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Ve S) = O = =r i. 4 a ye, es JLILSNI NVINOSHLINS S3!IY¥VYdIT LIBRARIES SMITHSONIAN _INST aes = is = < i ee) NX = 2 2 4: ay > \ ES t= > ke yy . i“ *. = - MS: 2 =. he? m YN \S . m 2 , m ep) - = a) a n ARIES SMITHSONIAN INSTITUTION NOILALILSNI NVINOSHLINS S3li JLILSNI NVINOSHLINS S31YVYE!IT_ LIBRARIES SMITHSONIAN INST NVINOSHLIWS ~» SMITHSONIAN NVINOSHLINS SMITHSONIAN Ys Gy NVINOSHLIWS = x és - a = ai W Uy, 5 4 a 4 = tihipy, A — “ SS oe = a4 ot i z @ oe z ” Bie NLILSN! NVINOSHLINS S3IYVYEIT LIBRARIES SMITHSONIAN INS 8 w Fad ees (op) —_ s = y = WS = Sou z = ee i AS ‘Ss 4 zs : IGM AWS 3 2X E o Gig = S\ 2 = = > = . > = w Ps wn ee ” SARIES SMITHSONIAN INSTITUTION NOILNLILSNI NVINOSHLINS S31 = x. w QE ©) 4, SN N Dy: es PAY i eS Es sO, SON 7 ; A << ian gh ae v4 Pe J ey cy - AN ac. 18 Lp = ([z cA 6) Sf ILSNI FES nics Ads is, . « 1. if Miva ‘ . Vane THE ANNALS AND MAGAZINE OF NATURAL HISTORY, INCLUDING ZOOLOGY, BOTANY, ann GEOLOGY. (BEING A CONTINUATION OF TIE ‘ANNALS’ COMBINED WITIL LOUDON AND CHARLES WORTH’S ‘ MAGAZINE OF NATURAL HISTORY.’) CONDUCTED BY ALBERT C. L. G. GUNTHER, M.A., M.D., Ph.D., F.R.S., WILLIAM CARRUTHERS, F.R.S., F.L.S., F.G.S., AND WILLIAM FRANCIS, Ph.D., F.LS. VOL. X.—SIXTH SERIES. ae a a a a iat xhsonia j / o he Ccres Wotin, LONDON: PRINTED AND PUBLISHED BY TAYLOR AND FRANCIS. SOLD BY SIMPKIN, MARSHALL, HAMILTON, KENT, AND CO., LD. ; WHITTAKER AND CO.: BAILLIPRE, PARIS = MACLACHLAN AND STEWART, EDINBURGH : HODGES, FIGGIS, AND CO., DUBLIN: AND ASHER, BERLIN, 1892. “ Omnes res create sunt divine sapientix et potenti testes, divitie felicitatis human :—ex harum usu onitas Creatoris; ex pulchritudine sapientia Domini ; ex ceconomid in conservatione, proportione, renoyatione, potentia majestatis elucet. Harum itaque indagatio ab hominibus sibi relictis semper estimata ; a veré eruditis et sapientibus semper exculta; maleé doctis et barbaris semper inimica fuit.”’—Linnaus. “Quel que soit le principe de la vie animale, il ne faut qu’ouvrir les yeux pour voir qu’elle est le chef-d’ceuvre de la Toute-puissance, et le but auquel se rappor- tent toutes ses opérations.”—Bruckner, Théorie du Systéme Animal, Leyden, 1767. yo 3S ee sien. -Dhersylvan) powers Obey our summons; from their deepest dells The Dryads come, and throw their garlands wild And odorous branches at our feet; the Nymphs That press with nimble step the mountain-thyme And purple heath-flower come not empty-handed, But scatter round ten thousand forms minute Of velvet moss or lichen, torn from rock Or rifted oak or cavern deep: the Naiads too Quit their loved native stream, from whose smooth face They crop the lily, and each sedge and rush That drinks the rippling tide: the frozen poles, Where peril waits the bold adventurer’s tread, The burning sands of Borneo and Cayenne, AU, all to us unlock their secret stores And pay their cheerful tribute. J. Tayror, Norwich, 1818. CONTENTS, OF VOL, X. [SIXTH SERIES.] NUMBER LV. I. Natural History Notes from H.M. Indian Marine Survey Steamer ‘ Investigator,’ Lieut. Gordon 8. Gunn, R.N., commanding. —Series II., No. 4. Some Observations on the Embryonic History of Pteroplatea micrura. By A, Aucock, M.B., Surgeon-Naturalist to pe SOE GOVE eee Inte DE Vio) code usclate nis doe. Sank ove ce Gay whee aa mks IT. On some new or little-known Fishes obtained by Dr. J. W. Evans and Mr. Spencer Moore during their recent Expedition to the Province of Matto Grosso, Brazil. By G. A. BouLENGER. (Plates Rent meee ats eta ei erase in wie dsl a Sains yh Nd eee aan gh oh IIf. On some Teeth of new Chimeroid Fishes from the Oxford and Kimmeridge Clays of England. By A. Smrra Woopwarp, F.LS., F.Z.S., of the British Museum (Natural History). (Plate II.) IV. On the Genus Hypocala, a Group of Noctuid Moths. By POUT, Gets ere BSE Ay OCs 6 viele «ale « didn eal Kale oa V. Description of a new Species of Acomys. By OLDFIELD MAS een Lara Ade ere aries nee ach avs La oi Vee nsf a Walser E «el de VI. General Observations on Fission and Gemmation in the Animal Kingdom. By Dr. Franz von Waanprr, Assistant in the Zoological Institute of the University of Strassburg ...........005 VII. On some undescribed Cicadide, with Synonymical Notes. aE CeO SANNAY lena ete nua sais Rae aa «ok ase wt ese U5 mele Mos VIII. The Apodemes of Apus and the Endophragmal System of Astacus. By Henry M. Bernarp, M.A. Cantab. (Plate V.).... IX. On a new Genus of Oligochieta, comprising Five new Species, belonging to the Family Ocnerodrilide. By Frank E. Brpparp, M.A., F.R.S., Prosector to the Zoological Society of London. CieMeiieseg Vilar Aer WEES git datas whic pa wicld okies Vie Hie a ke as weer Page 9 74 1V CONTENTS. Page X. Notes from the St. Andrews Marine Laboratory (under the Fishery Board for Scotland).