialized trachese. Reasons have, however, already been given for believing that these posterior trachea persisted until comparatively recently, inasmuch as we still have the seven pairs of functional inter-diverticular blood- passages persisting along the dorso-ventral muscles (PL XXXIV. flg. 3). The blood flowing ventrally and laterally along the abdomen finds its way up, partly through the lateral muscle or inter-diverticular blood-passages, and partly through the coils of the hind-gut, above the genital glands, into a dorsal median sinus, from which it is drawn by the fan-shaped posterior end of the heart {cf. p. 367). The circulation in the Aranese has been cai'efully studied and described by Claparede (25), and it agrees with the scheme common to all Arachnids which we have so far described. The blood discharged forward by the heart flows back freely through the lacunse of the cephalothorax ; passing through the waist (there being no neural arch, as in those Arachnids which possess diaphragms), it flows on each side of the alimentary canal (PL XXXIII. fig. 6). On reaching the abdomen a great part of it flows immediately to right and left through the specialized lung-books of the 2nd segment (which have been pushed forwards). The rest appears to run on, in the Tetrapneumones, to flow up through a second pair of lungs, or, in the Dipneumones, freely through the alimentary diverticula towards the pericardium. According to Claparede, the posterior prolongation of the heart is an artery, as may perhaps be the case in Scorpio. In both cases I should consider it as a secondary specialization, in the interest of the spinning-glands or tail. It may be noted that the ostia in the hearts of both the Spiders and Scorpio would apparently admit of blood flowing either forward or backward. In Galeodes it can flow only one way, i. e. forward ((/. PL XXXIV. fig. 6). The Blood-corpuscles. — The blood-corpuscles are, as a rule, round cells with large nuclei. They measure from 4- to 10 n. I have been unable to determine their origin, as no blood-forming gland, nor any j)rocesses of division of the corj)uscles, could be detected in my preparations. In Scorpio the blood-corpuscles are very uniform in size and shape, ca. 8-12 fi. As one source of these free cells, I have elsewhere (11) suggested the detached mid-gut cells, which find their way into the COMPAEATIVE MORPHOLOGY OF THE GALEODID.^. 371 liind-gut and are eitlicr lost in vast numbers or else pass out into the body through the wall of the hind- gut. It appears to me highly improbable that these active, living, and, to the last moment, digesting cells can be lost in such numbers, and even more unlikely that they again become epithelial cells after travelling into the hind-gut. This detachment of digesting-cells appears to be very general among Arachnids, altliough I have found no cells in the stercoral pockets either in Galeodes or the Spiders. Whether in these animals also they become blood-cells or, after digesting their food contents, are themselves rejected with the faeces, is a matter deserving investigation. In Thehjphonus, I have noticed large, clear, nucleated cells in the blood-plasm in the heart, which are much larger than the ordinary blood-ccUs ; perhaps these were mid-gut cells escaped through the wall of the hind-gut. X. PtESPIRATORY SYSTEM. ResiDiratiou in the Galeodicliie is effected by means of tracheal tubes ramifying among the tissues. These open to the exterior through three pairs of stigmata, and, in some cases, through an extra median stigma (PI. XXX. fig. 13). The Stigmata. — The first pair open behind the coxae of the second pair of legs (on the 4th segment). It is protected by an elaboi-ate arrangement of setfe forming tree- and bush-like fringes, which allow the air to pass in while barring the entrance against foreign particles (PI. XXX. fig. 18). Some of the flat-headed setse shown in tliis figure within the ajDerture, appeal- to open at their tips, and may be sensory, i. e. olfactory. The 2nd pair of stigmata open slantingly on the 2ud abdominal segment, either under folds of the integument, or, in a few cases, on the surface of the body, and near the median line, while the 3rd pair open still nearer the median line. Tliese are simple chitinous slits (PL XXX. fig. 19), being protected under folds of the skin. In the genus Galeodes the posterior edges of these folds are furnished with remarkable rows of bristles, the " stigmatic combs " (PI. XXIX. fig. 10, PI. XXX. fig. 16, co). These,, perhaps, serve to keep a passage open for the air when the abdominal segments are telescoped together. On the 4th abdominal segment in some Galeodidse there is a single median stigma, which often appears to be altogether closed (see the figures). It seems to l^e quite absent in the genus Bhax. The position of these abdominal stigmata can best be explained on the assumjitiou that they were apertures on the posterior faces of the coxae of tlie limbs. If the limbs of the 2nd and following abdominal segments folded back in the median line, like the genital appendages themselves (PI. XXIX. fig. 11), the stigmata would be brouo-ht together. This would also explain their slanting positions under folds of the integument. The fact that, in the Galeodidfe, we actually have stigmata in the act of aborting" on segment iv., associated with the remains of limbs closely resembling those vesti""es of limbs which function as stigmatic opercula on segments ii. and iii., leads almost inevitably to the conclusion that stigmata have already disappeared from between the similar rudiments of limbs found on segments v. and vi., and perhaps also from those still further back. That there were stigmata at least as far back as the vith abdominal segment in Galeodes may also be inferred from tiie presence of six pairs of ostia in tlxe abdominal portion of the heart, and six pairs of dorso-ventral muscles. These latter, as 49* 572 ME. H. M. BERXAED ON THE we shall see further, imply at least six pairs of inter-diverticular blood-passages through which the blood once flowed upwards to the heart (PI. XXXIII. fig. 12). There is evidence to show that in the primitive Arachnid a pair of respiratory invaginations projected into each of these inter-diverticular spaces, aerating the blood as it passed. The same argument would lead us to infer that there were at one time three pairs of stigmata in the cephalothorax, as we have one aborted and two functional cardiac chambers. The cephalothoracic stigmata persisting in the Galeodidse would be the first of these pairs. A comparison o£ the stigmata of the Arachnida yields interesting results. In Thelyphonus, which has the longest heart with traces of ten cardiac chambers, nine being still functional, there are no stigmata now in the cephalothorax, although, if we may judge from the heart and the veno-pericardial muscles, there were certainly three pairs, as we infer that there were in Galeodes. Along the abdomen we have two pairs of functional stigmata, and five pairs of stigmatic scars, reaching back to the viiith segment. These scars occur in connection with faint vestiges of limbs closely resem- bling the similar vestiges of limbs in Scorpio (15 and PI. XXVII. figs. 16, 17). Above the first four of these scars (as above the functional stigmata) there is a blood-space held up by a veno-pericardial muscle- strand. This arrangement implies that there was formerly an open passage up between the segmental diverticula of the alimentary canal to the heart. The presence of scars on the viiith segment suggests that there was at one time an extra [i. e., 11th) pairof ostia and veno-pericardial connections which have now vanished. Even though the stigmatic scars no longer persisted, I should have felt justified in concluding from these points in the internal anatomy of Thelyphonus that there had at one time been stigmata on ten segments, from the 4th cephalothoracic to the viith abdominal (PI. XXXIII. fig. 12). While the limbs forming the genital opercula folded back on to the median line, those which followed retained their lateral transverse positions ; we therefore have (in Thelyphonus) no approximation of the stigmata such as we have in Galeodes {cf. PI. XXIX. figs. 11 and 13). In Scorpio there are seven pairs of ostia and seven pairs of veno-pericardial muscles, all, owing to the great secondary compression of the cephalothorax, confined to the abdomen. These imply again that there were once seven open inter-diverticular passages into each of which a tracheal invagination once projected. Four pairs of invaginations only have been retained, viz., on the 3rd to the 5th segments. The limbs to which the stigmata belonged, though not folding back into the median line like the genital opercula, clearly sloped backward in various degrees (PI. XXIX. fig. 12). The Aranese oS'er, in some respects^ a curious parallel to Galeodes. There are never more than two pairs of stigmata, viz., on the 2nd and 3rd abdominal segments. In some cases the posterior pair have met in the middle line, which suggests that the limbs on which they occurred were also folded backward near the middle. This is rendered stiU more probable from the fact that the spinning-mamillae, also the remains of limbs, approximate in the middle line. In the foregoing cases we have in all traces of the remains of stigmata on 1 1 segments, 3 cephalo- thoracic and 8 abdominal ; some still persist, some show merely as scars, others are only inferred from the presence of cardiac chambers and veno-pericardial muscles. Taking these systems of organs, respiratory and circulatory, together, with perhaps the series of dorso-ventral muscles which give rise to the inter-diverticular passages, as, owing to their close physiological connection, we are justified in Helation of the Hypothetical Form to other Artliropoda. — This important subject can only be briefly touched upon. I may perhaps be allowed to suggest a few considera- tions which I think may serve to elucidate the different origins oi' the Arthropoda. It seems to me that the contrast above described (p. 388, PI. XXXIV. tig. 17) between the primitive segmentation of the Arachnida on the one hand, and of the Trilobites and primitive Crustacea on the other, in adaptation to two different and directly opposite methods of feeding, suggests that the Hexapods and Myriapods may be intermediate specializations. In these last-uamed Artlwopods, the first pair* of limbs, like the chelicerse of Arachnids, moved upward and forward, but, as sensory feelers, they did not require the powerful muscular attachment necessary for prehensile limbs : hence there wei*e no cephalic lobes. The next two pairs of limbs were specialized as chewing-jaws within the mouth-aperture, while the fourth pair might either be free to do the same or fuse with the under-lip to form a compound labium. The anterior position of the mouth would render it not easy for many pairs of limbs to function as jaws ; in order to enable even two or three pairs to do so, the anterior segments have had to be so compressed, that a distinct region, the head, has been formed. We thus have the Hexapods with an initial specialization of segments differing from that either of the Arachnids or of the Crustacea. Whereas in the former there was a backward and dorsal distortion of the 1st segment, and in the latter a ventral bending of the 1st segment, in tlie Hexapods the first four segments were merely longitudinally compressed in order to allow the limbs of the 2nd, 3rd, and 4th segments to function as jaws round an anterior mouth-aperture. This applies also to the Myriapods, but in them we find a varying number and different arrangement of limbs functioning as jaws. This difference between the Myriapods would thus separate them entirely from the Hexapods and also from one another. One other difference between the Arachnids, the Crustacea, and the Hexapoda appears to me to be fundamental. If my deduction of tracheal invaginations from acicular glands prove correct it would suggest different origins for the limbs in these three derivatives of the Chsetopoda. I would deduce the Crustacean limb from the Annelidan paraj)odinm by ventral displacement, so that the ventral jmrapodia became the chewing-jaws, the dorsal the swimming (and ultimately walking) limbs, which carried cirri (exopodites) and gills (ej)ipodites). The dorsal portion of the limbs probably long continued as swimming- plates, during which time their special groups of sette were dispersed, wliile the supporting aciculae of the original parapodia were lost (see, however, footnote, p. 380). On the ventral portion of the limbs the seta? may have furnished the bristle-like teeth and other hairs. (PI. XXXIV. fig. 18, A.) The ancestors of the Arachnids, like those of the Crustacea, ajipear to have developed the dorsal parapodia into the walking-legs. But these limbs probably passed through no flat swimming stage. The ventral parapodium disappeared or became merged in the coxal joint of the more developed limb. The acicular gland of the dorsal branch as it became a long limb degenerated, but that of the ventral and less specialized branch persisted as the tracheal invagination (PI. XXXIV. fig. 18, B). This figure is not 63* 404 MR. H. M. BEENARD ON THE altogether an imaginary drawing. While closely watching an Epeira in a bottle, protruding and retracting its spinnerets, I noticed that in their most protruded condition they had the shape represented in this figure. The spinning-glands might thus well be the setiparous sacs of the original setae at the tips of the branches of the parapodia. This origin of the limbs will explain the two series of glands on each side, above referred to (p. 383), one opening at the ends of limbs or laterally, and the other near the median line. In this way we might have spinning-glands placed distally on the limbs, tracheae derived from the specialized aciciilar glands of vanishing parapodia laterally along the ventral surface, and spinning- and cement-glands near the median line. Turning lastly to the Hexapods and Myriapods, we find that the leg can be deduced from the venti'al parapodium, while the dorsal parapodium disappeared, leaving, however, the acicvilar gland as a tracheal invagination, and the setiparous areas either scattered as hairs or persisting in areas (pupa of Orgia antiqua) or partly developing into stink- glands (foramina repugnatoria of the Myriapods). PI. XXXIV. fig. 18, C, is not so unlike the section of a Lepidopterovis larva in which the stump-like legs are armed at their distal ends with numerous hooked setae. Here, again, as in the case of the Arachnids, we should have the acicular glands only persisting where a parapodium has vanished. These three possible origins of the trunk appendages of the chief divisions of the Arthropods are as distinct as are the specializations of the anterior segments with their appendages for the purposes of feeding above suggested. I am thus disposed to look upon the Crustacea, the Arachnida, the Hexapoda, and the Myriapoda as distinct specializations of a Chaetopod Annelidan type, and in no way deducible the one from the other. REFERENCES. 1. Balfouk. — Notes on the Development of the Araneina. Quart. Journ. Micro. Sci. xx. 1880. 2. Beck, Miss. — Description of the Muscular and Eadoskeletal Systems of Scorpio. Trans. Zool. Soc. xi. p. 311. 1885. 3. Benham. — Description of the Muscular and Eudoskeletal Systems of Limulus. Trans. Zool. Soc. xi. p. 339. 1885. 4. Bernard. — The Apodidse. ' Nature ' Series. London, 1893. 5. Bernard. — The Apodemes of Apus, and the Endophragmal System of Astacus. Ann. & Mag. Nat. Hist., July 1892. 6. Bernard. — Some Observations on the Relations of the Acaridae to the Arachnida. Journ, Linn. Soc, Zool. xxiv. p. 279. 1892. 7. Bernard. — An Endeavour to show that the Tracheae of the Arthropoda arose from Setiparous Sacs. Zool. Jahi-b. Abth. Anat. Bd. 5. 1892. 8. Bernard. — Additional Notes on the same subject. Ann. & Mag. Nat. Hist. xiii. 1894. 9. Bernard. — Tne Head of Galeodes, and the Procephalic Lobes of Arachnidan Embryos. Zool. Anzeiger, no. 426. 1893. 10. Bernard. — Notes on the Chcrnetida\ Journ. Linn. Soc, Zool. xxiv. 1893. 11. Bernard. — Notes on some of the Digestive Processes in the Arachnids. Journ. R. Micro. Sci. 1893. 12. Bernard. — The Coxal Glands of Scorpio. Ann. & Mag. Nat. Hist. xii. p. 55. 1893. 13. Bernard. — The Endosternite of Sco/yio, &c. Ann. & Mag. Nat. Hist. xiii. 1894. [ COMPARATIVE MOEPHOLOGY OP THE GALEODID^. 405 14. BEENARD.^-Latcral Eyes of the Galpoclid». Anu. & Mag. Nat. Hist. xiii. 1891. 15. Bernard. — Vestigial Stigmata in the Arachnida. Ann. & Mag. Nat. Hist. xiv. 1894. 16. Bertkau. — Uber den Bau und die Function des sog. Leber bei den Spinnen. Arch, mikro. Anat. xxiii. p. 214. 17. Bertkau, — Uber den Verdauungsapparat der Spinnen. Arch, fiir mikro. Anat. xxiv. 1885. 18. Bertkau. — Beitrage zur Kenntniss der Sinnesorgane der Spinnen. Arch, mikro. Anat. xxvii. p. 589.- 19. Bertkau. — Uber die Coxaldriisen der Arachniden. SB. Niederrh. Ges. 1885. 20. Bertkau. — Uber Sinnesorgane in den Tastern und dem ersten Beinpaar der Solpugiden. Zool. Anz. 15 Jg. 1892. 21. BiRULA. — Zur Kenntniss der Russischen Galeodiden. Zool. Anz. 13 Jg. 1890. ■22. Birula. — Einiges iiber den Mitteklarm der Galeodiden. Biol. Centralbl. xi. 1891. 23. Birula. — Untersuchungcn iiber den Bau der Geschlechtsorgane bei den Galeodiden. Horse Soc. Ent. Ross. t. xxviii. p. 289. 1894. 24. Blanchard. — Les Arachnides. L'Organisation du Regne animal. 25. Claparede. — Etude sur la circulation du sang chez les Aranees du genre Lycosa. Mem. Soc. Phys. Geneve, xvii. pt. 1. 1863. 26. Croneberg. — Uber ein Entwickelungsstadium von Galeodes. Zool. Anz. 10 Jg. 1887. 27. Croneberg. — Beitrage zur Kenntniss des Baues der Pseudoscorpione. Bull. Soc. Imp. Nat. Moscou, t. ii. 1888. 28. Croneberg. — Die Mundtheile der Arachniden. Arch. Naturgesch. 1880, p. 285. 29. Daday. — Iiber den Circulatiousapparat der Pseudoscorpione. Term. Piizetek, iv. p. 331. 1881. 30. Dahl. — Das Gelior- und Geruchsorgan der Spinnen. Arch, mikro. Anat. xxiv. 1885. 31. DuFOUR, L. — Anatomic, Physiologic, et Histoire naturelle des Galeodes. Mem. presentes Acad. Sci. Paris, vol. xvii. 1862. 32. Gaubert. — Reclierches sur les Arachnides. Ann. Sci. Nat. serie 7, t. xiii. 1892. 33. Hansen, H. J. — Organs and Characters of Arachnids. Copenhagen, 1893. 34. Herbst. — See Lichtenstein. 35. Jaworowski. — Die Entwickelung der sog. Lunge bei den Arachniden. Zeitschr. wiss. Zool. Iviii. 1894. 36. KiNGSLEY. — The Classification of the Arthropoda. Tuft's College Studies, no. 1. 1894. 37. KiNGSLEY. — The Embryology of LimuJus. Journ. Morph. 1893. 38. V. Kennel. — Die Verivands.chaftsverhaltnisse der Arthropoden. Sch. naturf. Gesell. Univ. Dorpat, vi. 1891. 39. v. Kennel. — Lehrbuch der Zoologie. Stuttgart, 1893. 40. KiscHiNouYE, K. — On the Development of Araneina. Journ. Coll. Sci. Imp. Univ. Japan, vol. iv. 1890. 41. Kittary, M. — Anatomische Untersuchungcn der gemeinen und furchtlosen Sulpuga. Bull. Soc. Imp. Nat. Moscou, vol. xxi. 1848. 42. Koch, C. — Die Arachniden, xv. 1848. 43. Lankester, E. Ray. — Limidus vin Axa.Q\\md. Quart. Journ. Micro. Sci. xxi. 1881. 44. Lankester, E. Ray. — Notes on certain points in the Muscular and Endoskcletal Systems of Limulus and Scorpio. Trans. Zool. Soc. xi. p. 372. 1885. ■ 45. Lankester and Bourne. — Lateral and Central Eyes of Scorpio and Limulus. Quart. Journ. Micro. Sci. xxiii. 1883. 46. Laurie, M. — The Embryology of a Scorpion. Quart. Journ. Micro. Sci. xxxi. 1890. 47. Laurie, M. — The Morphology of the Pedipalpi. Journ. Linn. Soc, Zool. xxiv. 1894. 48. Lichtenstein and Herbst. — Naturg. Insecten, Gattuugen Solpuga und Phalangiurn. Berlin, 1797. 49. LiNDSTRoM. — See Thorell. 406 MK. H. M. BERNAED ON THE 50. LoMAN. — Altes und ueues iiber das Nephi'idium (die Coxaldriise) der Arachniden. Bijd. tot de Dierkunde, xiv. Amsterdam, 1887. 51. Macleod. — Recherehes sur la Structure et la Signification de I'Appareil respiratoire des Arachnides, Arch. Biol. v. 1884. 52. Macleod. — La Structure de I'Intestin anterieur des Arachnides. Bull. Acad. Belg. serie 3, viii. p. 378. 1884. 53. Macleod. — Sur la presence d'une Glande coxale chez les Galeodes. Tom. cit. p. 655. 1884. 54. Metschnikokf. — Embryologie des Scorpions. Zeitschr. wiss. Zool. Bd. 21. 1871. 55. Metschnikoff. — Entvvickelungsgeschichte der Chelifer. Zeitschr. wiss. Zool. Bd. 21. 1871. 56. Michael. — British Oribatidaj. Ray Society. 57. Murray. — Economic Entomology. South Kensington Mus. Sci. Handbook. 58. Newport. — On the Nervous System of the Macrourous Arachnids. Phil. Trans, vol. cxxxiii, 1843. 59. PococK. — Liphistius and its bearings upon the Classification o£ Spiders. Ann. & Mag. Nat. Hist. x. 1892. 60. PococK. — Notes on the Morphology of the Arachnida. Ann. & Mag. Nat. Hist. xi. 1893. 61. St. Remy. — Contributions a TEtude du Cerveau chez les Arthropodes tracheates. Poitiers, 1890. 62. ScHiMKKYiTCH, W. — Btudes sur 1' Anatomic de I'Epeire. Ann. Sc. Nat. serie 6, xvii. 1884. 63. ScHiMKEviTCH, W. — Ubcr Bau und Entwickelung des Endosternites der Arachniden. Zool. Jb. Abth. Auat. viii. 1894. 64. Schneider. — Systeme stomatogastrique des Araneides. Tabl. Zool. ii. 1892. 65. Simmons, O. L. — Development of Lungs of Spiders. Amer. Journ. Sci. xlviii. 1894. 66. Simon, E. — Les Arachnides de France. Vol. vii. 1879. 67. Stecker. — Anatomisches und histologisches iiber Gibbocellum. Arch. fUr Naturg, 42 Jg. 1876, 68. Spencer, W. B. — The Anatomy of Pentastomum teretiusculum, Baird. Quart. Journ. Micro. Sci, xxxiv. 1892. 69. Strubell. — Zur Entwickelungsgeschichte der Pedipalpen. Zool. Anz. 15 Jg. 1892. 70. Sturany, R. — Die Coxaldriisen der Arachnoideeu. Arb. Zool. lust. Wien, ix. 1891. 71. Tarnani. — Die Genital-Orgaue des Thelyphonus. Biol. Centralbl. ix. 1889-90. 72. Thorell and Lindstrom. — On a Silurian Scorpion from Gotland. K. Vet.-Akad. Handl. 1885. 73. Wagner, J. — Die Embryonalentwickelung von Ixodes calcaratus, Bir. Arb. Zool. Lab. Imp. Univ, Petersburg, no. 5. 1894. 74. Wagner, W. — La Mue des Araignees. Ann. Sci. Nat. serie 7, vi. 1888. 74 a. Wasmann. — Anatomic der Spinnen. Abh. nat. Ver. Hamburg, 1846, p. 133. 75. Walter, A. — Transkaspische Galeodiden. Zool. Jahrb. Abth. Syst. Bd. iv. p. 1095. 1889. 76. Winkler, W. — Anatomic der Gamasiden. Arb. Zool. Inst. Wien, t. vii. 1888. (? 1886-87.) Supplementary List. 77. Bernard. — Spinning-glands in Phrynus. Journ. Linn. Soc, Zool. no. 161, p. 272. 1895. *78. Brauer, a. — Beitrage zur Kenntniss der Entwickelungsgeschichte des Scorpions. Zeitschr. wiss, Zool. Bd. lix. 1895. *79. PuRCELL, F. — Note on the Development of the Lungs, Entapophyses, Tracheae, and Genital Ducts in Spiders. Zool. Anz. Oct. 14, 1895. * The last two papers were not seen by me in time to be dealt with as fully as the important conclusions arrived at by their authors require. I must content myself with stating my conviction [and this applies also to Wagner's paper (73)] that all conclusions based upon transitional phenomena in the development of single speciaUzed types will have ultimately to be tested by a prdfounder and more extended comparative study of existing forms, including their many instructive generic and specific variations. COMPAEATIYE MORPHOLOGY OF THE GALEODID.E. 4!07 EXPLANATION OF THE PLATES. Plate XXVII. Fig. 1. A specimen of Cleobis, dorsal aspect to sho\v the metamerism. 3, 4, 5, 6, cephalothoracic segments. I-X abdominal segments. Immediately behind the cephalic lobes {d), a pair of triangular selerites represents the remains of the tergum of the 3rd segment (3). The tergum of the 4th segment (4), transformed into a pair of solid rods, which anteriorly hold up the cephalic lobes, and posteriorly are continued in the lateral walls as strong pillars, rising from the ventral skeletal framework (c/. PI. XXVIII. fig. 15, r). The terga of 5 and 6 differ in no important respect from those of the abdominal segments. Flexible membranes form the sides of the body, a, specialized area of the cephalic lobes. 2. Side view of the same, showing the flattened cephalic lobes characteristic of Cleobis. The eyes project from a slight forehead-like bend of the anterior edge of the cephalic lobes. The rod-like formation of the tergum of the 4th segment supports the posterior edge of the cephalic lobes. The sides of the body are covered with a flexible membrane through which muscle- strands can be seen. The lateral eye is on the specialized area (a). 3. Sketch of the cephalic lobes of Solpui/a paludicolla, Pocock, showing the strong suture and the projecting ocular tubercle. The tergum of the 3rd segment, only partly covered by the paired cephalic lobes. The supporting rods (tergum of the 4th segment) nearly meet in the middle line. 4 . Part of the anterior dorsal surface of Galeodes caspius, Birula. 5. Lateral view of the same region in Galeodes arabs, C. Koch, showing the cephalic lobes at an angle with the tergum of the 3rd segment, a large portion of which remains uncovered in this genus. € & 7. Dorsal and lateral views of the same region in Rhax termes. The tergum of the 3rd segment reduced to a very narrow border behind the short, round cephalic lobes. 8. A, B, C, D. Diagrams to show the possible origin of the cephalic lobes (cl) as lateral portions of the 1st segment (1) shifted on to the dorsal surface {ds) above the labrum (L), owing to the translocation of the 1st pair of appendages [ch) from a lateral to a preoral position. The ocular tubercle is the remains of the old dorsal surface [ds] (cf. fig. 10). For the develop- ment of the chelicerje, cf. PI. XXIX. fig. 1, a, b', c' . 9 a. Partly diagrammatic section through Galeodes (traced with camera lucida), showing the relative sizes and positions of the chelicerje {ch) and the pedipalps {pp). L, the labrum or beak. 9 6. The same of Scorpio, showing the small size of the chelicerse (ch) as compared with the pedipalps (pp). The cephalic IoIjcs have shrunk to a flat carapace on each side beyond the chelicerse. L, labrum ; /j and L, spoon-like processes of the coxae of the 1st and 2nd legs (appendages 3 and 4) ; ff, section through the gutter on /j. 9 c. The same of Obisium. I, labium. For the sections through these beaks, cf. PI. XXVIII. figs. 3, 9, 10. 10. Dorsal surface of Palceophorms nuncius, after Thorell and Lindstrum, showing the ocular tubercle as portion of original dorsal surface {ds), being grown over by the cephalic lobes {cl). 11. Part of a dissection from the side of Galeodes arabs, right cephalic lobe and right chclicera cut away. The cephalic lobe is seen to end posteriorly as a blind pocket, resting on the tergum of the 3rd segment. The median suture («) is seen as a longitudinal ridge projecting inwards. The inner side of the left chelicera is seen, showing the basal smooth area 408 ME. H. M. BEENARD ON THE {cf. text, p. 321, and PI. XXIX. figs. 1, a, U, c'). The beak (B) is seen in situ, the right pedipalp having been removed. st, the strainer composed of bristles, joined together as shown on PI. XXVIII. fig. 6. /, flabellum. Fig. 12. Transverse section through a Galeodes (? Rhax) , showing the blind pockets of the cephalic lobes (c/). m.ch, muscles of the chelicerse, which fill up the cephalic lobes, s, suture between the cephalic lobes, e, endosternite, on which lie the elevator muscles of the pedipalps, and the mid-gut. n, nerve-cords, eg, coxal glands, tr, trachea near the stigmata. 13. The posterior end of a Rhax, showing the anal segment, as if surrounded by a large tergite. The anus, indicated by an asterisk, is quite ventral in this genus [cf. PI. XXIX. fig. 6). 14. The ventral surface of the first three segments of a Solpuga. The beak seen from below. The chitinous plate (shaded) supporting the labium is seen to be a continuation of the fused sternites between the coxse of the pedipalps {/rp) and of the 1st pair of legs (/;). st, the strainer seen from below, as in horizontal section, br, the feathered bristles on the labium {cf. fig. 11). sp, rigid sensory process on the coxse of the pedipalps. 15. Ventral surface of a Galeodes, showing the meeting of the coxae in the middle line' along the whole length of the body, completely obliterating the sterna, with the exception of the plate supporting the labium {cf. fig. 14) and the triangular piece between the last pair of legs. The paired sternal areas of the abdominal segments are the remains of limbs which have vanished, the coxae of which also met in the middle line {cf. text, p. 328, and PI. XXIX. figs. 6-11). 5^^^, stigmatic aperture. Remains of sternites shaded, la, remains or traces of abdominal appendages, go, genital operculum. 16. The ventral surface of a Scorpio {Palaninmis) showing the approximation of the coxae and obliteration of the sterna in the first four segments. The true sternites (shaded) persist on all the following segments, excepting where covered by the genital opercula or lost in the specialization of the tail, la, the areas marking the former presence of appendages. 17. The ventral surface of a Thelyphonus, showing the fusion of the coxae of the pedipalps {pp) ; the position of the beak is indicated by dotted lines. The sternal plate supporting the labium persists, enclosed between the fused pedipalps {cf. sections, PI. XXVIII. fig. 14, Ir), and rujis back to join the sternum of segment 3, which forms a fold under the anterior end of the large sternite of segment 4. The limbs (/,) belonging to segment 3 have also been squeezed out of the ventral surface, apparently by the enormous backward development of the coxae of the pedipalps. A small oval sclerite indicates the sternite of segment 5, and sternite 6 is well marked. On the abdomen the sternites persist, from that of segment ii. (covered by the genital operculum, //o) to the commencement of the " tail " segments. Well-marked sternites persist in segment 8, which in Scorpio forms part of the tail. 18. The venti-al surface of Phrynus. The anterior prolongation of the sternum (sternites 1 and 2) is not squeezed up between the coxse of the pedipalps, but is forced downward by the meeting of these coxae above it. The sternites of the three posterior cephalothoracic segments are clear, but divided (? folded) into areas. The appendages forming the genital opercula persist as the so-called " penis." Plate XXVIII. Fig. 1. Ventral surface of the cephalothorax of a young Epeirid just hatched and cleared in cedar-oil, also showing areas marked off on the sternal plate as in Phrynus, the chief differences being the absence of the median row of areas and the presence of the clearly- marked sternum of the 3rd segment, which in the Pedipalpi is almost {Phrynus, PI. XXVII. fig. 18). or quite {Thelyphonus, PI. XXVII. fig. 17) suppressed. COMPAEATIVE MORPHOLOGY OF THE GALEODID^E. 409 Fig. '2. Veutral surface of an unspecified Psendoscorpion, showing the complete obliteration of the sternites on the ccphalothoracic segments. 3. Section through the beak of Galeodes near the line a-h (fig. 5), showing its fusion with the coxas of the pedipalps {pp) ; m, the flexible membrane between the bases of the chelicerfe and above the beak, sa, sucking-apparatus ; Ir, supporting rod of the labium (cf. PI. XXVII. fig. IJ'), attached by muscles, fc, flexible cliitin. 4. Section through tip of the beak near c-d (fig. 5 ) ; the labrum (L) has a thick solid chitinous dorsal keel, the labium (/) is divided into two soft lobes (PI. XXVII. fig. 14). 5. Longitudinal section through the beak. The sucking-apparatus is confined to the beak, and consequently anteriorly to the central nerve-mass (shaded). a-b and c-d, approximate lines of section of figs. .3 and 4. m, the membrane shown in fig. .3. 6. Portion of the straining arrangement of bristles, which projects from the tip of the labrum, covering the mouth-aperture. It is composed of plumose setaj joined by trabeculse. pic/f pigment, travelling uj) through the thick chitin {cf. PL XXIX. figs. 16, 17). 7. Sagittal section through tlie mouth of Fhryims. The labrum L is much retluced ; the labium is little more than the sternal supporting rod, Ir. The sucking-apparatus is both in front of and behind the central nerve-mass (shaded). m, flexible membrane between bases of chelicerae, the position of which is indicated [ch), although they could not appear in a true median section. 8. Sagittal section through the mouth of a Spider ; labrum (L) and labium (/) bent downward ; the sucking-apparatus almost entirely behind the central nerve-mass ; ch, as in last figure. 9. Diagrammatic section through the mouth of Scorpio ; the sucking-apparatus is confined to the beak, which, however, is much shortened. /, the spoon-like processes of the first leg, /[, to prevent the escape of juices crushed out of the prey [cf. p. 357 & PI. XXVII. fig. 9 6). 10. Diagrammatic section through the beak of a Pseudoscorpion ; the sucking-apparatus is concen- trated in the posterior end of the beak. 11. The same of Tlielyphonus, the sucking-apparatus extending along the beak as in Galeodes. 12, 13, 14. Three cross sections through the beak of Thdyphonus. 12 near the tip; 13 at the beginning of the pumping-apparatus ; and 14 at its junction with the body. It is held between the fused coxal joints of the pedipalps {pp), which together make a kind of trough in 12, from which the juices of the animals crushed by the chelicerte {ch) are sucked. It, the supporting rod of the labium, the persistent sternum of the 1st and 2nd segments {cf. PL XXVII. fig. 14). st, the fine straining-bristles lining the inside of the mouth. 15. Ventral chitinous framework of Galeodes arabs dissected out and cleaned with caustic potash. (The beak and the endosternite are placed in line at the side, fig. 15 ff.) In addition to the transverse folds between the coxae, are seen the median folds, which may be the remains of sterna pressed up into the body by the approximation of the coxse in the middle line : a pair of chitinous rods {chr) at the inner ends of the ccphalo- thoracic stigmata (stiy) support the endosternite {cf. figs. 16, 19). A pair of lateral rods (r) form the ventral attachments of the modified tergites of the 4th segment {cf. PL XXVII. figs. 1-6). b, the buttresses upon which the limbs rotate, chf, chitinous folds, which serve to hold the nerves to the last pair of legs in place [cf. PL XXXI. fig, 6). (', attachment of the right half of the endosternite. Ir, labial supporting rod. 15 a. The endosternite removed to one side, but in a line with its proper position on the skeletal framework (fig. 15). p, fibrous plate, attached by tendons to the exo- and eudo-skeleton. eg, main duct of the coxal gland, which appears to end on p. L, labrum or beak. SECOND SERIES. — ZOOLOGY, VOL. VI. 54 410 ME. H. M. BERNAED ON THE Fi^. 16. Side view of the endosternite, fibrous plate {p), the supporting rod (chj-), and the eoxal gland (cff). e, point of origin of rigiit half of the endosternite. 17. From a section through e (fig. 16), showing the endosternite as an infolding of the cuticle. 18. Transverse section through the endosternite, showing the interlocking of the right and left halves [e^, C;) in the middle line and the ftision with the supporting rod {chr) [cf. figs. 15, 16). The fibrous tissue (ft), binding the portions together, stains deeply. The nature of the endosternite as a chitiuous infolding is apparent (cf. fig. 17). 19. Longitudinal section through the fibrous plate (p). Plate XXIX. Fig. 1. Diagrams to suggest an origin for the two types of Arachnidan cheliceras from an original 3-jointed limb, a, b, c, is the order of development for the type found in the Spiders and Pedipalpi. a, b' , the same for that of Scorpio, Phalangids, and Pseudoscorpions. a, b' , c' , for Galeodes, Gamasus, and other Acari. In c , str represents the position of the stridu- lating apparatus found in certain Galeodidse {cf. text, p. 322). 1, 2, 3, the three joints and their modifications, o, ocular tubercle, cl, cephalic lobe. 2 (twisted round by mistake). Section through the tip of a cheliccra of P//?'yMi<,s, showing what may be a trace of a lost joint, 7. fc, flexible chitin ; set, setae, ? homologous with the spinning- glands of Pseudoscorpions, and poison-glands of Spiders, opening in practically the same spot. 3. Side aspect of the anterior end of a small Galeodes, showing the relative sizes and positions of the pedipalps (^pp) and 1st pair of legs, also the enormously long sensory hairs, only a very few of which are drawn, ol, joint containing the olfactory organ at the tip of the pedipalps [cf PI. XXXI. figs. 10-17). 4. The same of a Rhax, showing the relative sizes and position of the same limbs. The terminal joints of the pedipalps {ol) are immovable, le, lateral eyes. 5. Hypothetical diagram, showing the character and position of the three first limbs in the primitive form [cf. fig. 14) . 6. Ventral aspect of Rlia.v to show the sequence between the coste of the cephalo thoracic limbs and the paired ventral plates of the abdominal segments. 7. To show the continuity between the genital operculum [go] of a Galeodes and the cephalo- thoracic limbs ; the chitinous folds {cf) of the former continue the interarticular folds (between coxa and trochanter) of the cephalothoracic limbs (cf. fig. 11). 8. Ventral abdominal surface of a Galeodes intrepidus, Savigny, in the British Museum (abdomen not distended), showing the ventral plates (limb-areas), continuing the plates forming the genital opercula. 9. The same of a specimen of G. fat alls (abdomen somewhat distended), showing the sequence of the paired plates (/a). 10. The ventral median line of a Galeodes (?sp.), also in the British Museum, showing in more detail the characters of the limb-areas, ffo, genital opercula ; stiff. o, stigmatic opercula. 11, 12, 13. Hypothetical restorations of abdominal limbs to explain the position of the stigmata. 11. Galeodes. The stigmata on the posterior faces of the coxae (5//^.o = stigmatic opercula) have been brought in towards the middle line by the bending backward of the limbs. 12. Scorjjio. The limbs retained their lateral positions, but sloped backward. 13. Thely- phonus or Phri/nus. The spinning-glands {r/ff) in the genital limb (go) (" penis " of Phrynus) appear to be homologous with the glands {gy) on the same limbs in Galeodes. eg, aperture of the coxal gland; stig, stigmata, persistent or aborted. COMPARATIVE MORPHOLOGY OF THE GALEODID^. Ill Fig. 14. Hypothetical restoration of the common racial form. L, labrum ; I, labium, the latter being the sternum of the 1st segment; tliese together formed the primitive beak; 1, cheliccra?, limbs of 1st segment ; 5/3, .':ind sternite ; 2, pedipalps ; 3, 1st leg. The abdominal limbs with stigmatic apertures are shown along the whole abdomen, the last pair on segment xii. probably forming the sting of Scorpio, thereby accounting for the paired poison-glands ( /)(/.) The dotted lines indicate the number of the abdominal segments subsequently specialize, diapliragm. 19. Optical section of one of the above mid-gut diverticula, cleared in cedar-oil. Itn, longitudinal ; an, circular muscles. Plate XXXIII. Fig. 1. Diagram of the alimentary system in the abdomen, to show the position of the dorso-ventral muscles cut through. The diverticula filling the whole abdomen [cf. fig. 5) have only one pair of apertures (ap) into the central canal {mg), viz., in the first segment. They, the diverticula {div), open along the rest of the abdomen into two lateral canals [Ic] ; mat, Malpighian tubules ; stp, stercoral pocket. 2. A transverse section (camera lucida), taking in a portion of the diaphragm (D), cut tangcntially, showing the small size of the aperture for the alimentary canal {in); b, the heart; //•, trachea. 3. Slightly further back (drawn to the same scale), letters as in last figure. dim, dorsal longi- tudinal mu.scles ; w, neural aperture. 4. Still further back, showing the pair of apertures {ap) of the diverticula into the central canal, drawn to the same scale ; letters as before. Only a very few of the crowded diverticula are drawn, and some are drawn empty. n, the neural sinus, continuing the neural arch of the diaphragm conveying the blood from the cephalotliorax into the abdomen ; the nerve- strands are in its base, y, genital atrium, the chitinous lining has left the epithelium ; ^^, accessory glands, opening one on each side of the genital aperture, and belonging morpho- logically to the opercula {cf. yg, PI. XXIX. figs. II, 13) ; cf, chitinous thickening shown in Plate XXIX. fig. 7, as continuations of the inter-articular fold between coxa and trochanter of the preceding limhs ; /, faeces. 5. Section of a distended abdomen (camera lucida), the diverticula drawn empty, g, genital glands ; tr, main trachea {cf. PI. XXX. figs. 13 and 14) ; do, fragment of a dorso-ventral muscle; vim, ventral longitudinal muscle-band; lin, lateral muscles; /, faical masses in the mid-gut. 6. Section through the waist of a Spider, to show the possibility of constricting the alimentary canal {in) by means of dorso-ventral muscles, h, heart (artery) ; n, nerve. 7. Transverse section through the posterior end of mid-gut {mg), where the lateral canals (/c) are closely applied to it on each side (see diagram, fig. I). The mid-gut is surrounded by circular and longitudinal muscles, outside which are tracheal tubes embedded in a spongy layer of coagnlum, fluid-passages and ? cells {cf. sp, figs. 8, 9, 11). This spongy mass surrounding the mid-gut is embraced by the lateral canals (/c), which are joined together above and below the mid-gut by transverse muscles {tni}. The epithelium {mep) of the lateral canals where they are in contact with the mid-gut is modified as described (text, p. 360). The rest of the epithelium is so crowded with food-globules, that the individual cells are no longer distinguishable. /, fsecal masses ; mal, Malpighian tubules ; tr, tracheae ; n, nerves ; div, digestive diverticula witli epithelium disorganized by food-globules. 8. Longitudinal section through the junction of the mid-gut and hind-gut of a distended Galeodes. mg, mid-gut; /ig, hind-gut; .^tp, stercoral pocket; tm, muscles binding the lateral canals on each side of the mid-gut {cf. fig. 7) ; sp, spongy layer surrounding the posterior end of the mid-gut. The crowded contents of the mid-gut, hind-gut, and stercoral pocket omitted. The complicated folding of the chitinous wall of the stercoral [locket is suggested. The thread-cells (fig. II) outside the commencement of the hind-gut gradually change to a tesselated epithelium covering the end of the hind-gut and the stercoral pocket. 416 jme. h. m. beenaed on the Fig. 9. End of mid-gut of a fasting Rhax, jammed against the stercoral pocket {stp), thereby closing the passage ; letters as before. 10. Longitudinal section through the wall of mid-gut at the wide anterior portion (segments 2 and 3 of fig. 1). Im, longitudinal muscles ; cm, circular muscles. The epithelial cells stand on a membrane [m) thrown into folds by the contraction of the longitudinal muscles. The epithelial cells of mid-gut are being traversed by strings of food-globules {fg). Average length of cell 20 /i. 11. Enlarged portion of fig. 8. mg, mid-gut cells, which near the junction with the hind-gut are 80 yx long and 3 to 4 /x thick ; long strings of food-globules traverse them, hg, chitin-lined hind- gut secreted by long, thread-like cells which appear to change into a fine tesselated epithelium covering the stercoral pocket. /?«, longitudinal muscles; tin, transverse muscles binding the lateral canals together (fig. 7) ; sjj, spongy layer composed of fluid-passages, cells, and coagulum ; tr, trachea ; cm, //«', the musculature proper of the mid-gut, a continuation of the muscles shown in fig. 10. 12. Diagram showing the primitive relations which existed between the diverticula of the alimentary canal [mgd), the dorso-ventral muscles [dv), the tracheal invaginations {tr) , and the heart (A) with its ostia. The dotted lines on the right indicate the extent to which this primitive condition is still traceable in three Arachnids, viz. Thebjphorms, Scorpio, and Galeudes ; D, the position of the diaphragm. (N.B. This figure should have been on the next Plate.) Plate XXXIV. Figs. 1-5. Diagrams of the abdominal alimentary system. 1. Scorpio. 2. Thelyphonm. 3. Obisium. 4. Galeodes. 5. Hypothetical primitive arrangement with at least 7 pairs of diverticula from which the former can be deduced. In Scorpio the two posterior pairs have been suppressed, the fifth pair lengthening backward. In Galeodes all but the first pair have been suppressed, this single pair stretching backward outside the dorso-ventral muscles. In Thelyphomis 4 or 5 pairs persist, the 4th or 5th (?) stretching back inside the dorso-ventral muscles and being themselves constricted. This process has gone still further in the Pseudoscorpions, reaching to the 2nd segment, the ' hind-gut' being coiled. (J. Longitudinal section through the last chamber of the heart of a Rhax, passing through an ostium ; VI, VII, sixth and seventh abdominal segments ; h, heart ; fc, large cells (?fat cells) ; v, the posterior vein ; fl, flexible chitin of intersegmental membrane ; cm, muscle-fibres forming the tunic of the heart, cut through. 7. Ventral aspect of a portion of a heart, dissected out. cm, the circular muscle-fibres shown in section in last figure ; n, layer of single nerve-fibrils with spindle-shaped nuclei. 8. Diagram of the circulation in the abdomen of Galeodes. The blood, entering the abdomen through the neural arch of the diaphragm, follows the mid-gut and nerve-strands in the ventral sinus {vs), from this it escapes on both sides among the mass of digestive diverticula, reaching the heart after circulating among them ; tr, tracheae near a pair of abdominal stigmata; g, genital gland; h, heart [cf. Plate XXXIII. fig. 5). 9. Diagram of circulation in the abdomen of Scorpio ; the left half represents a section posterior to that of the right half; h, the heart, on the right it is discharging blood through a short passage (artery) among the digestive tubules below the visceral membrane (?«). Lb, lung-book, the leaves of which are so arranged that blood both from the ventral sinus [vs) and from the alimentary diverticula can flow out sideways between them. nc, nerve-cord with an accompanying blood-vessel, which discharges its blood into the ventral sinus (? and among COMPAliATIVE MOliPHOI.OGY OF THE GALEODID.E. 417 the digestive tubules) . On the left, the visceral membrane is held down dorsally and raised vcutrally by muscle-fibres, the " veno-pericardial " muscles. The blood-space below and the pocket above are the remains of the original inter-diverticular spaces [cf. fig. 5). Dv, portion of a dorso-ventral muscle. Fig. 10. A portion of the main duct of the coxal gland in G. arahs, highly magnified. The connective- tissue envelope contains blood-lacunse [b) and tracheie {tr) ; a group of the gland-cells are seen with dividing nuclei deeply stained, in the other cells the nuclei are vesicular. 11. A few cells of the same more highly magnified, the nuclei measured by eyepiece micrometer. 11 a. A dividing, deeply-stained nucleus, with measurements. 12. A section of the main duct of the coxal gland near the aperture ; the cells are less differentiated, 13. A portion of the spongy mass of tubules developed at the proximal end of the main duct of the coxal gland {cf. PL XXXI. figs. 4, 5). 14. Portion of the same, highly magnified, be, blood coagulum ; /, tracheae ; p, large solid masses of protoplasm (? cells) traversed by tracheal tubes. 15. The genital and stigmatic opercula of a specimen of Rhax Kvyserlingii, Pocock (in the British Museum), g', anterior aperture (?), which may be the genital aperture; g", the ordinary position of the genital aperture into which the cement-glands open ; stig, the positions of the stigmata; cf. the sequence ^^, stigi, stig, (Plate XXIX. fig. 11). 16. Portion of a transverse section through an ovary, ep, ovarial epithelium ; m, felt of muscle- fibres ; /, trachea ; /, follicular membranes, the one on the left is shrunk after the tUscharge of an egg; em, egg-membrane showing two zones ; y, yolk-granules. 17 A, B. Diagrams to compare the initial modifications of the anterior segments. A, of the Arachnids; B, of the Crustacea and Merostomata ; p, prostomium. 1, 2, 3, 4, the 1st four segments. In A a sucking-beak results, while in the latter the appendages can function as jaws round or within the mouth. 18. Diagram showing in transverse sections the origin of the limbs and tracheaj (or glands) of the three chief divisions of the Arthropods, from the parapodia and setiparous glands of a Chsetopod Annelid. A, Crustacea; B, Arachnida ; C, Hexapoda. d, dorsal; v, ventral branch of the parapodium; a, acicular gland; g, gill; p,v, exopodite ; c, sensory cirrus (tf. text, pp. 403-404). SECONU SERIES. — ZOOLOGY, VOL. VI. 55 .vd s M] \ "^1 :J \\ V. A /^--^^~% y-. /.H 9o- ,j' lOU) w ■1 '/r A ii 12 1^' .Kj\ ' w i \ t :>h^ .X. IL. ^■-'^ > iG r^ rv ■IT ViU "7 n I 0 1 , O G Y 0 1-'' a iA i . K C' i. ) I •", s i i 18 West NewTTuiTi in\> B( 15 16 • c/"- 10 ^/! : U P M 1 J ! . O G Y O P G A 1 Wf-si N'*wrnaij irnfj Liernard. Trans, Linn. Soc Ser .'' ZoclVol, 0 :^er'riarcl ^HAriS Lll3N SoC.SiiR 11^ ZoOuVolM PI bO '~9 ^^ ■■'IT -^lyr >s ? -^- 1_ ..-f 10 -^>^' (if ^kmj 18 ;io HP HO LOGY OB' 3 ALE ODE." / 13 IS 4 V / f < '\ ;>^ 'C3> i^ \ ^ > ."■ \n7 ./'r'NyvvT, /r-' *) .Ps,^' i'/T^nS^-V \ vni P.I ; 111 ^ 4^ 11 'X.3..i..i..IuJ^''>"*^ ^ :^" '■'V.-.V^ ••f' SA ^A:^: 15 .j;?' 10 13 le .U c««! 14- A B p. i. 17 18 vi r LINNEAN SOCIETY OF LONDON. MEMOEANDA CONCERNING TRANSACTIONS. The First Series of the Transactions, containing both Botanical and Zoological contributions, has" been completed in 30 Vols., and a few entire sets are still for sale. Only certain single volumes, or parts to complete sets, may be obtained at the original prices. The price of the Index to Vols. 1-25 is 8s. to the public, and Gs. to Eellows ; to Vols. 26-30, 4s. to the public, and 3s. to Fellows. The Second Series of the Transactions is divided into Zoological and Botanical sections. 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A REVISION OF THE BRITISH COPEPODA BELONGING TO THE GENERA BRADYA, Boeck, AND ECTINOSOMA, Boeck. BY THOMAS SCOTT, F.L.S., MEMn, SOC. 7.001.. FRANCE, NATUIIALIST TO THE FISHERY BOARD FOR SCOTLAND, AND ANDREW SCOTT, FISHERIES ASSISTANT, UNIVERSITY COLLEfiK, LIVEHPOOI,. LONDON: PRINTED FOR THE LINNEAN SOCIETY BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. SOLD AT THE SOCIETY'S APARTMENTS, BURLINGTON-HOUSE, PICCADILLY, W., AND BY LONGMANS, GREEN, AND CO., PATBRNOSTER-ROW. Jime 1896. SEP ^' 189i [ 419 ] V, A Bevision of the British Copepoda heJoiiging to the Genera Bradya, Boeck, and Ectinosoma, Boeck. By Thomas Scott, F.L.S., Hem. Soc. Zool. France, Naturalist to the FisJiery Board for Scotland, ««(/ Andrew Scott, Fisheries Assistant, Unioersity College, Licerpool. (Plates 35-38.) Bead 19tli November, 1894. Introductory. IN the course of our study of tlie British Entomostraca during- tlie past few years, we have observed fi'om time to time specim.ens of Copepoda belonging apparently to one or other of the genera Bradya and Ectinosoma, wliicli, so far as known to us, could not be identified Avith any of the described species of eitlier of these two genera. Moreover, as considerable dilBculty was sometimes experienced by iis in satisfactorily diagnosing the characters by which these sjoccimens differed from, and by which they agreed with, species already described, it was decided to delay beginning a critical study of the several forms which had been observed until, if possible, a more extended inquiry had been made. With this object in view, gatherings of tow-netted and dredged material from various jilaces around our coasts have been examined as opportunities occurred, and numerous specimens collected. Careful dissections have been made of all doubtful forms, and, wherever necessary, accurate detailed drawings have been prepared. The results of these researches we now propose to lay before the Linnean Society in the form of a revision of the British Copepoda belonging to the genera Bradya and Ectinosoma, with flgiu'es of all the species described. We have described and figured the few species already described and figured in works on British Copejjoda as well as those which, so far as we know, are new to science, in order to bring into prominence certain obscure jioints not fully illustrated in previous works, as well as to allow of the various species, old and new, being compared with each otlier, with greater certainty and ease. Though this revision has been the result of much careful research, it cannot be considered exhaustive; but if it tends to simplify the study of these two somewhat troublesome genera we shall feel amply rewarded for our labours. We projiose to take the genus Bradya first, as the structure of the anterior foot-jaws in this genus shows, in our opinion, a closer affiuity with the Calanidce than does that of theu' homoloo-ues in Ectinosoma. SECOND SERIES. — ZOOLOGY, VOL. VI. 56 420 MESSES. T. AND A. SCOTT— EEVISION OF THE BEITISH COPEPODA The following is a list of the species described in this memoir, arranged in alphabetical order : — Genus Bradya. Bradya elegans, sp. n., p. 422. „ fusca, sp. n., p. 424. „ hirsuta, sp. n., p. 423. „ minor, sp. n., p. 425. „ similis, sp. n., p. 424. „ typica, Boeck, p. 421. Genus Ectinosoma. Ectinosoma armiferurn, sp. n., p. 434. „ atlanticum, Brady & Robertson, p. 437. Ectinosoma curticorne, Boeck, p. 430. „ trythropn, Brady, p. 431. „ gracile, sp. n., p. 429. Herdmani, sp. n., p. 432. longicorne, sp. n., p. 439. „ melaniceps, Boeck, p. 434. „ Normani, sp. n., p. 435. „ propinquum, sp. n., p. 428. pygmceum, sp. n., p. 433. Sarsi, Boeck, p. 427. tenuipes, sp. n., p. 436. tenuireme, sp. n., p. 439. 3) Genus Bradya, Boeck (1872). Description. Body elongate, fusiform ; abdomen not distinctly separated from the thorax. The antennules are usually short and composed of live to eight joints. The antennae are 3-jointed, and the secondary branches of the antennae are 2- to 3-jointed, usually slender, and of variable lengths. The mandibles are each furnished with a well-developed palp, composed usually of a stout basal joint bearing two 1-jointed branches, one of which is apical and the other marginal. The maxilla? are well developed. The anterior foot-jaws are of considerable size and composed of five joints ; the first tw^o joints are large and the articulation between them is strongly hinged ; the first joint also bears three setiferous marginal processes ; the three terminal joints are usually very small. The posterior foot-jaws are smaller than the anterior and are 3-jointed; the end- joint is shorter than the preceding one, and is usually provided with three apical setae. The first four pairs of swimming-feet are all somewhat similar in structure; both branches are composed of three subequal joints, and the outer are usually somewhat shorter than the inner branches. Fifth pair small, composed of two joints, a basal and a secondary joint. Hemm^ks. The most important diflFerence between Bradya and Ectinosoma is to be found in the structure of the anterior foot-jaws. In Bradya the anterior foot-jaws are composed of five distinct joints, the first two of which are usually large, while the other three are very small ; the articulation between the first two joints is strongly hinged, and in all the " spirit " specimens examined by us the large second joint (together with the three small terminal joints) is bent at, or nearly at, a right angle to the first joint. Moreover, the secondary branches of the antenna? vary in the number of joints from two to three, whereas in all the specimens of Ectinosoma examined by us the secondary BELONGING TO THE GENEKA BKADYA AND ECTINOSOMA. 421 branches were ahvays 3-jointecl. The labium iu Ijoth Bradya and Ectinosoma is frequently in the form of a hook-like process. Bradya typica, Boeck (1872). (PI. 35. figs. 1, 11, 11, 22, 26, 32, 39, 44 ; PL 36. figs. 1 and 12.) 1872. Bradya typica, Boeck (2), p. 15. 1880. Bradya typica, Brady (3), vol. ii. p. 17, pi. xxxviii. figs. 1-10. 1893. Bradya tyjncUj I. C. Tliompsou (16), p. 22, pi. xix. figs. Sb-c. Description. Length '8 mm. (-3^ of an inch). Body moderately robust, fusiform ; forehead produced into a short, narrow, but distinct rostrum, which reaches to about the second joint of the antennules. Antennules very short, stout, and 8-jointed ; the first three joints are subequal and longer than the others, as in the annexed formula, which shows the approximate j)roportional lengths of all the joints ; — No. of the joints, counting from the head : 1 . 2 . P) . 4 . 5 . 6 . 7 . 8 Proportional lengths of the joints : 77t)2yy43 The secondary branches of the antenna? are rather longer and more slender than the primary branches, and 3-jointed, the middle joint being very small (PI. 35. fig. 14). The mandibles are stout and armed at the truncate apex with a number of slender teeth ; mandibular palp well developed, having the basal joint robust and furnished with several plumose sette at the apex in addition to the two setiferous secondary branches (PL 35. fig. 22). Anterior foot-jaws stout, the first two joints large and subequal, the last three very small (PL 35. fig. 26). The end-joints of the posterior foot-jaws are very small ; two elongate but unequal seta? sjn'ing fi-om the inner distal angles of the first joints, while the second joints are each provided with a row of small teeth that extend from the lower proximal angle obliquely across tlie joint to the upper distal angle ; a plumose seta also springs from the lower distal angle; the small terminal joint forms the base of a stout, elongate, and slightly curved setose spine, and a spiniform plumose seta springs from the inner margin of the same joint (PL 35. fig. 32). First four pairs of swimming-feet moderately stout ; outer branches of the first pair considerably shorter than the inner branches ; in the fourth jjair both branches are about equal in length (PL 35, figs. 39 and 44). The fifth pah" are small ; the short produced interior portion of the basal joint, which is about as broad as long, bears two apical setae — the inner one very long, spiniform, and slightly plumose, the other shorter and more slender; a moderately long and slender seta springs from the slightly produced outer portion of tlie same joint ; secondary joint small, subquadrangular, and furnished with three slender setie, the two inner ones being very long, while the other is much shorter (PL 36. fig. 1). Caudal stylets short, and about equal in length to the last abdominal segment (PL 36. fig. 12). 56* 422 MESSES. T. A]\'D A. SCOTT — EEVISION OF THE BRITISH COPEPODA KabHat. Off Port Cressa Bay, Scilly Islands ; and off Hartlepool {G. S. Brady). West of May Island, Firth of Fortli. Port Erin, Isle of Man (7. C. T.). Bemcu'ks. The Firth of Forth specimens differ in one or two minor points from Dr. Brad3''s description and figures in his excellent Monograph of the British Copepoda, i. e. the antennules in the Forth specimens are 8-jointed and the secondary branches of the antennae are 3-jointed (in this latter particular they agree with Boeck's description), but in all the more important characters they agree with the description and figures contained in Dr. Brady's valuable Avork. Bradya elbgans, sp. n. (PI. 35. figs, i, 10, 15, 25, 29, 36, 38, 46 ; PL 36. figs. 4 and 11.) Description. Length 1-2 mm. (-/r of an inch). Body elongate, slender ; rostrum prominent, seen from above broadly rounded. Antennules very short, stout, 5-jointed, strongly setiform, the second and last joints shorter than the others ; the approximate proportional lengths of the joints are shown by the formula : — No. of the joints : 1.2.3.4.5 Proportional lengths : 7 3 5 5 3 AntennsB stout ; secondary bi'anch shorter than the primary, 2-jointed, the first joint very short, the second elongate and becoming gradually dilated towards the distal end, provided with two elongate, somewhat unequal, and densely plumose apical setoe ; the last joint of the primary branch bears a number of setae that are coarsely and somewhat irregularly plumose (PI. 35. fig. 15). Mandibles somewhat stylet-shaped ; both branches of the palp, which are subterminal on the basal joint, are strongly setiferous (PL 35. fig. 25). Anterior foot-jaws small; basal joint stout, the three setiferous marginal processes nearly alike; second joint much narrower and somewhat dilated distally ; the last three joints are very small (PL 35. fig. 29). Posterior foot-jaws somewhat similar in structure to those of Ectmosoma Sarsi, Boeck, but smaller (PL 35. fig. 36). The first four pairs of swimming-feet are proportionally more slender and elongate than those of Brachja typica, Boeck (PL 35. figs. 38 and 46). The fifth pair are moderately large and broadly subquadrangular ; the produced inner portion of the basal joint is cylindrical and twice as long as broad, and armed at the apex with a moderately long spiniform seta, and a stout spine about half the length of the seta; the outer angle of the basal joint, which is not produced, is provided with a single slender hair and a few small spines ; the inner margin is fringed with small setae, and there is an oblique row of similar setae on the lateral aspect of the joint ; the secondary joint is broad and nearly square in outline ; the truncate aj)ex, which does not extend beyond the end of the produced inner portion of the basal joint, is irregularly serrate and bears three elongate sjiiniform setae arranged widely apart ; the middle one is considerably longer than the one on either side ; there is also a slender seta on the outer angle, and an oblique row of minute spines near the inner margin (PL 36. fig. 4). BELONGING TO THE GENERA BRADYA AND ECTINOSOMA. 423 Habitat. Lar'D A. SCOTT— EEVISION OF THE BRITISH COPEPODA we caunot say. The formula shows approximately the proportional lengths of the ioints : — No. of the joints : 1 . 2 . 3 ■ 4 . .5 . 6 _ Proportional lengths : 14 9 12 5 7 9 The secondary branches of the antennae are very slender and 3-jointed, and shorter than the primary branches ; first two joints, hut especially the second, very short (PL 35, fig. 13). Mandibles well developed, the biting part broadly truxicate and armed with several blunt-iiointed teeth ; the branches of the palp are fiu-nished with plain seta? (PL 35. fig. 2i). Anterior foot-javrs stout, the first joint furnished with two marginal seliferous processes in addition to several setae (PL 35. fig. 31). Posterior foot-jaws small ; the first joint bears on its distal end two long and stout setae, which are plumose only on one side, and tlie second has its inner margin fringed with cilia (PL 35. fig. 31). The first four pairs of swimming-feet are somewliat similar in structure to those of BradyafHsca. The fifth pair somewhat resemble those of Bradya fusca, but the inner portion of the basal joint is not so much produced and does not reach the middle of the secondary joint; the two terminal spines of the produced inner part of the basal joint are very unequal in length, and there are a few small teeth round the inner margin and end of this part of the joint ; the exterior angle of the same joint is also produced into a long conical lobe that extends well down the side of the secondary joint, and terminates in a slender hair ; the secondary joint is broadly oblong, and ends in a trilobed extremity which reaches considerably beyond the basal joint ; the middle lobe is larger and more produced than the lateral ones, which are subequal ; each lol^e forms the base of an elongate and spiniform plumose seta ; the middle seta is rather longer and stouter than the other two ; a slender seta springs from near the base of the same joint, and there are transverse rows of niinvite seta? on the lateral aspect of the basal joint, as shown m the figure (PL 36. fig. 5). Caudal stylets short, about equal in length to the last al)dominal segment (PL 36. fig. 9). Colour brownish. Habitat. Pirth of Forth, off St. Monans; rock-pools on the shore of Hilbre Island, Liverpool Bay. Bemurks. The eye-like dusky pigment-si^ot at the base of the antennides, together with the structure of the autennai and mouth-organs, are characters which readily distinguish this from other British species of Bradya. Genus Ectinosoma, Boeck (1864). Descrijjtioit. Body elongate, fusiform, similar to that of Bradya. Antennules 5- to 7-jointed, not longer than the first thoracic segment, and usually tapering more or less towards the distal end. BELONGING TO THE GEXEEA BKADYA AND ECTINOSOMA. 427 Aiiteuute similar to those of Bradya. Mandibles usually cleft at the apex and armed with strong teeth ; mandibular palp similar to that of Bradya. Anterior foot-jaws usually composed of two robust joints, and armed at the extremity with two moderately stout and elongate spiniform claws and a few setae ; the first joint is also furnished Avith two or three setiferous marginal processes. Second joint usually larger than the other. Posterior foot-jaAvs elongate, slender, three-jointed, and in structure resembling those of Bradya. Five pairs of thoracic feet similar to those of Bi^adya. Remarks. As already pointed out in. the description of the genus Bradya (ante, p. 420), the difference in the structure of the anterior foot-jaws is the most important and the most constant difference between Ectiuosoma and Bradya, and so great is the resemblance otherwise between species belonging to these two genera that frequently we have found it almost imj)ossible to distinguish without careful dissection whether the specimen that haj)peued to be under examination belonged to the genus Ectinosoma or to Bradya. EcTiNosoMA Saesi, Bocck (1872). (PL 36. figs. 14, 2G, 42 ; PI. 37. figs. 1, 21, 38, 52 ; PI. 38. tigs. 10, 22, 32, 51.) 1872. Ectinosoma Sarsi, Boeck (2), p. -io. 1880. Ect'iHosuma spinipes, Brady (3). vol. ii. p. 9, pi. xxxvi. figs. 1-10. 1885. Ectinosoma Sarsi, Poppe (9), p. 198. 1888. Ectinosoma spinipes, Scott (12), p. 239. 1892. Ectinosoma Sarsi, Cami (6), p. 152. 1893. Ectinosoma spinipes, I. C. Thompson (16), p. 18, pi. xviii. fig. 8. Description. Length 1"2 mm. (^/j- of an inch). Body, seen from the side, slender fusiform ; rostrum prominent, blunt-pointed, and reaching to near the extremity of the antennules. Autennules short, robust, 5-jointed, gradually tapering towards the distal end, and strongly setiferous. The proportional lengths of the joints are nearly as shown in the formula : — No. of the joints : 1.2.3.4.5 Proportional lengths : lo 12 9 (riO ' Antennse large, 3-jointed, joints subequal in length, the terminal joint furnished with a number of stout sette, coarsely plumose on the upper margin, and with several short spines ; secondary branch elongate, 3-jointed, arising from the end of the first joint of the primary branch; the last joint of the secondary branch is equal to nearly twice the combined lengths of the other two joints; the first two joints are each armed with a spiniform seta, that of the first joiat is short, but that of the second is elongate and coarsely plimiose on the upper edge ; the last joint bears two long terminal setre, also plumose on the upper edge (PI. 37. fig. 1). Mandibles armed Avith a fcAV strong irregular-sized teeth and a small plumose seta ; the basal joint of the palp, Avhich is nearly equal in size to the mandibles, bears SECOND SERIES. — ZOOLOGY, VOL. VI. 57 428 MESSES. T. AJyD A. SCOTT— EEVISION OF THE BEITISH COPEPODA a few terminal setoe in addition to the apical and marginal 1-jointed branches ; the marginal branch is nineh smaller than the other (PL 37. fig. 21). Anterior foot-jaws composed of two large, strongly dilated joints ; the first joint bears tnree marginal processes on the distal half ; the middle process is much smaller than the other two ; the end joint bears two vinequal and moderately short setose spines on the inner edge and two elongate subequal spiniform claws and a few setse at the extremity (PI. 37. fig. 38). Posterior foot-jaws elongate, moderately stout, tapering towards the distal end ; a long plumose seta springs from near the end of the first joint ; the second joint is strongly ciliate on the upper margin, while the last joint bears two subterminal plumose spines and one long and one short terminal seta, as shown in the figure (PL 37. fig. 52). The first four pairs of swimming-feet are robust ; the interior marginal setse on both branches are stout and strongly plumose, while the exterior margins are fringed with small sj)ines ; the outer marginal spines of the outer branches and the spiniform terminal setse of both outer and inner branches are stout, and strongly setose on the exterior edges ; a stout spine springs from the interior distal angle of the second basal joint of the first pair (PL 38. figs. 10 & 22). The fifth pair are sub quadrangular in outline ; the produced inner portion of the basal joint is cylindrical and twice as long as broad ; its extremity is somewhat bilobed, and reaches to near the end of the secondary joint ; the inner mai'gin bears several small setse ; each of the terminal lobes forms the base of a spine, the inner one of which is stouter and more elongate than the other ; the secondary joints are subquadrate, but rather longer than broad, and terminate in three unequal lobes, each of which is the base of a moderately stout spine, and is fu.rnished Avitli three apical spine-like teeth ; the middle one of the three spines is longer than the one on either side ; there are a few spine-like teeth on the lateral aspect of the basal joint, as shown in the figure (PL 38. fig. 32). Caudal stylets short and moderately stout (PL 38. fig. 51). Habitat. All roimd the British coasts ; moderately common. Remarhs. This species is readily distinguished from the other Ectinosomata by the form of the animal, and the structvire and armature of the swimming-feet. EcTiNOSOMA PKOPiNQUUM, sp. n. (PL 36. figs. 19, 27, 46 ; PL 37. figs. 2, 15, 32, 55 ; PL 38. figs. 9, 23, 34, 54.) Description. Length 1"1 mm. (2^ of an inch). Body seen from the side fusiform ; rostrum prominent and projecting nearly straight forAvard, somewhat spoon-shaped, or with the sides slightly decurved and the apex rotm^ded. Antennules short, stout, strongly setiferous, and composed of five joints. The pro- portional lengths of the joints are nearly as shown by the formula : — No. of the joints : 1.2.3.4.5 Proportional lengths : 11 9 12 7 12 Antennte nearly as in Ectinosoma Sarsi (PL 37. fig. 2). Mandibles also somewhat similar to those of that species (PL 37. fig, 15), but two of the terminal setae of the apical branch of the palp are united for a short distance at the base. BELONGING TO THE GENEEA BKADYA AND ECTINOSOMA. 429 The lahiuni consists of a bifid and strongly-hooked j)rocess, a lateral view of which is shoAvn in the figure (PI. 36. fig. 27). Both pairs of foot-jaws are somewhat similar to tliose of Ectiiiosoma Sarsi (PL 37. figs. 32 and 55). The first four pairs of swimming-feet are also somewhat like those of that species ; but in the first pair the inner branches are proportionately shorter, while lioth branches in the fourth pair are of nearly equal length, and the second basal joint of the same pair is furnished Avitii an elongate slender spine on the exterior angle (PL 38. figs. 9 and 23). The produced inner portion of the fifth pair is cylindrical in form, the length of which is equal to about one and one-third times the breadth; the secondary branches are nearly quadrangular in outline — the length only slightly exceeding the breadth; tlie armature of the fifth pair is somewhat similar to that of Ectinosoma Sarsl (PL 38. fig. 34). Caudal stylets short, but rather longer than broad and a1)out equal in length to the last abdominal segment. The posterior margins of the abdominal segments are all more or less fringed with cilia. Habitat. Firth of Porth, off Musselburgh. Memarks. This species comes near Ectinosoma Sarsi, Boeck, but difl'ers in the following particulars : the proportionate lengths of the joints of the antennules are greater, the mandible is furnished with more small teeth on its biting-edge than that of E. Sarsi, the anterior foot-jaws are stouter, the armature of the swimming-feet is somewhat weaker, and' the fifth feet are much shorter, being nearly as long as broad. Ectinosoma gracile, sp. n. (PL 36. figs. 18 and 37; PL 37. figs. 13, 28, 45 ; PL 38. figs. 3, 27, 30.) Description. Length -7 mm. (^^ of an inch). Body seen from the side very slender, nearly cylindrical. Rostrum prominent. Antennules (PL 36. fig. 37) elongate, slender, composed of seven joints ; the penultimate joint is nearly equal to the combined lengths of the two preceding joints, as shown by the annexed formula : — No. of the joints : 1.2.3.4.5. 6 .7 Proportional lengths : S 8 5 8 4 11 4 Antennae elongate, moderately stout ; the secondary branches small and 3-jointed, not reaching to the end of the second joint of the primary branches ; the first two joints are short, the other elongate, being nearly twice the entire length of the first two (PL 37. fig. 13). Anterior foot-jaws elongate, moderately stout ; the end-joint about twice as long as broad, and armed at tlie extremity with two long slender claws and two elongate slender setee (PL 37. fig. 28). Posterior foot-jaws slender, considerably shorter than the anterior foot-jaws ; end-joint about half the length of the preceding one (PL 37. tig. 45). Inner branches of the first four pairs of swimming-feet moderately slender and 57* 430 ]\1ESSRS. T. AXD A. SCOTT — EEVISIOX OF THE BEITISH COPEPODA elongate ; outer branches very slender and considerably shorter than the inner branches ; the first joint is nearly equal in length to that of the next two together (PI. 38. figs. 3 and 27). Fifth pair small ; apical setfe slender, the middle seta of the secondary joint very long and slender, being considerably longer than the outer elongate and slender seta of the produced part of the basal joint ; a moderately long slender seta springs from near the middle and on the lateral aspect of the secondary joint, — this joint extends very little beyond the end of the produced part of the basal joint (PI. 38. fig. 30). Habitat. Off St. INTonans, Firth of Forth ; vicinity of Port Erin, Isle of I^Ian. Hemarks. The structure of the antennules, together with that of the antennte, the mouth-organs, and fifth pair of thoracic feet, are characters by which Ectinosoma. g^xicile may be distinguished from any other species described in this memoir. Ectinosoma cubticorne, Boeck (1864). (PL 36. figs. 22, 30, 34; PI. 37. figs. 10, 24, 41, 48 ; PL 38. figs. 8, 20, 35, 44.) 1864. Ectinosoma curticorne, Boeck (i). 1885. Ectinosoma curticorne, Poppe (g), p. 194, Taf. 6. figs. 1-12. 1890 ? Bradya Edwardsi, Eichard (lo), p. 214, witli 10 figures in the text. 1893? Ectinosoma Edtvardsi, Schmeil (n), p. 92, Taf. viii. figs. 1-21. 1893. Ectinosoma ctirHcorne, I. C. Thompson (i6), p. 192, pi. xviii. fig. 8e. Description. Length '7 mm. (-^g of an inch). Somewhat like Ectinosoma Sarsi in general appearance ; rostriun short and stout. Antennules very short and robust, 6-jointed; a somewhat roundish and dark-coloured blotch occurs on tlie second joint of the antennules, as shown in the figure (PL 36. fig. 34). The proportional lengths of the joints are nearly as shown in the formula: — No. of the joints : 1 . 2 . 3 . 4 . .5 . 6 _ Proportional lengths : 9 2 5 3 4 5 AntennfB nearly as in Ectinosoma Sarsi, but the secondary branches are shorter than the primary ones (PL 37. fig. 10). The biting part of the mandibles is broad and armed interiorly with several small teeth, but the outer teeth are large ; the branches of the mandibular palp are not so wide apart as in Ectinosoma Sarsi (PL 37. fig. 24). Anterior foot-jaws somewhat like those of Ectinosoma Sarsi, but very much smaller (PL 37. fig. 41). Posterior foot-jaws short, moderately stout ; two plumose setse springing from the end of the basal joint, while the terminal joint, which is very small, bears two lateral plumose and spine-like sette and a plain and slender terminal hair (PL 37. fig. 48). The first foiu' pairs of swimming-feet are somewhat like those of Ectinosoma Sarsi, but smaller ; the outer and inner branches of the foiu-th pair are also of nearly equal length, and the lower marginal seta of the third pair is considerably longer than the others (PL 38. figs. 8 and 20). The inner produced portion of the fifth pair extends to about the middle of the secondary joint ; the terminal spines of both basal and secondary joints are long and moderately stovxt, and l)oth joints (but especially the basal joint) BELONGING TO THE GENERA BRADTA AND ECTINOSOMA. 431 are fvimished Avitli many small seta^ arranged in straight or curved rows, as shown in the figure (PI. 38. fig. 35). Caudal stylets short, apparently 2-jointed, and equal in length to the last abdominal segment (PI. 38. fig. 44). Colour chocolate-brown. Habitat. Firth of Forth, off Burntisland ; Cromarty Firth, near the mouth of the River Alness; iu the stomachs of young dabs from Blackpool, Lancashire; head of West Loch Tarbert, Argyleshire. jRemarks. This species resembles Bradya minor in having an eye-like pigment-spot at the base of each antennule, and may therefore be mistaken for it unless some care is taken and dissections made. It is, however, quite distinct from that species, as a com- parison of the parts will show. Ectinosoma curticorne appears to form a source of food for the young dabs {Pleuronectes Umaiula) on the Blackpool closed fishing-grounds : as many as sixteen sj)ecimens were counted in one stomach. The difference between Bradya Edicardsi, Eichard, and Ectiiiosoma curticorne, Boeck, is, so far as we can make out, scarcely sufficient to warrant us in separating them. EcTiNOSOMA ERYTHROPS, Brady (1880). (PI. 36. figs. 24, 31, 30 ; PL 37. figs. 14, 18, 37, 42; PL 38. figs. 13, 15, 39, 48.) 1880. Ectlnosoma erijthrops, Brady (3), vol. ii. p. 12, pi. xx.Kvi. figs. 11-17'. 1890. Ectinosoma erythrops, Scott (13), p. 318. 1893. Ectinosoma erythrops, I. C. Thompson (16), p. 192, pi. xviii. fig. 8 c, d). Description. Length -73 mm. (-^^ of an inch). Body slender fusiform; rostrum moderately prominent, incurved (PL 36. fig. 24). Antennules short, setiferous, gradually tapering to the slender extremity, 5- (?or 6-) jointed; the last joint is long and narrow and appears to be composed of two coalesced joints ; the proportional lengths of the joints are nearly as shown in the formula : — No. of the joiuts : 1.2.3.4. 5 Proportional lengths : 11 6 11 5 (7 7) ' Antenmx; elongate, the last joint sparingly setiferous ; the secondary branch, which does not extend much beyond the end of the second joint of the primary branch, has the first two joints very small, while the last is long and slender (PL 37. fig. 14). Mandibles rather smaller, and with the palp more elongate than the same appendages in Ectinosoma Sarsi (PL 37. fig. 18). Anterior foot-jaws are also somewhat similar to those of that species, but the last joint is more elongate, and the terminal claws arc also proportionally longer (PL 37. fig, 37). Posterior foot-jaws small and slender (PL 37. fig. 42). The first four pairs of swimming-feet are considerably longer than those of Ectinosoma Sarsi ; the inner marginal setae on both branches are plain and more slender than those of that species, and the terminal spines are also more elongate ; the second joint of the inner branches has the outer distal angle produced into a long spine-like process, that extends downward in front of the upper half of the thii'd joint (PL 38. figs. 13 and 15). The inner portion of the basal joint of the fifth pair is not much produced ; the 432 MESSES. T. AND A. SCOTT — REVISION OF THE BRITISH COPEPODA secondary joint is broadly subcylindrical, with the extremity irregularly trilobed and armed with three long spines, the middle one of which is considerably longer than the other two ; two small settu .also spring from near the base of the joint ; the inner produced part of the basal joint is furnished with two spines, the inner one being very long and powerful, the other smaller; all the large spines are plumose (PI. 38. fig. 39). Caudal stylets short, but rather longer than the last abdominal segment (PL 38. fig. 48). Sabitat. Pirth of Porth, off St. Monans. Remarks. As all the specimens of this Copepod had been in spirit for some time before being identified, we were unable to see the red pigment-sj)ot to which the species owes its name. The form of the animal, together with the divergent setse of the fifth feet, serves to distinguish it when mixed up with any of the other members of the genus. EcTiNOSOMA Herdmani *, sp. u. (PI. 36. figs. 16, 44 ; PI. 37. figs. 8, 16, 29, 54 ; PL 38. figs. 7, 25, 33, 47). Description. Length "8 mm. (3^- of an inch). Body, seen from the side, fusiform and somewhat similar to Ectinosoma Sarsi, but proportionally narrower ; rostrum prominent. Antennules (PL 36. fig. 44) 6-jointed, moderately slender, the first joint considerably longer than any of the others, as shown by the annexed formula: — No. of the joints : 1.2.;^. 4. 5. 6 Proportional lengths : 13 7 9 6 4 4 ' Antenna? somewhat similar to those of Ectinosowa Sarsi, but smaller, and the first two joints of the secondary branch are together nearly equal in length to the third joint (PL 37. fig. 3). Mandibles very small, but with a proportionally larger palp than in those of Ectino- soma Sarsi (PL 37. fig. 16). Anterior foot-jaws robust, somewhat similar in form to those of Ectinosoma Sarsi ; the first joint bears only two small marginal processes at the distal end, and the terminal claw-like spines are very long and slender (PL 37- fig. 29). Posterior foot-jaws elongate and slender ; the middle joint is about four times the length of the end one, and is fringed with twelve or fourteen moderately stout hairs (PL 37. fig. 64). The first foiu* pairs of swimming-feet somewhat like those of Ectinosoma Sarsi, but much smaller and with the marginal sette plain (PL 38. figs. 7 and 25). Pifth pair also similar to those of that species, but the inner portion of the basal joint is less produced ; the secondary joint is shorter, and the ajoical spines are longer and are all of nearly equal length (PL 38. fig. 33). Caudal stylets very short and about equal in length to the last abdominal segment (PL 38. fig. 47). HaMtat. Pirth of Forth, off St. Monans ; Port Erin, Isle of Man. Hemarks. The elongate form of this species, together with the somewhat slender * In compliment to Prof. W. A. Herdman, F.R.S. BELONGING TO THE GENEEA BEADY A AND ECTINOSOMA. 433 antennules and broadly subquadraugidar form of the llftb. pair of thoracic feet, the apical spines of which are all of nearly equal length, are characters by which it can be readily distinguished. EcTiNOSOMA PYGM^UM, sp. n. (PI. 36. figs. 15 and tl ; PL 37. figs. 5, 20, 39, 43 ; PL 38. figs. 4, 26, 31, 55.) DescrijjtioH. Length "33 mm. {-f-^ of an inch). Seen fiom the side the thoracic portion of the body is moderately stout, with the dorsum considerably arched, but the abdomen, Avhich is comparatively narrow, is only slightly tapering ; rostrum prominent (PL 36, fig. 15). Antennules 6-jointed, short, moderately stout, gradually tapering to the apex and furnished with numerous hairs ; the proportional lengths of the joints are nearly as sliOAvn in the formula : — No. of the joints : 1.2.3.4.5.6 Proportional lengths : 6 ^34222 ' Antennic larger than the antennules ; the secondary branch is composed of three nearly equal joints, but tlic middle one is slightly shorter than the one on either side (PL 37. fig. 5). Mandibidar palp well developed; basal joint large, with two plumose apical setae ; the subapical branch is much larger than the marginal one ; two elongate teeth spring from a notch near the middle of the inner margin of tbe mandibles, and reach to the trimcate and slightly-toothed apex (PL 37. fig. 20). Anterior and posterior foot-jaws somewhat similar in structure to those of Ectinosoma Sarsi, but very small (PL 37. figs. 39 and 13). The first four pairs of swimming-feet are also somewhat similar to that species, but are more slender ; the marginal setoB are plain, the first pair want the transverse rows of small spines possessed by those of Uctinosoma Sarsi, and the outer branches of the fourth jmir are proportionally longer (PL 38. figs. -1 and 26). The fifth pair are small and furnished with elongate fusiform spines, which become extremely slender towards the extremity ; the secondary joint, Avhich extends considerably beyond the inner produced portion of the basal joint, is irregularly trilobed, and each lobe forms the base of a s})ine ; the two outer spines are of nearly equal length, but the inner one is scarcely half the length of the one next to it ; the outer portion of the basal joint is produced into an elongate and very narrow appendage bearing a slender apical seta (PL 38. fig. 31). Caiidal stylets very short, being scarcely equal in length to the last abdominal segment (PL 38. fig. 55). Habitat. Firth of Forth, and in the vicinity of Port Erin, Isle of Man. Remarks. This is the smallest species of Ectinosoma known to us. The structure of the secondary branches of the antennae and of the mandibles, together with the peculiar fusiform sjnnes of the fifth pair of thoracic feet, appear to be sufiiciently characteristic to distinguish it from any of the others described in this memoir. 