—No. XIII. By Prof. M‘Inrosu, M.D EDS Ee RS., dec. ey (Plate WL) x was cieleve «iim nye iein oie 97 XI. Descriptions of Seven new Species of Birds from the Sandwich Islands. By the Hon. WALTER ROTHSCHILD ..-....e+ seer eee es 108 Proceedings of the Geological Society ....seeeseeceereeees 112—115 On some new Coccidiide parasitic in Fishes, by M. P. Thélohan; On the Dissemination of Hirudinea by the Palmipeds, by NM Jules de Guwerke! <2 xe we cine cle cto etree etm einoiele wre emer 115—117 NUMBER LVI. XII. On the Shells of the Victoria Nyanza or Lake Oukéréwé. By Ep@ar A.Smiru. (Plate XII. figs. 3-6, 8-16.).............. 121 XI. Further Additions to the known Marine Molluscan Fauna of St. Helena. By Enear A. Smitru. (Plate XII. figs. 1, 2, & 7.) 129 XIV. Further Notes on the Oviparity of the larger Victorian Peripatus, commonly known as P. Leuckartz. By ArtHur Drenpy, PDS Cian « Povepewtigs ae Ops Sangalo.» Gel Moet os aioe au oleae at ee tea 136 XV. On British Myside, a Family of Crastaeea Schizopoda. By the Rev. Canon A. M. Norman, M.A., D.C.L., F.R.S., &e. (Plates TX: SX ayre 56 Sagi ce diufsneted de Schon cai et Ap tae ee 143 XVI. Notes on the Genus Coturniz. By W. R. Oatrviz-Grant, Napural-Eitstory seu 4p. oc tce) oo ote a ates tae oboe mites eae eae 166 XVII. Deseriptions of Three new Species of Saturniide in the Collection of the British Museum. By W. F. Kirpy, F.L.S., F.ES., Assistant in Zoological Department, British Museum (Natural History). (Plater Xi). sisi. .t sneak oS eee eee 1738 XVIII. Supplementary Note on the Neuroptera of the Hawaiian Islands. By Ropert McLacuian, F.R.S. &e. XIX. Descriptions of Three new African Muride. By OLDFIELD SPAOMAB * «.-5:.:%. s'eNele% 81-0 ausaie i ait foe eke te ORReRSRNG lek”. Tole a me ees 179 XX. On the Japanese Cleride. By G. Lewrs, F.L.S........... 183 XXI. ee ae of anew Species of Ornithoptera, of the Priamus Group, in the Collection of the Hon. L. Walter Rothschild. By ROBT T eel UEPP ON 6 9.2 ood toate dkte hol oten dtea See Siete 198 Diagnosis of a new Mexican Geomys, by Oldfield Thomas; The History of the Freshwater Nemerteans, their Geographical Distribution and their Origin, by M, Jules de Guerne .... 196, 197 CONTENTS. NUMBER LVII. XXITJ. On some new or rare Crustacea from the Firth of Forth. By Tuomas Scort, F.L.S., Naturalist to the Fishery Board for Scotland, and ANDREW Scotr. (Plates XV.& XVI.)............ XXIII. Natural History Notes from H.M. Indian Marine Survey Steamer ‘ Investigator,” Lieut. Gordon 8, Gunn, R.N., commanding. —Series II., No. 6. A case of Commensalism between a Gymno- blastic Anthomedusoid (Stylactis minoi) and a Scorpenoid Fish (Minous inermis). By A. Aucock, M.B., Surgeon 1.M.S., Surgeon- BUR UTM LO; CHE SHEV Gil nay clsinih occ.56 0) wi, edn we eimps, cian mie Fishes tcn_ase coon 2 XXIV. Descriptions of Two new Bornean Squirrels. By OLDFIELD PERMA eae ecy caatnsur os sits) ate%, sv afelicieke bates in S 6M n io) 6 nla PONDS 8 a9) oid XXY. Spiders from Madeira. By Crecty Warsurron, M.A., Christ’s Co i XX VI. On the Preservation of Teleostean Ova. By Warter E, Corum, St. Andrews University.) 