434 MESSES, T. AND A. SCOTT— liEVlSlOJN' OF THE BEITISH COPEPODA EcTiNOSOMA MELANiCEPS, Boeck (1864). (PL 36. figs. 13, 28, 45 ; PI. 37. figs. 11, 22, 40, 49 ; PL 38. figs. 2, 21, 41, 4G.) 1864. Ectinosoma melaniceps, Boeck (i), p. 30. 1880. Ectinosoma melaniceps, Brady (3), vol. ii. p. 11, pL xl. figs. 17-20. 1890. Ectinosoma melaniceps, T. Scott (13), p. 318. 1893. Ectinosoma melaniceps, I. C. Tliompsou (16), p. 18, pi. xxi. fig. 2 a. Description. Length -63 mm. [-}q of an inch). Eostrum elongate, slender, ciu'ved downward. Antennules short, 7-jointed, gradually tapering from the moderately stout base to the slender apex ; the third joint is considerably longer than any of the other joints, as exhibited by the formula, which shows the proportional lengths uearly of all the joints: — No. of the ioints : 1 . 2 . 3 . 4 . 5 . G . 7 Proportional lengths : 9 6114552 Antennae elongate ; basal joint stout and equal to about two-thirds the length of the next one; the second and third joints are more slender than the basal joint, and the last is somewhat shorter than the preceding one ; the secondary branch has the middle joint very small, while the first and third are comparatively elongate (PL 37. fig. 11). Moitth-organs nearly as in Ectinosoma Sarsi, but much smaller (PL 37. figs. 22, 40, 49). The outer branches of the first pair of swimming-feet are equal to about three fourths the lengtii of the inner branches ; the first and second joints only of the outer branches are furnished witli elongate spines, and the interior marginal setae of both branches are slender and not plumose ; in the fourth pair tlie outer and inner branches are about equal in length (PL 38. figs. 2 and 21). The produced inner portion of the basal joint of the fifth pair, which is cylindrical in outline and reaches only a little beyond the middle of the secondary joints, is provided with a moderately long apical seta and stout conical spine serrate on the edges, while the secondary joint bears one slender and three spiniform apical setae, the second one from inside being very long with a tenuated extremity (PL 38. fig. 41). Caudal stylets very short (PL 38. fig. 46). Habitat. Generally distributed, and usually among weeds, in the laminarian zone. Memarks. This species is readily distinguished by its having a considerable portion of the front part of the head of a dusky colour, as well as by the structure of the antenniiles and fifth pair of feet. Ectinosoma armiferom, sp. n. (PL 36. figs. 20 and 43; PL 37. figs. 4, 17, 31, 53; PL 38. figs. 14, 19, 37, 43.) Description. Length -97 mm. {-.h^ of an inch). Body stout; rostrum prominent (PL 36. fig. 20). Antennules 5= (?or 6-) jointed, very short and robust, strongly setiferous, especially towards tlie distal end, where there are several strong and very elongate plumose setae BELONGING TO THE GENEEA BEADYA AISJ) ECTINOSOMA. 435 (PI. 36. fig. 43). The ujoproximate proportional leng-tlis of tlic joints arc shown by the formula : — No. of the joints : 1 . 2 . 3 . 4 . 5 . (? (i) Proportional lengths : 15 y II b 3 (73) Antennules stout, -well developed, armed with strong plumose sette ; secondary branches 3-jointed, shorter than the primary branches ; the middle joint is equal to about half the length of the first and a third of the length of the last joint (PL 37. fig. 4). Mandibles stout, furnished at the apex with tw^o strong teeth, — one bifid, the other conical, — and a few small spines ; mandibular palp somewhat like that of Ectinosoma elongatum, but more strongly setiferous (PL 37. fig. 17). Anterior foot-jaws dilated, apparently 5-jointed ; the first joint is considerably larger than all the others together, the terminal joints very small; two of the marginal processes are each armed with a stout spine and a few seta?; the subapical claws are strong and slightly curved, the terminal setoe few and comparatively short (PL 37. fig. 31). In the structure of the anterior foot-jaw's this species connects Ectinosoma with Bradya. Posterior foot-jaws cylindrical and slightly distorted, much smaller than those of Ectinosoma Sarsl ; the end-joint, which is equal to about one-third the length of the middle joint, bears one stout and strongly plumose, and one long, slender, and plain terminal seta ; a short seta also springs from near the proximal end of the upper margin (PL 37. fig. 53). The outer branches of the first pair of swimming-feet are short, being only about three-fifths of the length of the inner branches ; a long plumose seta sj^rings from the oviter angle of the second basal joint, and a moderately stout spine from the interior angle; the fourth pair are somewhat like the first, but the outer branches are proportionally rather longer, and the seta on tlic outer angle of the second basal joint is plain, and there is no spine on the inner angle (PL 38. figs. 14 and 19). The fifth pair is small ; the secondary joint is subqnadrate and scarcely reaches beyond the produced inner portion of the basal joint ; the middle apical seta of the secondary joint, and the inner one on the truncate apex of the produced inner portion of the basal joint, are stout, slightly curved, and of great length (PL 38. fig. 37). Caudal stylets very short and somewhat wide apart ; abdomen clothed wdth transverse rows of minute hairs (PL 38. fig. 43). Habitat. Firth of Porth, west of May Island, Hemarks. The species now described is readily distinguished from any of the others recorded in this Report, by its robust form, by the structure and armature of the antennules and antenna;, and especially by the form and by the peculiarly elongate setffi of the fifth pair of thoracic feet. Ectinosoma Normani*, sp. n. (PL 36. figs. 21, 29, 39; PL 37. figs. 12, 26, 34, 51 ; PL 38. figs. 5, 18, 42, 45.) Description. Length "55 mm. (^5- of an inch). The thorax seen from the side is broadest at the posterior end of the first body-segment, and from thence the * In compliment to the Rev. A. M. Norman, F.E.S., &c. SECOND SERIES. — ZOOLOGY, VOL. VI. 58 436 JIESSES. T. AND A. SCOTT — REVISION OF THE BRITISH COPEPODA dorsum tapers gradually to the extremity of the abdomen ; the anterior part of the eephalothoracic segment curves gently and regularly to the apes of the comparatively small rostrum. On the lower rounded angle of the eephalothoracic segment, and imme- diately j)osterior to the base of the antennules, there is a small but distinct and bright- red pigment-spot, as shown in the full-size di'awing of the animal (PI. 36. fig. 21). Antennules small, moderately stout, 7-jointed ; the proportional lengths of the joints are nearly as shown in the formula : — No. of the joints : 1.2.3.4.5.6.7_ rroiiortional lengths : 7 7 7 4 3 3 3 ^ Secondary branches of the antennae 3-jointed, and reaching to near the middle of the last joint of the primary branches ; the middle joint is very small, while the end-joint is equal to about one and a half times the length of the first joint (PI. 37. fig. 12). Mandibles armed at the apex with a stout irregularly trifid process and a strong conical blunt-pointed tooth ; a small and moderately stout plumose marginal seta springs from a little below the base of the conical tooth ; the basal joint of the mandibular palp bears a single short subapical seta in addition to the two 1-jointed branches (PI. 37. fig. 26). Anterior foot-jaws very small, but moderately stout; marginal processes small and crowded near the end of the first joint; terminal claws slender, curved, their inner margin ciliate on the distal half (PL 37. fig. 34). Posterior foot-jaws very small, but similar in structure to those of Ectinosoma Sarsi (PI. 37. fig. 51). The first four pairs of swimming-feet are slender, the outer branches considerably shorter than the inner ones ; marginal setae elongate, slender, and not plumose (PI. 38. figs. 5 and 18). Eifth pair somewhat like those of Ectinosoma temilpes (to be described), but the lobes of the secondary joints are separated from each other by a deep sinus ; there is also a transverse row of cilia at the proximal end (PI. 38. fig. 42). Caudal stylets nearly twice as long as broad (PI. 38. fig. 45). Ovisac large. Habitat. Pirth of Porth, off Burntisland ; Barrow Channel, near Barrow-in-Furness. Memarks. This is not the Ectinosoma erythrops of Dr. Brady's ' Monograph of the British Copepoda,' though it agrees wdth the descrij^tion of that species in so far as it possesses a red pigment-spot near the lower anterior angle of the eephalothoracic segment. Ectinosoma Normani distinctly differs from that species, as well as from the others described in these pages, by the structure of the mouth-organs and of the fifth pair of thoracic feet. The red pigment-spot, though very conspicuous Avhen freshly preserved, disappears after being in spirit for a few days. Ectinosoma tenuipes, sp. n. (PI. 36. figs. 25, 32, 35 ; PL 37. figs. 9, 19, 30, 47 : PL 38. figs. 12, 17, 36, 52.) Description. Length -6 mm. (-/,- of an inch). Seen from the side the thoracic dorsum is very gently curved and tapers gradually to the moderately stout abdomen ; rostrum prominent (PL 36. fig. 25). Antennules 7-jointed, rather longer and much less rolmst than those of Ectinosoma BELONGING TO THE GEXERA BKAUYA AND ECTINOSOMA. 437 Sarsi, sjiaringly setiferous ; a long slender sensoiy filament springs from the third j oiut, the ujiper distal angle of wliich is produced to form the base of the filament (PL 36. fig. 35j. The annexed formula exhibits the proportional lengths of the joints very nearly : — No. of the joints : 1.2.3.4.5.6.7 Proportional lengths : 8^"~9 5^8 4 4* Antennas slender ; secondary branches S-jointed, very slender, scarcely longer than the second joint of the jirimary branches ; the first joint is rather shorter than the last, while the middle ono is small (PI. 37. fig. 9). . Labium with a very slender " hook " (PI. 36. fig. 32). Mandibles armed on one side of the apex with a broad tridentate process and on the other side with a moderately stout spine, w^hile between these is a large conical tooth ; the branches of the palp are slender (PI. 37. fig. 19). Anterior foot-jaws somewhat like those of Ecti)iosoma Sarsi, but scarcely so stout (PL 37. tig. 30). Posterior foot-jaws very slender, and the end-joint is nearly equal to half the length of the one immediately jireceding (PL 37. fig. 47). The first four pairs of swimming-feet have the inner branches moderately stout and elongate, but the outer branches are considerably shorter than the inner one and very slender (PL 38. figs. 12 and 17). Pifth j)air small ; the produced inner portion, of the basal joint is furnished with a short stout spine and a long spiniform seta ; the secondary joint is nearly as broad as long and does not reach much beyond the jiroduced part of the basal joint ; its outer margin is broadly rounded, but the inner margin is nearly straight ; the apex is broadly truncate and indistinctly four-iobed — each lobe forming the base of a seta ; the outer seta is stout and elongate, the next is short and very slender, the third seta is stout and considerably longer than the outer one, while the inner seta is short and spiniform (Pi. 38. fig. 3G). Caudal stylets equal to about two-thirds the length of the last abdominal segment (PL 38. fig. 52). Habitat. Firth of Porth, off St. Monans. Remarks. The slender posterior foot-jaws and outer branches of the first foiu* paii-s of swimming-feet serve to distinguish Ectinosoma teiiuipes from the other species described in this memoir. EcTixcsoMA ATLANTICUM (Brady and Ptobertson). (PL 36. figs. 17 and 40; PL 37. figs. 6, 23, 35, 50 ; PL 38. tigs. 11, IB, 38, 53.) 1873. Microsetdla atlantica, B. & E.. (5), p. 130, pi. ix. figs. 11-16. 1880. Ectinosoma atlanticum, Brady (3), voL ii. p. 13, pL xsxviii. figs. 11-19. 1883. Ectinosoma atlanticum, Brady (4), p. 100, pL iv. figs. 10-14. 1887. Ectinosoma atlanticum, Jules de Gueruc (8), p. 344. 1891. Microsetdla atlantica, Scott (14), p. 302. 1892. Microsetdla atlantica, Giesbrecht (7), p. 550, Taf. 44. 1893. Ectinosoma atlanticum, I. C. Thompsou (16), p. 192, pi. xix. fig. 1. 1894. Microsetdla atlantica, T. Scott (15), p. 91. 58* 438 MESSES. T. AND A. SCOTT — BE VISION OF THE BRITISH COPEPODA Description. Length '55 mm. (^^5- of an inch). Body very slender; the forehead, seen from the side, is small and sharply rounded to form the small beak-like rostrum > hirsuta, n. sp. 3. >) simUis, n. sp. 4. a elegans, n. sp. 5. i) mitior, n. sp. 6. )) fusca, n. sp. 7. » similis, n. sp. 8. » hirsida, n. sp. 9. » minor, n. sp. 10. )f elegans, n. sp. 11. i> typica, n. sp. 12. •> fusca, n. sp. 13. >> minor, n. sp. 14. >) typica, n. sp. 15. )J elegans, n. sp. 16. )} shuilis, n. sp. 17. )l hirsuta, n. sp. 18. 3> fusca, n. sp. 19. J) hirsuta, n. sp. 20. » fusca, n. sp. 21. >> minor, n. sp. 22. )} typica, n. sp. 23. ?f hirsuta, n. sp. 24. 1) miiwr, n. sp. 25. J) elegans, n. sp. Female seen from left side. One of the antennules (female). One of the antennre. Labium. Mandible and palp. X 53. X 53. X 53. X 53. X 80. X 80. x380. X380. X 380. X253. x253. X 380. X 333. x253. X253. x253. x253. x253. x304. x304. X500. x253. X 253. x304. X 253. 442 MESSES. T. AND A. SCOTT — EEVISION OF THE BEITISH COPEPODA ig. 26. Brady a iypica, n. sp. 27. 3) similis, ii. sp. 28. 3J hirsuta, n. sp. 29. jy elegans, n. sp. 30. }y fusca, n. sp. 31. }> minor, n. sp. 32. >i fi/pica, n. sp. 33. >) similis, n. sp. 34. }> hirsuta, u. sp. 35. » minor, n. sp. 36. )} eleyans, u. sp.' 37. » fusca, n. sp. 38. » elegans, n. sp. 39. J) fi/pica, 11. sp. 40. >> hirsuta, n. sp. 41. }} similis, 11. sp. 42. >} minor, u. sp. 43. }> fusca, n. sp. 44. )} iypica, u. sp. 45. }> fusca, n. sp. 46. }! elegans, ii. sp. 47. >y hirsuta, n. sp. 48. >> similis, ii. sp. One of the anterior foot-jaws. One of the posterior foot-jaws. Foot of first pair of swimming-feet. Foot of fourth pair of swimming-feet. » X 304. X 500. x380. x380. x380. x500. x500. x500. X380. xoOO. x380. X380. Xl26. xl26. xl26. xl90. xl26. xl26. X126. xl26. Xl26. Xl26. xl90. Fi£ Plate 36. 1. Bradya iypica, Boeck. Foot of fifth pair (female) . x253. 2. j> hirsuta, n. sp. » }> x253. 3. » similis, n. sj). » }> x253. 4. >} elegans, n. sp. » 1) x253. 5. >y minor, n. sp. 1) » x253. 6. >} fusca, u. sp. » )3 x253. 7. » hirsuta, u. sp. Abdomen and caudal stylets. x 53. 8. 3> fusca, n. sp. )j >} X 53. 9. !) minor, n. sp. >i » X 80. 10. }> siiniUs, n. sp. )} » X 53. 11. }> elegans, n. sp. » » X 53. 12. >J typica, u. sp. 3> >> X 53. 13. Ectinoso7na melaniceps, Boeck. Female seen from left side. X 64. 14. 3) Sarsi, Boeck. » » X 40. 15. )! pygmoBum, n. sp. » » X 80. 16. }! Herdmani, n. sp. » » X 53. 17. » atlanticum (Brady » » X 64. & Roloertsou), 18. >y gracile, n. sp. >} 1) X 48. 19. >t propinquum, n. sp. }> )3 X 40. BELONGING TO THE GENERA BEADYA AND ECTINOSOMA. 443 Fig. 20. Ectinosoma armiferum, n. sp. 21. 1) Normani, n. sp. 22. ') curticorne, Boeck. 23. fj longicorne, n. sp. 24. J} erythrops, Brady. 25. >) tenuipes, n. sp. 26. » Sarsi, Boeck. 27. >) propinguum, n, sp. 28. » melaniceps, Boeck. 29. I) Normani, n. sp. 30. » curticorne, Boeck. 31. }> erythrops, Brady. 32. » tenuipes, n. sp. 33. » tenuireme, n. sp. 34. }> curticorne, Boeck. 35. j> tenuipes, n. sp. 36, j> erythrops, Brady. 37. jj gracilc, n. sp. 38. 3> longicorne, n. sp. 39. J> Normani, u. sp. 40. 3) atlanticum (B. & R. 41. )) pygnKSum, n. sp. 42. }> Sarsi, Boeck. 43. l> armiferum, n. sp. 44. » Herdmani, u. sp. 45. » melaniceps, Boeck. 46. J) propinguum, n. sp. Female seen from left side. Labium. One of the antennules (female). X 40. X 80. X 53. X 64. X 53. X 64. xl90. x253. x253. X380. x253. x253. x304. x253. X 253. x218. x218. xl70. X 253. x218. X 253. x500. x253. x218. x253. x253. xl90. Plate 37. Fig.l 2. 3. 4. 5. 6. 7. 8. 9. 10. n. 12. 13. 14. SECOND SERIES. Ectinosoma Sarsi, Boeck. „ propinquum, n. sp. ,, Herdmani, n. sp. „ armiferum, n. sp. j> pygnueum, n. sp. „ atlanticum (B. & R.). ,, longicorne, n. sp. J, tenuireme, n. sp. „ tenuipes, n. sp. „ curticorne, Boeck. „ melaniceps, Boeck. „ Normani, n. sp. „ gracile, n. sp. „ erythrops, Brady. ZOOLOGY, VOL. VI. One of the autennre. X200. x200. X300. Xl70. X 380. x300. x300. X300. X 300. X300. x300. X300. x333. X300. 59 ■144 MESSRS. T. AND A. SCOTT — EEVISION OF THE BEITISH COPEPODA Fis 15. 16. 17. 18. 19. 20. 21. 22. 23. 2-1. 25. 2G. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. Ectinosoma prupinquum, n. sp.' ;, Herdmani, n. sp. „ armiferuin, n, sp. „ erythrops, Brady. „ tenuipes, n. sp. J. pyyinaaum, n. sp. „ Sarsi, Boeck. „ melaniceps, Boeck. ,, atlanticuni (B. & R.) „ curticorne, Boeck. „ longicorne, n. sp. „ Normani, u. sjj. ,, tenuireme, n. sp. „ gracile, n. sp. „ Herdmani, i\. sp. „ tenuipes, n. sp. „ armiferum, n. sp. „ pjrojnnqmim , n. sp. ,, lonyicorne, u. sp. ,, Normani, n. sp. „ atlanticum (B. & R.) ,, tenuireme, n. sp. „ erythrops, Brady. „ Sarsi, Boeck. „ pffi/KPum., n. sp. „ melaniceps, Boeck. „ curticorne, Boeck. „ erythrops, Brady. „ pygm(Eum, n. sp. „ lonijicorne, n. sp. „ gracile, n. sp. „ tenuireme, n. sp. „ tenuipes, u. sp. ,, curticorne, Boeck. „ melaniceps, Boeck. „ atlanticum (B. & R.). „ Normani, n. sp. ,, Sarsi, Boeck. „ armiferum, n. sp. ,, Herdmani, u. sp. „ propinquum, n. sp. Mandible aud palp. » One of the anterior foot-jaws. J? >> >i One of the posterior foot-jaws. xl70. X540. X253. X253. x253. X 380. X 170. X253. x2o3. X253. x333. X 253. X 253. X200. X380. x300. X 200. X I'JO. X 380. X 380. X 380. x250. xl90. X 190. x500. X380. X380. X380, X380. X 333. X333. X 253. x380. X 380. X380. X 380. x380. x253. X333. x570. X 190. BELONGING TO THE GENERA BEADYA AND ECTINOSOMA. M5 Fig.l. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. Ectitiosoma ienuireme, n. sp. ,, 7nt'lafiice/js, Bocck. „ (jracile, u. sp. ,, jnjgiucBum, u. s|). „ Normani, n. sp. „ lomjicorne, ii. sp. „ Hcrdmani, ii. sp. „ curticorne, Boeck. „ propinquuni, u. sp. „ Sarsi, Boeck. „ at/anticum (B. & R.). „ ienulpes, n. sp. ,, erythrops, Brady. „ armifcruiii, n. sp. „ enjllirops, Brady. „ atlanticum (B. & R.). „ tenuipvs, 11. sp. „ Normani, n. sp. „ armiferum, n. sp. ,, curticorne, Boeck. „ melaniceps, Boeck. „ Sarsi, Boeck. „ prupinijHHin, u. sp. ,, tenuireme, n. sp. „ Herdmani, n. sp. „ pygmfi'Uin, ii. sj). ,, graclle, n. sp. ,, longicorne, n. sp. ,, lonyicorne, n. sp. „ grarile, u. sp. '! piigmcenin, u. sp. „ Sarsi, Boeck. „ Herdmani, w. sp. „ propinquum, ii. sj). ,, curticorne, Boeck. ,, tenuipes, ii. sp. „ armiferum, n. sp. „ atlanticum (B. & R.) ,, erythrops, Brady. „ tenuireme, n. sp. ,, melaniceps, Boeck. „ Normani, u. sp. „ armiferum, ii. sp. „ curticorne, Boeck. „ Normani, u. sp. Plate 38. Foot of first pair of swimming-feet. J) J) Foot of fourth pair of swimming-feet. Foot of fiftli pair (female). Abdomen and caudal stylets. xl40. X 140. X 140. x250. xl40. Xl40. X 140. X140. Xll5. Xll5. X230. x230. x230. xllo. x230. x230. X230. xloO. xllo. X 150. Xl50. xllo. xllo. X l.JO. XloO. X 253. Xl70. xl70. X253. X 253. X 380. X 145. X220. Xl45. X 253. X253. xl90. X 253. X 253. X 190. X 190. xl90. X 53. X 80. X 80. 446 COPEPODA BELONGING TO THE GENERA BEADTA AND ECTINOSOMA. Fig. 46. Ectinosoma melaniceps, Boeck. Abdomen and caudal stylets. 47. 48. 49. 50. 51. 52. 53. 54. 55. Herdmani, n. sp. erythrops, Brady. tenuireme, n. sp. longicorne, n. sp. Sarsi, Boeck. tenuipes, n. sp. atlanticum (B. & R.). propinquum, n. sp. pygm^.- v^'tK^ \ iS=-'^*^x .^■^' i '* N'-v, ■.I ,i' \ • tin'^ |j \ I 1 \VA: ^ f|| K J 1 ■ I A-^x .^. i H \ H 3H^ '\ Trans. Linn, Soc . Zooi. Sfb. 2. Vo1.\1.P1.36. ./ ill , ! .'^f y ^ ■1 <^.- ^ ^m /; #^: ).-riS..n,n|l /^■> '^%;i \ '^'■^ '^V 3?.ITISH COFZPODA. BRADYa AND ECTINOSOMA, Trak3 Limn Sog Zooi..Ser.2 VolVL.P137 Andrew Scott dr.l. ad nat A THcOiick lith W^st.Newiuan, Hi.p BRITISH COPEPODA. EGTINOSOM. 'T^ATT^^ ^INI-; vAil • K rh lf\ 3 ' m h\ .V W- Hi \ •/ -,. '■■*■ " v/ Xf 4. 1 1 •' ;,' \ ^^-/ "1 ^ A% « 1 rA^' s f) f' i ^ j "Z ^^•/r' 1 ^f^i P /I --"rf V. f i liflfl II *■■ ^ m i"T^ f \>. ,. Andre^ff Scott <1&1 £ ATHDllicklitii. V,>-t l^tvni: BRITISH COPEPODA, ECTINflSOMA LINNEAN SOCIETT OF LONDON. MEMORANDA CONCERNING TRANSACTIONS. The First Series of the Transactions, containing both Botanical and Zoological contributions, has been completed in 30 Vols., and a few entire sets are still for sale. 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(Plates XXXIX. & XL.) Read 5th December, 1895. IHE Phasmida' are in many respects a very interesting group of insects, but their study has been comparatively neglected. They attain a larger size than any other existing insects known, and many of the species are of brilliant colours ; but they take up much space in a cabinet, and when preserved in spirit, as is too often the case, their colours are discharged, and they become brittle and unsightly grey, yellow, or brown objects. (I never lose an opportunity of protesting against the indiscriminate use of spirit by collectors. It is a most convenient mode of collecting, but is adapted only for hard shining insects like bugs, beetles, and cockroaches, w^hich have no delicate colours to bleach, exposed wings to tear, or pubescence to mtit.) Again, the Bhasmidce are sluggish insects, highly protective in their apjiearance, and generally to be found resting motionless on their food-plants. They are therefore difficult to see and collect, and, as they are little studied, they have no market value ; and amateurs who send out collectors to obtain butterflies or beetles sometimes expressly discourage their collectors from paying attention to groups of insects which do not interest them. The Phasmidce are pre-eminently a tropical group, and probably attain their maximum of size and l)eaiity in the Eastern Archipelago, from the Malay Islands to Australia inckisive, though the number of species is perhaps greater in Trojiical America; and in both these particulars they resemble butterflies. Foiu- small species only are found in Europe south of the Alps, and of these only one, Fhasma gallicum, Charpentier, extends as far north as South France, where it appears to be rare. In the United States likewise only a few sjiecies occur, only one of which, Diapheroinera Sayi, Gray, crosses the St. Lawrence into Canada, where it is found at Montreal. Several species are found in China and Ja2)au, but their northern extension in Eastern Asia is not yet accurately known. Southward, they extend to the Cape of Good Hope in Africa, and at least as far as Chili in South America. Many of the species are apterous in one or both sexes, while others have very large wings. Sometimes they are perfectly smooth and rod-like ; but more frequently they have spines on the head, legs, and body, sometimes simple, sometimes broad and triangular, and often accompanied or replaced by large leaf-like expansions, especially in the species of the Eastern genus PhylUum, IlHger, which present the exact appearance of green veined leaves, and have always been known as " Walking Leaves." The Fhasmid^ in general are known as "Walking Sticks," " Stick Insects," or " Spectres ;" and many of the wingless species exhibit a very curious resemblance to dead twigs. Others are SECOND SERIES. — ZOOLOGY, VOL. VI. 60 448 MK. W. F. KIRHY ON NEW OR EARE green, with jointed bodies (r. //. the genus HennarcJms, Stal), and present an exact resemblance to slioots of l)anilioo, being seven or eight inches long, and as thick as a finger. Smaller species, belonging to the genns Grcnffea, Bninner, are sometimes extremely injurious to the cocoanut-trees in the South Sea Islands ; so much so that the chiefs sometimes issue orders for their destruction bj'^ chopping them to pieces. Many Phasmlda; exude a liquid from the l)ody when alarmed ; but this cocoanut feeder is said to have the jiower of squirting a fluid, sufficiently acrid to cause blindness if it touches the eyes, to a distance of four feet. Otherwise the Phasmidce appear to be generally harmless, except sometimes, to vegetation ; and it is probably only a few species which cause much mischief in this respect. The largest species known belongs to the genus Pharnacia, Stal. It is from Borneo, and the name of Pharnacia serratipes. Gray, has been provisionally attached to it in the public Insect Room at the Natural History Museum, South Kensington. Accurate measurements, taken by Mr. C. O. Waterhouse, will be found in the present paper ; but in this place I need only say that it measures nearly 13 inches from th.e front of the head to the extremity of the abdomen. Another specimen, from a doubtful locality, measures only 10^ inches in total length ; but without more specimens it is impossible to ascertain positively whether they belong to the same species or not, for except size, and a possible difference in the comparative size of the spines (a character not easily estimated when comparing a dried and a spirit specimen), I have not been able to detect any characters by which to separate them. Moreover, in many Phasmidce, the males differ very much from the females, being much smaller, slenderer, and with the spines, &c., much less developed ; and it is therefore unsafe to attempt to pair the sexes, unless they are received from the same locality and in the same collection. The type of Pharnacia serratipes. Gray, is a slender winged insect, only the arms of which run to the eyes. The front ends in a slight transverse ridge in front of the eyes, with a rudimentary horn on each side. Segments of the abdomen slightly carinated, more distinctly so towards the apex; the two penultimate segments mvich expanded, the last twice as long as broad, and cleft nearly to the base, the femora slightly dentated at the extremity of the femora beneath, most strongly on the middle femora. Dimensions. Long, corporis 100 millim. ., capitis , pronoti ., raesoiioti „ metanoti, cum segmento mediano .... , segmenti mediani „ femorum anticorum ,, ,, medianorum ....... „ „ posticonim 24 4 >j 3 >' 23 n 18 » 4 i> 24 !) 20 PHASMID^ IN THE BRITISH MUSEUM. 459 The British Museum has a long series of both sexes from Baram, North Borneo, collected bj^ Mr. C. Hose. The female is well represented by De Haan's figure ; but the male from Java, to which he refers it, is evidently distinct. The males of Phasmidce are very ditfereut from the females, and can rarely be satisfactorily paired with them without evidence. DiXIPPUS SODALIS, sp. n. Male. Long, slender, olive-brown, very finely and closely granulated. Head scarcely longer than broad, with two short horns projecting forward, above and a little in front of the eyes, and witli a row of four small tubercles at the hinder extremity above. Antennae with the scape much tliickened, and twice as long as broad ; the greater part of the flagellum, except towards the base, is blackish. Front tarsi blackish from beyond the middle of the first joint to the extremity; the first joint is about as long as the three following, which successively diminish in length. Legs slender, with two pairs of large teeth at the extremity of the middle femora beneath, and two very small pairs on the other femora. Abdomen with the terminal segment but slightly expanded. Apical segment cleft to the base, about three times as long as broad. Dimensions. Long, corporis 95 mill „ capitis 3 , ,, pronoti 3'5 „ mesouoti 25 ,, metauoti, cum segmento mediano .... 18 „ segmenti mediaiii 4 „ femorum auticorum 25 „ ,, mediaiiorum 15 „ „ posticorum 21 . Hah. Baram District, Borneo. Collected by Mr. C. Hose. Closely resembles the male of D. snmatranus, with which it was received, but diff'ers by the short horns, and the different shape of the terminal segments of the abdomen. DiXIPPUS CORNUTUS, sp. n. Female. Cylindrical, brown, speckled, and varied with grey ; finely and thickly granulated. Head oblong, scarcely narrowed behind, and luirdly granulated; face mostly green; two large horns on the vertex between the eyes, bordered with black on the inside ; and there is a short black streak between each horn and the eye. Prothorax with cross-shaped grooves, and two more transverse grooves on the front lialf ; behind it a well-marked but slender carina runs down the rest of the body. Mesothorax slightly expanding behind, with lateral carinte ; and towards its extremity two short black carinse run backward from each side, meeting on the central carina at four-fifths of its 460 ME. W. F. KIEBT ON NEW OR EAEE length. Median segment one-third as long as the metanotum, the front curving slightly backward on the sides ; at about half its length is a slightly marked brown carina, on each side, curving inward to the middle. Segment 7 of abdomen only slightly shorter than 6 ; segment 8 about two-thirds as long as 7, and as long as 9 and 10 together ; 10 rather longer than 9, and widely concave at the extremity above. Legs short and thick, slightly compressed ; all the femora lobate-dentate at the extremity beneath on each carina, and the base of the tibiae furnished with a centi-al lobe beneath, which fits in between the femoral lobes ; first joint of the front tarsi strongly lobate above; middle and hind femora with the grey dusting forming a broad band towards the extremity ; segment 7 of the abdomen moderately lobate beneath on the lateral carinse at the extremity ; segment 6 only slightly so. Dimensions. Long, corporis 115 millim. „ capitis 6 „ ,, proDOti 5 „ „ mesouoti 24 „ „ metauoti, cum segmento niediano .... 20 „ „ segmenti mediaui 5 „ „ femorum anticoruin 20 „ „ mediauorLim 18 „ „ posticorum 20 „ 3t Hah. Hong Kong. Not unlike D. nodosus, De Haan, but with shorter legs, much longer horns, and the middle femora not lobate above. DiXIPPUS (?) INSTJLARIS, Sp. n. Female. Cylindical. Brown, granulated, head with a low transverse crest on the vertex, between the eyes, curving downward and inward at the ends ; a row of raised warts, larger than the others, before the extremity of the head. Scape of the antennae very broad and flattened, broadest in the middle, and about half as long again as broad ; down the middle of the body runs a low median carina, except on the prothorax, which is marked with a shallow cross-shaped depression. Pront femora beneath with a central ridge, and a pair of outer carinae, closely api^roximating, at the sides, the outermost denticulated towards the extremity, and the innermost serrulated throughout its length. The front tibiae are greatly compressed, and the upper ridge is slightly waved and at the extremity it projects obtusely forward. The first joint of the front tarsi has a flattened foliaceous ridge above, Avhich raises it to the height of the tibite; it is nearly as long as the remaining joints together. The four hinder femora are slightly denticulated at the extremity beneath ; and their tibiae are slightly lobate near the base beneath, and are also slightly thickened towards the extremity. The median segment is rather long PHASMID.E IN THE BEITISH MUSEUM. 461 for true Dl.nppfis; and the fifth and sixth segments of the abdomen are somewhat exi^anded. Dimensions. Long, corporis 140 millim. ,, capitis 6 „ „ pronoti fi „ „ mcsonoti 32 „ „ metanoti, cum segmento mediano .... 20 ,, „ segmenti mecliani 8 „ femorum anticorum 33 „ mcdianornm 22 „ posticorum 27 JIab. Thursday Island. The type is not in very good condition, but I think it well to describe it, as very few PJiasmkhe are knoAvn from the New Guinea district. It has considerable resemblance to D. crawangensis, De Haan, from Java, but is much stouter. Phasgania Everetti, n. g. et sp. (Plate XL. figs. 2, 2 a.) Female. Cylindrical, brown, granulated dorsally and laterally as far as the middle of the mesothorax, with larger lateral tubercles on the sides of the mesothorax. Head unarQied, rather long, rounded and depressed, about as long as the prothorax, the rest of the body with a slight longitudinal carina, exce^jt towards the end of the mesothorax, which is much dilated behind, and marked with several slight transverse carince, as is also the median segment, and the extremities of the metatliorax and of most of the abdominal segments. Prothorax scarcely thickened, and metatliorax not at all. Median segment aljont one-fourth as long as the metatliorax. Abdomen with segments 3-6 much tiiickened, nodose, the 7th as long as the 6th, but only half as broad, even at the extremity, which is broadest ; the 8tli narrower, and about two-thirds as long as the 7th ; the 9th broader than long ; the lOtli narrower, slightly longer ttian the 9th ; and the 11th forming a spine, longer than the 9th and 10th together, and jirojccting far beyond the ojierculum. Legs, especially the two front pairs, much comjiressed and carinated, but the carinations are only slightly lobate towards the base of the middle tibiae beneath; the first joint of the front tarsi, however, which is longer than the three following joints, bears a foliaceous expansion, as in Dlxippus. The middle femora are armed at the extremity beneath witii a closely approximating pair of two very strong teeth ; the front and hind femora are only armed with one conspicuous tooth and some smaller denticulations. 462 ME. W. F. KIEBY ON NEW OE EAEE Dimensions. Long, corporis 135 millim. ,, capitis 6 ,, „ pronoti 5 „ ,, mcsonoti 31 „ „ metanoti, cum segmeiito mediano .... 24 ,, „ segmenti mediam 7 ,, „ femorum anticorum 30 ,, ,, ,, mediauorum 21 „ „ J, posticorum 24 „ Sah. N.W. Borneo {Everett). This interesting sjjecies, vcliich I have named after Mr. A. Everett, who has done such good work in collecting in the East, is allied to Dixippus, hut its rounded head and the peculiar formation of the abdomen will readily distinguish it. In several respects we fijid a resemblance to it in the female of {Lonchocles) brevipes, Gray, which has the metathorax not expanded, hut some of the abdominal segments swollen, and the last slightly produced over the operculum. [L.) brevipes, and perhaps (i.) tmiformis, Westw., may ultimately form a new genus allied to Phasgaiiia. Sthenob^a tuberculata, sp. n. Female. Cylindrical, moderately stout, rufo-testaceous ; antennse spotted with black at the joints ; liead long, slightly attenuated behind, with a transverse crest in front, between the eyes, slightly raised at each angle; front femoi'a obtusely serrated above, and front tibia? both above and below; first joint of the front tarsi rather longer than the three following, and furnished with a leaf-like expansion ; middle and liind femora serrated or rather waved in a similar manner", and with leaf-like expansions on the upper surface of the femora near the base, largest on the middle femora. Several conspicuous black tubercles arranged, not uniformly, but irregularly in rows on the upper surface and sides of the thorax and abdomen, and much more numerously in a row on each side of the median line on the under surface ; oj^erculum very broad and concave, as long as the terminal segment. Dimensiofis. Long, corporis 91 millim. „ capitis 5 ,, „ pronoti 3 „ ,, mesonoti 23 „ „ metanoti, cum segmento mediano .... 11 „ „ segmenti median! 3 „ „ femorum anticorum 28 „ „ „ mediauorum 23 ,, „ „ posticorum 22 „ Hob. Rejang Eiver, Sarawak. Presented by Mr. H. Brooke Low. A rather isolated species. PHASMIDyE in the BRITISH MUSEUM. 465 Bactricia, gen. uov. Apterous in both sexes : very long and slender ; liead with two strong spinous processes on the vertex in the male ; lamellated processes in the female placed near together; legs inibescent, especially the tarsi ; tirst joint of tarsi as long or longer than all the rest, not apjiendiculated, but carinated in the female ; legs unarmed in male, armed with strong subtriangular spines in female, on the carinas above and below ; median segment one-tifth the length of the metanotum in male, one fourth in female ; styles of male large, broad, almost spatulate, and strongly curved, crossing each other ;_. operculum of female very long, longer than the last three segments of the abdomen together ; obtusely rounded and slightly expanded at the extremity. The type is Bactricia Trophimus. (Plate XXXIX. tigs. 3, 3 «, d ; figs. 1, 4 a, ? .) (^. Bacteria Trophimus, Westw. Cat. Pliasiii. p. 30. ii. 85. pi. v. fig. 5 (1859). ? . Bacteria bituberculata, Westw. 1. c. ]j. 180. n. 467 (1859); Scliaum, Monatsb. Akad. Wiss. Berlin, 1857, p. 423 ; Peters, Reise nach Mossambique, v. p. 558 (1862). The female figured is from Natal, but appears to agree with the description given by Westwood of the typical specimen in the Berlin Museum. Unlike as the sexes ajipear at first sight, they present so many points of resemblance on a close examination, in everything except the form of the horns, and in the appendages of the legs in the female, that I feel justified in placing them together. Besides the typical male, there are two other males very closely resembling it, also from Natal, in which the cephalic horns are reduced to mere tubercles. In the absence of a sufiicient series, I content myself with simply recording the fact. I am not certain of the real affinities of this genus, and place it in the Lonchodince with some doubt. There are one or two other East-African species allied to Bactricia in the Bi'itish Museum, but in poor condition and only in single specimens. One of these, from Natal, appears to be referable to Phibalosoma calametmn. Bates (Trans. Linn. Soc. xxv. p. 3il), and differs from Bactricia in the sides of the tarsi being raised. In [Phasma) calcaratum, De Haan, the median segment is likewise very short. Promachus sordidus, sp. n. (Plate XL. figs. 4, 4 a.) Female. Dark brown, rugose, with a depressed line on the head and prothorax, and a crossed depression on tlie latter ; the rest of the body strongly carinated on the median line. Pcniora with three or four rows of small teeth on the carina3. Head with two strong spines at the back, followed by two in front of the prothorax and two behind ; mesonotum with three strong spines on each side, two central ones just behind the level of the middle lateral ones, and two more central ones at the extremity. Metathorax, median segment, and the remaining segments of the abdomen all with a single spine towards the extremity, on the central carina, gradually diminishing in length towards the end of the body. Metathorax with a long spine, preceded by a short one on the sides, and another strong spine lower down, in front of the hind coxae. Segments 2-(> second series.— zoology, vol. vi. 62 464 ME. W. F. KIEBY ON NEW OR RARE of tlie abdomen eacli with a moderately long spine on the sides. Abdominal spine extending for nearly half its length beyond the operculum. Dimensions. Long, corporis 55 millim. ,, capitis 4 „ „ pronoti .3'5 ,, „ mesonoti 19 „ „ metanoti, cum segmento mediauo .... 6 ,, „ segmenti mediani 3 „ „ femorum auticorum 15 „ „ „ medianorum 13 ,, „ „ posticorum 16 „ Hob. Thursday Island. Collected by the late Rev. R. Toy. Described from two specimens, in one of which, which is slightly smaller than the type, the spines and denti dilations are less strongly develojjed. Allied to P. doreyaniis, Bates, but this species has the legs unarmed, except slight denticrdations at the ends of the femora beneath ; there is only one spine instead of two at the back of the metathorax ; the mesothorax is more slender, and the first pair of lateral spines is wanting, besides other differences. Bacunculin^. Several genera referred by Brunner de Wattenw^yl to his family BacteriidtB would be more naturally placed here, such as Bacteria, Serv., and Phanocles, Stal, which seem to be nearly allied to Calynda, St&l. In the place of Brunner's Bacteriidce, I propose to institute a subfamily PaJophhue, to include large species, with winged males. Caulonia spinosissima, sp. n. (Plate XL. figs. 5, 5 a.) Female. Moderately stout, greenish brown, the sutures of the prothorax and the median carina on the meso- and metathorax marked with a black line, which is expanded ' on the front of each. Head greenish, short, vertical, face rather long ; a black median line, on each side of which are three long spines and a longer and more oblique one out- side the second. Antennse very long and slender. Prothorax bilobate, with two spines on each lobe, the front spines separated by the median depression, but beyond the trans- verse depression the two spines are central, with a groove running on each side beyond them. Mesothorax with six longitvidinal rows of spines, of four each, but not placed under each other ; a double central row separated by the median line ; a longer row lower down, and a lateral row of short ones. Metathorax similarly armed, but the central and lower spines nutnbering three each, and the intermediate row of large spines two ; there are also tw^o central spines on the median segment, and two in front of the hind coxpe. Second segment of the abdomen (reckoning the median sen^ment as the first) with two spines at the base, two at the extremity, and one on each side below the latter. Third segment w^ith the opines similarly arranged, but larger, and the terminal central ones preceded by tw o small ones ; segments 4, 5, and 6 similarly armed at the extremity only; but the spines, except those at tlie sides, become gradually smaller, and PHASMID^ IN THE BEITISH MUSEUM. 465? on 6 tlie lateral spines ave absent. Segment 7 has only two short central terminal spines. The remaining segments are more slender, and unarmed. Operculum large, extending considerably beyond the terminal segment. Legs rather long and slender ; front femora with a single row of triangular teeth beneath, placed at about equal distances ; the 4th largest; fovu" hinder femora with two rows of larger ones of five each on the under surface. On the vinderside of the body there is a double row of short median spines. Dimensions. Long, corporis 58 millim. ,, capitis 2"5 ,, „ pronoti 3 „ „ mesonoti 14 ,, ,, metanoti, cum segmento mediano .... 