05.5 csi ee nee ecene ase XXVIT. On Fretmotus and Epiechinus (Histeride). By G. Lewis, PLGA, Saat GEIS PAA) aceaPsh,viap Siero aia ctvohanater aie wes CL Urs dlale nieve «Mishaelt XXVIII. Descriptions of Thirteen new Species of Terrestrial and Freshwater Mollusca from South Africa. By James Cosmo MEL- vitt, M.A., F.L.S., and Joun Henry Ponsonsy, F.Z.S. (Plate RAIN Oe acr CBE. ASE) Yaerclg So alte cpt ieron thighs one brejey ad sane g aree}ne Sue epee XXIX. On British Mystde, a Family of Crustacea Schizopoda. By the Rey. Canon A. M. Norman, M.A., D.C.L., F.R.S., &e. ... XXX. Note on the Steatomys of Angola. By OLpFIrLD THoMas. Proceedings of the Geological Society .............00ceecees 265 Note on Dr. Hinde’s Tertiary Sponge-spicules, by Dr. R. v. Lenden- feld; A Contribution to the Knowledge of the Male Sexual Organs of the Diptera, by N. Cholodkov sky, St. Petersburg; A Contribution to the Embryogeny of the Chalcidide, by M. PSB EE PUMEONDV au. Ghote cha ec. 6. wings susoafiase. chess syspn ee 268- NUMBER LVI. XXXI. Notes on the Cuvierian Organs of Holothuria nigra. By EK. A. Mincuin, B.A., Assistant in the Department of Comparative Anatomy, Oxford, eat aaa Vale Meee a tects ale ae tos chars te ns 2 XXXII. Descriptions of some new Species of African es By W. J. Hoxiuanp, Ph.D., F.E.S., Pittsburgh, U.S.A XXXIII. Description of a new Genus and Species of African Moths. ‘By AjG, Burin, EVLS., BiZS., C..00 cocci eae ces XXXIV. On the Noctuid Genera allied to Hypetra of Guenée. Bye oa nere, Gr Burren ELIS. 6B ZSry Cs sie wee ee evel als vlviele wale Idee, Canibridee: (Plate KEV) cai ne.5 were ceed < P Page 201 a 264 —267 271 284 295 297 vi CONTENTS, Page XXXY. Description of a new Species of Helix of the Subgenus Plectopylis. By Lieut.-Col. H. H. Gopwin-Avsren, F.R.S., &e. .. 800 XXXVI. Descriptions of new Reptiles and Batrachians fo the iio: Choorlslands: By G. A: BOUEMNGER {C8 «aie ies «iain ls/olnasssls eta 302 XXXVII. On the Larva of Molge Montandoni. By G. A. Bou- SLU HOLDS eee p inne Gee ee aie remo oe Oilers, Niskpeigegtan unten 304 XXXVUI. Liphistius and its bearing upon the Classification of Spiers 1 Byer POCOCKNS, csc Aen elomuatens vtplsee eateries 306 XXXIX. Revision of the Noctuid Genus Medipotis, Hiibn., with Descriptions of Two new Species. By Arrnur G. Burirr, F.LS., HRA SaaOUC, ver thienase'e os Gute fevemsie byaion) ake puna cg WOM rune atk, ok es 315 New Books :—The Study of Animal Life. By J. ARrHuR THomsoN, M.A. &e., Lecturer on Zoology, School of Medicine, Edinburgh. —Rhopalocera Exotica ; being idlaeerani ane of New , Rare, and Unfigured Species of Butterflies. By H. GrosE Surrm and W, B Kenny, Val 1500 ei abe) eae, SO 828-352 Proceedings of the Geolosical Society ...0 5.5.2.0. russ Sane 333-885 Additional Note on the Occurrence of Lichia vadigo on the Cornish Coast, by Dr. A. Giinther, F.R.S.; On the Stridulating- apparatus of the Red Ocypode Crab, by A. Alcock, M.B.; The Coxal Gland of the Scorpion and its Morphological Relations with the Excretory Organs of the Crustacea, by M. Paul Marchal ; On the Bicahar ater Fauna of Iceland, by MM. Jules de Guerne and Jules Richard; On a Sporozoon parasitic in the Muscles of Decapod Crustacea, by MM. F. Henneguy and P. Wielolian ic. «.cs\s Ina Recle i anueg ste Cesage erence teenie eee eae 300-342 NUMBER LIX. XL. Natural History Notes from H.M. Indian Marine Survey Steamer ‘ Investigator, Lieut. G. S. Gunn, R.N., commanding. —Series II., No. 5. On the Bathybial Fishes collected during the Season of 1891-92. By A. Atcock, M.B, Surgeon-Naturalist to pen SamMeye. » (tate XViD) ao. 5 jaeve tee cbaiepetave-sQeis nabelalen de gh totee vents 345 XLI. On the Origin and Development of the Mammalian Phylum. By er VV URNA asp Sine re eed yee ea easel hers late eee ete 365 XLII. Additions to the Shell-Fauna of the Victoria Nyanza or maker Oukeréw6. By EDGar ‘A. SMITH § wrenrs oe cues eee eae 380 XLII. New and obscure British Spiders. By the Rey. FrrepERIcK OUPickanp-CamBemcE, (Plates XX: & XK XM) eke eee 384 XLIV. Description of a new Moth of the Genus Anaphe from Madagascar, with a Note on the Natural Position of the Genus. By ARTHUR Gurren, F.L.Si, E85 ke. ba weeks oarsmen oe 398 XLV. The Interpretation of the Sponge Organism, and some Recent Works on Sponges. By Dr. Orro Maas ................ 399 CONTENTS. XLVI. Description of a new Species of the Homopterous Family Cicnwti ee ae WN Rte MEST ANE! oe ws ck Gh ea eek ds Ov sifhvaen ees XLVII. Contributions to a Knowledge of the Entomology of the Araue tale Pivot, DUER DANDY << ol cin cc detniginiate sie bop cee sa 8's ola a bce 497 XLVIII. Description of a new Bat of the Genus Artiheus from Tnmdad. -By OLDFInLD THOMAS 03.0.0 ece ce lessees Sotto e wes 408 XLIX. Note on Mexican Examples of Chilonycteris Davy?, aed eget eR OMAR Oe. Sao cu cia yale nee ht wwe ewan gih sly oo . 410 L. Two new Buprestide from Damma Island. By Cuartss O, BUN SeISER TE CRORE SIE oe aecruryior ara Sie: siyceretae Wiese sf sirstitsieaNeval aby chard arm alse ah ain le et RSs 410 Doubly-armoured Herrings, by A. Smith Woodward; The Develop- ment of the Gemmules of Ephydatia fluviatilis, Auct., by W. Zykoff, of Moscow ; On the Habits of Gelasimus annulipes, udw. By A. Alcock, Te Seth aE a ia eg ea 412-415 NUMBER LX. LI. On a new Spider from Calcutta. By the Rev. O. P. CAMBREDGE, NAS) EUR Sins (Blate SAUL) ines oo awwais welns odae's 417 LIT. On the Development of the Pedipalpi. By Dr. A.SrruseEtt, of the Zoological Institute of Bonn am Rhein .......... sete date 419 LIL. Limav maximus, L., and its Variety cinereo-niger, Wolf. By Water E, Cotirner, Demonstrator of Biology in Mason alleen RMP RAM $55, Piacoa AE see wad vis Saline Cera sewe ees 425 LIV. Descriptions of Three new Species of Butterflies captured by Mr. D. Cator in British North Borneo, in the Collection of Mv. Grose SeBitns = ytd, GQROSH SMITE «. ca. ve cs ce wrens oes Sipe 426 LY. On the Morphology and Phylogeny of Insects. By N. Cxo- PARDO WRI a)e oc.cve cs sone ess es Ra eieCeiecatat sath» aialgighcfapers aston Initia roars 429 LVI. Preliminary Descriptions of new Species of Madrepora in the Collection of the British Museum.—Part II. By Grorer Mee OuieeHe Dio, Sais ayers gatas x adinee ears © oe eeekn Cees he ells 451 LVII. Description of a new Species of Slug from South Africa. Pomp Mail Ait SA PANEER ta et iete rine Petes iad ys we tic ds 2 sla es tos.ece 8 465 LVIII. A Criticism of a Modern Hypothesis of the Transmission of Hereditary Characters. By R.S. Beren, of Copenhagen ...... 467 LIX. Description of a remarkable new Semnopithecus from Sarawak. By OLpFIELD THOMAS .............. TRO COE Reon es 475 LX. Description of a new Mexican Bat. By OLpFIrLp Tuomas. 477 New Books :—Fur-bearing Animals in Nature and in Commerce. By Henry Potanp.—Horn Measurements and Weights of the Great Game of the World : being a Record for the use eof Sports- men and Naturalists. By Rownanp WarD .........+.; 478- 480 Vill CONTENTS. Page The Embryonic Development of Comatula (Antedon rosacea), by Oswald Seeliger, of Berlin; On Deglutition in the Synascidie, Dy os.yd DUMONT 2.1. a nuts cae Geet more ae coke aie 48], 482 WIN Ox bes ng Se ee ie Sey wick aa era ao atet AMIS Tc Tea Sra re ahehcvo ta is o 6igrake ook REL OEE PLATES IN VOL. X. Priate I. Loricaria Evansii. II. Tetragonopterus Moorii.—Brachychalcinus retrospina. III, Teeth of New Chimeroid Fishes. IV. Pteroplatea micrura. V. Apodemes of Apus. VE VIL. VII. Clymene ebiensis.—Larva of Lamellaria. ery British Mysidee. XI. New Species of Saturniide. XML New Shells. XIV. Madeiran Spiders. XV. Lichomolgus agilis. XVI. Enterocola eruca. XVI. Cuvierian Organs of Holothuria nigra. XVIII. Hephthocara simum.—Alepocephalus edentulus.—Xenoderm- ichthys Guentheri, XIX. Eretmotus and Epiechinus ae New British Spiders. XXI. XXII. Ariamnes simulans. Anatomy of Gordiodrilus, THE ANNALS AND MAGAZINE OF NATURAL HISTORY. [SIXTH SERIES.] etieee Seencraeneser ss per litora spargite muscum, Naiades, et circiim vitreos considite fontes: Pollice virgineo teneros hic carpite flores: Floribus et pictum, dive, replete canistrum. At vos, o Nymphe Craterides, ite sub undas ; Ite, recurvato variata corallia trunco Vellite muscosis e rupibus, et mihi conchas Ferte, Dez pelagi, et pingui conchylia succo.”’ N. Parthenii Giannettasti Ecl. 1. No. 55. JULY 1892. I.—Natural History Notes from H.M. Indian Marine Survey Steamer ‘ Investigator, Lieut. Gordon S. Gunn, R.N., commanding.—Series II., No. 4. Some Observations on the Embryonic History of Pteroplatea micrura. By A. Aucock, M.B., Surgeon-Naturalist to the Survey. [Plate IV.] 1. Introduction. Proressor Woop-Mason and I have shown that in Ptero- platea micrura the ovum is retained within the uterus, and, further, that the uterine mucous membrane is furnished with nursing-filaments, or trophonemata, which secrete a ‘ milk ”’ that supplies the embryo with nutriment during the later stages of its development and up to the day of its birth. Though we had examined a good many pregnant females, we had not up to the time that our researches were published met