11 ,, ,, segmenti racdiani 2*5 ,, „ femorum aiiticorum 20 ,, „ „ medianorum 13 „ „ „ posticorum 20 „ HaJ). Archidona. This species appears to belong to Ccmlonia, but is much more spiny than any previously described. C. hifoUa, Stal, probably approaches it most nearly in this respect. Palophin^. This subfamily includes, inter alia, a series of interesting African Pliasmidcp, in which the males are slender, with large wings ; and the females are stout, with shorter wings. They have usually foliaceous or large spiny prominences on the legs, and the head is crested, or more or less spined. The terminal segment is broad, slightly concave at the extremity, and extends far beyond the operculum in the female. They are generally classed under the genus Palophus, Westwood, but have been divided into several genera. The genera already named are the following. (How far they are truly distinct Avill best be seen when we receive more specimens of both sexes.) . . Palophus, Westw. Palophus, Westw. Cat. Phasm. p. 90 (1859) ; Brongniart, Nouv. Ann. Mus. Paris (3) xii. p. 193 (1892). The types are P. Haworthii, Gray (South Africa), and P. centaurus, Westw. (West Africa). They have a long double pointed crest on the vertex, between the eyes, and the thorax, though strongly granulated, has no raised spines. The second joint of the front tarsi is lobate as well as the first. I have both sexes of these species before me, but only females of any of the allied forms. These two species are perhajis not con- generic ; for in the female of P. Haworthii the wings are no longer than broad, while in that of P. centaurus they are nearly twice as long as broad, and the.mesothorax is much longer and slenderer in proportion than in P. Saioorthii. But I do not propose to separate these species generically, until more sj)ecimens are obtained. I imagine that Palophus miiiotauriis, Gerstaecker, from the Gold Coast, is probably congeneric with P. centaurus. 62* 466 MR. W. F. KIRBY ON NEW OR RA.RE IscHNOPODA, Grandidier. I.tchnopoda, Grandidier, Rev. Zool. xxi. p. 292 (1869) ; Lucas, Ann. Soe. Ent. Fr. (4) ix. p. 430 (1870). The type of this genus is I. Beyl, Grandid., from the Zambesi. To the same genus belong Bactrododema brevitarsls, Stal, from Damara-land, and a fine new species from Tanganyika, which I describe below. The females vary considerably in comparative length and. breadth of wing, but have always at least two strong diverging spines (not symmetrical) about the middle of the mesothorax, and the boss on the tegmina is rather long and pointed. The first joint only of the front tarsi is lobate. ISCHNOPOBA. EPISCOPALIS, sp. n. Female. Grey, varied with darker, a high double laminated crest, obtuse above, between the eyes ; head thickly tuberculate, the rest of the body coarsely granulated, and. striated, the rugse forming irregular stria? on the pro- and mesothorax ; two sharp spines, black at the tiji, standing obliquely outwards before the middle of the mesothorax ; segments 5 and 6 of the abdomen with a slight crest on each side before the extremity ; tegmina grey, rather long, with a high rounded elevation near tlie base, tipped with blackish ; wings with the costal area grey, indistinctly varied with darker, and broadly black at the base ; wings long and broad, black, with irregular yellowish hyaline bands, converging, anastomosing, and disappearing beyond the middle of the wing. Legs more or less banded with grey and In'ow^n ; front femora with three triangular elevations below and one about the middle, above ; front tibiae with two raised crests above, and first joint of front tarsi laminated ; the first and fifth joints (without the claws) are of about equal length, and longer than joints 2-4 together. Antennae a little longer than the front femora. Middle femora with large triangular elevations near the base, one pair below, and a single one, just beyond it, above ; before the extremity is a pair of smaller teeth on the carinse beneath. Middle libiae with two crests above; first joint of middle tarsi as long as the three following. Hind femora curved, toothed beneath at the extremity, and very slightly so above ; hind tibiae with from two to four triangular teeth above, and sometimes a small one towards the base below ; first joint of hind tarsi rather longer than the three following together. • Dbnensions. Long, corporis 215 millim. „ capitis 11 ,, ,, pronoti 11 ,, „ niesonoti 3G „ „ tcgminuni 25 „ Exp. al ] 70 „ Loug. femorum anticorum 5;i „ „ ,, niedianonun 'M) ,, „ ,, jjosticoruni iG „ Mab. Tanganyika. This fine species is closely allied to /. Beyl, Grandidier, as figured by Brongniart, but is rather smaller, and the wings are much larger; it is probably quite distinct. There are two female specimens in the collection of the Museum. PHASMID^ IN THE BRITISH :MUSEUM. 467 Since the above dcscrii)tion was written, another new species of this genus has been received from Somali-land, obtained l)y Mr. and Mrs. Lort Phillips, after whom I have much pleasure in naming it. Mrs. Pliillips rescued it from a tame monkey, which caught it and was about to eat it. IscHNOPODA Phillipsi, sp. n. (Plate XL. figs. 3, 3 a.) Female. Grey, bead strongly tuberculate, and with a high double laminated crest above, between the eyes. Behind the crest a narrow but well-marked groove runs back- ward nearly to the extremity of the prothorax ; the rest of the thorax and the basal segments of the abdomen are marked with a slight median carina. The insect is more or less granvilated, most strongly on the head and thorax, and the prothorax is marked witli a deep transverse groove just behind the front legs. Mesothorax with two sti^ong spines at two-fifths of its length, opposite to each other and nearly upright ; behind the left- hand one is a smaller tubercle. Abdomen with sei^ments i-7 witli slight crests on each side before the extremity, those on the 5th segment largest ; tegmina grey, moderately long, with a rather pointed pyramidal elevation near the base ; costal area of wings grey, with a black band near the base, and a slight elevation towards the costa before the middle ; wings about half as long as broad, black, with yellowish-hyaline spots, running from the costa in irregular rows, fading away beyond the middle, at least on the outer half of the wings, right front femora with three laminations ahove, the terminal one largest, and another beyond tlie middle in front ; left with only the upper terminal one slightly marked, and the front one reduced to a spine ; right front tibise with two strong triangular laminse on the front edge ; left with 3 smaller ones, the second double ; first joint of tarsi about as long as the remainder, and crested for its whole length ; middle femora grey, banded with brown, and with foliaceous elevations towards the base and extremity beneath, and two before the middle, above ; tibite with two foliaceous crests above, one towards the base, the other beyond the middle ; hind femora with a triangular elevation towards the extremity beneath, and tibiae with three or four above. The metathorax and median segment are unusually well separated in this species. Dimensions. Long, corporis 185 millim. „ capitis 8 „ ,, pi'onoti 10 „ „ mesonoti 30 „ ,, metanoti 9 „ „ segmenti mediani 17 „ „ tegminum "23 ,, Exp. al 114 „ Long, femorum anticorum 52 „ „ ,, medianorum -41 „ ,, ,, posticorum 43 „ Hub. Somali-land. 468 ME. W. P. KIEBY ON NEW OR RARE Closely allied to I. hreritarsis, Stul, but in that species the spines on the mesothorax are oblique, and not parallel; the wings are shorter and the vitreous spots less numerous, &c., &c. Bactkododema, Stal. Bactrododema, Stal, CEfv. Vet.-Akad. Furh. xv. p. 308 (1858) ; Bihang Svensk. Akad. ii. (17) p. U (1875), iii. (14) p. 12 (1878) ; Recens. Orth. iii. p. 32 (1875). The type of this genus is B. tiarata, Stal, from Damara-land. The British Museum possesses two females from the Transvaal, which agree with Stal's description, except that he does not mention the spines on the mesothorax, of which there is a large central pair, and, in one specimen, a shorter pair between these and the front of the mesothorax. From Ischno2)oda the genus differs in its much shorter, broader, and more lacerated cephalic crests, and in the fasciculated crests which terminate several of the middle segments of the abdomen, which, in Ischnopoda, have only a single small leaflet on each side. Cyphocrania cestuans, Westwood, and Bactrododema millaris and B. Welwitscid, Bolivar, may be referred provisionally to Bactrododema ; but here the cephalic crests are still further reduced, almost to spines. On tlie fifth segment of the abdomen in two specimens of this section before me is a terminal raised crest. Enetia spinosissima. Enetia spinosissima, Kirb. Ann. Nat. Hist. (5) viii. p. 151 (1891). Sab. Madagascar. This fine insect is evidently allied to Achriopiera fallaa;, Coq. (Ann. Soc. Ent. Erance,- (4) i. p. 495, pi. 9. fig. 1, 1860) ; but can hardly be the female of that species, or even congeneric. Both genera, however, belong to the Falophince rather than to the Acropihyllma;, though their short spiny legs, and the long operculum of Enetia ally them to the latter subfamily. ACROPHYLLIN^. Vasilissa, gen. nov. Male slender, winged ; female (perhaps immature) with tegmina only ; front legs much longer and slenderer than the others ; first joint of their tarsi as long or longer than all the rest together ; four hinder legs much shorter, of about equal length ; the femora and tibiae armed with shoi't sj)ines ; the basal joint of the tarsi as long or longer than the three following joints, which successively diminish in length; styles of the male shorter than the last segment; of the female about two-thirds as long as the last segment, slender, pointed ; operculum very long, j)ointed at the extremity. This genus appears to be allied to Biura, Gray. PHASMID.E IN THE BRITISH MUSEUM. 469 Vasilissa Walkeki, s}). n. Male. Pale ochreous, perhaps green during life, especially the tegmina ; antennae 24- jointed, scape oblong, about twice as long as broad, the second joint annular, tlie fourth scarcely longer than broad, the third, fifth, and sixth about twice as long as broad, but increasing in length slightly and progressively; the following joints linear, first increasing and then decreasing in length, the sixth terminal ones much shorter, and therefore comparatively thicker .than the others ; terminal joint pointed. Head and prothorax of about equal length ; mesothorax nearly four times as long as the prothorax ; four hind femora with three rows of short black spines below, and an incomplete row of from 2 to 0 placed widely apart on the basal half of the middle line above ; four hinder tibiae set with short hair, and furnished Avith one row of short black spines beneath. Tegmina and costal area of wings probably green in life. Wings rather short, subhyaline, with two round brown spots on each of the cross-nervures. Female (described from an immature specimen in which the wings are not developed) similar, bvit much stouter ; the spines on the legs are less numerous, especially on the upper surface of the femora, where they are reduced to two. The antennae are much shorter than in the male, the longest joint being the 11th, and the length of the others rapidly decreasing towards the base and tip. In the female the hinder lobe of the median segment is pointed, and almost as long as the segment itself ; in the male it is rather more than half as long, and sends off a ridge which extends to the front of the median segment. Sab. Queen's Islet, N.W. Austraha. .Collected by Mr. J. J. Walker, R.N. Dimensions. 6. ?. miUim. millim. Long, corporis 85 135 „ capitis 4 7 Lat. „ 3 4 Long, antennarum 27 19 „ pronoti 3 5 „ mesonoti 14 25 ,, metanoti, cum segmento mediauo . . 12 16 ,, segment! mediani 7 9 „ femorum anticorum 25 32 „ medianorum 18 21 ,, posticonim 00 22 „ tibiarum anticarum 25 36 „ „ medianarum 15 20 „ operculi . — 13 470 ME. W. F. KIEBY ON NEW OE EAEE Xenomaches, gen. nov. Male. Antennae extending' a little bej^ond the front femora, 2i-jointed ; scape and 3rd joint about twice as long as broad, 2nd and 4th joints hardly longer than broad, the rest gradually increasing in length to the 15th, the middle joints being long and cylindrical ; the IGth is shorter than the 15th, but the 17th is nearly as long ; the next five gradually shorten; the 23rd is again longer, and the terminal joint longer still. The head is long, not narrowed behind, convex above. The prothorax, mesothorax, and sides of the nietathorax ai-e set with long conical spines ; the front femora are armed with a double row of strong spines beneath, the middle femora only witli one or two towards the extremity, and the hind femora with a row on the central ridge, but only one or two at the extremity of the lower lateral ridges. Hinder legs rather sbort and stout ; front legs long ; first joint of tarsi nearly as long as the remainder ; in the other pairs it is much shorter. Pulvilli very large. The mesothoi-ax is nearly three times as long as the prothorax, and slightly widened behind ; the median segment is nearly twice as long as the metanotum. The abdomen is cylindrical, the .segments are longer than broad, and the middle ones much thickened ; it then tapers rapidly to the extremity, and the cerci are very long, slender, and pointed. The tegmina and Aviugs are rudimentary in the specimens before me. This genus is allied to Bhaphidenis, from which its much stouter build, shorter antennae, and rudimentary organs of flight will easily distinguish it. The types of Hhaphiderus inhabit the Mauritius. The new genus Xenomaches is founded on the following species from Rodriguez : — Xenomaches incommodus. Bacillus incommodus, Batler, Ann. Nat. Hist. (4) xvii. p. 410 (1878) ; Phil. Trans, clxviii. p. 148,- pl. liv. figs. 4, 4 a-c (1876). As Dr. Butler has already described and figured this insect, it will not require further notice here. Megacrania phelaus. Platycrania 'phelaus, Westwood, Cat. Phasm. p. 113. n. .288, pi. xxvii. fig. 5 (1859). The original type of this species (a female from Fiji) is in the British Museum. Three more specimens of what appear to be the same species, from the Solomon Islands, have lately been added. They are less discoloured than the type ; the head, legs, and thorax are green, and the abdomen light mahogany-brown, with irregular longitudinal yellowish-grey markings, and shading into darker brown towards the ends of the segments. The male differs little from the female, except in being more slender, and in- the greater expanse of the wings (nearly 4 inches). PHASMID^ IX THE BlilTlSH MUSEUM. 471 Megacrania Batesii, sp. U. Platycrania alpheus, var., Bates, Trans. Linn. Soc. Lond. xxv. p. 347 (1865). The type of 31. alpheus, Westwood, from Ceylon, tas the thorax but slightly granulated, the tegmina nearly round, and the hind wings very short : " tegni. lin. 7|, alar, expans. lin. 26." But in all the specimens from the Malayan and Papuan Islands the thorax is very strongly granulated, the elytra are more oval, and the wings are much larger. All the specimens in the British Museum are females : they are from the Solomon Islands, Aru, and Kei Dulan. The Philippine specimens, one of which is immature and the other has damaged wings, probably belong to this species. Bates mentions specimens from Goram, Gilolo, and New Guinea, and describes a supposed male from Amboina. The dimensions of the tegmina and Avings (on the same scale as Prof. Westwood's measure- ments) are as follows in the Solomon Island specimen, which is a very tine one, measuring upwards of 5 inches in length : — Lmgth of tegmina, 8 lines ; expanse of wings, 2 in. 101 lines. Are,hid-5;us Stali, sp. n. Hale. Slender. Head black, with a large reddish spot in front of the vertex, extending from before the autennoe (the two basal joints of which are likewise reddish) to one-third of the distance between tlie eyes and the occiput ; tliis patch is W-shaped behind. Prothorax and metathorax black or deep chocolate-brown, with a broad rufo- testaceous stripe on each side of the upper surface ; the space between is dotted with the same colour. Abdomen luteous, brown aljove, except on the last four segments ; the last three, however, have an irregular reddish stripe in tlie middle line above, and the cerci are red, lined with yellow on the sides. Tegmina and wings blackish, with yellow costa and nervnres. Wings reaching nearly to the end of the sixth segment. Coxae black, lined or spotted with yellow ; femora very slightly denticulated before the extremity. Female rather stout, yellowish green, head with a broad black band on the sides, expanding in front of the eyes, and extending, varied with yellow, over the upper part of the face ; coxse striped with black below, and front coxae also above; legs pubescent, reddish, spotted Avith yellow ; middle femora towards the base, and hind femora, very finely denticulated ; tegmina and wings brown or reddish brown, with the costal area and the nervures brown. Wings short, only just passing the fourth segment of the abdomen ; abdomen wide in the middle, and then tapering ; the segments of nearly equal length, except the last three, of which the middle one is nearly twice as long as the other two, which are much shorter than the preceding segments of the abdomen. Dimensions. ^ j _ millim. millim. Long, corporis 60 86 „ capitis 5 10 „ pronoti 3 5 „ mesonoti 10 16 „ femorum anticorum .2-i 30 „ „ medianoruui \'Z 13 „ „ posticorum 15 20 SECOND SEELES. — ZOOLOGY, VOL. VI. 63 472 ME. \V. F. KIEBT ON NEW OE EAEE Hab. Albay, N.E. Luzon [Whitehead Expedition). Seems to be intermediate between A. paUmbrus, Westw., and A. nigricornis, StSl. A species wbich belongs to tbis genus, but wbicb. has not yet been referred to it, is Phasma rosea, Stoll. Ctenomorpha albopuxctattjm, sp. n. Male. Greenish brown, probably green during life; head with 7 fine longitudinal lines behind, 5 ferruginous, and the outermost but one on each side grey. Mesothoras with 6 or 7 sharj) black spines, irregularly paired, and one or two smaller ones ; front legs much longer than the others, the femora very finely denticulated above and below ; four hind femora with three rows of well-marked spines on the lower surface. Tegmina, and costal area of wings greenish grey, finely reticulated with yellow ; tegmina with a black spot on the hump, and a very conspicuous round whitish spot towards the inner margin. Costal area of wings Avith a short black basal streak; the rest subhyaline, with brown spots on the nervures. Cerci short, oval, compressed. Costa of tegmina and wings with an ivory-white stripe. Dimensions. millim. Long, corporis 83-87 ,, tegniinum 8-12 Exp. al 89 Hab. Queensland. I suspect that Dinra briareus, Gray, is the female of this species, in which case the name briareus must be retained for it. Hetekopterygin^. Brunner calls this subfamily Cladomorphidce, owing to Stal having incorrectly used the name Cladomorphus, Gray, in a different sense to Serville. Heteroptertx atjstralis, sp. n. Male. Dark brown, striped with testaceous on the head, prothorax, and mesothorax before the wings. Head with 12 spines ; two rows of four very long spines towards the back; two shorter spines in front of these, nearly in a line with the outer ones ; and two very short ones close together in the median line, beyond the level of the three in front. Prothorax bordered all round, the central part divided equally into two, of which the front lobe bears two very long sharp spines, and the hind one only a few tubercles ; the lateral borders have three spines, one at the angle in front, another a little within the hind border ; there is also a short one on the pleura lower down. Mesothorax with several longitudinal rows of very large spines ; the central series consists of a pair in front, a pair in the middle, and a cluster of four between the bases of the tegmina. On the lateral borders of the central ridge is a strong spine in front, and three or four tubercles behind ; on the PHASMID.E IN THE BRITISH MUSEUM. 473 pleura, and on the outer side of the mesopectus, are rows of three large spines on each' besides numerous tubercles. On the central line of the meso- and metapectus is a well- marked carina, attenuated in front, and on the metapectus are four strong spines on each side, besides smaller ones in the middle. The tegmina have a sliort spine at the base ; the base is black, except along the costa ; the outer half is testaceous. There is a strong ridge over the black portion ; the testaceous portion is partly reticulated with black. On the metapleura is a very strong spine below the middle of the wings, a shorter one more in front, and several strong ones along the lateral ridge. Beyond the wings, which, so far as can be seen, are f usco-hyaline, with reddish nervules, are two strong spines in the middle, on each of the two following segments, besides numerous small ones. The lateral ridges are also thickly spined. The extremity of the abdomen (the last four segments) is much enlarged in the middle. There are four strong spines, gradually diminishing, besides smaller ones on most of the segments of the abdomen ; the last four segments being almost destitute of spines, or even tubercles both above and below. Tlie coxsB, femora, and tibia? are strongly spined on nearly all the carina? and on the fore hinder legs, on the front legs more sparingly. On the hinder ones, numerous small teeth fill up the interspaces between the others, which are often rather wide apart. The female is a dark brown insect, spined nearly as in the male, but larger and more bulky. It differs from that of S. Dehaanii, Westw., by its much larger tegmina, the larger and more regular series of spines on the sides of the abdomen, and the much stronger spmes on the legs, &c. Dimensions. J. ?. millim. raillim. Long, corporis 85 104 „ capitis 7 9 ,, pronoti 8 11 „ mesonoti ]4 17 ,, tegminum 16 22 „ femorum anticorum 21 22 „ „ mediauorum 17 23 „ „ posticorutn 25 35 Jffab. Australia (locality not specified). PsEUDOPHASMIN^. Genus Pseudophasma. Phasma, St.-Farg. & Serv. (nee Illiger), Encycl. Method., Ent. x. p. 100 (1828). The type of Phasma, Illiger, was fixed by Latreille as Mantis rossia, Fabricius, which was subsequently taken as the type of Bacillus, St.-Farg. & Serv. They took Mantis necyduloides, Linn., as the type of Phasma, and have been followed in this by recent 474 ME. W. F. KIRBT ON NEW OE KAEE authors ; but now that the error has been discovered, the apterous genus Bacillus (an inconvenient name at best) sinks as a synonym of Fhasitm; and the winged genus Phas))ia, auct., with necydaloldes as the type, may be called Fseudophasma. This will involve a little alteration of the subfamilies, for Brunner's BacilUdce must now be called Phasmince, and his Phasmidce must be called FseudophasmincB. Stratocles bogotensis, sp. n. Male. Black. Head black above, antennge black, pubescent, face and under surface rufous ; ocelli yellow. Two yellow lines run from the ocelli, and two more on each side, one behind each eye, and another, broader, below each eye, all slighly converging to the occijmt ; there is a green spot above each antenna, and a slender green line at the end of the scape. Prothorax and mesothorax with a green stripe on the back, partly bifid in front; the lateral ridge of the prothorax is also marked with a narrow green line. Coxae yellow, femora testaceous, tibiiB and tarsi black, pubescent ; a broad green stripe runs along the pectus from the front to the middle coxa?, and from the latter to the hind coxJB, and is continued more narrowly along the abdomen ; under the wings is a narrow yellowish-green line. Tegmina black, lined with green ; opaque portion of wing reddish brown, lined with green towards the costa nearly to the extremity; hind wings smoky hyaline, with a broad curved milk-white band across the middle, not extending to the costa or inner margin. Terminal segments slightly expanded ; cerci rather long, crossed at the extremity. Female nearly as in the male, but larger, and with more green lines on the head, including three meeting in front, behind the ocelli, and an additional line on each side, meeting in front of the ocelli. The green lateral stripes on the pectus and abdomen are much less continuous; the vipper appendages are black, and about as long as the last segment but one. The hinder half of the abdomen is testaceous beneath, and projects about as far beyond the abdomen as the cerci, like Avhich it is pubescent. Dimensions. i. ?. millim. millim. Long, corporis 36 46 „ capitis 2 3"5 ,, pronoti 3"5 3"5 ,, mesouoti 2'5 3 ,, luetauoti, cum segmeoto mediauo . . 7 7'b ,, segmenti mediani I'l 3 ,, femorum anticorum 13 10 „ ,, medianorum 10 10 „ „ posticorum 12 12 ,, tegminum 4"5 6 Exp. al. 57 76 Not closely allied to any known species. PHASMID^ IN THE BRITISH MUSEUM. 475 ASCHIPHASMIN.^. Genus Presbistus. Asc/iipasma, Brimner, Ann. Mus. Genova, xxxiii. p. 100 (1893). In lS3i ATestAvood founded a genus Aschlphusma, and in 1835 Gray founded a genus Ferlamorphiis. The type of the former is A. annulipes, Westwood. ; and that of Gray, PerlamorpJms Jiieroghjphlcus, Curt. MS. P. peleus, Gray, was added as a second species, but has no chiim to be considered the type of Pe^^lamor pirns; and as P. hieroglyphicus. Gray, is considered to be synonymous with Asclt/'phasma anniUipes, Westw., Gray's genus and species both fall. But Brunner, who adoj)ts Westwood's later and incorrect spelling Asclitpasma, divides the genus as follows: — 1. Femora antica carinata et basi curvata Ascliijxisma, Westw. I'. Femora antica subteretia, basi non curvata Perlamorpha, Serv. As A. ani/nl/pes, Westw., the type of the genus, belongs to Pcrlamoiplia, Brunner, which must, as we have seen, take the name of A.^chiphasma, it is necessary to rename Asch/'pasma, Brunner, which I therefore designate Presbistus, and indicate Perlamorplius peleus. Gray, as the type. P H A S M I N .E. Genus Abkachia. Ahrachla, Kiib. Ann. & Mag. Nat. Hist. (C) iii. p. 503 (1889). On re-examining my A. brevicornis, the type of this genus, I find that it possesses triangular clefts at the ends of the tibire, which, coupled with the short antennae, will bring it at least provisionally into this subfamily. The types are from Theresopolis, Brazil. Bacteria longimana, Saussure, from Bahia, is certainly congeneric, and is possibly the same species. EXPLANATION OF TEE PLATES. Plate XXXIX. Fig. 1. Cliondrostethus Wooilfordi, Kirb., J". (Head, fig. 1 a. 2. Ditto, ? . (Head, fig. 2 m.) 3. Bacteria Trophimus, Westw., (J. (Head, fig. 3«.) . 4. Ditto, ^ . (Head, fig. 4a.) Page 455 463 Plate XL. Fig. 1. Hermor/enes Hosei, Kli'b., ? . (Head, fig. 1 «.) 2. Phasgonia Evere/ti, Kirb., ? . (Terminal segments, fig. 2 a.) 3. Ischnopoda PhiUipsi, Kirb., ? . (Head, fig. 3 «.) .... 4. Promachus sordidus, Kirh. (Head, fig. 4 a.) 5. Cmdonia spinosissima, Kirb. (Terminal segments, fig. 5 «.) 457 4G1 467 463 464 SECOND SERIES.^ — ZOOLOGY, VOL. YI. 64 Kirby. Trans. LiNiT Soc.Zool.Ser.2.Vol.VI.P1.39. FH Michael. ad nat ael el hth West,Ne\Tiiiai"i imp NEW AND RARE PHASMIDjE, Trans Linn. Soc, Zool. Ser. 2 VolVI- PI. 40. FHMichael,aiinat dd etlitli West.Newnian iml P NEW AND RARE PHASMID^ LINNEAN SOCIETY OF LONDON. MEMORANDA CONCERNING TRANSACTIONS. The First Series of the Transactions, containing both Botanical and Zoological contributions, has been completed iu 30 Vols., and a few entire sets are still for sale. Only certain single volumes, or parts to complete sets, may be obtained at the original prices. The price of the Index to Vols. 1-25 is 8s. to the public, and 6s. to Fellows ; to Vols. 26-30, 4s. to the public, and 3s. to Fellows. The Second Series of the Transactions is divided into Zoological and Botanical sections. The prices of the Zoological parts of these which have been published are as undermentioned (for the Botanical parts see Botanical wrapper) : — When Price to the Volume. Published. Public. £ s. d. Second Seeies. — Zoologt. I. Part I. 1875 1 4 0 . Part II. 1875 0 6 0 . Part III. 1876 1 8 0 . Part IV. 1877 0 16 0 . Part V. 1877 0 18 0 . Part VI. 1877 1 2 0 . Part VII. 1878 1 16 0 . Part VIII. 1879 1 0 0 . II. Part I. 1879 1 4 0 . Part II. 1881 0 15 0 . Part III. 1882 1 8 0 . Part IV. 1882 0 7 6 .. 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The Internal Anatomy of Bdella. £y A. D. Michael, V.P.L.S., F.Z.S., F.B.3I.S. (Plates 41-43.) Head lOth April 1896. Contents. Introductory Observations. Modes of Investigation 477 Species used 478 Position, Characters, and Subdivision of the Bdelliuaj .... 479 Food of the Bdellinfe 480 Former Eesearches 480 The Trophi and Mouth-organs. Maxillary Lip and Exoskeleton of Rostrum. 482 Palpi 483 Mandibles 483 Epipharynx 483 Lingua 484 The Alimentary Canal and Excretory Organ. Pharynx 485 (Esophagus and Sucking-stomach 487 Ventriculus 489 Excretory Organ 489 The Salivary Glands. General 492 Tubular Gland 493 Main common Duct 493 Eeniform Gland 494 Anterior Gland 494 Pericibal Gland 495 Azygous Gland 496 The Brain and Nervous System. The Brain 497 The Nerves 499 The Eyes 503 Page The Eeproductive System. The Male. General 503 Testes 504 Embedding-sacs 505 Testicular Bridge 506 Mucous Glands 507 Glandular Antechambers 508 Penial Canal 509 Azygous Accessory Gland 511 Laminated Gland 512 Air-chambers 513 External Labia 514 Spermatozoa 514 Course of the Spermatozoa to the Exterior and Functions of Organs 515 The Female. General 516 Ovary 516 Oviduct 517 Eeceptaculum aeminis 518 External Labia 518 The Eespiratory Organs 518 The Dermal Glands 519 The Endosternite 519 The Musculature 52i) The External Cuticle 522 Bibliography 523 Explanation of the Plates 524 Intkoductoky Observations. J. HIS paper contains the results of work extending over a period of more than three years, and involving the careful dissection of several hundred specimens, besides the preparation and study of numerous serial sections cut in all directions — i. e., sagittal, hori- zontal, and transverse. The dissections have been made partly on sj)ecimens freshly killed , SECOND SERIES. — ZOOLOGY, VOL. VI. 65 478 MR. A. D. MICHAEL ON THE either with boiling water or chloroform; but a large number also have been made on individuals hardened in alcohol and other hardening reagents : this is advantageous for some organs, but usually in Acari I prefer the fresh specimens. The dissections have mostly been stained on the slide with borax-carmine or picro-carmine. The sections have been made from specimens killed with hot water, fixed with picro-sulphuric acid or Flemming's fluid, stained on the slide with ha^matoxylin (Ehrlich's), and mounted in balsam. I may say that Flemming's fluid appears to give somewhat the best results when it penetrates, but that its penetrating power is so inferior to picro-sulphuric acid in the case of Acari that a considerable number of specimens are lost when that reagent is employed. Whereas j)icro-sulphuric acid can be relied on to penetrate such Acari as Bdella with sufficient rapidity it is probably best to use it, although the results will not be quite equal to really good Flemming's fluid-hardened specimens. Other reagents which I have tried have not, I think, produced an equally satisfactory fixing of the histological condition. The species which I have used has been chiefly Bdella. Basteri (Johnston, 7 *), because, through the kindness of Professor Herdman and the officers of the Biological Station (at Port Erin, Isle of Man) of the Liverpool Marine Biological Committee, I have received supplies of large numbers of this species at frequent intervals and at various seasons; these have enabled me to pursue the enquiry in a manner which I could not otherwise have done ; and I beg to tender my best thanks for the assistance. I was anxious to obtain this species because it is, in my judgment, the best suited for research of those that I know, being large (for a Bdella) — its total length isa bout 2-5 to 3 mm., and being also very strong and vigorous, with the parts well developed. I have also used Bdella vulgaris, B. capillata (Kramer), and some others, but could not obtain them in equal numbers or with equal certainty. Wherever in the following paper an organ or structure is mentioned without the species of Bdella being named, it belongs to B. Basteri. I have adopted the name of B. Basteri for the species because there is no doubt that it is the creature described by Johnston under that title in 1847, while it is quite uncertain whether it is the species referred to by any earlier writer. Thus it has been supposed that B. Basteri is the same species which is called Acariis longicornis by LinnjEus is his ' Fauna Suecica,' but this is very doubtful. I hardly see how the opinion is arrived at. Moreover Andrew Murray f considered that Linngeus has described a different species under the same name in the ' Systema Naturae,' and that this latter is the species to which the name is now generally applied. Bdella sanguinea, Trouessart, 1894 (21), wliich that author, following Andrew Murray, places in a subgenus Molgus (Dujardin), is, I think, a synonym ; indeed, Trouessart himself calls attention to the probability of its being so, but was not able to obtain Johnston's original paper. Trouessart does not describe the hairs on the mandibles, which are important according to Kramer's tables of the genus, therefore I * This figure, and all similar figures throughout the jjaper, refer to the list of authorities quoted (Bibliography) page 523. t 'Economic Entomology: Aptera' (London, 1876), p. 143. INTEEXAL ANATOMY OF BDELLA. 479 should not like to speak with absolute certainty ; but the palpus of his species is similar to that of B. Bastei'i (as I found it), and is not similar to the paljms of any other Bdella which I know of. Bdella tnarinu, Packard *, is probably also the same species. . Enpalus smiguineus, Trouessartf, is also a synonym (according to the author himself). Bdella villosa, Kramer and Neuman J, is either the same species or a very closely allied one ; but in the figure the fifth joint of the palpus is drawn a trifle shorter than the second, whereas in B. Basteri the second is a trifle shorter than the fifth; and the spines at the end of the fifth joint are drawn rather longer than those at the side, whereas in B. Basteri they are about equal in length : these, however, arc small points, and the probability that the creatures are identical is increased by the fact that Trouessart received some of his specimens of B. Basteri {sanguinea) from Iceland, and these had the fifth joint of the palj)us rather shorter than, in the French specimens, so that it seems probable that B. villosa is at most a local variety. I think there is very little doubt that Bdella arctica, Thorell, 1871§, is the same species, although here again the fifth joint of the palpus is said to be slightly shorter than the second. Bdella lapidaria, Kramer, 1881 (i 2. p. 28, Taf. 4. figs. 9, 9 «, 9 b,), and Bdella vulgaris, var. littoralis, Mouiez, 1890 (15), arc both sea-shore species, but they ai*e not identical with B. Basteri ; Trouessart suggests that they are probably both the same species. I am also greatly indebted to Mr. M. J. Michael, of the Davos Platz, Switzerland, who has cut the sections which I have used for the present study, and has otherwise assisted me. The Bdellinse are usually considered to be a subfamily of the Trombidiidse ; they are a very aberrant subfamily, and are raised into a family by such acarologists as Canestrini (3), Berlese ||, &c., who elevate the old family of the Trombidiidye iato an order under the name of " Prostigmata '' (Kramer), Trouessart (20) considers the Prostigmata to be a suborder, separates the Bdellinae from the Trombidiidte, but unites them with the Eupodinaj to form a family "Bdellidie"; his subfamily " Bdellinye," however, contains the same two genera for which I vise the term in this paper, but it also contains one other, Qrijptognathns (Kramer), which appears to me to be too different to be included. The two genera which I include in the Bdellinae are Bdella (LatreiUe, 1797) and Ammonia (Koch, 1842), distinguished according to Canestrini (2. p. 181), following Kramer's subdivision of the genus Bdella, by the long rostrum and long mandibles with very small chelae of Bdella, compared with the shorter rostrum and mandibles and comparatively substantial chelse of Ammonia; but distinguished according to Bevlese (1) by the second and third joints of the palpus being more or less fused, and by the presence of a fifth median eye and the absence of hairs between the claws in * ' The American Naturalist,' 1S84, pp. 827, 828, iig. 2. t Comptes lleudus de FAcad. d. Sci. 1S8S, t. cvii. jjp. 753, 755. + "Acariden wahrend dcr Vega-Expedition eiugesammelt," Yega-Expeditioneus Yetonskapliga Arbeteii, Bd. iii. p. 525, Tail. 41. § " Om Araelinider Mu Spetsbergen och Becren-Eiland," CEfversigt K. Yet.-Akad. Forhaudlg. 187 1, Stockholm, p. 698. li "Acarorum systematis Specimen,'" Boll. Soc. Entom. Ital. 1885, pp. 121-125. 65* 480 ME. A. D. MICHAEL OX THE Ammonia, compared with the five distinct palpal joints, foiir eyes, and hairy claws pulvilli) of Bclella. The anatomy in this paper is of the genus Bdella only ; I have not had the opportunity of studying that of Ammonia. The Bdellinse are sharply distinguished from all other Acari by their antenniform, non- raptorial palpi, ending in hairs. Karpelles (8), working upon Bdella arenaria, Kramer, which is supposed to he identical vdth Bdella vulgaris ^Hermann), states that the Bdellinse are exclusively (" ausschliesslich ") vegetable-feeders, and that the remains of mosses are found in their alimentary canal ; he also states that certain black matter often found in their canal is earth. I regret to say that I entirely disagree with him ; in my opinion all Bdellinse which I have studied have been predatory, living entirely by sucking the juices of other small creatures, principally Thysanuridae, which they capture with their mandibles. Bdella Basteri lives in chinks in the rocks of the sea-coast, and emerges when the tide goes down ; often at those times it is abundant upon the decaying seaweed, feeding on the Thysanurida? which swarm there. Trouessart, in his classification of the Acarina (20), says that the Bdellinse are " terrestrial Acari feeding upon living prey " ; and this eminent acarologist informed me by letter that he found that they lived greatly upon Thysanuridse, an opinion which he formed quite independently of my own, and mthout knowing that I took the same view ; and he states that Poduridse are the food of B. Basteri {sangidnea) in his paper on that species (21. p. 125). It may also be remembered that the name " Bdella " is a pure Greek word, signifying a leech, so that it is tolerably evident what Latreille's opinion was. Pinally, the trophi, and indeed the alimentary canal also, appear to me to be characteristic of a predatory animal living by suction and not of a vegetable-feeder. Karpelles himself says that the matter j)assed by the anus (as to which organ see below, p. 490) is liquid, and that he never found excrement balls, which scarcely seems quite consonant with his view that the vascular bundles of plants are found in the canal. The internal anatomy of Bdella may practically be considered an almost, if not wholly, new subject. The external anatomy and the trophi are described by Kramer (11); his descriptions, although not very full, are in my ojiinion almost always correct, so far as they go : therefore in this paper T have not referred to the external anatomy, except very shortly in one or two instances, where it seemed necessary in order not to break the continuity of study of organs which terminate at the exterior of the creature. The only paper which I am aware of that touches on the internal anatomy of Bdella is that by Karpelles (now Karell) before referred to (8). It is very slight indeed*. In the first place, Karpelles did not find the male, and therefore does not say anything about the male genital organs ; but it happens that it is in this set of organs that the greater part of the most sti'iking variations which distinguish the internal anatomy of Bdella from that of all other Acari which I know of exist. In the next place, unless Bdella arenaria (if really different from B. vulgaris) be very different from every Bdella * The whole nervous system and sense-organs occupy only about 20 lines, the respiratory organs about 4 lines, &c. INTEEXAL ANATOMY OF BDELLA. 