with any that exhibited the earlier stages of embryonic development. Butin February last, while the ‘ Investigator’ was surveying the Godavari Delta, I was fortunate enough to capture a female of Pteroplatea micrura (Bl. Schn.) in an early stage of pregnancy—double in the right uterus and triple in the left; and in this.paper I propose to give, first, a Ann. & Mag. N. Hist. Ser. 6. Vol. x. 1 2 Mr. A. Alcock on the short account of three matters of interest in connexion with this specimen, namely: (1) the form of the young embryo itself, (2) the structure and relations of the gill-filaments, which in this stage make up a large part of the bulk of the embryo, and (3) the structure of the maternal nursing-fila- ments, or trophonemata, which at this stage appear to be only preparing for their special secretory function—and, lastly, to offer some suggestions (1) as to the bearing of the facts of the individual history of these embryos upon the problem of the ancestral history of the genus, and (2) as to a possible interpretation through these embryos of the phenomenon of aplacental viviparity among the EKlasmobranch fishes. 2. The Early Embryo of Pteroplatea micrura. The embryo* now to be described is about 29 millim. long ; it has a remarkable generalized shark-like form (fig. 1), its snout, its gill-openings, and its tail having a Selachoid and not at all a Batoid appearance. The snout is produced far beyond the mouth and is bluntly conical. The gill-openings, from whatever aspect seen, are remark- able. From the dorsal view the branchial region forms on each side an inflated chamber in which the broad branchial bars are plainly visible ; anteriorly the first slit forms the wide-open spiracle, but the other slits, five in number, are closed, and are conspicuous only because of the large blood- vessels which run in them. From the side view six nearly equidistant clefts are seen, the first being the spiracle and the other five being still closed but very plainly visible on account of their vascularity. It is only ventrally that the gill-slits, here very short and comparatively inconspicuous, are open to give issue to a cloud of delicate filaments, many of which when straightened out are nearly twice the length of the embryo itself, and the sum of which forms at least one third of the whole volume of the embryo. The trunk is cylindrical and Selachoid and ends in a thick cylindrical shark-like tail, which bears terminally a long ventral and a shorter but deeper dorsal tail-fold. The pectoral jins are large, their base being coextensive with the length of the trunk; each is prolonged forward, parallel with but quite separate from the branchial region, and in the same plane with the head, into a tapering bar, which, however subsequently curled, starts with an inward * One embryo, typical of all, has been selected for this description. Embryonic History of Pteroplatea micrura. 3 twist. If the head were more depressed, and if at the same time the prolongation of the pectoral fins were broader and more truncated, the result would be a by no means fanciful resemblance to Rhina. The ventral fins are small and lie well free from the hinder limit of the pectorals. The embryo is still attached by a broad cord, about 12 millim. long, springing from the belly between the front border of the pectoral tins, to a large yolk-sac, which appears to consist entirely of a diffluent yolk hardly more stable than oil, enclosed in a membrane of extreme tenuity. The gill- filaments are in intimate relation with this yolk, closely and completely enveloping it on all sides. The cord of attach- ment is so delicate, yet so broad withal, that I have not succeeded in cutting complete transverse sections ; but this much is quite certain, both from examination of partial trans- verse sections and from examination of portions of a stained cord mounted flat as transparent objects in glycerine, that it consists of a solid mass of close-packed large-nucleated cells, and is longitudinally traversed by numerous lacuniform channels of very irregular outline and of unequal size, and that these channels contain NOT BLOOD-CELLS, BUT SMALL SPHERULES OF YOLK ONLY. In short, nothing of the nature of a distinctly defined artery or vein, or indeed of any vessel containing blood-cells, is to be made out; and this must be looked upon as a fact of the highest significance, not merely when we come to seek an explanation of the use of the gill- filaments in this species, but when we come to consider the much wider question of embryonic nutrition among the aplacentally viviparous EKlasmobranchs in general. 3. The Gill-filaments of the Early Embryo of Pteroplateea micrura. These issue ventrally from all the gill-slits except the spiracle, and closely embrace the yolk-sac; if they have any additional attachment to the uterine wall it must be of the feeblest nature. Their total volume in the fresh state was not less than one third that of the entire embryo. They vary in length, most of them being considerably longer than the embryo itself; their breadth is about 0°5 millim. and their thickness is quite inappreciable by the unaided eye. A filament stained with caimine, mounted flat in glycerine, and examined as a transparent object under a low power (fig. 2) has a uniformly granular appearance—due to the 1* 4 Mr. A. Alcock on the close crowding of the very large nuclei of epithelial cells that closely invest its surface—and shows a longitudinal light band occupying a little more than its median third, flanked by a dark band occupying on each side a little less than its marginal third; and when the end of the filament is brought into view the lateral dark bands are found to directly inoscu- late round its tip. The dark marginal band is in fact a broad capillary filled with blood-clot, disposed in a long narrow loop. Under a higher power the surface of the filament is seen to be uninterruptedly covered with polygonal epithelial cells in the closest possible contact with one another. These cells are remarkable in consisting of little but a large vesicular nucleus lying within a thin and difficultly visible capsule of cell-protoplasm ; the nuclei have a diameter varying from 7°5 to 10 micromillimetres, and are often polygonal by mutual compression. A transverse section of a filament looks like a pair of pince- nez (fig. 3), each lens of the pince-nez being formed of a cross- section of a simple capillary tube, with a wall one cell thick, enclosed in a frame formed by a single row of large nucleated epithelial cells, and the bridge of the pince-nez being formed of two rows of these cells with a layer of flat nuclei, continued across from the capillary wall on each side, between them. To recapitulate and restate: a gill-filament is nothing more than a long narrow loop of a capillary of wide bore with a wall one cell thick, enclosed in a folded sheet, also only one cell thick, of small epithelial cells which consist of little but a great nucleus. As to the function of the gill-filaments: their vascularity and the nature of their epithelium clearly indicate great activity. ‘They do not seem to have any attachment to the uterine wall, but, on the other hand, the manner in which they enfold the yolk-sac leads to the belief that they assist in absorbing the nutrient yolk. And the irregular indefinite nature of the channels of the stalk of the yoik-sac, which channels, moreover, seem to carry only yolk-particles and not blood, seems to give strong support to this view. 4. The Uterine Trophonemata of Pteroplateea micrura in the Earlier Stages of Pregnancy. The structure of the nursing-filaments when in active function for the benefit of the foetus has already been described and figured by Professor Wood-Mason and myself (vide ‘ Proceedings of the Royal Society,’ vol. xlix. pp. 359-367), Embryonic History of Pteroplatea micrura. 