481 which I have examined, I regret to say that I find myself unable to agree with Karpelles as to several of the descriptions which he gives: tliese divergences of opinion will be found detailed under the headings of the various organs as I come to them ; but there is one matter which it is best to deal with here, as no such organ as that described and flgvired by Karpelles will be found in my description. Karpelles shows an elaborate endoskeleton in the abdomen, composed of numerous large and strong chitinous rings and quadrangular frames pressed against or joined to each other, forming a very strong and conspicuous apparatus. I can only say that I have dissected and sectioned and carefully examined several hundred Bdclhe of various species and both sexes and of various ages, but I never saw a trace of such an organ, nor have I ever found anything of the kind in any Acarid ; but I have frequently seen, both in Bdella and other families, in sections of the adult female the exact appearance which Karpelles figures and describes; but in every case within my experience it has arisen in the following manner:— When the eggs are ripe in the body of the female they are often very large, and are in many genera, Bdella amongst others, provided with a strongly chitinized chorion : in preparing specimens for section-cixtting it is extremely difficult to get the paraffin or other embedding material to penetrate this chorion, it generally will not do so ; the chorion, however, although chitinized, is not so extremely brittle as, for instance, the exoskeleton of the Oribatidaj, and the razor cues it, forming rings and square frames of chitin, whicl), as the abdomen in females with mature eggs is generally full of them, press against each other and are fixed in the paraffin ; but the yolk and other contents of the eggs, not being reached by the paraffin and therefore not being fixed, drop out unless special precautions are taken to prevent it, when the precise appearance of Karpelles' figure arises : but such special precautions can l)e taken, and if they be the yolk- spherules are found filling the ring ; moreover, if the creature is dissected instead of sectioned the eggs are, of course, found whole. I hardly like to suggest that Karpelles may possibly have fallen into this error ; but the mistake is really an easy one to make in a case like his : where no male has been found to act as a check it is the more likely to have occiun-ed, so the paper referred to is, as far as I know, Karpelles' first anatomical paper upon the Acarina, and therefore he may not have experienced this difficulty before. If this be not the explanation, I am wholly unable to account for his figure and description of this supposed endoskeleton. One other publication must be noticed as giving some little information regarding the internal anatomy of Bdella. In Berlese's great work on the Italian Acari (r), which is still publishing in fasciculi, the author, when he has finished "a group, writes an introduction in which he gives type-plates of the respective families or subfamilies. In his introduction to his order Prostigmata (Trombidiidte), Professor Berlese gives two drawings of the rostrum and one or two adjoining parts of Bdella longirostris ; these appear to be drawn chiefly from sections, althougli it is not so stated ; he does not say a word about the internal anatomy in his letterpress, but he provides an explanation of the plates, which gives the names of such internal parts as he draws. Although the above are aU the writings wliich I know of on the internal anatomy of Bdella, yet as the BdelliniB are part of the great group of Acari which includes the TrombidiidEE, Hydrachuidte, &c., the various works which have beeu published on the 482 ME. A. D. MICHAEL ON THE internal anatomy of other memhers of that group must also he kept in view ; they will he found constantly referred to helow, and it will he seen that although Bdella differs widely from these types, it resemhles them more than it resemhles any other Acari. The principal works on the internal anatomy of these allied creatures ai-e those hy Croneherg (4, 5), Henkin (6), Pagenstecher (17), Schauh (18), and myself (14)- The Trophi and Mouth-okgans. (Eigs. 1, 2, 4., 29, 30, 31, 32.) Maxillary Lip and Exoskeleton of Bostrimi. — The extremely elongated rostrum of Bdella consists of a long, chitinous maxillary lip (fig. 29), very conca^-e iijjward, i. e., it is a half-tuhe with its convex side downward ; toward its proximal end it swells out greatly, hoth laterally and helow^ so as to form a hull) — or perhaps it would he more correct to say a half-hulh, the similar and superposed swelling-out of the mandibles forming the other half-hulh. The edges of this lij), except near the anterior end, curl over inward ; the portion so turning inward is flat, forming a partial roof to the rostrum ; above the bnlhoiis p)ortion of the lip these two flat pieces, one from each side, fuse, forming a perfect roof to that part of the rostrum (fig. 4) ; at its posterior edge this roof is strengthened hy a curved bar of thicker chitin, which in Trombkliiim Heukiu calls the " Chitiuhriicke " ; and about one-fourth of the distance from the bar towards the anterior end there is a longish spinelying flat upon and articulated near the edge of the roof. The anterior end of the maxillary lip is truncated abruptly ; its edge being almost a semi-circle convex downward, or even with the sides pressed together a little ; but the half-moon-shaped space thus left does not remain open to the exterior. Kramer and Karpelles following him draw the anterior edge of the lip as armed with a sei'ies of spines, w'hich are a continuation of the edge of the lip itself (see Ki-amer's fig. 5, c ; Karpelles' fig. 2), and Kramer suggests from this supposed formation that the lip is a piercing-organ. I do not find the arrangement so simple as this in those species which I. have examined : taking B. Basterl as an example, I find that inside the edge on each side, partly within the chitinous lip and partly protruding beyond it, is a very fine and extremely transj)arent membranous flap (fig. 32, iiif) ; on the inner side of this flap is a series of strong hairs or fine spines, all curved inward, especially near their tips. Fig. 32 shows the maxillary lip flatteaed out so as to exhibit these flaps ; but when it is in its natiu-al shape the curvature causes the flaps to stand nearly on edge, and they slope slightly inward so as to touch at their anterior edges, and the curved ends of the hairs cross, thus closing the mouth-opening and excluding dust, &c. (fig. 29), w^hen the lingua is not protruded ; when it is, it forces these flexible flaps apart. This apjiaratus is much more correctly drawn by Berlese (i), see his figs. 3, 4 It, and ^ g ; he calls it sometimes "galea," sometimes "lacinia"; it also has considerable resemblance to Henkin's " reusenformiger Apparat der Mundoffnung " in Trombidimn. From near the edge of the chitinous maxillary lip, on its outer (under) side, spring two chitinous apophyses on each side of the lip ; I'rom each apophysis a strong, curved, tactile hair (tigs. 29, 32, thl) springs, which projects beyond the edge of the membranous flap. INTERNAL ANAT03IY OF BDELLA. 483 Palpi. — To the hind corners of the maxillary lip the well-known " antenniform palpi " of JBclella (fig. 4, P) are jointed, not directly to the hard cliitin of the lip, but by means of the intervention of some flexible cuticle, which doubtless gives greater freedom of motion to these highly mobile organs. The palpi of Bdella differ from the corre- sponding parts in other Acarina, both in their great length and size, and in the position in which they are carried. The length is almost equal to that of the front legs in most species ; and the pi'oportionate length of the joints and the arrangement of the hairs or spines upon them form good and much-utilized specific distinctions. The three proximal joints are usually carried pointing almost perpendicularly upward, while the two terminal joints point almost horizontally forward or a little downward. The Mandibles (figs. 30 md and 31) lie close together upon the roof of the rostrum ; they differ from those of all other Acari, except the Ixodidte and a few isolated species such as Nicoletiella, (Zabidophorus, Kramer), in not being enclosed within the chitinous case of the rostrum, but being quite free and resting on the toji of it ; they are two-jointed chelate organs, the movable joint being placed ventrally, as is usual amongst Acarina. The chelae are extremely small and fine in most species ; and, in such as I have dealt with, simple without teeth. The mandibles are not eaj)able of being retracted into the body, as are those of the Gamasidfe and others ; indeed, the bulbous form of their proximal ends would prevent this ; but the whole rostrum can to some slight extent be with- drawn into the camerostrum. The inner and lower sides of the mandibles are almost flat ; the outer and upper sides curved — in fact one continuous curve forms the two. The shape of the mandibles and distribution of the hairs ujdou them are relied on for specific distinctions, and indeed the form is considered a generic distinction by some a^^thors. Between the two mandibles is a thin low jmrtition (fig. 30, ^;m) like a blade on edge ; this is the " tastcrformiges Organ " of Karpelles : I do not, however, see any evidence of its being of a palpus-like or tactile nature ; I am rather inclined to regard it as a simple partition which separates and guides the mandibles, and prevents their rubbing against each other ; it is not attached to the mandibles. The Epipharynx is an organ of considerable importance and complexity, which appears to have been entirely overlooked by Kramer, Berlese, and Karpelles. It springs from the anterior edge of the propharyngeal plate (figs. 1, 2, p)p), oi") rather, by means of a fold from the membranous sac which encloses the pharyngeal muscles a trifle above the propharyngeal plate ; thiis it projects into the mouth-cavity and overhangs the opening of the pharynx. It consists in B. Basferi of a very elongated, almost triangular piece which ends anteriorly in an extremely fine point; it is about "25 mm. long, and abou.t "07 mm. wide at the base. This central triangle is stiff and lancet-like; it is thickest in the median line, where there is a slight tendency to a longitudinal ridge in the posterior part of the organ ; to this ridge it slopes uji gently from the sides, but the median thickening is not great or conspicuous. The whole of the triangle, except its anterior end, is semiopaque, and is thickly and irregularly dotted with red pigment ; the pointed anterior end is of clear hard chitin. The ducts (fig. 2, dp) from the pedcibal salivary gland discharge on the underside of this triangle close to the hind angles 48'4 • ME. A. D. MICHAEL ON THE Along eiich lateral side of tlae triangle runs a border of clear, hyaline, flexible membrane, whicli falls slightly downward, so that the whole organ forms an inverted trough. From the lowest level of the anterior edge of the propharyngeal plate springs a half moon-shaped membrane (figs. ] , 2, km), which must be regarded as forming part of the epipharynx, although it is lower in level than the triangle ; it is thin, transparent, and highly tiexible ; its upper surface is armed with a large number of spines ; the flexibility causes this organ to hang downward, and thus the upper surface becomes the anterior surface, and the spines at its edge, which are about eleven in number, come in front of the opening of the pharynx, and ai^jmrently serve to stop all solid particles from entering ; such particles may often be seen collected in numbers on the spines. The Lingua (figs. 2, 4, li) is develojoed in a very special manner in Bdella ; it springs from near the lower edge of the pharyngeal opening, just as the epipharynx springs from its upper edge. Where it starts from the opening it is a flat tongue with the edges only slightly curled upward ; this curling upward very shortly increases, so that the two edges meet and fuse, thus forming a membranous tube, which is the nature of the lingua for the greater part of its length ; it is extensile, and can be extruded a considerable distance beyond the mouth-oiiening (fig. i), or it can be wholly withdraw^n into the mouth by invagination, being drawn inward like the finger of a glove. It is slightly enlarged at the distal end, and is capable of motion and flexion in every direction ; it is composed of thick membrane and provided with delicate muscles. From each side of the lingua, near where it springs from the oesophagus, a fine tendinous " tie " (fig. 2, tt) runs upw'ard to tlie base of the epipharynx, and nearly between these two ties a transverse line of minute tooth-like, but not pointed, projections runs across the base of the lingua ; probably the teeth at the edge of the semilunar membrane of the epipharynx meet these projections. This lingua is tJie organ through which the juices of the victims are sucked, the pharynx being the pumping-organ ; in specimens killed w bile feeding, or shortly after, the tubular lingua is often found full of the same food-material as that in the pharynx, sucking-stomach, and oesophagus. Kramer (ii) saw and has figured the lingua extended (his fig. 5, e); he figures and describes two appendages above its base Avhich he calls " wing-shaped," and supposes to be cuticular, but which I have not ever seen. Karpelles also has figiu-ed the lingua ihis fio'S. 2, 4, 7, 8, ce), but he calls it tiie " oesophagus " ; it cannot be considered as part of the oesophagus, because it is anterior to the pharynx and is situated in the mouth- cavity, lying, w^hen retracted, within the trough of the maxillary lip. The Alimentary Canal and Excretory Organ. (Figs. 1, 2, 3, 4, 5, 6, 7, 34, 41, 42, 43.) In the whole of the " Trombidnim " group of Acarina, and also in the Gamasidae and some other families, it is impossible to treat these as separate sets of organs, they are so closelv connected as to form one and must be dealt with together. INTERNAL ANATOMY 01' BUELLA. 485 The mouth-parts have ah'eady been described. The Pharynx is of the usual Acarine type, but exhibits a lew special features; it is well, ill the first place, shortly to state what that type is. The pharynx is the great sucking-organ in all Acari, and in most of those which live by suction, as practically all jjredatory Acari do, but especially in the Trombidium-groui^, the pharynx consists of two chitinous half-tubes, like gutter-pipes, concave upward, the upper fitting closely upon find within the lower. The lower is really the continuation of the maxillary lip and forms the fioor of the pharynx : the upper is the roof of the pharynx ; it is by the movements of this roof that suction is ett'ected. The following is the mechanism : bands of perpendicular muscle arise from the underside of the roof of the rostrum and are inserted on the upperside of the roof of the pharynx, which is raised when they contract : the food rushes into the partial vacuum thus created ; the anterior end is closed by a valve which prevents the food returning to the mouth. Between each band of perpendicular muscles there is a transverse muscle, usually round, running straio"ht across the upper tube I'rom one edge to the other ; when these mtiscles contract the edges are drawn together and the central parts of the vq^per half-tube are driven down upon the lower one, thus forcing the food on into the oesophagus. Even such Acari as can consume solid food, as the Tyroglyphida? and the Oribatidae, usually have the pharynx constructed upon some modification of tliis plan — which, however, is somew hat varied in the case of the Gamasidie and others, but the modifications are more of detail, in the form of the lumen and the conseqttent arrangement of the muscles, than of general principle. In most Acari the muscle-bands are numerous, and the " jierpendicular " ones or levatores are almost perpendicular. In Bdella the first modification of the general arrangement which is observed is that the roof of the pharynx is only slightly chitinized, and is indeed almost membranous ; the result of this is that instead of tlie whole roof rising in response to the action of the perpendicular muscles, each muscle only raises the part into which it is inserted ; the muscles apparently contract in succession from before backward : thus an undulatorv motion is caused, Avhich swiftly carries the food back to the oesoj^hagus ; the anterior perpendicular muscles relaxing, while those posterior to them are contracting, allow the anterior part of the roof of the pharynx to descend ujion the floor, forming the valve, Avhich is differently constructed in other allied families. The next variation from the tisual type is that, instead of the numerous bands of small muscles commonly fotmd in the pharynx of Acarina, Bdella possesses only a few bauds, which are necessarily larger. In Bdella Basteri there are six ^'dk^% of perpen- dicular muscles and six transverse muscle-bands, all considerably larger than in most iamilies. I have preserved the name of perpendicular nuiscles for the '■'levator tectl pharrjngls" or " dlstensor jihari/nffis " muscles (figs. 2, 3, ml^j) because the name has been so frequently used in relation to other families ; but the next variation from the usual type which has to be noticed is that in Bdella, doubtless as the result of the extreme length of the rostrum combined with Ihe small number of pharyngeal muscles, the levator muscles are not really perpendicular : they all arise from the hinder and stronger part of the roof of the SECOND SERIES. — ZOOLOGY, VOL. VI 66 486 MK. A. i). MICHAEL OX THE rostrum ; the posterior pair are an approach to tlie perpendicular aud are sliort ; those that are inserted further forward become successively longer and longer and more and more inclined forward, so that the anterior pair are quite long muscles and almost horizontal. All these muscles are inserted into the roof of the pharynx, either directly or each by means of a single tendon; not by numerous short tendons such as attach the corresponding muscles in Thyas petrophilus. The transverse muscles also vary consideral^ly from the usual type ; indeed it is evident that some modification would be rendered necessary by the mere fact of the roof of the pharynx being membranous, and consequently very flexible, instead of chitinous and only slightly so. The result of this would be that if the transverse (or occlusor) muscles only approximated the lateral edges of the roof or upj)er half-tube, this action would simply crumple it, and would not drive the central part down upon the lower half-tube or floor. This difficulty is obviated by the following arrangement in Bdella : the transverse bands are not round in section, but are broad flat bands ; each band is arched ; the posterior bands are arched upward, while one of the anterior, which is situated where the oesophagus turns sharply downward, is arched forward and seems on edge in the body. Beneath the anterior band there is a thickened plate, or mass, of tendinous material (figs. 1, 2, 5, 34, pp) in the roof of the pharynx, which doubtless enables the muscle to force it doAvn more effectually. Tlie plate is just where the pharynx merges into the mouth, and it is hard to say whether it is to be considered as wholly a part of the pharynx or wholly or 2:)artly a portion of the mouth ; I incline to the former view. I will, in order to distinguish it, call it the " propharyngeal plate." The plate itself is not a mere straight plate of even thickness ; it consists of two portions — a central plate of thick tendinous material, and a thinner border. The thick central plate is much narrower than the base of the epipharynx, and is considerably wider posteriorly than anteriorly ; its sides have a slightly concave outline when seen from above or below ; its thickness vai'ies in different parts, its ventral surface, adjoining the pharynx, being almost straight, while its dorsal surface curves rapidly upward ; thus the thickest part of the plate is almost at its posterior end ; this end is sharply truncated and has a perpendicular wall. Immediately behind this wall the second transverse band of pharyngeal muscles (constrictors) is placed nearly on edge, instead of having its broad side downward like the other muscles of the same series ; like them it is arched but has its concavity forward, thus when it contracts it must force the propharyngeal plate and epipharynx somewhat forward. One fasciculus of distensor (levator) muscles (fig. 5) on each side of the median line is inserted by a very short tendon into the supero- posterior angle of this thick central part of the propharyngeal plate, and another pair on its dorsal surface about a quarter of its length behind the anterior end. The posterior of these tendons may be traced some distance in the substance of the plate. The border is of tissue similar to the central portion, but much thinnei* ; it runs along the sides and rear, but not along the front, where the propliaryngeal plate joins the epipharynx ; it makes the whole plate form an oblong slightly wider than the epipharynx ; the border slopes slightly downward, and the portions of it at the sides of the central plate have a number of diagonal parallel ridges (or folds forming ridges) running backward and inteejSal anatomy of buella. 487 oiihvard horn the central portion. The transverse muscles are inserted at both ends at the level of the tioor of the pharynx; tlrus, when they contract, instead of pulling the lateral edges of the roof of tlie pharynx together they straighten losing their arched lorm, and then press upon the portion of the upper surface of the pharynx lyino> immediately beloAV them respectively, and thereby effectually close it. I have not liitherto detected similar curved constrictor pharyngis muscles in any of the Acarina. T/ie (EsoxjIukjuh follows immediately upon tlie pharynx, and is, as usual, a long and substantial membranous lube m the median line of the body, runnin"- rio-ht through the centre of the brain ; its com-se being backward and slightly upward. There is an indication of its being a little plicated into shallow longitudinal folds to allow of expansion and contraction ; it hardly .stains at all, but certain scattered, very minute nuclei on its exterior surface stain deeply. The folding and certain projections on the inner surface of the oesophagus produce a very irregular lumen (fig. 28) in the o«n«i'4- arduppus),'" Auniv. Men:. Boston Soc. lyat. Hist. 18bi). + Newport, in Todd's ' C'yclopEedia,' article " Insecta,'' tigs. 43(J, 431. 66* 488 MR. A. D. MICHAEL ON THB This organ lias possibly been imperfectly seeu by Karpelles (8) and by Professor Berlese; indeed, it is so conspicuous that no one dealing, even in the roughest manner, with the anatomy of Bdella could help seeing it. In bis great work on tlie Italian Acarina (l), wbich is systematic, not anatomical, Berlese does not say a single word about the internal anatomy of Bdella, but in the introductory portion of liis " Ordo Pro- stigmata " (Trombidiidas) he gives a plate of parts of the striicture of Bdella (chiefly external and the trophi). His fig. 3 is stated to be the rostrum seen from the side, and fig. 4 is stated to be the hypostoma (maxillary lip) seen from below : it is rather a difficult drawing to understand with any certainty, because other organs which lie above the hypostome are shown and there is not anything to indicate that they are seen through the hypostome ; thus the pharynx is drawn, and even the muscles on the dorsal side of the pharynx, although both the hypostome and the pharynx itself must lie between them and the eye of the observer. One of the organs figured, a long way posterior to the hypostome, is a sac, which is, I believe, the sixcking-stomach ; it is lettered "in" and in the explanation of the plate ^' in'" is given as "ingluvies": this is the whole of the information regarding it. Berlese comes tolerably near the function, but he entirely mistakes its anatomy and position in the body ; indeed, his fig. 4 does not agree with his fig. 3 : in the latter the oesophagus only is shown, but in the former the oesophagus, which would lie between the eye of the observer and the sucking- stomach, is not shown at all, and the pharynx is shown as leading straight into the "■ ingluvies," and the hinder portion of the canal as leading directly out of the i^osterior end of the same organ, thus making it a crop forming part of the main line of the canal itself. This is wholly incorrect, unless the species which he has drawn from differs entirely from every Bdella. which I have dissected or sectioned, in all of which the sucking- stomach has been a stalked blind-ended diverticulum of the dorsal side of the oesophagus. Karpelles, if he saw the sucking-stomach at all (8), had previously made practically the same mistake ; indeed he, if I understand his drawng, did a trifle worse, for lie drew tlie sucking-stomach as not only a part of the main tract of the alimentary canal but also as continuous at its i^osterior end with the ventriculus, without any constriction between the two. It is, I believe, now generally admitted that the svicking-stomach, although still called by that name, is not really a sticking-organ, biit is a stalked food-reservoir wherein, in the case of Bdella, the juices which have been sucked out of the creature's prey by the action of the pharynx, whicli is the true sucking-apparatus, are stored for a time The sac in Bdella is usually full, or partly full, and the contents are precisely the same as those found in the pharynx, cesophagus, and ventriculus — viz., the blood of the prey tliat the Bdella has been sucking. In two or three specimens of B. Basteri which were picked oft' seaweed, where they had been feasting upon Thysanuridse, and placed immediately in alcohol, a sagittal median section shows this food-mass in the sucking- stomach coagulated and cibsolutely continuous with a thin rod of the same coagukited material in the mouth, pharynx, and oesophagus, and even joined to tlie food-mass in the ventriculus. I have liitherto used the name of " sucking-stomach " for the organ, as it so well known in the Insecta ; but as it gives an erroneous idea of the function, and as the INTERNAL ANATOMY OF BDELLA. 489 ■word ingluvies is more properly used for a crop ia the direct liae of the caual, I propose the name of " receptaculiuii cihi " for the stalked food-sacs. The remainder of the oesophagus does not appear to require any special notice ; it terminates, as usual, in the ventriculus. The Ventriculus (fig. 6) is greatly flattened dorso-ventrally, forming a shallow layer near the dorsal surface; it is far best studied in young specimens, as in older ones, where the ventriculus is more distended both by the food in the lumen and by that which has been absorbed by the cells which form the walls of the organ, and where the genital organs are fully developed, the ventriculus is forced into every availalole space and its true foi*m is difficult to follow : this difficulty, however, does not exist in the younger creatures. Fig. 6 is drawn from a female of B. Basteri, matu.re but only lately emerged from the nymphal skin. It will be seen fx'om this drawing that the ventriculus consists of a short, more or less elliptical sac with a slight median projection forward, and having from its antero-lateral edge two rather short, paired caecal diverticula directed forward, and from its postero-lateral margin two broad and long paired caeca directed backward. These last-named caeca have the inner edge simple and almost straight ; but the outer edge is divided into rounded lobes, w^hich diminish in size from liefore backward — /. e. the anterior lobe is much the largest and the posterior mucli the smallest. Thus the whole organ forms a sort of irregular, comi^ressed, and elongated horse-shoe. The histology of the ventriculus is, as might be expected, very similar to that described by Heukin in Trombidmm fuUginosum ; of course there are some differences. The exterior of the organ is a fine tunica propria, so delicate that it is usually impossible to dissect the ventriculus out without breaking it ; on the inner side of this tunic is a single row of large columnar epithelial cells with small oval nuclei, about 8/i in diameter, very clearly nucleolated, placed near the exterior ends of the cells. The cells themselves vary greatly in form and size in difl'erent parts of the ventriculus, and of course in diffei'ent individuals ; the cells on the dorsal side of the ventriculus usually average longer than tliose on the ventral side. In an adult weU-fed male specimen of B. Basteri the cells are ordinarily from about "0 J. mm. to abou.t "12 mm., in the female they are even longer. The exterior portion of the cell is filled with fine reticular protoplasm ; the interior part, next the lumen, is generally crowded with food-droplets, precisely similar to the contents of the sucking-stomach ; this is even more marked in the female than the male, liut in both sexes the inner portions of the cells are usually almost full of them. Digestion appears to be iutra-cellular : no food-ball or mass, and indeed very little food, is usually found in the lumen of the viscus, unless tlie creature has been killed almost when feeding ; it is all in the cells. The process described by Hcnkin, that the inner ends of some of the cells get more or less filled with a granular dark material, and then are constricted ott* and fall into the lumen of tlie viscus, occurs also in Bdella, but apparently much less frequently and to a much smaller degree than in Henkin's Acarvs. Excretory Organ. — We now come to the subject of the hind-gut, h\xi in all the Trombidiuiu-grou]) of Acari it is impossible to treat this separately from the excretory organ ; the two are either identical or so intimately connected as to render it necessary 490 ME. A. D. MICHAEL ON THE to describe botli together. lu my late paper on Tlnjas petroph'dus (14), which is frequently referred to in this treatise. I have entered so fully into the history of wliat former authors have said upon this point that I do not think it would he proper tO' repeat it all here, and will only give such a short statement of it as is necessary in order that what I have to say about Bdella may be easily understood. Croneberg (4) describes the ventriculus of Ei/lais extendens (Hydrachnidije) and of Trombid'mm (5) as a viscus closed posteriorly and not connected with any anus ; he says that there is not any passage for ftecal matter or solid remains of food out of the ventriculus, and that the anus-like opening, which certainly exists, only gives exit to the excreta of the Malpighian vessels and does not communicate with the alimentary canal. This opinion of the extremely careful Kussian anatomist was in direct opposition to the previously expressed oj)inion of Pagensteclier (17) relative to Tromhidimn; he considered the opening to be the anus, and what Croneberg calls the " Malpighian vessel " to be the rectum and to be in communication with the mid-gut in the ordinary manner. Henkin, in his researches into the anatomy of Trombidimn fuUginostiin (6), failed to find any communication between the ventriculus and hind-gut or Malpighian vessel, whichever it should be called, but he thought that there must be one, although he could not see it; he says that where the Malpighian vessel of Croneberg overlies the A-entriculus the walls of the latter organ become vague, and that he should think there must be a communication tliere, although he could not find it. Next came Schaub : speaking about Hydrodroma (Hydrachnidis) (18), he agrees with Croneberg that the anus-like opening is not an anus, and that it is only the point of discharge of the Malpighian vessel, which does not communicate with the ventriculus or any part of the alimentary canal ; but he says that just anterior to the so-called anus there is a much smaller opening, which is the real anus; and he says that to this smaller opening a distinct hind-gut passes from the ventriculus, with which it is in communication. There is no doubt that this smaller opening exists in Sydi'odroma, and Haller* had seen and figured it before Schaub did. Haller simply calls it a preanal opening, without suggesting its function. No one has seen this smaller opening in any creature of the Tro7nliid'mm-gYo\n[) except Hydrodroma, and no one except Schaub has ever recorded seeing this hind-gut distinct from the Malpighian vessel. A year later Schaub published a paper (19) on Pontarachna (Hydrachnidse) : there he only figures a single opening, which he calls the " anus," precisely as previous writers had done in other members of the group ; he does not say whether it is the exit of the Malpighian vessel, or of the hind-gut, or of both; nor whether there is a hind-gut distinct from the excretory organs or not. Karpelles (8) ignores all previous autliors and treats the excretory organ of Bdella arenaria confidently as the rectum, but says that he never could find any food-ball in it. In Thy as petroph'dus (Hydrachnidse) (14) I certainly observed but one opening, and that decidedly communicated with the excretory organ (Malpighian vessel) and * "Die Aiteii unci Gattungeii der schweizcr HjdracLnidenfaune," Mittheil. Schweizer. entom. Gosellseli. ISbl', p. 18. INTERNAL ANATOMY .OF. BUELLA. 491 with that only; there clearly was not any separate hiad-g'ut. I was not able to trace any commLinication between the Malpighian vessel aad the ventricuUis, although I took great pains in searching for it in numerous specimens, still I do not deny the possibility of its existing at some time of year or at some period of life ; all I say is, that I could not find it, and that the walls both of the ventriculas and of the excretory organ appeared to me to be perfectly clear, without any vague places, in those specimens whicli I examined. Bdella would not be at all a favoural)le genus in which to investigate this question ; the walls of the ventriculus and excretory ox'gan are not so firm and sub- stantial as in Tlnjas, and in mature specimens the latter is so enveloped by the former as to make the exact relations of the two difl&cult to trace. I should not therefore base any opinion on the subject upon Bdella ; but, so far as it goes, I was not able to trace any communication between the ventriculus and the excretory organ in this creature any more than I could in Thjas ; still it is possible that such a communication might exist and be extremely difficult to see. It is quite certain that neither any second opening, such as that of Hydrodroma, nor any separate hind-gut, sucli as Schaub describes in that Hydraclinid, exists in any species of Bdella which I have investigated : it is equally certain that I have never found any trace of food-material or faecal matter in the excretory organ of any Bdella ; the contents have invariably been solely the white crystalline matter (appearing black by transmitted light on account of its opacity) which one usually finds in the so-called Malpighian vessels of Acarina. In considering the question of whether the mid-gut ends l^lindly or communicates witli a hind-gut and anus, it must not be forgotten that the creatures of this group are almost all strictly predatory and suctorial ; they never consu.me any solid food, but live entirely upon the juices of their victims ; this applies to Bdella. Were it not for Schaub's paper on Ihjdrodroma I should consider that the so-called Malpighian vessel in Bdella and other allied creatures was the homologue of the hind- gut in other Acari, and from disuse had become a Malpighian organ only ; but of course, if Hijdrodroma really has a hind-gut in addition to a similar Malpighian vessel, it would seem to prove that in all other investigated creatures of the Trotnbklmm-gron'p the hind- gut must have become obsolete, and vanished without leaving a trace of its former existence. In Bdella the excretory organ, whether it be the liomologue of the hind-gut or not, is exceedingly simple : it is an elongated sac (figs. 31<, E & 7), rather widest at the anus, or what is usually called the " anus," narrowest about the middle, and swelling out again somewhat at the anterior end. The organ is distensible, but is neither branched, folded, nor plicated; it is capable of considerable expansion and contraction; it runs along the median line of the body close to the dorsal surface, through the cuticle of which it generally shows as a strong white band ; its anterior end is usually about in the perpendicular plane of the coxa3 of the second pair of legs, i. e., pei-pendicularly above the hinder part of the sub-oesophageal portion of the brain ; it varies somewhat in length, and it immediately underlies the dorsal skin as far back as the genital aperture, then it turns somewhat downward to reach the anus, which, however, is subterminal. In young males its coiu-se may be plainly seen passing between the two great hind caeca of the 492 ME. A, D. MICHAEL ON THE ventri cuius, but separate from them. In mature specimens, especially females, in consequence of the great growth of the ventriculus and caeca and the distension of the cells composing their walls by the absorption of food-material, and partly also in consequence of the pressure of the immense genital organs, the ventirculus and caeca are forced into every available space, and tlie caeca are pressed against each other in the median line of the dorsum ; thus the excretory organ comes to be entirely surrounded by the ventriculus and its ctcca, and seems as if it passed through their substance (see figs. 34, 43). The walls of the Malpighian vessel consist of a strong, clearly marked external layer of more or less hexagonal pavement-epithelium cells, with conspicuous oval nuclei of about 5 ft to 10^, and nucleoli ; they are often doubly nucleated ; within this epithelium is a layer of almost cubical secreting cells. The contents of the Malpighian vessel in Bdella are small, crystalline, opaque, white, more or less globiilar concretions of urinary material, similar to that found in the Malpighian organs of other Acari ; in Bdella, however, they seem, in oldish specimens, to accumulate to such an extent that they adhere together and often form a solid rod almost filling the organ. This white matter usually shows through the dorsal cuticle, and often looks, at first sight, like a wliite, or pale yellow, stripe running longitudinally in the median line of the notogaster ; the rod when formed may sometimes be dissected out and remain quite unbroken and hard. In other specimens the granules do not adhere, but, although scattered, nearly fill the vessels ; in some cases, particularly where the sj)ecimen is young, the quantity of white matter is small. The anus (fig. 34, A), if that be its proper name, is a longitudinal slit near the hinder end of the creature, and is closed by two labia (cf. fig. 7), to which divaricator muscles (fig. 34, mda) are attached. The Salivary Glands (so-called). (Figs. 8, 9, 10, 11, 12, 34.) I retain the expression " salivary glands," because it has been used by so many authors, and is perfectly well understood as referring to tlie group of glands which I am about to treat of in this section : I have, however, in my paper on Thijas petrophilus (14) beibre referred to, expressed considerable doubts whether this important and varied series of glands really have solely the function which is implied by the name ; there does not seem to be any very convincing mode of settling this question, and I hardly see how to carry it further than can be gathered from the probabilities involved in the position of the points where their ducts discharge. In the same paper I have entered fully into what previous authors who have dealt Avith these glands in Acarina belonging to the Trombidium-gvou-p of families have said regarding them ; as in the case of other organs for Avhich I have done the same, I do not propose to repeat the whole bibliography here, bu^t rather to confine myself to the description of the parts in Bdella, referring only to former authors where it seems likely to give greater clearness or to assist in settling doubtful questions. INTERNAL ANATOMY OF BDELLA. 493 The general nature of tlie glands and their arrangement will be found, as might be anticipated, to correspond to a great extent with those of the Trombidiidaj and Hydrachnidie, but the diflerences are considerable. In Bdella this system of glands may be said to be divided into three groups ; of these there are two grouj^s of paired glands and one single azygous gland. The general arrangement of these glands and ducts will probably be best understood from the drawing (fig. 8) ; it must, however, be stated that this is a diagram in the sense that (to save space) it is not drawn quite to scale, although kept as near nature as possible. Group 1 consists, on each side of the body, of three glands, which viltimately discharge by one common duct (D), each gland and duct being paired by its fellow on the opposite side of the body. The exact shapes of the respective glands vary a good deal in different individuals, and probably in the same individual at different periods. One of these glands is placed at the posterior end of the main common duct, and is in position a con- tinuation of the duct ; this gland is what is known as the " tnhnlar salioary glantV {sfft) i n Tromhidium, the Hydrachuidae, and other forms. It is far simpler than the corresjjonding structiu-e in Thyas j^etrophilus, and in B. Basterl consists of a tubular or sausage-shaped gland having a diameter of from about "03 mm. to al)out '00 mm. and a less varying lumen of about 015 to "02 mm. It has thick fleshy walls composed of moderate-sized cells with small clear nuclei. The lumen of this gland is extremely small, but perfectly distinct. The point where the duct emerges from the gland is between tiie first and second legs, usually about halfway or rather nearer the first leg ; thence the gland runs almost straight backward near the side of the body ; this course is continued for more than half tlie length of the gland, then it curves sharply inward, and the curve is continued so as to Ibrm an approach to a semi-circle ; thence the gland runs forward again parallel to its former course, but nearer to the median line of the body ; it does not, hoAvever, reach anything like as far forward as the proximal end from which the duct starts. Einally, the gland once more turns backward and again runs parallel to its lormer coiuse, so that the whole gland is more or less S-shaped. The distal end is csecal and rounded ; from it and also from the first bend fine ligaments run to the side of the body ; that from the first bend, whicli is the strongest, runs to the cuticle near to the inner edge of the acetabulum of the first leg ; this to some extent resembles the arrangement described by Schaub in llijdrodroma (i8. his p. 123 and fig. 4) ; the ligaments at and near the distal end of the gland run to the cuticle further back in the body. In Bdella Basteri this gland bears a short caecum {ca's). The whole gland in Bdella is quite simple, without any of the corrugations found in 1 ht/as jjetmphilus din^i othev forms, and without the terminal bladder or reservoir found in that species. The Main Common Duct (D) starts from the anterior end of the tubular salivary gland {s(jt), and runs attached to, and during a large part of its course partly imbedded in, the cuticle of the side of the body. Although so vmited to the cuticle and so sunk in it, the duct does not really form part of it ; on the contrary, the greater part of the duct may occasionally, by careful dissection, be detached from the skin. The duct is substantial in the thickness of its waU, and usually preserves its round form in sections — i. e., it does not collapse : it generally shows more or less of a ringed structure ; often it is very SECOND SEllIES.