5 and all that is now necessary is to draw attention to the slight but significant differences which are observed in this earlier stage while the embryo has still an ample fund of yolk to draw upon—differences which enable us to picture the mode of development of the milk-secreting elements. In the specimen under notice the nursing-filaments mainly differ to the naked eye from those originally described in being altogether smaller and in being uniformly distributed like a coarse thick fur over the entire surface of the uterine mucous membrane, instead of being restricted to certain definite areas. Their average length is 11 millim. and their average width about 1°25 millim. at the base and about 0°75 millim. near the tip, and they are flat with a tendency to curl. When a trophonema is stained with carmine and examined in glycerine as a flat transparent object, under a low magni- fying power, the blood-vessels first attract attention. Running in the margin, from base to apex on each side, is seen a small artery which at the tip of the filament flows each into its fellow, either in a single loop or, after’ a single acute- angled bifurcation, in a double loop, as shown in fig. 4. All along its course this marginal arterial loop sends off from its concavity numerous small branches, which form a dense super- ficial capillary plexus with its long narrow meshes transverse to the long axis of the trophonema ; and deeply beneath this plexus, running up the middle of the trophonema in its basal half only, is a spiral vein of some size. Higher magnifica- tion shows that the surface of the trophonema is uniformly covered with pavement epithelium, which dips down, but does not become discontinuous, in the slightly excavated inter- capillary meshes. A transverse section of a trophonema (fig. 5) shows at either extreme the artery and near the middle the wider but not very much wider vein cut straight across, the superficial capillaries cut through in various planes, and at the circum- ference of the section an unbroken ring of pavement epithe- lium presenting slight depressions in many places between the cut capillaries. Beneath the epithelium, stretching from artery to artery but not round the arteries, on both faces of the narrow section, is a long close line of pocket- or bulb- shaped nests of cells, which in some cases are quite solid, in other cases are hollowed out in the centre, and in yet other cases form true acini “ pointing,” to use a surgical metaphor, towards the superficial intercapillary depressions of the surface epithelium above alluded to. It is unnecessary to go further into histological detail, since 6 Mr. A. Alcock on the enough has been said to enable us to understand the meaning of these appearances. In transverse sections of a trophonema taken from a long- gravid uterus in which the foetus, having used up all the yolk, is now demanding other nourishment, there is, as has been shown in the paper already quoted, little to be seen but two opposed rows of bulb-shaped milk-secreting glands with funnel-shaped mouths, separated by a vascular space. These glands take the place of the more or less solid nests of cells seen in the above-described sections of trophonemata from a gravescent uterus. And in comparing this less mature with that more mature stage we come to the conclusion that in Pteroplatwa micrura, as Professor Wood-Mason and myself have already shown to be the case in Trygon walga, the secreting glands of the nursing-filaments, like the alveoli of the milk-glands in Mammals, begin as solid nests of epithe- lium, which, with the onset of active secretion, gradually become hollow chambers by the breaking down and exfolia- tion of their core. 5. Considerations as to the Descent of the Pteroplatean Alliance. I hope before long to give a more complete account of the embryonic history of Pteroplatea micrura, from which perhaps it may be more permissible than it can be from the meagre facts just recorded to attempt to retrace the pedigree of the Trygons. But on account of the recent revival of interest in the phylogeny of the Batoidei it will, I trust, be considered pardonable to touch a few points, from all of which we can, without straining, bring these embryos into the field of vision. It is impossible to see these little embryos without in the first place being struck by their shark-lke form ; and when next attention is fixed upon the gill-openings—their con- spicuous dorsad extension and their relation to the prolonged pectoral fins—one is immediately reminded of Rhina. Indeed all that is needed is to straighten out and flatten the pectoral fins and to depress the head in order to get a strong resem- blance to that interesting intermediate form. Or, if we leave the pectoral prolongations untwisted and imagine them in this condition fused with the head, we get a remarkable like- ness to Ceratoptera and Dicerobatis. The descent of the Trygonide from a shark-like ancestor is of course, from what is well known of Raja and Torpedo, only what would be expected ; but I do not know whether or not the suggestion that the line of descent passes (1) through Embryonic History of Pteroplateea micrura. 