— ZOOLOGY, VOL. VI. 67 494 MR. A. D. MICHAEL ON THE plainly i-inged : this feature is frequently found in tlie principal ducts of the Acarina, in which order a ringed tube is more likely to be a duct thau a trachea. The course of the main common duct is as follows : starting from the tubular gland it runs forward a little, and then curves round the outer side of the acetabulum of the first leg ; it then runs forward along the shoulder of the creature, usually in a some- what undulating line, but on the whole tending slightly inward, until it enters the rostrum and apj)roaches very near to the palpus ; it then turns suddenly inward toward the median line, and runs across the upj)er surface of the chitinoiis roof upon which the mandibles rest, passing beneath the proximal ends of the mandibles ; on reaching nearly to the median line the duct turns slightly forward, joins its fellow from the other side of the body, and the two together discharge into a membranous space upon the chitinous roof and between the mandibles near their proximal ends. The Henifonn Gland. — A short distance anterior to the acetabulum of the first leg the common duct receives the special duct (fig. 9, dr) from a very large gland (tigs. 8, sgr); this duct is small and fine, does not show any ringed structure, and enters the upper surface of the common duct. The ghrnd which discharges by this small duct is one of the largest in the creature ; it is clearly the homologue of the " reniform salivary gland " in Thyas ■petropMlus, and of Schaub's " larger dorsal mouth-gland " in SyJrodroma. Pagenstecher, in TromJddium, and Guddon*, in Tyroglyphns, have also figured homologous glands, but without specially naming them. I liave retained the name " reniform gland," but the gland in Bdella (fig. 9) is somewhat different in form from any of those hitherto described : it cannot be called reniform ; it varies somewhat in shape, but is usually irre- gular, approaching an oval, and is flattened, its thickness not averaging above a third of its breadth ; it is placed on edge in the body, which is not the case with any of the other recorded homologous glands, and has the more pointed end forward ; its inner surface is nearly flat, but the outer surface is more convex ; probably adapting itself some- what to the form of the side of the body. This gland stains only slightly with hsematoxylin or carmine : it is composed of extremely large, almost gigantic, cells radiating from a centre ; these cells have an extreme length varying from about "15 mm. to over '2 mm., and an exti-eme width of about half those measurements, and have large, clear, elliptical nuclei of about "03 mm., somewhat regularly arranged, with very distinct nucleoli of about "015 mm. This gland always contains a chamber more or less wedge-shaped {cv) on its outer edge ; this chamber is apparently one of the cells broken down and transformed, for it often contains a nucleus, but it is usually filled with dark- coloured and highly-refractive granules, measuring from i ^ to 7 /i ; it communicates with a small central pocket, from which the duct starts. Sometimes this wedge-shajied chamber appears to invade and absorb the adjoining cells, and then becomes very large. The anterior Salivary Gland. — Just before entering the rostrum the upper surface of the common duct receives another special duct (fig. 8), which is much shorter and still finer than that from the " reniform gland " : the gland {sga) from which this duct leads will be the homologue of the " quadrate salivary gland '' in Thyas petrophilus, and of * " Beitrag zur Lehre von dcr Scabies," Wiirzburgcr medicinische Zeitsch. 1861, p. 801 ; and "Zweite vermehrte Auflage," AViirzburg, 18C3. INTEENAL ANATOMY OP BDELLA. 49.5, Scbaub's " smaller dorsal mouth-gland " iu Eydrodroma, if the place where the duct discharges, and the cunuectiou of that duct Ije, as usual, taken as dcteriuiniug the homo- logies ; but as it may be possible that this giaud is more to be regarded as the homolo'>'uo of the small gland which discharges by the duct " c/i^' in Tliyas petrophilus (fig. 10 ia my paper, 14), I have thought it best not to use the name " quadrate salivary eland" lor the gland in question: for the sake of clearness I shall call it the "anterior salivary giaud " in this paper. It is a rather small, rounded, or heart-shaped gland ]yin<» in the anterior corner of the dorsal vertex, and its posterior side is closely pressed a"-aiust the front end of the reniform gland when the two are in situ ; so that it is very difficult to distinguish this gland from tbe reniform in sections, and, indeed, it can only be done by the thin ttuiica propria which envelops the gland, and Ijy the fact that the anterior salivary gland stains more deeply than the reniform, and has a slightly ditferent histolu- giciil structure, its secretion is a mass of dark-coloured granules. The Fericibal Salloary Glands. — The two other paired salivary ^lands (fio's. 10 and oli sgp) lie one on each side of the receptaculum cibi (sucking-stomachj, and clasp that organ ; they are apparently the " preventricuiai- glands " of Karpelles (8). These glands,, which I will call the pericibal salivary glands *, bear considerable resemblance in "-eneral form and appearance to the reniform gland, against which their outer sides are closely pressed ; like it they stand on edge in the body, and are a flattened oval or almost elliptic ; the outer sides adapt themselves to the form of the inner sides of the reni- form giaud, while their inner sides adapt themselves to the receptaculum cibi (suckino-- stomach); they embrace practically almost the whole sides of that organ except the narrow neck, and by an increase in their thickness they curl over the top of its posterior portion. They are composed of large cells nidiating from a centre and provided with large and distinct roundish nuclei and nucleoli ; the cells, however, are not so lar"-e as those of the reniform gland. The contents of these cells stain deeply with hematoxylin, and then present more the appearance of a network, and less of granulation than those of the reniform gland. In the centre of the gland, where the apices of the cells come together, there is a very minute open sx)ace from which the duct starts. There is a small valve at the commencement of ihe duct of this, and indeed of each of the paired glands except the tubular, formed by the thickening of the walls of the duct, so as to constitute tAvo labia pressed against each other. The duct itself is long and fine ; in well-preserved specimens it exhibits a slightly ringed structure of its inner coat ; it passes along the side of the receptaculum cibi (sucking-stomach) in an almost straight Une, goes just below the chitinous bridge and chitinous roof, and discharges by a small opening just at the proximal corner of the epipharynx (tig. 2, dpj). From the position of the mouth of the duct it would appear probable that this gland is a true salivary gland ; whether those that discharge by the common duct into the space between the mandibles and above the chitinous bridge have the same function must be more doubtful ; it would seem possible that they lubricate the mandibles, but glands of such importance would scarcely be wanted for that purpose only. * I do not use Karpellcs's name of " preventriculur glands," because they are not iiomologous with the "-lands which bear that name in the UribatidiB. 67* 496 MK. A. D. MICHAEL ON THE "Whether tlie pericibal gland of Bdella can be considered as the homologue of any particular gland in Thyas, TromhicUmn, and Hijdrodroma, seems to me to be uncertain : the fact that each pericibal gland of Bdella discharges by its own special duct into a place different from, the point of discharge of the common duct, whereas all those of Thyas and Tromhidium discharge by the common duct, is greatly against such homo- logy ; but, on the other hand, the number of glands is the same in all : if there be any homology it would be between the pei'icibal gland of Bdella, the quadrate salivai'y gland of Thyas, and the smaller dorsal mouth-gland of Sydrodroma ; but this can only be the case if the anterior salivary gland of Bdella be the homologue of the small gland to which the duct " dsa " leads in Thyas. The Azygous Salivary Oland. — The last of the so-called salivary glands to be described is the azygous (figs. 10 and 34, so, and 12). Whether this gland can be considered to be tlie homologue of the " azygous salivary gland" in Thyas petrophilus, the only species in which an azygous salivary gland has been described, is again a question which admits of differences of opinion : the mere fact that such a gland exists in each would raise a presumption that they were homologous ; but not only has the gland in Bdella an importance immensely in excess of that of the gland in Thyas, but the gland of Thyas is situated in the rostrum, whereas that of Bdella is in the cephalothorax behind the rostrum ; that in Thyas is about the middle (dorso-ventrally) of the rostrum, whereas the gland in Bdella is jiressed against the extreme dorsal surface of the cephalothorax. The duct in Thyas discharges much further forward than that of Bdella ; and, finally, the histology is about as different as that of two glands can well be ; the gland in Thyas having a minute structure very like that of the tubular salivary glands of Bdella, while the gland in Bdella is a solid, but not fleshy, organ, with a very small irregular lumen, or sometimes without any distinct lumen, from the fact that its sides may become pressed together, and composed of largish columnar cells, which have the ends which come to the exterior of the organ slightly enlarged ; in these enlarged ends are situated the small nuclei, with very distinct and dark-staining, but small, nucleoli (fig. 34j. The cell- contents hardly take stain at all; the cell-walls * do not stain, but yet are very easily seen. In Bdella Basferi the cells have an average length of about "04 to '05 mm., but some near the posterior end are longer, by an average breadth of about 10^ to 12 /«. The nuclei have an average diameter of about 5 /», and the nucleoli of under 2 in. For the same species the cell-contents have the appearance of a very fine network ; whereas in some of the smaller Bdellce, e. g., B. vulgaris, the gland is even more solid and has the appearance of having an almost tendinous consistency (fig. 12). The azygous gland is a very large one ; in B. Basteri it has an average lengtli of about •4 mm. in the male, and of about "5 mm. in the female, with a breadth of about '17 mm., and a thickness of about '15 mm. to '19 mm. in its thickest part. In some of the smaller species it is even larger in proportion. In B. Basteri the exterior of the gland, when * The expression " cell-wall " in this paper is not employed in the restricted sense in which it is used by many modern writers on vegetable liistology, viz. as meaning formed (secreted) material only ; it is used, for want of any other equivalent expression known to me, in a general sense to signify the partition between cell and cell irrespective of how that partition originates or of what it is composed. INTERNAL ANATOMY OF 13DELLA. 497 dissected out, is naturally deep red, which makes it conspicuous. TIic form of the organ varies considerably in difTerent species, and even varies in different specimens of the same species ; but such variations in the one species only involve differences in the proportion of length to breadth, and of the comparative lengths of the anterior and posterior points, and such matters ; the general plan of tlie form is always similar in the same species, so far as I have seen. The shajje, being rather complicated, will be much better understood from the drawings than from descriptions. In Bdella Basteri the ventral surface of tbe organ, wiiich is pressed against the dorsal surface of the rcceptaculum cibi, is almost flat, but cut away from the ventral surface at the anterior end, i. e. the dorsal part of the anterior end overhangs ; the posterior end bends slightly downward ; both anterior and posterior ends are broad pointed projections, Avith convex sides; behind the anterior pi'ojection the gland widens suddenly, and forms a kind of shelf or platform near, but not at, the ventral surface of the gland ; upon this platform, commencing a little way behind its anterior edge, are two large rolls of substance arranged longitudinally, and with their inner sides so closely pressed together that they often practically fuse in the adults ; but in the nymphs they are distinct, and give the gland the appearance of having had a double origin, or at all events that this part of it has been a horseshoe- sliaped structure, which has become pressed together; this horseshoe shape is very apparent in horizontal sections of the gland, even in the adults. These rolls continue for about half the length of the organ ; then rolls and platform, and the rest of the organ, gradually merge and lose their identity, all contributing to form the posterior portion. The duct from this gland is siiort and straight, but is ratber large in diameter and somewhat wrinkled longitudinally, and is evidently capable of expansion ; it springs from the median line of the gland between the anterior ends of the two rolls spoken of above ; in sections it may be traced some way into the substance of the gland. The anterior end of the duct is enlarged, and forms an ovate membranous chamber (fig. 11), which is generally more or less filled with the secretion of the gland. This chamber commences behind the mandibles, but reaches a little between their proximal ends ; there this gland-serving chamber discharges into a space continuous with the air-chamber from which the principal tracheal trunks spring. The secretion found in the glandular chamber is a yellow oily liquid, and in specimens which have been in alcohol a yellow fibrous or crystalline ball may frequently be found in the chamber. The Brain and Nervous System. (Figs. 13, 11, 15, 27, 31.) The so-called brain — i. e., the great central nervous mass — in the Arachidna doubtless represents an oesophageal collar, consisting of a sujira-oesophageal ganglion and a sub- ousophageal ganglion joined together by commissures. In the Acarina, however, the concentration of the ganglia is so extreme, and the commissures are so short and broad, that the distinction of parts is usually almost or entirely lost. Thus, for instance, in the llydrachnidse the brain has usually become one elliptical or almost globular organ, pierced by the passage for the oesophagus, but in which it is very hard to distinguish 498 ME. A. D. MICHAEL ON THE any parts; there is not any sign of commissures, and the fusion between the supi'a- and sub- CESOjihageal ganglia is so intimate that it is impossible to say where one terminates and the other commences. This will be well seen in Schaub's figures and descriptions of the brain of Hydrodroma *, and in my own figures and descriptions of Thyas petrophilus f . It will be seen by Henkin's figure of a section of the brain of TromMdium fuliginosumX that the form tbere is not so globular, notwithstanding the close connection between Tromhidium and the Hydrachnidse ; it will also be seen, by my paper on the brain in Oribatidaj and other forms §, that the spherical form is not usually approached so closely in other families of Acarina as it is in the Hydrachnidce ; still the whole usually forms one mass, which may be irregular in shaj)e, but in which all sharp demarcation of parts is lost. Bdella can hardly be said to form any excej)tion to this rule ; it would scarcely be possible to say where the commissures are ; the supra- and sub-oesoj^hageal ganglia practically join one another ; still the origin from the two separate ganglia is far more clearly shown, and the two are more distinct, than in any other Acarid with which I am acquainted. Taking Bdella Basteri (which is an exceedingly good example) as a type, the sub- oesophageal ganglion (fig. 13, 34, gsu) consists of an almost oblong layer of ganglionic matter having an average length (in the male) of about '4 or '42 mm.,, by an average breadth of about "17 mm. It is much flattened dorso-ventrally, the thickness not being above 08 mm. where it meets the sujora-oesophageal ganglion, diminishing almost to an edge at its posterior end ; it lies almost touching the ventral surface, and extends from a little in front of the first pair of legs anteriorly to about midway between the second and third pairs of legs posteriorly. The supra-oesophageal ganglion {gso) is about % of the length of the sub-oesophageal ; it is situated upon (above), and slightly in advance of, the sub-oesophageal, so that the anterior edge of the former overlaps the anterior edge of the latter. The oesophagus runs between the two ; both, but chiefly the supra-oesoj)hageal ganglion, are excavated to afi"ord it a jiassage ; the sub-oesophageal is thickest, dorso-ventrally, just where it meets the posterior edge of the supra-oesojjhageal, and then thins away toward its own anterior edge, and the under surface of the supra-oesophageal follows and joins it. The oesophagus does not run in a horizontal line through the brain, but in a diagonal, sloping upward and backward ; it enters the anterior edge of the brain at its ventral surface and sloping strongly upward emerges at the posterior edge of the supra- oesophageal and lies upon (above) the part of the sub-oesophageal which lies posterior to the supra-oesophageal, i. e. about two-thirds of the length of the former. Looking at the whole brain in a general view, the supra-oesophageal ganglion appears quite sharply divided from the sub-oesophageal and perched on top of it ; it is only when one attempts to separate the two, or cuts sections, that the fusion of theii- peripheral parts is appreciated. What may be called the ground-plan of the supra-oesophageal ganglion, as seen from above, is almost a square, with the corners somewhat rounded, and a projection near the middle of each lateral edge, from which projection the palpal nerve arises. * i8 ; his Taf. V. figs. 2, 3. t 14. figs. 20, 23, and p. 1!)9. J 6 ; his Taf. xxxiv. fig. 7. § " On the Form and Proportions of the Brain in the Oribatida; and in some other Aoarina,'' Journ. R. Micr. Soc. 1895, pp. 274-28.;. INTERNAL ANATOMY OF BDELLA. 499 Viewed from the side, or in sagittal section, the supi'a-a?sophageal ganglion is almost triangular; tliis form is caused hy its being thin at its anterior edge, and thick, dorso- ventrally, at its posterior, its uj)per surface sloping rapidly upward fi'om before back- ward, and then falling, almost perpendicularly, to the sub-oesophageal ; the upper surface is somewhat concave, and faces upward and forward ; the posterior edge forms a wall standing almost, but not quite, uj) right upon the sub-oesophageal ; round this wall great bundles of tracheae are wrapped, as hereafter described in the section on the respiratory organs {wfra, p. 518). The neurolemma is very fine and delicate, and difficult to see, extremely different from the substantial neurolemma of the Hydrachnidse. The layer of cortical dark-staining cells, which is so conspicuous in many of the Acarina, is but feebly developed in Bdella, and is entirely absent from those parts of the sub-oesophageal from which the six pairs of large nerves, which arise from that ganglion, start. With regard to the Nerves I have, in the above-named j^ajoer upon Thyas fetrophilus (14), stated fully what previous writers have said respecting the nerves of such species of the Trombidiidoe and allied faimlies as have been studied from the point of view of their internal anatomy ; I do not therefore intend, in this paper, to refer more to the bibliography of the subject than is necessary for the proper understanding of any doubtful or disputed points, the settlement of which may be facilitated by what I have been able to ascertain in the present investigation : in other cases I shall confine myself to stating what I find in Bclella. The ample supply of specimens of Bdella Basferi which I have received has enabled me to devote a large number to tracing the nerves only, sacrificing all other organs : this has been done partly by dissection and partly by sections ; but, on the whole, I have found the former method rather the more efficient on account of the extreme difficulty of obtainin"' anv stain which will differentiate the nerves in the Acarina from the surrounding tissues — with me gold chloride, in whatever way employed, has entirely failed to do so. In no case has a single dissection or section been relied on for a nerve or branch of one ; I have not put anything into fig. 13 until I have seen it in several cases : I think, therefore, that all the detail which I am able to give may be relied on ; I have been able to trace a fair number of the finer branches, but I have little doubt that plenty of others exist which I have not seen. The creatures are so small, and tlie nerves so extremely fine and difficult to trace, that it can only be by slow degrees, and a certain amount of good luck, that jinything like completeness can be obtained in their study. As might be anticipated, I find that the nerves agree fairly well with what I found in Thyas petrophihts, without more difference than would be looked for between two families which are very distinct, although allied, and differ so much in the anatomy of other organs. I have been able to trace in Bclella Basferi one median nerve and ten pairs of bi- laterally symmetrical nerves ; of these the median nerve and three pairs of the paired nerves arise from the supra-cesophageal gangKon, and seven pairs of paired nerves from the sub-a?sopliageal ; those arising from the supra-oesophageal are all small, those from the sub-ffisophageal mostly large nerves. 500 ME. A. D. MICHAEL ON THE The median nerve (fig. 13, wjjA) is the pharvugeal nerve; this, as in all other Acarina in which it has been traced, is a thin nerve which arises in the centre of the anterior edge of the supra-oesophageal ganglion immediately above the oesophagus, and follows straight along, or rather parallel to and just above, that organ to its distal end : there it breaks up into a number of fine twigs, some of considerable length; one of these twigs is sent to each muscle of the sucking-pharynx. In Bclella, however, a compli- cation of this pharyngeal nerve exists which has not been recorded, and probably does not exist, in any Acarid the anatomy of w'hich has been studied ; I believe it to be entirely novel : it is that the pharyngeal nerve, a sliort distance from the brain, splits into two main branches, an uj^per and an under — the under goes on, as before described, to supply the pharyngeal muscles, and in fact represents the whole nerve in other families : the upper branch {nc) runs between the oesophagus and the receptaculum cibi, and terminates just where the two join; it innervates the ring of sphincter muscle which surrounds the neck of the receptaculum cibi (sucking-stomach), and possibly sends twigs to other portions of the sucking-stomach ; but I was not able to make certain of this. In fig. 13 this upper branch of the pharyngeal nerve is shown turned a little to the right; if it were left in its natural position, it would entirely hide the lower branch and there would not be anything to show that two existed. Of the paired nerves from the supra-oesophageal ganglion those situated a trifle the nearest to the median line are a pair of very delicate nerves (««;) which innervate the dorso-ventral muscles near the base of the rostrum ; in reality this pair of nerves, the mandibular nerves, and the palpal nerves lie almost in a perpendicular line one below the other, the palpal being lowest, the pair now treated of next, and the mandibular nerves highest ; in the drawing the mandibular has been bent a trifle to the left, and the present ])air a trifle to the right in order to show them ; the present pair is, however, a very little nearer to the median line than the mandibular. JNotwitlistauding this I think the mandibular must really be regarded as the tirst, and the present as the second pau", which is tiie same as in Thyas. At a distance from the brain rather less than half the length of the brain itself this nerve {nv) branches dichotomously. I was not able to trace its further branching. The next pair of nerves from the supra-oesophageal ganglion are the mandibular (;iw); these are situated considerably further towards the lateral edge of the ganglion than they are in Thyas ; and the reason for this is not difficult to understand. In Thyas the mandibles are much compressed laterally and lie together close to the median line ; in Bdella the proximal ends of the mandibles are swollen into large bulbs, tlse two of which together are as wide as the rostriun. About as far from the brain as two-thirds of the length of the brain itself there arises from the mandibular nerve a branch-like structure, which will be best understood from the drawings (figs. 13, 14). The nerve gives off what may be called a branch, or may be considered a gangHon ; I am inclined to look upon it in the former light : it is a thin sheet of nervous tissue, rather thicker at tlie edges, and resembles in form a flattened hour-glass, Avith the corners drawn out into points and the waist not so thin as in that instrument. Trom each of the two distal corners of this expansion proceeds a very thin nerve-branch ; these tw^o are, I think, distributed to INTEENAL INATOMl OF BDELLA. 501 some of the mandibular muscles, but I was not able to ascertain precisely which : the main trunk of the nerve proceeds into the mandible in the usual manner. The third and last pair of nerves which I could trace from the supra-oesophageal ganglion are the optic nerves (no) ; these arise from small eminences about the middle of the respective lateral edges of the ganglion ; they are the stoutest i^air of nerves which arise from the ganglion, Ijut are not proportionately as thick as they are in Thy as, Tromhidium, Uydrodroma, and other forms. I was able to trace one fine branch («o 1) abovit as far from the brain as two-thirds of the length of the brain itself, which branch ends in a very small ganglion. The principal trunk of the nerve proceeds to the hinder and outer of the two eyes (on each side), and there on its outer side expands into a sort of retinal disc {rd) (figs. 13, 27), which is almost sessile upon the nerve ; the principal trunk then inclines more forward and less outward, and terminates in an almost similar disc for the other eye on that side of the body. These retinal discs, although rather more flattened, are practically the same as those described by Henkin (6) in Tromhidium fuliyiuosum (his fig. 11, vn). I was not able to trace any homologues of the thin \)vav of nerves from the posterior part of the supra-oesophageal ganglion which I found in Tlujas, still it may be possible that they exist ; they were exceedingly fine in Tlu/as. The nerves arising from the sub-oesopliageal ganglion are six pairs of thick and odh pair of thin nerves. The courses of the six thick pairs may be most distinctly ti'aced in the ganglion itself, running almost to its centre ; they are even cons^iicuous. The first pair of thick nerves are the palpal nerves. Croneberg, speaking of Eylals extendens (4), considered that the palj)i were innervated from the sub-oesophageal ganglion. Nalepa (i6), speaking of Trichodactyliis anonymus (Tyroglyphidse), considered that the maxillae were served by the sub-, and the maxillary palpi by the supra-oesophageal ganglion. Schaub (i8) (speaking of Sydrodroma) stated that the palpi were innervated from the sapra-oesophageal ganglion. Henkin (6) did not trace the i:)alpal nerve. In Thyas petrophilus the two ganglia are so fused into a ball, and the palpal nerve arises so exactly on the level of the oesophagus that I was unable to say which ganglion it arose from. In Bdella Basteri, however, the matter is clear; the palpal nerve {up) sj)rings from the upper part of the anterior outer corner of the sub-oesophageal ganglion ; it is a thick nerve, much thicker in proportion than the same nerve in Thyas ; this doubtless is ex2)lained Ijy the great size and importance of the palpi. It seems to me most natural to sujijjose that the palpi would be innervated from the sub-oesophageal gauffliou, because that is the centre whence the maxillary nerves of insects arise ; but of course in insects the mandibnlar nerves also arise from the sub-oesophageal ganglion, whereas in the adult Arachnoidea the nerves which serve the mandibles (chelicerse) spring from the supra-oesophageal ganglion. This, however, is subject to three i-emarks, viz., first, that Winkler considered that in G<(masus he had found tiie root of the mandibular nei've in the svib-oesophageal ganglion, and that it passed right througli the substance of the supra-oesophageal ganglion before emerging — an observation which I have not been able quite to confirm, although I have a great respect for Winkler's general accuracv ; secondly, that many Avritei'S, such as Lang and others, consider that the very fact of SECOND SERIES. — ZOOLOGY, VOL. VI. 68 302 . ME. A. D. MICHAEL ON THE the different innervation prevents these organs in tlie Insecta and the Arachnoidea being considered homologons ; thirdly, that although nsually in adult Arachnida the mandibular (clieliceral) nerves, and possibly sometimes the palpal nerves, arise from the suj)ra-a3sophageal ganglion, in the young embryo the ganglia whence these nerves spring are not supra-oesopbageal, but work upward in the com-se of development. In Bdella a very thin branch, the destination of which I was not able to trace, arises on the outer side of the nerve almost immediately it leaves the brain. About as far from the brain as two-thirds of the brain itself the palpal nerve gives off a second and considerably larger branch, this time from its inner side ; this branch {up 2) innervates the maxillary lip ; at its distal end, at the lip, it branches and forms two cone-like structures (iig. 15), evidently of a sensory nature. The next four pairs of large nerves from the sub-oesophageal ganglion are the leg-nerves (N 1, N 2, N 3, N 4) ; these are of the iisual type, and are the largest nerves in the body ; each is accompanied on its anterior side by the so-called accessory nerve [iia) of Crone- berg, Schaub, and Nalepa. I think I showed in my treatise on Thijas petrophilns that these accessory nerves are really the first branches of the respective nerve-trunks, although in many instances they have come to arise from the brain itself just at the base of the leg-nerve : this, as will be seen by the drawings, is the case in Bdella Basteri in some of the legs ; but, as before stated, the leg nerve-trunks run far into the substance of the brain. The accessory nerve of the first leg {na 1), soon after leaving the brain, expands into an almost triangular lamellar process, similar in nature to that of the mandibular nerve, and two very fine nerve-branches arise from the anterior angles of this expansion. The accessory nerve of the second leg {na 2) gives off two thin opposite branches a short distance from the brain ; a little further on its course it gives off a rather thicker branch, which extends into a process nearly similar to that from the accessory nerve of the first leg, and like that gives off two fine branches from its anterior corners. The third and fourth legs also are accompanied by accessory nerves {na 3, na 4) ; I was able to trace two extremely fine branches from the latter, but not any processes on either similar to those on the first and second accessory nerves. The nerve-trunk to the third leg, about as far from the brain as half the length of the brain itself, gives off a branch on its inner side, and shortly afterwards a thicker branch on its outer side ; this branch soon divides dicliotomously : the trunk also gives off another branch on its outer side further on. The nerve-trunk of the fourth leg is accompanied by a branch springing from the brain on the inner side as well as the outer, in fact by a second accessory nerve {nas). The trunk, nearly as far from the brain as the whole length of the brain itself, gives off a substantial branch. I was able to trace this branch ; it goes to the nmscles in the body which move the coxa of the fourth leg. The remaining pair of large nerves are the genital nerves {ng) ; these arise close together in the centre of the posterior edge of the ganglion ; indeed, they are so close that just at first their inner edges fuse, making a square, central, posterior projection from the ganglion, I was able to trace five branches on the underside of each of these nerve-trunks ; that on the left is shown in. the drawing slightly turned over to expose I INTEENAL ANATOMY OF BDELI.A. 503 these branolies. These nerves run above, and are distributed to, the genitalia, and possibly to some other organs of the hinder part of the body. The thin pair of nerves from the sub-oesophageal ganglion is a very fine pair {nd) arising from the brain about midway between the second and third legs ; it innervates the large dorso-ventral muscles which are situated between these two pairs of legs ; I found one branch to this nerve. I believe the nerve has not been observed before in any of the Acarina. I was not able to find the fine, recurrent, median nerve which exists in Thyas. The Eyes. (Figs. 26, 27.) There is not much to be said respecting these organs, because they do not appear to vary greatly from the known types of simple eyes in other Arachnida ; they are, however, more highly developed than those usually found in such Acari as are provided with those organs. The optic nerve, as before stated, bifurcates slightly near its distal end— one branch being in etfect a continuation of the main nerve, and the other being very short; each branch expands at its end inio what I have called a retinal disc {rcl) ; this is an almost circular plate, only very slightly cup-shaped—/, e., only slightly concave on the side next the cuticle. These discs are composed of rather loosely packed ganglionic cells and are more than one cell thick ; the exterior cells, next the rods, are very distinctlv nucleated, the nuclei of the deeper cells being more irregular. Abutting on the outer cells of the disc are a considerable number of rods or retinulac {re) converging to the lens ; these rods have rounded posterior ends, and are remarkable for the almost entire absence of pigment between and around them ; much more pigment is found in the eyes of such Hydrachnidte as I have seen, although tlie rods there are not so distinct nor numerous. 'The smaller outer ends of the rods abut upon the lens {ol), which is bounded exteriorly by the extremely convex cornea, W' hich is more compact and highly refracting than the rest ol the lens. The two eyes forming the pair on each side are, from their situation, turned in slightly different directions ; they are not as close together as in most Hydrachnidse. The Eepeoductive System. Tlie JIale. (Figs. 17, IS, 19, 20, 21, 22, 23, 34, 35, 36, 37, 38, 39, 10, 11, 42.) The genital organs of the male Bdella have far more resemblance to those of Tromhidimii JuUyinosmn, as described by Henkin, than to those of any other Acarid of which these parts have hitherto been investigated ; indeed, his is the only drawing and descrijotion which can be said to form any guide to the general arrangement of the parts : still it is only in the general arrangement that this can be said. Henkin's descri])tion is, I believe, quite correct in almost every particular. I have dissected Trombidium Julicjiuosum and have much pleasure in confirming Henkin's work ; but when we compare it with Bdella, we find that although the two types are more like each 68* 504 MR. A. D. MICHAEL ON THE other than any other known form, yet that they are very different in a large nnniher of most important points ; and that in some of these points Bdella more resembles other families of Acarina, wliile in the greater number it is entirely special, and the features in which it differs from Ti'omhkl'mm cannot be homologized with any Acarus the anatomy •whereof is known. Anyone looking at Henkin's figure will be inclined to sav that the genital organs of the male TromhkUiwi are very complicated ; but they may almost be called simple in comparison with those of Bdella. Pagenstecher came pretty near to the correct drawing of the male organs of Tromhidmm ; but, as Henkin has already pointed out, Pagenstecher mistook the sexes, and what he figures as the female organs are really the male (17. pi. ii. figs. 12, 13, 11). The male organs of Bdella Basteri may be said to consist of: (1) the testes ; (2) the embedding-sacs ; (3) the testicular bridge ; (4) the great mucous glands ; (5) the glandular antechambers ; (6) the penial canal with its accessories ; (7) the azygous accessory gland ; (8) the laminated gland ; (9) the air-chambers ; and (10) the great external labia. The astonisliing part of this system is the great size and variety of the accessory glands. I have, in several instances, purposely given neutral names to the parts ; the homo- logies will be described later on. The Testes (figs. 17, 20, 35, 42, T) are two more or less pyriform masses on each side of the creature, which, when in slfu, stand almost upright in the body, the larger ends being upward and the smaller downward : at its smaller (lower) end each testis terminates in a very short duct (Id, fig. 20) not clearly marked off from the testis ; these two unite and form a short common duct which enters the end of the testicular bridge. The testes are in the hind portion of the body, a little behind the genital opening, and are placed immediately below the hind cfeca of the ventriculus. When the testes are ripe, they sometimes force their Avay between the lobes of the coecum or push it aside, and thus may be found pressed almost against the dorsal surface. The histology and construction of each of these testes bear considerable resemblance to those of the whole testicular mass, on each side of the body, in Thijas petrophilus ; and it must be remembered that that organ is divided into two lobes, seeming to give some indication of a double origin (14. pp. 193, 194, pi. viii. fig. 17, pi. ix. fig. 28). In Bdella Basteri the exterior timic of each testis, particularly where it rests against the embedding-sac, and the adjoining part of its outer side {i. e., that part of the testis which is most remote from its fellow on the same side of the body), is composed of largish cells (fig. 35, tp), but indistinctly demarcated, containing somewhat solid plasma which stains freely, and having very clear almost circular nuclei of about "01 mm. diameter, and nucleoli of about 3 ^ to 4 fi. These cells usually extend over portions of the inner and other surfaces ; but on the portion of the inner surface furthest from the embedding-sac, and the surface opposite the sac, and the adjoining parts of the outer surface, their character is entirely changed in the ripe male ; there these cells have become much more clearly marked off from each other, considerably larger, and very irregular in form, the nucleus has entirely disappeared, and t he cell-contents have become divided into numerous INTEENAL ANATOMY OF BDELLA. 505 spermatozoa in various stages of development, according to the age of the cell. These are, of course, the sperm-mother cells (figs. 35, 42) ; the inner wall of each cell eventually breaks down, and the sjiermatozoa are discharged into a hollow chamber forming the interior of the portion of the organ which has the nucleated cells as its outer tunic. When the organ is sectioned, it often appears solid ; this is because the chamber is so full of secretion and spermatozoa that its lunaen is obliterated ; often, however, it is only half-full, and then its real nature is seen. It is more than probable that this chamber is composed of a single cell, which is greatly distended, and has become a species of vesicula seminalis to receive the contents of the adjoining cells. My reason for making this suggestion is that tbe chamber frequently, indeed I may almost say usually, contains a a single, large, most distinct nucleus lying free in the midst of its contents. In some species, e. g. B. vulgaris, when the spermatozoa are thoroughly ripe, this chamber seems to occupy almost the wliole interior of the testis, particularly of the front one of each pair, and it is crowded with large spermatozoa in a ripe condition. The secretion with which, in addition to spermatozoa, the cell is generally filled must apparently either have arisen in the cell itself or entered from the embedding-sac (in £. Basteri) ; but if the latter be the case, it is not clear where the passage is, nor would this account for the presence of the secretion in the chamber of B. vnlr/atHs, which has not any embedding- sac. The testes are largish and fairly well developed in the nymph when approaching full growth, although of course not nearly so mu.ch so as in the adult, and they do not in the nymphal stage contain ripe spermatozoa ; but they are very large compared with the other male sexual organs, such as the great mucous and accessory glands and the embedding-sac, which at the same period are either very small or altogether absent. Tlie Bmhedd'mg-sac (figs. 17, 19, 35, es) is a large hollow viscus : on each side of the body, in an indentation of this viscus, the testes rest ; it is on the exterior side of the testes, and when in situ is on edge in the body. Although the testes simply lie on the inner side of the embedding-sac, and are easily removed by dissection, yet they are so pressed into the wall of tbe sac that two hollows (fig. 19) are formed in the wall of the embedding-sac, into which the respective testes fit, and in which they are buried to the depth occasionally of half their thickness. The wall of the emliedding-sac is forced up between the two testes, forming a considerable ridge. The lower edge of the embedding-sac rests upon the inner side of the ventral surface of the hind part of the body. In fig. 17 the two embedding-sacs {es) are shown with the testes in situ, but they are opened out and laid back, in order to show the testes, as the two valves of a cockle-shell might be in order to show the fish ; in reality, when in the body of the living creature the two embedding-sacs are closed together, like a living cockle-shell, and quite hide the testes, which are then on their inner surfaces. In fig. 19 one of the embedding-sacs is shown after the testes have been removed. The embedding-sac is somewhat folded and pressed so as to form lobes and folds, which vary in diff'erent individuals ; it will be seen by fig. 35 that its two surfaces are usually much j)ressed together, leaving a rather small and irregular lumen, which, however, is doubtless 506 - ME. A. D. MICHAEL ON THE capable of expansion. The walls of the organ are formed of columnar cells varying greatly in size in different parts ; they only stain lightly, but have large and clear, much flattened, oval nuclei of about 14 ^u and darkly staining nucleoli of about 5 /u. The embedding-sac has been most frequently empty in the specimens which I have sectioned ; but sometimes it has contained a fine granular secretion, which hardly stains at all, but which has apparently been of a slightly viscid character. I have never detected spermatozoa in it ; but it is just possible that if the secretion enveloped the spermatozoa and were impervious to stain, the spermatozoa might be present and not be visible, although this does not seem very probable. It is a very strange thing that I have not been able to detect any entrance to or exit from the embedding-sac either forming a connection with the testes or any other organ ; it appears to be a closed sac,, but it is difficult to believe that it always is so. The embedding of the true testes in the external wall of a hollow mass is very like the arrangement in the Oribatidge*. In these Acari the embedding-organ serves as a vesicula seminalis. Perhaps, however, of all published delineations of the genital organs of Acari, that by Prof. Berlese of a sagittal section of Actinecla corniger (i. prostigmata,. pi. vii.) comes nearest to the testis and embedding-sac of Bdella Basteri. Berlese does not say a word about the genital organs of his creature in the letterpress ; but, curiously enough, he has mistaken the male for the female, and in the explanation of his plate he marks the embedding-sac as being the ovary, and apparently considers the testis, which he draws very well, to be an egg ; he shows a communication ti-om the embedding-sac into the penial canal, which he calls the " plicae vulvares, or labia interna." The nearly full-grown nymph of Bdella Basteri shows, as before stated, the testes well developed, but the creature does not possess any embedding-sac; that seems to be developed in the adult only ; and moreover, strange as it may appear, it is a fact that I have been unable to trace any sign ot an embedding-sac even in the adults of any ot the other species of Bdella, three or four in number, which I have been able to examine. The true testes in these species come right down to the ventral surface. Tlie TestlciUar Bridge (figs. 17, 20, 34, tb) is so much a portion of the testes that it might perhaps have been more correctly described immediately after them ; but its exact position woiild not be so well understood before the description of the manner in which the testes of B. Basteri are partially sunk in the embedding-sac. The bridge is a tubular connection between the two testes on one side of the body and the corresponding joair on the other side ; it would not be useful to attempt to give its exact size, because it varies so much according to the amount of spermatic matter in its lumen for the moment and from other causes. It has already been mentioned that the two short ducts from the two testes on one side unite in a common duct which enters the end of the bridge; this common duct is so intimately connected with the bridge that it must be regarded as the commencement of that structure. The bridge curves round immediately behind the penial canal and, in B. Basteri, is between that organ and the lower part of the anterior edges of the embedding-sac ; but it is quite free from both ; is * ' iJritish Oribatidtc,' Michael (Eay Soc. 1884), p. 150, pi. F. figs. 1-5. INTERNAL ANATOMY OF BDELLA. 507 not in any way sunk in tlie embedding-sac or joined to tlie penial canal, althongli in ripe specimens all the organs become pressed against those adjoining them from the immense development of tlie genitalia. It forms a passage for the spermatozoa from the testes on each side of the body, and in specimens containing ripe spermatozoa it is usually crowded with the ripest of them. From this one Avould naturally anticipate that there would be some passage from the bridge into the penial canal, which it immediately adjoins; but, strange to say, this is just what I have been entirely unable to find by any amount of searching ; there does not seem to be any enti-ance from it into the penial canal, and I think I may say positively that there was not any such entrance in aay specimen which I have examined. The testicular bridge is probably the homologue of the short junction or bridge between the testicular masses on the two sides of the body found in Thijas petropJdlus (14. p. 193, fig. 17), although the situation is very different; the bridge in Thyas being at the extreme posterior of the testicular masses, whereas that of Bdclla is central. There is a kind of progression from the almost horseshoe-shaped testicular mass of Tromhidimn fuUginosnm (6. fig. 17) to that of Thyas, above referred to, where, although tlie liorseshoe form is more or less preserved, the two sides are almost separated ; and fiu-ther to the organs of BdeUa, where the two sides are wholly separated posteriorly and only joined by a central bridge. The histology of the bridge does not vary much from that of the testes ; the same layer of darkly staining, clearly-nucleated cells which forms the exterior tunic of the latter extends continuously over the former, and when the genital products are not fully developed constitutes the principal thickness of the organ, the lumen being small. At a later stage the lumen is greatly distended by the spermatic products, and the walls of the organ become thinner; there is never any sign, liowever, of the cells of the bridge becoming sperm-mother-cells, or of their giving rise to spermatozoa. The Mucous Glauds {glandulce mucosa-) (figs 17, 31 & 36, gm, & 37), as I call them, for the purpose of not binding myself to homologies, are almost, if not quite, the largest organs in the body of the adult male Bdella. The form of each is that of a great sausage-shaped sac bent upon itself in the middle, so that the two ends almost touch, and the two halves also almost touch at their inner edges and are parallel to each other; the great curved central bend is at the anterior portion of the organ, the ends being directed backward (fig. 36). The bend is not horizontal but perpendicular, so that the one half of the organ lies above, not at the side of the other ; the end which, as herein- after explained, comimmicates with the testiciUar bridge is the lower, and is usually more or less swollen and irregular in form, while shortly before the swelling there is a slight constriction. The walls of the organ are extremely thick ; they are composed of a substantial tunica propria externally ; on the inner side of this a single row of large, more or less columnar, somewhat irregular cells, varying in B. Bastcrl from about "06 mm. to about -1 mm. in length and about 15 f* to 25 ^ in width, which have extremely dense dark-staining walls where they adjoin each other, l. e. on their sides, and much thinner walls at the ends. The exterior end of the cell is filled with a layer or mass of protoplasm about -02 to -03 mm. thick on the average, which stains freely and contains the strongly 508 ME. A. D. MICHAEL ON THE marked, usually nearly circular nucleus, wliicli averages about 10 ^ and has a large distinct nucleolus of about 5 ^ to 6 /.i. The remainder of the cell is either entirely or partly filled with a finely granular secretion, whicli shows the largest granules near the exterior of the cell, bvit in the lumen of the organ becomes very homogeneous, and which stains but slightly ; or else is completely empty; the latter is the commonest condition. I say very homogeneous in the lumen, but of coxxrse a sufficient power shows this secretion to be granular even there, but as the granules are not above i n in diameter and extremely hyaline, it requires a comparatively high power of the microscope and some definition to see them clearly. What apparently takes place is that when the secretion is formed the wall of the inner end of the cell breaks down and the contents are discharged into the lumen of the organ, which is often quite full of it, although at other times empty. After the wall of the inner end of the cell has broken down and discharged its contents the other walls persist, forming deep pockets, so that the whole strvxcture looks like an almost empty honeycomb ; into these pockets the secretion continues to be discharged and to find its way thence into the lumen. These organs do not vary much in the other species of Bdella which I have been able to examine ; the principle and histology have always been the same; the chief difference which I have found has been that in some species, particularly the smaller ones, the organ is often thicker (i. e., has a larger diameter) in proportion to its length, and that the two parallel portions are consequently shorter and are more pressed against each other ; the result of this is that the whole mass, even in section, looks more globular. In some sj)ecies, e. g. B. vulgaris, it would be possible for a person seeing only the section to overlook the fact of its being a sausage-shaped organ folded on itself, and to take it for a globular one, if he had not seen B. Basteri or some other similar species to guide him to the true form ; of course a careful examination would reveal the true conformation of the organ in any species. There are two passages, and two only, ovit of, or into, each mucous gland ; these are at the two ends. In the upper more rounded end, but not median in that end, there is a very small but perfectly distinct entrance to the glandular antechamber (vestibulum glandulae mucosai) (fig. 19, v(j), Avhich entrance is ordinarily kept closed by the thick walls of the antechamber itself being pressed against one another. About the centre of the lower more lobose end is a much smaller passage ordinarily very tightly closed by a sphincter, which leads into the testicular bridge. Hound this passage a few cells of the mucous gland have usually entirely broken down, their latei'al walls even being destroyed ; thus an open space is left, \\ hich is generally wholly or partially filled Avith the secretion, unless the lumen of the organ be empty. The Glandular Antechambers {vestibulum (jlandiilm mucosa;) (figs. 20, 36, 38, vg, & 17, 18, & 41) are two paired chambers, one leading from the upper end of each of the great mucous glands into the head of the penial canal : each antechamber is almost in a line with the part of the mucous gland Irom which it springs, but turns slightly upward to reach the dorsal side of the head of the penial canal and to escape the edge of the testis; it is sharply divided from the uiucous gland by the constriction which forms the narrow passage before mentioned, and from the penial canal by a similar constriction ; so that it becomes an INTEENAL ANATOMY OF BDELLA. 509^ oval sac, which lias extremely thick walls and a small lumen. The greatest length of the organ in B. Bastevl is usually about "2 mm. The histology of the organ bears a resemblance to that of the mucous glands, yet tlie differences are considerable. The tunica propria is present, but is not nearly so easily seen as in the mucous glands, because the cell-contents and walls in the antechamher hardly stain at all, and therefore do not dilferentiate. The walls are composed of columnar cells radiating inward, and in B. Basteri mostly about -04 mm. in length ; but in tliat species they are very irregular in arrangement (fig. 38). In some other species, e. g. B. vulgmHS, they are remarkably regular, and the walls of the cells strong (fig. 41). The cell-contents are very compact and the nuclei extremely small, flattened, and indistinct ; indeed it would be difiicult to see them were it not for tho minute darkly staining nucleoli. In some specimens it will be found that the cells are empty and the nuclei gone, but the lateral walls of the cells still persist, forming a strong oj)en houeycomb-like reticulum. The secretion within the lumen of the antechamber is similar to that foimd in the mucous gland, and probahly conies thence. The Benial Canal (figs. 18, 21, 34, 42, ^jc, including pc^ and -pc^) is a very complicated organ, and one not at all easy fully to grasp the construction of; it varies considerably in detail in different species ; it must probably be considered a development of a ductus ejacidatorius. When looked at from the exterior this complication is not seen ; it then appears to be, and its external coating is, a large organ divided into two parts (fig. 18), an inner fleshy portion {pc^), and an outer membranous portion (^J6*-). The former of these is almost perpendicidar or tends somewhat backward, varying in different specimens, the dorsal end being the more anterior ; it is an approach to jj^-ramidal in form, but is curved, the dorsal end curving over toward the posterior end of the creature ; it also enlarges gradually, but not regularly, from the dorsal to the ventral end. It is round, or Jilmost so, in transverse section cut through its dorsal part ; more compressed laterally in its lower part. In some other species, e. g. B. vulgaris, the dorsal end of the penial canal is enlarged and is more turned to the rear. On the exterior of tliis organ near its lower edge is placed on each side a chitinous sclerite (as), which I will call the "amphioid sclerite " *, the anterior half of which is a plate of irregular form somewhat convex exteriorly, so that it looks semi- arcuate in longitudinal section ; this plate has a pointed anterior end, where it ajjproxi- mates to its fellow of the opposite side. The posterior half turns in a sigmoid manner, and is thicker and rod-like ; its hind end almost touches the tube which leads from the outer membranous chamber of the penial canal into the air-chamber on that side of the body. The anterior plate-like half of this amphioid sclerite is bordered by 4 or 5 spines ; its principal function appears to be to give attachment to muscles, although it probably is also protective ; from it spring the muscles (mdl) which divaricate the labia that close the entrance from the azygous accessory gland (gaa) to the penial canal. From the posterior dorsal angle of the plate arises a thick tendinous projection, and into the end of this a pair of large retractor muscles {mr) * 'A/^Kfii, both ; €Uos, shape. SECOND SEMES. — ZOOLOGY, VOL. VI. 69 510 MR. A. D. MICHAEL ON THE are inserted. From the posterior edge of the plate arises a series of fine constrictor muscles (mc), which pass round the outside of the penial canal. The other principal muscles connected with this part of the canal are a pair of central retractor muscles (mr^) inserted into the median posterior line of the lower part of the organ, and a network of constrictor muscles which completely envelop the upper end of the organ like a cap ; these are not shown in the drawing, as they would entirely hide that portion of the canal. The glandular antechamhers (vg) enter the upper end of the jienial canal as hefore stated, passing through this muscular layer. The outer portion of the l^enial canal (pc~) lies entirely ventral to the amphioid sclerite, and is a membranous structure somewhat wider than the inner portion (pc^), hut its exact Avidth and form depend on the amount of the retraction of the organ for the moment. It forms a thin- walled flexible chamber connecting the inner part of the penial canal with the great external labia (/na fcfcie to be improbable. I have been very unwilling to accept it as the true explanation ; it has even struck me whether it were possible that at some time of year which I have missed, or ixnder some circumstances, the testicular bridge does com- municate with the penial canal, and whether in that case it might be possible that the mucous gland not only discharged its principal contents, as it certainly does, through the antechamber into the penial canal, but also discharged some portion through the narrow constricted aperture into the common duct and bridge, where it served to nourish the spermatozoa, which appear so much better nourished in this place than anywhere else. I have not, however, been able to discover any sufficient evidence in favour of such a theory, and it is not by any means a theory to be accepted without evidence, as a gland discharging at both ends to different organs is not a thing which could be anticipated. The head of the penial canal is enveloped by a thick cap of muscles spanning it in all directions ; these doubtless are the ejaculatory muscles, and, probably, serve also to extrude the invaginated parts of the canal. What can be the office of the embedding- sac in £. Basteri, and what is the necessity for the number, variety, and immense size of the accessory glands in all species of Bdella it is very difficult to understand. The Female. (Figs. 24, 25, 43, 44.) In marked contrast to the extreme complication of the generative organs of the male- Bdella, those of the female are particularly simple, and we do not find a single accessory gland present to take the place of the numerous organs of that nature which are present in the male. Practically it is only in young specimens that these organs can be studied ; when the eggs are matured they fill the abdomen so miich that they push everything else out of position ; and if the genital organs be dissected out they are a mere lump of eggs which hide everything, and have distended some parts out of all shape, while sections at this time do not reveal much more. The organs of the female consist of: (1) the ovary ; (2) the oviduct; (3) the recep- taculum seminis ; (4) the external labia. The Ovary (figs. 24, 25). — This organ is a considerable variation from all homologous organs hitherto described in the Trombidlnm-gvow]) of Acarina (vide Heukin (6), Michael (14), Schaub (18)) ; in all these recorded instances the ovary has been almost ring-shaped and flattened, the paired oviducts completing the ring. In Bdella the ovary is a mere crescentic lump, which in the virgin female is quite small, but of course provided with ovarian ova ; the crescent is a short and slightly ciu'ved one (fig. 25, ov). As the INTEENAL ANATOMY OF BDELLA. 517 creature gets a little older the crescent becomes somewhat deeper, more approaching a horseshoe form (fig. 24, ov) ; but after impregnation, and when the ova are mature, the Avhole becomes one shapeless mass of large eggs A\hich enclose and hide the oviduct. The ova are formed and more or less matured in short pedunculated oocysts, each ovum apparently forming its own oocyst by pushing out the exterior tunic of the ovary, thus forming a sac in which the ovum lies. Exactly how the ovum gets from the oocyst into the oviduct is not by any means clear to me in Bdella, or, indeed, in many of the other Acarina, although it is evident enough in the Oribatidns and most Gamasidaj. The Oijidnct (figs. 21, 25 & 43, od, & 14). — In all described Trombidiidoe and Ilydrachnidse there are two oviducts whicli unite to form a common tube (the vagina) ; in Bdella, how- ever, there does not apj^ear to be any such arrangement ; in all s^^ecies which I have examined there ajipears to be one single fleshy tube leading from the centre of the ovary to the external labia. Some authors would probably divide this tube into oviduct, uterus, and vagina ; in reality, however, I do not see any distinction of regions which is at all permanent : it is one unbroken tube, in some parts a little larger, in others a little smaller, but still the one tube, and the enlarged portions are apt to vary with age and contents. It is only in the young specimens that this tube can be clearly seen or dissected out; when distended by maturing or mature eggs it becomes a great irregular sac, the walls of which have lost their extremelv thick and irlandular character to a ijreat extent. The oviduct when in situ is not straight or perpendicular ; it is in effect rolled round the ovary ; so that when dissected out the whole forms a rounded mass, which can be uncurled in fresh specimens of the young female, but which it is extremely difficult to stretch out when the eggs are mature. The ovary and oviduct of a young specimen of B. vulgaris partly uncurled, so as to show them, are delineated at fig. 25 ; it will be seen that the oviduct here is longish and is corrugated, showing evident signs of capability of expansion ; at its distal end it enlarges considerably, and were this permanent it might, perhaps, be called a uterus, but I do not see that it is so. Eeyond this enlarged portion, i. e. between it and the external labia, is a short flexible portion of the tube, which might be called the vagina, if that name be used at all. In B. Basterl (fig. 24) I have not seen any such enlargement in the young female. The figure is drawn as In sltn, only a little uncurled, but the oviduct is, I think, much shorter and thicker in pro^wrtion than in B. vulgai-is. The external labia and membranous portion of the duct are not repeated in this figure ; they would not vary from the other species. The oviduct is an organ with extremely thick fleshy walls (fig. 44) (in some places as thick as "1 mm.) and consists of an almost structureless tunica propria, within which are usually several row s of deeply staining cells, containing a granular protoplasm and small round nuclei (about 2>n) which do not stain much more deeply than the general cell- contents. The AA'alls vary greatly in thickness in difi'erent parts, and according to the amount to which the organ is distended in the particular place at the time. The cells are extremely loose and irregular, crowded together, l)ut not so as to press strongly against one another ; thus they have rounded and otherwise curved outlines, and are not forced into hexagonal or other angular forms. The layers are often folded so as to make great projections into the lumen of the duct. The outer layer of cells, adjoining SECOND SKKIES. — ZOOLOGY, VOL. VI. 70 618 ME. A. D. MICHAEL ON THE the tuuica propria, have a tendency to be columnar, but the deeper layers are more round, the innermost being often more or less comma-shaped, with swollen ends, which project into the lumen. The eggs lie some time in the oviduct, and develop greatly there : yolk-division commences, and proceeds to a considerable extent, before the ova pass into the duct ; but it is completed there, and. the egg increases in size greatly while there ; it is in this organ also that it receives the strong chitinous covering with which it is provided before it leaves the body of the female. The thick walls of the duct are manifestly secretory ; in joung females, before yolk-division has commenced, the lumen of the duct is generally full of a granular secretion, which probably is a nourishing fluid ; it is found in more mature specimens, but then the ova so fill the duct as to allow but little room for other things. The Receptaculmn semlnis, or spermatheca (figs. 25, 43, rs), is an azygous sac formed by an in-pushing of the wall of the oviduct not far from the external labia, but still not in the flexible membranous portion of the duct which adjoins the labia; it is but slightly seen in immature females, and sometimes not at all in very old. ones after the eggs are all, or almost all, impregnated ; in females which have arrived at maturity only a short time but have been impregnated, this sac is crowded with spermatozoa. It is not hard or chitinized, but is a soft and flexible organ with its walls composed of rather columnar cells, and its exterior in most parts covered by a layer of fine constrictor muscles. The External Labia do not difi"er from those of the male, except in being somewhat larger and rather more spongy in construction. The Respiratory Organs. (Fig. 45.) These organs have a general resemblance to the corresj)onding parts in Trombidimu, which have been admirably and correctly figured and described by Henkin (6. fig. 7) ; but they vary considerably from that type; they are almost similar in the different species of Bdella which I have examined, any small points in which they do not agree will be noticed. In Bdella Basteri there is, on each side of the body, a long tubular air-chamber (fig. 45, ac) which has an almost even diameter, usually of about -05 mm. throughout. This air-chamber commences immediately behind the mandible, and continues backward in a course which typically should be almost straight, but which generally becomes slightly tindulating from the pressure of other organs, until it reaches the genital organs ; it even passes among these, usually penetrating between the two arms of the great mucous gland of the male, and between the ovary and the alimentary canal of the female. It ends blindly both anteriorly and posteriorly ; both ends are rounded. The anterior end is attached by a double tendinous ligament {tl) to a fold of the cuticle close to the lower posterior corner of the mandible. At a distance from the anterior end of the air- chamber eqvial to abovit two-thirds of the length of the air-chamber itself, there springs from the dorsal side of the chamber a main tracheal trunk {tra), about one-third or one- quarter the diameter of the air-chamber ; it turns sharply forward inmiediately and runs parallel to the anterior part of the air-chamber the whole length of that organ. In the drawing the two are slightly separated in order to show them distinctly, but in nature, when INTERNAL ANATOMY OF BDELLA. 519 thej are in si(n, they actually toucli along their whole length— indeed, for the greater part of their course, they are surrounded hy a single enveloping tunic common to both. These two vessels are striated, the air-chamher very finely and regularly, the tracheal trunk much more coarsely and irregularly. The tracheal trunk enlarges somewhat near its anterior end, and when it has arrived at the termination of the air-chamber it tm*ns suddenly upward behind the mandible, forming a somewhat curved air-passage, which is almost divided uj) into sections by partial constrictions and irregular broken semi- partitions or laminae jn-ojecting into the lumen. At the upper end of this jiortion of the tracheal trunk is the stigma (S), of which there is only the one pair in the body, communicating with the small external air-chamber between the mandibles. There are not any other tracheal trunks in the body, but from the ventral side of the posterior thu'd of tlie air-chamber, and from the actual posterior end and a small portion of the dorsal side of the chamber, there arise a multitude of extremely fine, unbranched, and unstriated tracheae (^r), which are distributed to all parts of the body ; only the commencement of them is shown in the drawing. Some of these tracheae turn forward and serve the tropin and anterior organs, some run backward and turn forward afterwards ; but far the greater number of them run backward toward the posterior end of the creature. A thick fasciculus of these small tracheae tiu'ns across the body immediately behind the supra-oesophageal ganglion of the brain, thus lying upon the sub-oesophageal ganglion and upon the oesophagus itself. The fasciculi from the two sides of the body meet and cross behind the supra-oesophageal ganglion, the posterior side of which is almost hidden by them until they are removed. In Bdella capilluta, Kramer, which I examined, the arrangement is similar, except that the number of fine tracheae is very much less than in B. Basteri, and that the tracheal trunk does not enlarge until it turns ujjward ; but then it enlarges comparatively more than in B. Basteri. The Dermaiv Glands. (Fig. 10.) Instead of assuming the importance which the similar organs do in the Hydi'achnidae, the dermal glands of Bdella are apparently few in number (I have only traced one pair) and are extremely small and difficult to find ; when found, however, they bear a resemblance to those of the Water-Mites, but on a very much smaller scale, and are simpler. In B. Basteri they consist of minute sacs, averaging about 25 ^i in extreme length, placed immediately beneath the hypoderm, each having one small duct placed excentrically, which passes to the outer surface of the cuticle, where its mouth forms a very small pore which is not protected hy any sj)ecial hair or spine, l)ut which is doubtless sheltered by the sharp wavy ridges with which the whole cuticle of Bdella is covered. The contents of the sac are a few masses of protoplasm which stain freely, and which are joined by irregular protojilasmic strands. It is possible that they may not be homologous with the dermal srlands of the Hvdrachnidse. a' The Endosternite. I have not figured this organ because it is of the type well known in the Acariua, e. g. the Gamasidae and other forms ; but I mention its existence, particularly as it is 70* 520 :MR. a. D. MICHAEL ON THE extremely well developed in Bdella. It forms a thick tendinous plate, which, in B. vulgaris, shows signs of being formed by the compression of a sac ; at all events, it has thick upper and under walls, which in a transverse section of the creature show a narrow but distinct lumen between them ; which, however, is crossed by " ties " between the upper and under walls. The endosternite lies between the ventriculus, which is above it, and the hind part of the brain (not quite its posterior end), which is below it. It forms a point of attachment for numerous muscles, principally the great muscles of the legs, which are tlie largest in the body. The endosternite is slung from above by dorso-ventral muscles and muscles from the lateral surface of the body, and by connective tissue ; the muscles converge to it from all sides. The Musculature. A large number of the muscles have been described in connection with the various organs ; I do not propose to enter into any exhaustive desci'ij)tion of the remaining ones, particularly as some of them are figured by Karpelles ; but there are some which I may mention. I have not draAvn any of the musculature except that incidental to other figures, because doing so would have involved having another plate. All the muscles described below are paired muscles corresponding on the two sides of the body. LonyitucUnal 3fuscles. — From the dorsal cuticle nearly above the fourth leg, and almost close to the hind fasciculus of dorso-ventral muscles, two bundles of powerful muscles arise ; both of these are horizontal muscles running for their whole length almost immediately under tlie dorsal cuticle. The anterior of these bundles runs forward above the alimentary canal and the paired salivary glands ; it spreads out and is inserted partly in the dorsal cuticle about where the dorsum begins to sink toward the rostrum, partly in the upper proximal edges of the mandible, and partly in the cuticle behind the lower proximal edge of the mandible The other bundle runs backward, and is inserted in the dorsal cuticle near the posterior end of the hoAj ; thus these two sets of horizontal muscles, starting from one point, embrace between them almost the entire length of the body, except the rostrum. They manifestly serve to compress and shorten the body longitudinally and to retract the rostrum. Prom the dorsal cuticle just in front of the ventriculus two fasciculi of numerous muscles, much sligliter than those last described, arise ; one of these is inserted in the rostrum just below and behind the mandible, the other in the cuticle just above and behind the mandible. From the anterior end of the endosternite a fasciculus of strong muscles runs to and is inserted in the lower posterior edge of the rostrum near the median line. Perpendicular Muscles. — I was able to distingviish eight fasciculi of dorso-ventral muscles, all strongish, viz. : — 1. A fasciculus arising from the dorsal cuticle in front of the reniform and pericibal salivary glands, and not very far from the median line of the body ; this bundle is inclined slightly forward, and is inserted in the hind edge of the rostrum. 2. A fasciculus arising from the same place, but passing almost perpendicularly down- ward and inserted into the ventral cuticle. INTERNAL AXATOMY OF BDELLA. 521 3. A fasciculus arising from the dorsum a little in fi-ont of the auterior eye, rather more toward the side of the l)ody than numbers 1 and 2, and inserted in the ventral thickened sclei'ite or ridge at the jiosterior edge of tlie aeetal)ulum of the first leg. 4. A fasciculus arising from tlie dorsum a little beliind the posterior eye, and inserted in a similar manner to No. 3 at the posterior edge of the acetabulum of the second leg. 5. A fasciculus close to the side of the body arising from the dorsum a little behind the vertical plane of the coxa of the second leg; passing diagonally backward and down- ward and inserted in the ventral surface a little before the third leg. 6. A fasciculus arising from the dorsum just anterior to the genital organs, i. e., just anterior to the great mucous glands of the male, passing almost perpendicularly down- ward and inserted in the ventral cuticle. 7. A fasciculus arising from the dorsum a little anterior to the embedding-sac in £. Basteri, and in a corresponding position in the body of such species as have not any embedding-sac, and inserted in the posterior edge of the acetabulum of the foiu'th leg. 8. A fasciculus near the side of the body arising from the dorsum about the middle of the embedding-sac, but outside that organ, and inserted in the ventral cuticle some little distance posterior to the fourth leg. There is also a fasciculus of rather fine muscles arising from the dorsum and inserted in the anterior part of the endosternite, and another of stronger muscles arising from the dorsum and inserted near the posterior termination of the endosternite. The Muscles of the Mai/ d ib I es.— The muscles which move the small terminal joint of the mandible, i. e. the movable joint of the chela, are shortish ; they are wholly contained in the bulbous proximal part of the mandible, and are inserted into the terminal joint by means of very long tendons passing the whole length of the narrow distal part of the mandible. The retractor muscles, which serve to open the chela, are few and arise from the roof of the mandible; the extensors, which close the chela, are more numerous and more powerful ; they arise from the lower a,nd outer sides of the mandible. The teudou.s from each set of muscles unite with their fellows of the same set, and form a single tendon which is inserted as stated above. The levator muscles of the whole mandible appear to be a group of short, thick, diagonal muscles arising from and just behind the lower posterior edge of the mandible and inserted into its i;pper posterior edge, which bends shari^ly but diagonally upward, and extends further backward than the lower edge. There are also some muscles apj)arently serving to give a slight lateral movement. The muscles of the legs do not differ sufficiently from what has previously been described by various authors relative to more or less closely allied creatures to make it worth while to describe them at any length. As before stated, the principal muscles which move the whole leg arise from the endosternite ; but some few serving to give a somewhat revolving motion arise from the epimera, which are very slight structures, in fact little more than thickened margins to the acetabula of the legs, and from the neighbouring cuticle : all are inserted in the proximal end of the coxa. The muscles which move the individual joints of the legs usually arise just in front of tlie posterior 522 MR. A. D. MICHAEL ON THE edge of one joint and are inserted into the posterior edge of the next more distal joint; the exact jmrt of the edge from near which they respectively arise or into which they are respectively inserted depending in each case upon the direction of the motion the muscle is to give. The External Cuticle. (Figs. 33, 34, 41, 42, 43.) This can hardly be said to form part of the internal anatomy, which is the subject of this paper ; but as it is invaginated in several places, and is thus associated with the inner organs, and is also somewhat peculiar and interesting in itself, I think it best to say a few words regarding it. The skin of Bdella is extremely fine : it is composed of a thin epidermal layer which in B. Basteri is only about 1 ^ thick ; this layer is highly flexible and quite transparent and colourless ; the whole of the brilliant red pigment which makes the creatures so con- spicuous lies in the deeper layers, I. e. hypoderm and fat layer, and on the exterior of the internal organs themselves. The exterior of this epiderm (fig. 33) is marked with the fine, wavy, jmraliel lines so common in many of the soft-bodied Acarinn, e. g. the Sarcoptida) and others ; in B. Basteri they are about 600 to the millimetre. These lines in Bdella are of an exceptional character ; instead of being mere markings they are ridges, which are thicker at the base where they start from the cuticle than at their distal edges, so that a section through one of tliem is like the section of a narrow knife-blade ; this appearance is increased by the marvellous sharpness and fineness of the edge. The fine lines springing from the exterior of the cuticle in all drawings of sections of the whole creature (figs. 34, 41, 42, 43) are not hairs, but are these ridges cut through. The height of the ridges is considerably more than tlie thickness of the solid part of the epidermal layer : in B. Basteri tlie ridges in their liighest part are about 2"5 /x liigh, more than twice the thickness of the layer ; but the height of the ridge, /. e. the amount of its projection, is not equal in all parts, for the following reason : — Each ridge is not an even one of a fixed thickness and projection throughont, it is a series of small drawn-out swellings of different sizes and lengths joined by their fine ends ; the ridge never ceases and never loses its distal knife-edge, but it swells out and contracts irregularly, so that when looked at from above it appears like a string of irregular beads, each bead drawn out to a point at both ends and joined to the next bead by an extremely fine thread. The height of the ridge in section naturally depends on whether the section cuts a large or a small swelling or falls between two swellings. It is not possible to depict this irregularity in drawings on the scale of the figures above enumerated. The hypoderm is a much thicker tunic than the epiderm, and is of the usual character in the Acarina, with loosely joined living cells of irregular size which have very distinct elongated nuclei and elliptical nucleoli. IXTERXAL ANATOMY OF BDELLA. 523 Bibliography of the principal works I'eferred to in the foregoing memoir or giving information respecting the Bdellinte, not including works which only record species. 1 . Berlese, Antonio. — .A.cari, Miriapodi, e Scorpioni italiani. Padua and Florence. Being published in fasciculi ; first jiart issued in 1882, still continuing; Bdelliiia; finished in "Ordo Prostigmata" (Trombidiidie), 1893. 2. C.4NESTRINI, Giovanni. — Prospetto delP Acarofauna italiana. Parte ii. Padua, 1886. 3. Canestrini, Giovanni. — " Abbozzo del Sistema acarologico," Atti R. 1st. Veneto di Sci. &c., t. ii. ser. 7, 1891. Keprinted in the above-named work TNo. 2), Parte v., Padua, 1892, pp. 560- 587. 4. Croneberg, a. — " Oil the Anatomy of Eylais extendens, Muller, with observations on allied forms," in Russian in ' Nachr. Ges. d. Freunde d. Naturkuude,' Moscow, 1878. A short summary in German, called '•' Ueber den Bau der Hydrachnideii," in Zool. Anz. 1878, Nr. 14, p. 316. 5. Cronebeug, A. — " Ueber den Bau von Trombidiuin," in Bull. Soc. Nat. de Moscou, 1879, part 2, p. 234. 6. Henkin, H. — " Beitriige zur Anatomie, Entwicklungsgeschichte uiid Biologic von Trombidium fuliyinosum, Herm.," Zeitsch. wiss. Zool. Bd. xxxvii. (1882) pp. 554-663. 7. Johnston, George. — "The Acarides of Berwickshire specifically described," Trans. Berwickshire Natui-alists' Field-Club, vol. ii. (1847) p. 221. 8. Karpelles, Ludwig (now Karell, L.). — " Zur Anatomie von ^rfe/Za arewaria, Kramer," in Verb. k.-k. zool.-bot. Ges. Wien, Bd. xliii. (1893) pp. 421-430. 9. KocH, Carl Ludwig. — Deutschlands Crustaceen, Miriapoden und Arachniden. Regensburg, 1835-1841. Forming Hefte 1-40 of Herrich-Schaffer's edition of Dr. G. W. F. Panzer's ' Deutschlands Insecten.'' 10. Koch, Carl Ludwig.— Uebersicht der Arachniden-Systems. Niirnberg, 1837-1850. 11. Kramer, P.—" Die Familie der Bdelliden," in Areh. f. Naturg. Bd. xxxxii. fl876) pp. 183-196. 12. Kramer, P. — "Beitrage zur Naturgeschichte der Milben," in Zeit. ges. Naturwiss. Bd. Ii. (1878) pp. 552—3. 13. Kramer, P. — " Ueber Milben," ibid. 1881, section 7, pp. 24-32. 14. Michael, A. D. — " A Study of the Internal Anatomy of Thyas petropMlus, an unrecorded Hydrachnid found in Cornwall," in Proc. Zool. Soc. London, 5 March, 1895, pp. 174r-209. 15. MoNiEZ, R. — " Aeariens et Insectes marins des cotes du Boulonnais," Rev. Biol. d. Nord d. 1. France, t. xi. (1890) pp. 1-28. 16. Nalepa, A. — "Die Anatomic der Tyroglypheu," Sitzb. k. Akad. Wiss. Wien, Bd. xc. Abth. 1 (1884), p. 198, Bd. xcii. Abth. I (1885), p. 116. 17. Pagenstecher, H. A. — Beitrage zur Anatomie der Milben. Heft i. Leipzig, 1860. 18. ScHAUB, R. VON. — " Ueber die Anatomie von Hydrodroina (C. L. Koch). Ein Beitrag zur Kenntniss der Hydrachniden," Sitzb. k. Akad. Wiss. Wien, Bd. xcvii. Abth. 1 (1888), p. 98. 19. ScHAUB, R. VON. — " Ueber marine Hydrachniden ,uebst einige, Bemerkungen iiber Midea (Bruz.)," ibid. Bd. xcviii. Abth. 1 (1889), p. 163. 20. Trouessart, E. L. — " Considerations gciierales sur la classification des Acariens, suivies d'un essai de classification nouvcUe," Rev. d. Sci. nat. d. I'Ouest, t. ii. 1892, pp. 35-44. 21. Trouessart, E. L. — " Note sur une grande espece de Bdelle maritime originaire d'Islande," Jourii. Anat. et Physiol. (Robin's), xxx. An. 1894, no. 1, pp. 117-125. 524 ME. A. D. MICHAEL ON THE EXPLANATION OF THE PLATES. Lettering. A. Anus (so called) . This is really the orifice for the discharge of the excretory organs only, not apparently of the alimentary canal. ac. Air-chamher of respiratory system. acg. Air-chamber in genital organs of male. acp. Passage from acy to the outer part of the penial canal. as. Amphioid sclerite of penial canal. B. Chitinous bar at the rear of the roof of the rostrum. Henkiu's " Chitinbriicke." bh. Brushes of hair or spines inside penial canal. br. Brain. C. Cuticle. C(S. Anterior cieca of ventriculus. cap. Posterior caeca of ventriculus. cas. Caecum of tubixlar salivary gland. ct. Connective tissue. cu. Cuneiform chamber of reniform salivary gland. D. Common duct of three of the salivary glands, viz., the tubular, the reniform, and the anterior. da. Duct from the anterior salivary gland. dp. Duct from the pericibal salivary gland. dr. Duct from the reniform salivary gland. dsa. Duct from the azygous salivary gland. E. Excretory organ. el. External labia of genital organs. eph. Epipharynx. es. Embedding-sac of male genital organs. ew. Excretoiy (urinary) white matter. fg. Food-globules absorbed and lying within the cells of the ventriculus. gaa. Azygous accessory gland of male genital organs. gl. Laminated gland of male genital organs. gin. Glandulaj mucoste (the great mucous glands) ; probably modified vasa deferentia. gso. Supra-oesophageal ganglion (upper part of brain). gsu. Sub-ffisophageal ganglion (under part of brain) . H. Hypoderm. hm. hp. K. La. Ian. le. U. mc. mcr. md. mda. VI dl. me. mf. mfp. ml. mlp. mop. m,p. mr. mrp. n\. n'2. 71 3. n 4. na 1. nu )i. na 3. na 4. nus. nb. nc. Half-moon-shaped spiked membrane of epi- pharynx. Hamuli (hooks) of the membranous lobes of the central tube of the penial canal. Entrance from the mucous gland to the testicular bridge. Labia closing the duct from ,the azygous salivary gland. Labia ani. External labia of genital aperture. Lingua. Constrictor muscles of penial canal. Constrictor muscles of receptaculum cibi. Mandibles. Divaricator muscles of the labia ani. Divaricator muscles of the labia which close the duct from the azygous accessory gland of the male genital organs. Dorso-ventral muscles. Membranous flaps at the distal end of the maxillary lip. Membranous flaps at the end of the central tube of the penial canal. Maxillary lip. Levator muscles of the roof of the pharynx (dilatores pharyngis) . Occlusor (constrictor) muscles of the pha- rynx. Partition between the mandibles. Anterior retractor muscles of penial canal. Posterior retractor muscles of penial canal. Nerve to first leg. Nerve to second leg. Nerve to third leg. Nerve to fourth leg. The branch of the nerve of the first leg which is the honiologue of the accessory nerve of Croneberg, Schaub, Nalepa, &c. The like of the second leg. The like of the third leg. The like of the fourth leg. Second accessory nerve of fourth leg. Posterior branch of the fourth leg-nei've. Branch of the pharyngeal nerve going to the receptaculum cibi (sucking-stomach) . INTERNAL ANATOMY OF BDJILLA. 525 nd. Nerve to dorso-vcntral muscles between second and third legs. ng. Genital nerve. nm. Mandibular nerve. no. Optic nerve. no' . Branch of the optic nerve. np. Palpal nerve. np". Branch of ])alpal nerve distributed to the maxillary lip. nph. Pharyngeal nerve. nv. Nerve to muscles running from the dorso- vcrtex to the maxillary lip. 0. Ova. oc. Cornea of the eye. od. Oviduct. ce. Qilsopliagus. 01. Lens of the eye. OS. Eyes. ov. Ovary. P. Palpus. pc'. Penial canal, dorsal portion. pc~. Penial canal, ventral portion. pe. Penis? ph. Pharynx. pp. Propharyngeal plate. pr. Roof of the pharynx. R. Roof of rostrum. re. Receptaculum cibi (sucking-stomach). rd. Retinal disks. re. Retinulae (rods) of the eye. rs. Receptaculum seminis. S. Stigma. *«. Azygous salivary gland. s(/u. Anterior salivary gland. sgp. Pericibal salivary gland. sgr. Rcniform salivary gland. sgt. Tul)ular salivary gland. *//. Hollows in embedding-sacs to receive testes. sni. S perm-mot lier-cells. T. Testes. til. Testicular bridge. td. Duct of the testis. tdm. Common duct of the two testes on one side of the body. thl. Tactile hairs of maxillary lip. tl. Tendinous ligament between respiratory air-chamber and cuticle. tp. Exterior fleshy cells of testis. //•. Tracheae. tra. Principal tracheal trunk from stigma to air- chamber. //. Tendinous tie between epipharynx and lingua. tvs. Portion of testes functioning as a vesicula seminis. V. Ventriculus. vg. Vestibulum glandula; mucosae (glandular antechamber). ]V. Wedge-shaped chamber in reniform salivary gland. All the figures, except where specialli/ mentioned, /lace the anterior end, where there is one, nearest to the top of the page. All the figures, except 12, 2u, 41, and 42, represent Bdella Basteri. Plate 41- Fig. 1. (Right central part of Plate.) The epipharynx, propharyngeal plate, and associated muscles seen from below : x 220. The propharyngeal plate with its membranous wrinkled border is at the lower end of the drawing ; tlie one of the occlusor muscles of the pharynx which curves over and depresses the plate passes transversely above it and is partly hidden by it. The epipharynx with its membranous border is the upper part of the drawing, and its semi- lunar spiked membrane is shown at its hind margin. 2. (Right top of Plate.) The epipharynx, lingua, propharyngeal plate, and part of the pharynx and pharyngeal sac seen from the right side : x 220. The lingua is cut short ; the propharyngeal plate, occlusor (constrictor) j)liaryngis muscles, and part of the levator tecti pharyngis muscles are seen through the wall of the pharyngeal sac in consequence of its transparency. The duct from the pericibal salivary gland is seen discharging near the hind corner of the epipharynx. SECOND SERIES. — ZOOLOGY, VOL. VI. 71 526 ME. A. D. MICHAEL ON THE Fig. 3. (Left middle of Plate.) The posterior part of the pharynx, tlic receptaculum cibi (suckiug- stomach), and anterior jiart of the ojsophagus seen from the right side : x 70. The darkish mass inside the receptaculum cibi is the food-contents. 4. (Right top corner of Plate.) The receptaculum cibi, maxillary lip, and left palpus seen from above, x 70. The end of the lingua is shown protruded ; the oesophagus is hidden. 5. (Right a little below centre of Plate). The anterioi' end of this figure points to the right. The pharyngeal plate and its levator (distcnsor pharyugis) muscles seen from the right side : X 320. 6. (Lower edge of Plate.) Ventriculus from above : x 30. This figure is drawn from a young female, mature, but only one egg showed any sign of yolk-segmentation. In older specimens the form of the ventriculus is generally lost from distension and the pressure of other organs. 7. (Lower edge of Plate.) The excretory (Malpighian) organ from the left side: X 120. The white matter within the viscus is the secretory (urinary ?) matter. 8. (Left top corner of Plate.) The tubular, leniforni, and anterior salivary glands on the left side of the body with their common duct : X 120. The reniform gland is seen almost on edge. This drawing is slightly diagrammatic in the sense that it is not quite drawn] to scale (to avoid waste of space) and that the parts are a little separated in order to show them. 9. (Lower left corner of Plate.) The left reniform salivary gland and duct seen from the side : X 120. The duet is cut short. 10. (Right centre of Plate.) The azygous and pericibal salivary glands with their ducts in situ in the body, seen from above : x 55. A small part of the posterior end of the receptaculum cibi is seen between the pericibal glands. 11. (Right lower corner of Plate.) The azygous and the left pericibal salivary glands with their ducts seen from the inner side : x 120. The azygous is to the left, the pericibal to the right of the figure; the duct from the latter is cut short. 12. (Below centre of Plate.) Sagittal median section through the azygous salivary gland oi Bdella vulgaris : x 1 80. 13. (Central upper figure.) The brain and nerves seeu from above : X 100. The hole where the oesophagus passed between the supra-cesophageal and the sub-cesophageal ganglia is shown, but the oesophagus itself has been removed, except a small portion anterior to the brain. The nerve to the receptaculum cibi has been tui'ued a little to the right to show the pharyngeal nerve from which it springs and which it would hide. The mandibular nerve is turned a little outward, as it would lie over the palpal nerve. The left genital nerve is slightly turned over to show the branches on its under surface. The whole length of the optic nerve is shown ; the other nerves are cut short. 14. The branching of the mandibular nerve : x 200. 15. The termination of the labial branch of the palpal nerve in the maxillary lip : x 400. 16. One of the dermal glands and duet : x 700. Plate 42- Fig. 17. The reproductive organs of the male spread out so as to show details : x 70. The embedding-sacs {es) are turned to the right and lelt, carrying their respective pairs of testes with them; in situ they would lie close together, present their edges to the observer, and hide the testes between them ; the azygous accessory gland would be more closely jiressed by the great mucous glands, which would probably hide the laminated gland. The almost globular organ in the centre of the group is the head of the peuial canal looked down on perpendicularly ; the glandular antechambers are seeu entering it. The laminated gland is seen in the median INTERNAL ANATOMY OF BDELI.A. 527 line directed to the top of the Plate; it enters tlie peuial canal mucli below the head, but looking down ])erpendicularly this is not appreciated. Fig. 18. The penial canal, external labia, laminated gland, air-chamber, and parts of the azygous accessory gland and glandidar antechambers seen from the side : x 120. 19. One of the embedding-sacs after the testes and other organs have been removed from it, seen from within : X 70. The hollows in which the testes lay are shown ; the azygous accessory gland, laminated gland, penial canal, and external labia are attached ; the labia are partly seen from the exterior. 20. The testes which have been removed from fig. 19, together with half the testicular bridge, one of the great mucous glands, the glandular antechambers, &c. : X 70. 21. Central tube, hamuli, and detailed structure of penial canal : x 250. The outer wall of the penial canal is partly cut away so as to show the interior. 22. One (the right) of the chitinous air-chambers which is sunk in the cmbedding-sac, from the exterior : x 200. The chamber has been dissected out of the sac. 23. A portion of the interior of the laminated gland, showing the principal laminte and the oblique lesser lamclhe : X GoO. 24. Genital organs of young female in situ, the oviduct being only slightly uncurled: x 120. The reeeptaculum seminis is hidden. 25. Genital organs of young virgin female (reared) of Bdella vulgaris, slightly spread out; but the curl of the oviduct is natural. 26. Perpendicular section through one of the eyes : x 550. 27. Horizontal section through the terminal part of the optic nerve and the retinal discs : x 200. The section cuts the lower eye through the rods (retiuulee), the cells of the disc only showing near the periphery ; the upper eye is cut wholly in the retinal disc. 28. Transverse section of the oesophagus between pharynx and braiu, to show the irregular shaped lumen : x 650. A typical section was selected, but probably no two sections were ever really similar ; they vary widely. 29. Maxillary lip from below : x 80. 30. The mandibles in. situ, seen from above : x 80. 31. The left mandible seen from the inner (flat) side : x 80. 32. Terminal portion of maxillary lip from below, showing the membranous flaps inside (above) the lip : X 450. The lip has been flattened out to show the flaps ; in reality when the lingua is not protruded the sides of the lip curl upward and the two flaps lie against each other, closing the entrance anteriorly. 33. A small portion of the external cuticle showing the wavy irregular ridges composed of long- shaped raised dots, joined by the lower parts of the ridge : x 550. Plate 43. Fig. 34. Median sagittal section of male : x 50. The section is a thick one, so as to show some organs which are not in the actual median plane where they are not hidden by other organs which arc in that plane. Thus one mucous gland is shown with a portion of the azygous accessory gland and the genital nerve passing over it. The caeca of the ventriculus have practically closed over the excretory organ from the pressure of food-coutents and other causes. Numerous small traclie:e (not lettered) are seen between the brain and the ventriculus and mucous gland. The resophagus is seen passing through the brain, and the reeeptaculum cibi (sucking-stomach) sjirings from its dorsal side. The cells of the ventriculus are crowded with food-droplets, the excretory organ with the usual white matter. 528 ON THE INTERNAL ANATOMY OF BDELLA. Fig. 35. Sectiou througli the testes and embedding-sac on one side of the hody : x60; showing that the latter is a hollow visciis, although the lumen is small in comparison to the size of the organ The sperm-mother-cells are seen on the right part of the testes, the portion functioning as a vesicula seminis on the left nearest to the embeddiug-sac ; these portions are full of spermatozoa. 36. Median sagittal section througli the mucous glaud (vas deferens?) and glandular antechamber on one side of the body : x 100. The cells have all di?charged their contents and are empty, their walls remaining, forming pockets ; the outer fleshy walls with the nuclei persist. 37. Section of a portion of the mucous gland when partly filled with secretion : x 140. 38. Median sagittal section of one of the glandular antechambers of the male: x 400. 39. Median sagittal section through the laminated gland of the male : X 150. 40. Longitudinal section through the air-chamber of the male genital organs, to show the spines projecting into the interior : x 400. In this figure the lower end is slightly the anterior. 41. Transverse section of male Bdella vulgaris cut in the plane of the glandular antechambers to show the difference of their cellulation from those of B. Basteri. The muscles arising from the amphioid sclerite are inserted into the labia which close the ducts from the azygous accessory and laminated glands; just the end of the last-named gland is seen above the labia. The inner portion of the mucous gland on the right side is shown just at its end, where the minute passage from the testes exists ; this is shown by the small circle in the middle of the light spot ; the other parts of the mucous glands are cut a little deeper in the wall of that organ. 42. Transverse section of male Bdella vulgaris posterior to fig. 41 and taken in about the central plane of the peuial canal (the head of the canal bends over in this species). The small part of the azygous accessory gland is seen cut through transversely immediately above the penial canal. 43. Transverse section of female in the plane of the receptaculum seminis : x 30. The oviduct is distended by eggs, some nearly I'ipe for discharge. The cells of the cseca of the ventriculus are full of food-droplets. The walls of the oviduct have become very thin in consequence of the distension 44. Section through part of the wall of the oviduct of a young female: x2o0; showing the thickness of the wall, the mode of folding, and the cellulation. 45. The respiratory organs : x 65. The Avhole of the air-chambers and principal tracheal trunk are shown, but the finer tracheae are cut short. i,ff-- ^^' ■-r- i ' \ np ^%v 13. rip c t,p/, Trans. Linn Soc.Zool Ser ZVol.VLPl*!, \ ,j,.,. /'/' /+ ■'/' ■ ■/.I, to. •A f% '■'/-' /K " € ^ '■r- -'^$) \. :.'.<) ..-rTe^^V. Mli^.-: ^1 :'•/. i\ : A\ ;^' ANATi'.'MY OF KDELLA, Trak;; 1.!; V:?i.43. "-/' JV. ■A -r -■ ':*/ ^ ^*. /ltd t/'ti; ■■''^; ^MV:/? .;:?■ •>57' •f/. feV / ,77. prl I ^ 'e^4 ,1 %%, ^'^VSi^ ^?t J!<;^'. .•.>=^ -a ;• k I. ^:: -9^" ... ^ rt.C ^^ *". A D, Michael ,id n.il.rt)?i«-,47S, 514, 519. lapidaria, Kramer, 479. longirostris, 481. marina, Paclard, 479. sanguinea, Trouessart, 478, 479, 480. villosa, Kramer 4" Neum., 479. vulgaris, Uerm., 478-480, 496, 505-528. ,var. littoralis, Moniez, 479. Bdellida?, 479. Bdellina% 479, 480, 481. Bernard, H. M., The Comparative Morphology of the Galeodidas, 305-417. Biton, Karsch, 309. Boruta, Wrze.iiiiowsl'i, 180. tenebrarum, Wi'zcsniowsli, 172, ISO, 269. Brachydesmus, Ileller, 265. subterraneus, Heller, 265. Bradya, Boecl-, and Ectiiiosoma, Boecle, A Revision of the British Copepoda bidonging to the Genera, by Thos. Scott & A. Scott, 419- 446. Bradya, Boeclc, 92, 420 ; meutioced, 23, 426, 427. brevicornis. Scott *, 92 ; men- tioned, 23, 92, 154. Edwardsi, llichard, 430, 431. elegans, T. Sf A. Scott*, 422 ; mentioned, 420, 425, 441, 442. fusca, T. 4- A. Scott *, 424 ; mentioned, 420, 426, 441,. 442. hirsuta, T. 4- A. Scott*, 423 i mentioned, 420, 424, 441, 442. minor, T. 4- A. Scott*, 425 ^ mentioned, 420, 431, 441, 442. similis, T. 4- A. Scott*, 424; mentioned, 420, 425, 441, 442. typica, Boecl; 420 ; mentioned, 92, 93, 421, 422, 425, 441, 442. Cfficidotaja, Pacl-ard, 170, 175, 176, 178, 254, 261, 263, 269. microcephala, Cope, 170. nickajackensis, Packard, 175, 178. pallida, PacJcard, 272. stygia, Pacl-ard, 170, 175, 178, 272. •, var. pallida, P((c/i-arrf,j272. Calanida>, 24, 419. Calanopia, Bona, 77. brachiata, Dana, 77. Calanus, Leach, 24 ; mentioned, 23, 26, 28. arcuicornis, Dana, 73. atteniiatus, Dana, 28. comptus, Dana, 13, 23, 26, 149, 150. finmarchicus, Gunner, 26. gracilis, Dana, 13-21, [23, 25,, 26. mirabilis, Lubb., 28. parvus, Glaus, 26. pavo, Dana, 37. phimidosus, Claus, 39. propinquus, Brady, 13-23, 25. pygmnous. Clans, 27. stylifer, Dana, 75. tonsus, Brady, 20, 23, 25. turliinutus, Dana, 76. valgus, Brady, 13-24. Caligus, Midler, 129: mentioned, 23, 132. INDEX. 531 Caligus bcngoensis, Scott*, 130 ; men- tioned, 23. dubius, Scott *, 130 ; meutinned, 23. Muri'iiyanus, Scott *, 1.-9 ; men- tioned, 23. (?) Thymni, nana, 129 ; men- tioned, 23. CaUiope, Spence Bate, 181. subterranea, Chilton, 180, 181, 234. Calliopius, Leach, 163, 181, 233. fluviatilis, O. M. Thomson, 235, 253, 256, 257, 262, 301. subtcrraneus, Chilton, 163,172, 181, 184, 185, 200, 225, 234, 235, 246, 248, 253-262, 269, 283, 284, 301. €alocalauus, Gichr., 37 ; mentioned, 23. pavo, Dana, 23, 37 ; mentioned, 13, 15-17, 39, 150. plumulosus, Chnis, 39 ; men- tioned, 16,23, 39, 145, 150. €alynda, St?d, 464. €alyptomera, 133. Calyptopis-stage, 297, 298. Cambarus, Erichs., 256, 257, 275. Bartonii, Fahi:, 257. pellueidus, Tellkampf, 25G. stygius. Bandy, 2bl. Candace, Dana, 60 ; mentioned, 23. bispinosa, Claits, 63. curta, Dana, 61. intermedia, Scott *, 61 ; men- tioned, 13-16, 19-23, 62, 148. paebydactyla, Dana, 60 ; men- tioned, 13-23, 01, 02,63. pectinata,7?/-o(/v, 61 ; mentioned, 13-23, 62, 63. tenuiremus, Scott MS., 62. truncata, Dana, 63 : mentioned, 16-20, 23. varicans, Gieshr., 62 ; meu- tioned, 18, 23, 148, 151. €andacia, Dana, 60. Caudona Candida, Miillei; 134. Canterbury (N.Z.), General Fauna of the Subterranean Waters of, 246- 248. Plains and their underground Waters. 248-253. Canthoeamprina3, 96. Canthocamptus roseus, Dana, 92. Caprella, Lam., 205. Caprella deutata, Haller, 299. Caprellida;, 209, 299. Carciiius, Latr., 298. Catopia, Dana, 77. furcata, Dana, 77. Caulonia, St8l, 465. bifolia, St,V, 465. spinosissima, Kirhy*, 464, 475. Centropages, Krih/er, 77 ; mentioned, 23, 78. bracliiatus, Dana, 77; men- tioned, 21-23. furcatus, Dana, 77 ; mentioned, 15, 16, 19, 21, 23. violaceus. Clans, 78; mentioned, 15-19, 23. Cerapinae, 225. Cerapus tubularis, Say, 226. ChaUmus, Burm., 132. Characters, special, of the Subter- ranean Fauna, 259-268. Chelifer cancroides, Linn., 514. Chernetidce, 316, 324, 348. Chilton, Chas., The Subterranean Crustacea of New Zealand, with some general Remarks on the Fauna of Caves and Wells, 163- 284. Chondrostethus, Kirhy *, 455. Woodfordi, Kirhy*, 455, 456, 475. Chthonius, Koch, 261. Cladocera, Latr., 132. Cladomorphidse, 472.] Cladoniorphus, Gray, 472. Cladoxerus serratipes. Gray, 450. Clausoealanus, Gieshr., 72 ; men- tioned, 23. arcuioornis, Dana, 73 ; men- tioned, 13-16, 18, 23, 153. furcatus, Brady, 72 ; mentioned, 1.5, 16, 18, 23. latipes, Scott *, 72 ; mentioned, 23, 153. Cleobis, Sim., 307, 309. Cleta, Claris, 96. serrata. Clans, 96. Clefcodes, Brady, 23, 98. linearis. Clans, 23, 98, 157. Clytemnestra, Daiui, 106 ; men- tioned, 23. Hendorffi, Poppe, 109. rostrata, Brady, 106 : men- tioned, IS-is, 18-21, 23, 157. Clytemnestra scutellata, Dana, 106, 108. tenuis, Lulib., 106. Conchoecida;, 141. Copepoda, A Revision of the British, belonging to the Genera Bradya, Boeck, and Ectinosoma, Boecl; by Thos. Scott and Andrew Scott, 419-446. Copilia, Dana, 113 ; mentioned, ftnote 13, 23. denticulata, Claus, 23, 113, 114. Fultoni, Scott *, 114 ; men- tioned, 23, 156. mirabilis, Dana, 113 ; men- tioned, 13-23, 114, 115. quadrata, Dana, 113 ; men- tioned, 21, 23. Rattrayi, Scott, 21. Corophium, Latr., 205. excavatum, G.M. Thomson, 301. Coryca-'idas, Dana, 110, 111. Corycseus, Dana, 110 ; mentioned, 23. anylictis, Lubb., 112. ftircifer, Claus, 110. limbatus, Brady, 111 ; men- tioned, 14-23. obtusus, Dana, 112 ; mentioned, 18-23, 113. pellueidus, Dana, 110 ; men- tioned, 13-23, 111. rostratus, Claus, 110. epeeiosus, Dana, 112; men- tioned, 8, 13-23. styliferus, Lubb., 110. varius, Dana, 110; mentioned, 8, 13-23. venustus, Dana, 111 ; men- tioned, 13-20, 23. Corynura, Brady, 64, 65. gracilis, Brady, 65. Corynuropis, Scott MS., 64. tenuieaudatus, Scott MS., 64. Crabro, Fahr., 487. Crangouyx, Spence Bate, 163, 168, 173, 176-180, 218, 245,251-255, 261, 263, 269. antennatus, PacJcard, 176, 178. bifurcus, Hay, 176, 218. compactus, Chilton, 220 ; mentioned, 163, 166, 172, 174, 180-185, 218-220, 229, 245, 246, 254-257, 261, 262, 269, 282, 301. 72* 532 INDEX. Crangonyx Ermaniiii=Gammarus Ermannii, Milne- Edw., 168, 256. gracilis, Smith, 170, 172, 176, 179, 218-220, 256. lueifugus, Mmj, 176, 178, 219. mucronatus, Forhes, 173, 178, 219, ftnote 220, 269. Packardii, Smith, 176, 178, 179, ( = C. vitreus, Pachard) 1 78. pungeas, Musvj., 256. recurvatiis [recurvus], Orube, 170. recurvus, Gruhe, 169. subterraneus, Spence Bate, 168-174, 256, 276. tenuis. Smith, 172, 176. vitreus, Packard, 170, 172, 176, 178, 256. vitreus, Smith, 178, (^Siygo- bromus vitreus. Cope) 178. (Stygobromus) vitreus, Cope, 172. Cruregens, Chilton, 163, 167, 209- 218, 245, 256, 262. fontanus, Chilton, 211 ; men- tioned, 163, 176, 180-185, 200, 255, 257, 259, 264- 269, 282. Crustacea, Subterranean, of New Zealand : with some general Remarks on the Fauna of Caves and Wells, by Chas. Chilton, 163- 284. Crustacea, Subterranean, origin of, 253-259. Cryptognathus, Kramer, 479. Ctenomorpha, Gray, 472. albopunotatum, A'tVSy *, 472. briarous, Gray, 472. Cyamida;, 209. Cyamus, Lamx., 205. Cyathura carinata, Kroyer, 213. Cyclopicera, Brady, 23, 127. lata, Brady, 23, 127, 158. Cyclopidae, 89. Cyclops chelifer, Miiller, 102. lonyicornis, MiiUer, 70. novae-zealaiidia>, O. M. TJioms., 247. pulcbcllus, Koch, 272. Cymothoa, Fahr., 267. Cymothoidas, 206, 209. Cypbocrania aestuans, Westw., 468. Cyjjhophtbalmus, Jos., 348. Cypria, Zeid-er^ 132, 134. C3-pria atlautica, Scott*, 132, 134; mentioned, 136, 138, 161. exsculpta, Fischer, 134. ophtbalmica, Jurine, 134. CypridiE, 133, 134. Cypridinidffi, 140. Cypris prasina, Fischer, 134. Cythere, MiiUer, 132, 133, 137. costellata, Roemer, 139. multieava, Scott *, 137 ; men- tioned, 132, 160. radula, Brady, 132, 138. rimosa, Scott*, 138 ; men- tioned, 132, 160. sculptilis, Scott *, 137 ; men- tioned, 132, 160. thalassica, Scott*, 138; men- tioned, 132, 160. venusta, Scott *, 138 ; men- tioned, 132, 160. Cytherella, Jones, 132, 144. africana, Scott *, 144 ; men- tioned, 132, 160, 161. pumila, Scott *, 144 ; men- tioned, 132, 160. soolica, Brady, 144. CytbereUidffi, 144. Cytheridce, 133, 137. Cytheridea margaritea, Brady, 139. Cytheropteron, G. 0. Sars, 132, 139. trilobites, Brady, 132, 139, 160. Cytberura, G. 0. Sars, 132, 139. simulans, Scott *, 139 ; men- tioned, 132, 160. Dactylopus, Clans, 23, 98, 100. latipes, Scott *, 99 ; mentioned, 23, 155. propinquus, Scott *, 99 ; men- tioned, 23, 100. Stromii, Baird, 99, 100. tisboides, Claus, 99. Danais arcbippus, Fahr., 487. Descent, Theory of, the Bearings of the rheuomtna of Subterranean Life on the (Chilton), 266-272. Desamine, Leach, 300. Diapheromera Sayi, Gray, 447. Diaptomus, Luhh., 75. duhius, Lubb., 75. lotiyicawlatus, Lubb., 76. Dias, Lilljeb., 65. Diura, Gray, 468. Diura briareus. Gray, 472. ' Dixippus, Stai, 461, 462. cornutus, Kirhy *, 459. crawangensis, De Haan, 461. insularis, Kirhy *, 460. nodosus, De Haan, 46U. sodalis, Kirhy *, 459. sumatranus, De Haan, 458, 459. Donatia, Nardo, 301. Drassidoe, 310. Drepanopus, Brady, 73. furcatus, Brady, 72. pectinatus, Brady, 73, 74. Ectinosoma, Boeck, and Bradya, Boecl; A Eevision of the British Copepoda belonging to the Genera, by Thos. Scott and A. Scott, 419- 446. Ectinosoma, Boecl; 23, 9], 92, 420, 426. armiferum, T. tj- A. Scott *, 434 ; mentioned, 420, 443-445. atlanticum, Brady ^ Roberts., 91, 420, 437, 438, 443- 446. Chrystalii, Scott *, 92 ; men- tioned, 53, 154. curticorne, Boeck, 420, 430, 431, 443-445. Edwardsi, Schmeil, 430. erytbrops, Brady, 420, 431 436, 443-446.' gracUe, T. Sf A. Scott*, 429 mentioned, 420, 439, 440 442-446. Herdmani, T. ^ A. Scott* 432; mentioned, 420, 442- 446. longicorne, T. , 479. Eusiroides c^saris, Stehhim/, 237, 262. Euterpe, Claus, 23, 93. gracilis. Clans, 23, 93, 94, 156. , var. armata, Scott *, 93 ; mentioned, 14, 19-23, 156. Evadne, Loven, 132, 133. Nordmanni, Loven, 132, 133. Eylais extendens, MiiUer, 490, 501, 523. Fauna of the subterranean waters of Canterbury (X.Z.), 240-248. of the Canterbury Plains and their underground waters, 248- 253. Food of subterranean animals, 263. Furcilia, Dana, 298. Gai'tanus armiyer, Giesbr., 71. Galeodes arabs, Koch, 307, 319, 3.34, 336, 351, 374, 385, 38G, 407, 409, 412, 413. aranoides, Fahr., 307, 384, 386 ; genital apertures of, 386. ater, Bir., 374, 384, 385 ; genital apertures of, 386. barbarus, Lucas, 351, 353. caspius, Birula, 407. fatalis, Licht. <|- fferhst, 410. ' gra^cus, Koch, 307. intrepidus, Savigny, 307, 329, 410. Galcodida", The Comparative Morph- ology of the, by H. M. Bernard, 305-417. Gamasidff, 382, 483, 484, 517, 519. Gamasus, Latr., 356, 501, 516. nervous system of, mentioned, 342. Gammarella, Spence Bate, 255. Gammarus, Fahr., 226 ; mentioned, 163, 164, 168, 179, 180, 219, 223, 255, 257, 262, 279, 299. ca3cus, Forel, 171. Caspary, Pratz, 169. Ermannii, Afilne-Edtv., 166, 168. fluviatilis, liiisel, 167, 170, 174, 179, 25b. {=G. Eoeselii, Gervais), 107. , var. d'Emmerin, 179, 200, 272. fossarum, Koch, 168, 171, 255. fragilis, Chilton, 227 ; men- tioned, 163, 172, 179-185, 200, 245, 246, 255, 257, 262, 266,269, 283,301. lacteus, Gervais ^- van Beneden, 166. lougicaudatus, Costa, 167, 169. minutus, Gervais, 172. montanus, Costa, 167. Gammaru neglectus, G. 0. Sars, 225, 227, 228, 229, 232, 237. pule.x, Fahr., 165-167, 171- 178, 257, 258, 280. , var. jun. ?, 167. , var. subterraneus, Schn., 178, 179, 260, 272, 279. pules minutus, Gervais, 166, 174. pungens, Milne-Edw., 166, 168. puteauus, Koch, 166-175, 179, 18.5, 274,276,280. , var. Forelii, Uumhcrt, 174. recurvLis, Gruhe, 169. rhipidiophorus, Catta, 173, 274. lloeselii, Gervais, 166, 167. ( = G. fluviatilis, lioesel), 166. stygius, Sehiodte, 166. subterraneus. Leach, 167. (Niphargus) puteanus, Koch, 174, 276. GibboceUum, Steck:, ftnote 317, 406. Glomeris, Latr., 205. Gluvia, Kuch, 307. Glyptonotus cntomon, Linn., 301. Gnathostoma, Thorell, 24. Goniopelte, Claus, 106. f/racills, Claus, 106, 108, 109. Gouiopsyllus, Brady, 10(). rostralHs, Brady, 106, 108, 109. Goplaua, Wrzesniowski, 180. Grasffea, Brunner, 448. Greenia, Kirhy *, 456. furcatus. Bates, 456. Gynomera, 133. Halocypvinai, Dana, 141. Halocypris, Dana, 132, 133, 141. a.culeata.,Scott*, 142; mentioned, 132, 160, 161. atlantiea, Luhh., 132, 141, 142. brevirostris, Dana, 132, 141. elongata, Scott*, 141 ; men- tioned, 132, 160, 161. imbricata, Brady, 142. punica, Scott *, 143 ; mentioned, 132, 160, 161. torosa, Scott *, 142 ; mentione.j 132, 160, 161. Haplocheira, Hasw., 205. Harpacticinai, BoecJc, 98. Harpacticus, Mihic-Edw., 23, 102. chelifer, MdUer, 23, 102, 157. 534 INDEX. Harpacticus, Brad}-, 102. , Clans, 102. Hemicalanus, Ctaits, 32; mentioned, 8, 23, 31-34. aculeatiis, Brady, 33. longicaudatus, Claus, 17, 34. longicornis. Clans, 32 ; men- tioned, 8, 13-23, 32, 34, 35, 37, 64. lonr/isetosiis, Scott MS., 35. mucronatus, Claus, 33 ; men- tioned, 15, 18, 20, 23, 33. orientalis, Brady, 33. plumosus. Clans, 33 ; mentioned, 13, 17, 21, 23, 145, 150. Hermarchus, St&l, 448. "Hermogenes, 8tSl, 456. cristatus, Kirhy *, 457. femorata, Stall, 456. Hosei, Kirhy ^, 457, 475. personatus. Bates, 456. verrucosus. Be Haan, 456, 457. Hersiliodes, Cann, 23, 118. Livingstoni, Scott *, 118 ; men- tioned, 22, 158. Hessella, Brady, 131 ; mentioned, 8, 23. cyliudrica, Brady, 131 ; men- tioned, 23. Heterocalanus, Scott *, 39 ; men- tioned, 23. serrieaudatus, Scott, 41 ; men- tioned, 13, 23, 39, 146. Heterocha3ta, Clems, 43 ; mentioned, 23. spinifrons, Clavs, 43 ; men- tioned, 13-21, 23, 44. Heteropteryginas, 472. Heteropteryx anstralis, Kirhy *, 472. Dehaanii, Westw., 473. Hyalella, Smith, 254. Hydrachnidse, 490, 498, 499, 503, 517. Hydrodroma, Koch, 490, 491, 494, 496, 498, 501. Hj-menoptera, parasitic, 450. Hymenosoma lacustris, 301. Hyperina, Erichs., 204, 206. Hyssura, Norm, tf- Stehhing, 206, 207, 217, 218. producta. Norm. S,- Stehhimj, 210. lanthe, Bovallins, 202, 203, 274. Ichnosoma, read Ischnosoma. G. 0. Sars, 203. Ichtliyophorba, LiUJeh., 77. violacea, Claus, 78. Icilius, Dana, 205. Idotea, Fair., 170, 205, 209. elongata, xMiers, 205, 208. lacustris, G. M. Thomson, 253, 254, 300. Idoteidifi, 204, 206, 207, 208, 214. Ifionys, Kroi/er, 60. Ilyopsyllus, Brady ^- Roberts., 101 ; mentioned, 23. afflnis, Scott*, 101 ; mentioned, 8, 23, 100, 155. coriaceus, Brady cj- Roberts., 101. Iphigenia, G. M. Thomson, 205. Iscbnopoda, Grandidier, 466, 468. brevitarsis, StSl, 466, 468. episcopalis, Kirhy *, 466. Phillipsi, Kirhy *, 467, 475. Reyi, Grandidier, 466. Ischnosoma, G. 0. Sars, 203. Isopoda, 163, 167, 185-218. Itea erassicornis, KocJi, 177. Ixodes, Latr., 382. calcaratus, Bir., 406. Isodida?, 483. Janira, Risso, 202. Kirby, W. F., On some new or rare Phasmid* in the Collection of the British Museum, 447-475. Labidocera, Luhb., 82 ; mentioned, 23. acuta, Dana, 85 ; mentioned, 23, 83. acutifrons, Dana, 85 ; men- tioned, 20, 23, 83. Darwinii, Luhb., 83 ; mentioned, 23, 85, 151. detruncata, Dana, var., 17, 2.3, 83. , var. intermedia, Scott *, 82; mentioned, J 3, 14, 17, 151. Lnhhocldi, Giesbr., S3. Labidophorus, Kramer, 483. NicoletieUa, 483. Laophonte, Philipin, 96 ; mentioned, 23. brevicornis, Scott *, 97 ; men- tioned, 123, 155. curticauda Boeck, 97. Laophonte longipes,/Sco<<*, 96 ; men- tioned, 20, 23,, 154. pygmjca, Scott *, 97 ; men- tioned, 20, 23, 154. serrata. Clans, 96; mentioned, 23, 99, 156. similis, Clems, 97. Leander fluviatiUs, 301. Leuckartia, Clans, 44 ; mentioned, 23. flavicornis, Claus, 44 ; men- tioned, 13-21, 23. Lichomolgus, Thorell, 120 ; men- tioned, 23, 44. congocnsib, Scott*, 120; men- tioned, 23, 121, 158. fucicolus, Brady, 1 20, 121. propinquus, Scott, 22. Lilljeborgia, Claus, 98. linearis, Claus, 98. Limnoria, LeacJt, 206, 208, Limnoriidae, 209. Limnorina, 209. Limulus, Mailer, 305. Lonchodes Batesii, Kirhy *, 452. brevipes. Gray, 453, 462. Catori, Kirhy *, 454. furcatus. Bates, 456. nigropunetatus, Kirhy *, 453. personatus. Bates, 456. PfeifFerae, Wesiw., 451. uniformis, Westw., 462. virgatus, Kirhy *, 452. Whiteheadi, Kirhy *, 451. Lonchodinse, 450, 463. Longipedia, Clems, 91 ; mentioned, 23. coronata, Giesbr., 91. , var. minor, T. & A. Scott, 91. minor, T. ^- A. Scott, 91 ; men- tioned, 18, 22, 23, 156. Longipediinoe, Boeck, 91. Lubboekia, Claus, 115; mentioned, 23. squillimana, Claus, 115; men- tioned, 14-23. Lumbriculidse, 247. Lycosa, Latr., 331, 332. Lysianassidoe, 205. Lysiopetalum lactarium. Say, 257, 265. Machairopus, Brady, 104 ; men- tioned, 23. INDEX. 535 'Machairopus idyoides, Brady, 104 ; mentioned, ] 4, 20, 23. Machilis variabilis, Say, 106. Maia, Lavr., 298. Malacostraca, Lair., 166. llalpighian vessel, 490. Mantid*, or Praying Insects ( W. F. Kirhy), 449. Mantis necydaloides, Linn., 473, 474. rossia, Fahr., 473. Mecynocera, /. C. Thomps., 80 ; mentioned, 23. Clausi, /. C. Thomps., 80 ; men- tioned, 15-18, 21, 23, 145, 146. Megacrania Batesii, Kirhy *, 471. phelaus, Westw., 470, 471. Metopa, Boecl; 20 7. Metridia, Boecl; 41. Michael, A. D., The Internal Anatomy of BdeJla, 477-528. Microstella, Brady i|' Eoberis., 91 ; mentioned, 23. atlantica, Brady tf- Eoherts., 91 ; mentioned, 13-21, 23, 437. Miracia, Dana, 102 ; mentioned, 23. efferata, Dana, 102; mentioned, 13-21, 23, 103. minor, jScoW *, 102 ; mentioned, 28, 104, 155. Molgus, Dujardin, 478. Monops, Lubh., 87, 88. Montagua, Science Bate, 207. Mornionilla, Gieshr., 64 ; mentioned, 23. phasma, Gieshr., 64 ; mentioned, 18, 21, 151. Munna, Kroyer, 203, 275. Munnopsis, Hars, 205. Mygale, Latr., 338, 378. brain of, mentioned, 344. Myodocopa, 134, 140. Myronides Pfeiffera>, var. (?), Westxv., 451. Mysidopsis incisa, Sars, 301. Mysis, Latr., 298. Naidomorpha, 247. Nauplius, Miiller, 297. New Zealand, the Subterranean Crustacea of : with some General Remarks on the Fauna of Caves and Wells, by Chas. Chilton, 163- 284. Niphargus, Schiodte, 164-170, 173- 180, 218-225, 245, 251, 254, 255, 258, 259, 263. a.<\u\\e-s., Schiodte, 165-173, 179. caspius, Grimm, 174, 175. croaticus, Jui-inac, 178. fontatius, Spence Bate, 168, 169, 172, 266, 276. Forelii, Humbert, 175, 177, 252, 258, 260 ( = N. puteanus, A'ot7i, var. Forelii, Humbert), 258. Kochianus, Spence Bate, 168, 169, 171, 172, 276. Monie/.i, Wrze'sniowski, 180. montanus, G. M. Tliomson, ftnote 254, 285, 301. Mortoni, G. M. Thomson, ftnote 254. orcinus, Joseph, 170, 176, 177. pontious, Cxei-niavski, 169, 175. puteanus, Spence Bate, 168, 173-180,222,226,237,261, 274, 277, 278. , var. Forelii, Humbert, 165, 166, 171, 173,175,177,226, 230-258, 277. , var. onesiensis, 173, 179. -, var. Vejdovskyi, Wrze'- nioirski, 180. ratisbonensis, Wrzeiniowski, 166. Btygius, ScJdudte, 167, 168, 169, 171, 172, 177. subterrancus, £<2. acuta, Dana, 85. acntifrons, Dana, 85. inermis, Brady, 85 ; mentioned, 21, 22, 24,"86. mediterranea, Claus, 86 ; men- tioned, 24, 87, 151. , var. gaboonensis, Scott *, 86. plumata, Brady, 89. securifera, Brady, 86 ; men- tioned, 21, 22,^24. turgida, Dana, 89. PontellidsB, 40. Pontellina, Dana, 88 ; mentioned, 24. mediterranea, Claus, 86. plumata, Dana, 88 ; mentioned, 13-20, 24, 89. PontellinsB, 82. Pontellopsis, Brady, 87 ; mentioned, 24. villosa, Brady, 87 ; mentioned, 14, 21, 22, 24, 88, 151. Pontia, Milne-Ediv., 85. Pontia brassicffi, Linn., 487. Pontocypris, G. 0. Sars, 136 ; men- tioned, 132. subreniformis, Scott *, 136 ; mentioned, 132. trigonella, G. 0. Sars, 136 ; men- tioned, 132. Pontopsj'Uus, /Scoii*, 131 ; mentioned, 24. elongatus, Scott *, 131 ; men- tioned, 24. Potamopyrgus, Stimps., 248. autipodum. Gray, 246. , var. spelsea, Frauenf., 246. Praying Insects, 449. Presbistiis, Kirhy *, 475. peleus, Gray, 475. Prisomera, Gray, 456. spinicollis. Gray, 456. Promachus, St&I, 449. doreyanus, Bates, 464. sordidus, Kirhy *, 463, 475. Prostigmata, 479, 480, 481, 488. Pseudanthessius, Claus, 121 ; men- tioned, 24. propinquua, Scott *, 121 ; men- tioned, 24, 158. ThoreUi, Brady, 121. Pseudophasma, Kirhy *, 473, 474. INDEX. 537 Pseudophasma necydaloides, Linn., 473, 474. Pseiidophasmiiia?, 473, 474. Pseudosforpionidie, 308, 314, 3:i4. Pseudotremia, Co^je, 2(51. cavernarum, Cope, 257, 265. Rattray, John, Ecport on Entomo- straea from the Gulf of Guinea, collected by (Thos. Scott), 1-161. , Introductory Remarks, 2. Reproductive organs of Galeodids, 384. Rhaphidorus, Serv., 470. Khax, Hcnn., 307-309, 313, 318, 326, 346, 349-355. melana, Koch, 347. nig;rocincta, Bernard, 384 termes, Karsch, 407. Rhincalanus, Dana, 30 ; mentioned, 24, 32. aculeatus, Scott *, 31 ; men- tioned, 24, 32, 146. cornutus, Dana, 30 ; mentioned, 8, 13-22, 24,31, 40. gigas, Brady, 31. Ruppia maritima, mentioned, 264, 260. Saphir, Linn., 106. rostratus, Linn., 106. Saphirella, Scott*, 126; mentioned, 24. abyssicola, Scott *, 126 ; men- tioned, 17, 24. 158, 159. Saphirina, /. C. Thomps., 122; men- tioned, 24. (yUndrica, Lubb., 125. elec/nns, Lubb., 122. inaequalis, Dana, 122; men- tioned, 16-22, 24. metallina, Dana, 125 ; men- tioned, 13-21, 24, 156. nigromaculata, Claus, 18, 122. opaca, Lxdih., 124 ; mentioned, 15-19, 24. opalina, Dana, 123; mentioned, 15, 19, 22, 24. ovalis, Dana, 122; mentioned, 13-19, 24. eerrata, Bradi/, 123 ; mentioned, 17, 20, 21,' 24. sinuicauda, Brady, 125 ; men- tioned, 24. SECOND SERIES. — ZOOLOGY, VOL Saphirina splendcns, Dana, 124 ; mentioned, 15, 17, 19, 21, 22, 24. stellata, Gieshr., mentioned, 122. stijUfera, Lubb., 113, 126. ThoiHSoni, Lubb., 123. Saphirinella, Claus, 126 ; mentioned, 24. pellucida, Claus, 113. styUfera, Lulih., 126; mentioned, 13-22, 24. Sarsiella, Norm., 140 ; mentioned, 132. Murrayana, Scott *, 140 ; men- tioned, 132, 160, 161. SchizonotidiB, 314. Schizonotus, 30s, 310, 313, 324, 326. Schizopod, On a Freshwater, from Tasmania, by G. M. Thomson, 2So- 303. Scolecithrix, Brady, 47 ; mentioned, 24, 48. ahyssalis, Giesbr., 52. affiuis, Dana, 51. Bradyi, Gieshr., 51 ; mentioned, 13-20, 24, 149. ctenopus, Gieshr., 48 ; mentioned, 13-18, 24, 49. Danae, Lubb., 49 ; mentioned, 13-22, 24, 47-55. dubia, Gieshr., .53 ; mentioned, 24, 147. latipes, Scott *, 52 ; mentioned, 24, 147, 149. longicornis, Scott *, 50 ; men- tioned, 17, 24, 140. major, Scott *, 52 ; mentioned, 24, 147, 149. minor, Brady, 50 ; mentioned, 13, 16, 21, 24. securifrons, Scott *, 47 ; men- tioned, 13, 24, 47, 50, 51, 148, 149. simidans, Scott MS., .53. tenuipes, Scott*, 48 ; mentioned, 13, 14, 18, 149. turaida, Scott *, 52 ; mentioned, 24, 53, 147. Scorpio, Litm., 312, 314, 316, 324. ScorpionidsB, 308, 314, 348. Scott, Andrew, A Revision of the British C'opepoda belonging to the Genera Bradya, Boecl; and Ecti- VI. nosoma, BoecJc: see Scott, Thos., 419-446. Scott, Thos., Report on Entomostraca from tho Gulf of Guinea, collected by John Rattray, 1-161. Scott, Thos., & Scott, A., A Revision of the British Copepoda belonging to the Genera Bradya, BoecL; and Ectinosoma, Boeck, 419-446. Sense-organs of Galeodidae, 345. Serpukc, 264. Setella, Dana, 109 ; mentioned, 24. gracilis, Dana, 1U9 ; mentioned, 13-21, 24. Siphonostoma, Erichs., 127. Solpuga, Uerhst, 307, 309, 311. fiaveseens, Koch, 353. paludicolla, Pucock, 407. " Spectres," 447. Sphferoma, Latr., 300. Sphtcromidac, 209. Sphinx ligustri, Linn., 487. Stenetrium, 202, 205. Stenhelia, Boeck, 95 ; mentioned, 24, 99. accraensis, Seott *, 95 ; men- tioned, 19, 24, 154. hispida, Brady, mentioned, 96. ima, Brady, mentioned, 96. Stenheliina3, 95. Stenothoe, Dana, 207. Sthenobasa tuberculata, Kirhy*, 462. " Stick Insects," 447. Stratocles bogotensis, Kirhy *, 474. Stygobromus, Cope, 218. vitreus, Cojie, 170, 172, 178. Subterranean animals, food of, 263. Crustacea of Xew Zealand ; with some general Remarks on the Fauna of Caves and Wells, by Chas. Chilton, 163-284. Crustacea, origin of, 2.53- 259. Fauna, special characters of the, 259-268. — — , arrested development, 265. , colour, 259. , compensation for loss of eyesight, 261. , habits, 265. , loss of eyes, 260. 73 538 INDEX. Subterranean Life, bearln<2:s of tlie phenomena of, on the Theory of Descent, 2G6-272. Waters of Canterbury (N.Z.), Fauna of, 248-253. Tachidiinfe, 93. Tanaidip, 204, 205, 206. 207. Tanais Oerstedii, Kroyer, 205, 274. Tarantula tessellata, Pococh, 312. Tasmania, On a Freshwater Schizopod from, by G. M. Thomson, 285- 303. Temora, Baird, 75 ; mentioned, 24. armata, Claus, 77. dubia, Liihh., mentioned, 21, 22. duhki, Brady, 75. finmarchica, Baird, 70. longicornis, Miiller, 76 ; men- tioned, 16-22, 24, 1.53. stylifera, Dana, 75 ; mentioned, 8, 13-20, 76, 77. Temoropia, Scott *, 79 ; mentioned, 24. mayumbaensis, Scott*, 79 ; men- tioned, 24, 153. Thalestris, Clans, 100 ; mentioned, 24. forficula, Claus, 100; mentioned, 24, 101, 157. Thaumatopsyllus, Scott MS.. 104. Thelyphonidte, 308, 314, 326. Thelyphonus, Latr., mentioned, 310- 316, 318, 324, 326, 337,338, 348, 355, 356. Theory of Descent, bearings of the phenomena of Subterranean Life on the, 266-272. Theridion, Walch, 247. Thomson, George M., On a Freshwater Schizopod from Tasmania, 285- 303. Thrasyllus, Stdl, 455. macilentus, Stdl, 455. Thyas, Koch, 491, 496, 500, 501, 507. petrophilus, Michael, mentioned, 486, 490-504, 507, 523. Thysanopodidae, 285. ThysauuridK. 480, 488. Titanethes, Schiodte, 167, 175, 177. albus, Schiodte, 167, 168. albus (=Pherusa alba, Koch), 177. alpieola, Heller, 177. brevicornis, Joseph, 1 77. feneriensis, Parona, 175, 177, 278. fracticornis, Joseph, 177. graniger, Frivcddsl-y, 177. TrachysphiEra, Heller, 265. S'chmidtii, Helle.r, 265. Triarthrus Beckii, Green, 380. Trichodactylus anonymus, Berlese, 501. Trinra, TellTcampf, 166. cavernicola, Telllccnnpf, 166. TrombidiidK, 479, 480, 481, 488, 499, 517. Trombidium, Fahr., 334, 482-496, 501, 504, 512, 515, 518. Trombidium fuliginosum, Herni., 489, 490, 498, 501, 503, 507, 511,512, 523. Tryphosa antennipotens, StehUng, 237. Typhloniscus, Salt., 168, 177. ateimi, ScJibbl, 168, 175, 177. stygins, Joseph, 177. Tyroglyphida-, 485, 501. Tyroglyphus, Lcttr., 494. Undina, Dana, 44; mentioned, 24,46. Danee, Lubb., 49. Darwini, Lid)h., 45. longipes, Lubb., 45. messinensis, Clans, 46. pulchra, Lubb., 57. vulgaris, Dana, 44 ; mentioned, 8, 13-22, 24, 45. Vasilissa, Kirbi/ *, 468. Walkeri, Eirh)/ *, 469. Vermilia, Lam., 264. VorticeUa, Linn., 246. " Walking Sticks," 447 Xenomaches, Kirhy *, 470. incommodiis, Butler, 470. Xestoleberis, 0. 0. Sars, 139 ; men- tioned, 132. margaritea, Brady, 139 ; men- tioned, 132. rRINTED BY TAYLOE AND FKAKCIS, BED LION COURT, FLEET STKEET. ERRATA. Page 132, line 17, for pumilla read pumila, Scott. Page 203, line 33, for Iclinosoma read Ischiiosoma. Page 209, line 8, for Sphaeronidse read SjjhEeromidae. Page 247, line 22, for Phreotoicus read Phreatoicus. Page 280, first line, for vol. xxiv. read vol. xxix. Page 468, line 20, for Ann. Nat. Hist. (5) viii. p. 151 (1891) read (6) viii. &c. LINNEAN SOCIETY OF LONDON. JIEMUilANDA CUNCEKNING TllAXSACTIONS. The First Series of the Transactions, coutaiiiing both Botanical and Zoological contributions, has been completed in 30 Vols., and a few entire sets are still for sale. Only certain single volumes, or parts to complete sets, may be obtained at the original prices. 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