7 a Rhina-like form, and (2) through a Myliobatoid form, is equally familiar. At any rate it is a suggestion that arises quite naturally from an external view of the pectoral fins and gill-slits of these embryos of Pteroplatea micrura. Professor G. B. Howes, in his most interesting paper ‘ On the Pectoral Fin-Skeleton of the Living Batoid Fishes” &c. (P. Z. 8. 1890, pp. 675-688), incidentally suggests an alliance between hina and the Ceratopterine Myliobatoids; and Herr Otto Jaekel (SB. Ges. nat. Fr. Berlin, March 1890), in a paper of great interest, for the knowledge of which I am indebted to Professor Howes, has drawn attention to the importance of the disposition of the gill-slits in relation to the pectoral fins for the purposes of a natural (phylogenetic) classification of the entire order, and has laid stress upon the Batoid affinities of Rhina. 6. Considerations as to the Origin of Aplacental Viviparity among the Elasmobranchs. If it-is premature to jump from these embryos back to their supposed ancestral relatives, it is equally premature to attempt from them alone to interpret the meaning of the aplacental Viviparity of the Batoid fishes as a whole. The subject, however, is so very tempting that one cannot refrain from recording certain suggestions that naturally arise out of an examination of the yolk-sacs and umbilical cords of these embryos of Pteroplatea. The methods of reproduction among EHlasmobranchs are three, namely (1) oviparity, (2) viviparity with the forma- tion of a placenta, and (3) viviparity without the formation of a placenta. We know how the second naturally arises directly out of the first; the large egg is retained in the terminal portion of the oviduct, and in the process of development, from early common arrangements by which ‘ nutriment from the yolk- sac is brought to the embryo partly through the umbilical canal and so into the intestine, and partly by means of blood- vessels in the mesoblast of the yolk-sac” * and so into the general circulation, we come at last in these viviparous forms to later special arrangements by which, when the yolk is finished, nutriment from the maternal blood-vessels in the uterine mucous membrane is brought to the embryo by means of the greatly developed foetal blood-vessels of a yolk-sac which has now, after the disappearance of the yolk and the * Balfour, ‘Comparative Embryology, 2nd edition, vol. ui. p. 64, 8 On the Embryonic History of Pteroplatea micrura. obliteration of the communication between the umbilical canal and the intestine, become a placenta. Now from the non-vascular condition of the yolk-sac and umbilical canal in the embryos under consideration we may venture to surmise the possibly equally direct origin of aplacental viviparity from simple oviparity. Here again the large egg remains in the terminal portion of the oviduct, and in the process of development external gills which had originally “ very possibly become specially developed to facilitate respiration within the egg” * become otherwise specialized to absorb nutriment from a yolk-sac which has only the single communication with the embryo through the umbilical canal and intestine. When the yolk is all finished the nutriment which is secreted from the maternal glands naturally follows, in the absence of any absorptive blood-vessels in the empty yolk-sac, the already established route through the branchial clefts, one of which (the spiracle), being unobstructed by gill-filaments, becomes at last the exclusive channel of supply. I should like, in concluding this paper, to express my obli- gations to Professor Howes for his extreme kindness in sending out to me on loan, at great risk owing to distance, his own copies of Herr Jaekel’s and others’ papers on the subject of the affinities of the Batoids—an act of kindness and considera- tion which a ship’s naturalist, cut off for months from all but a few standard classics, ean hardly over-appreciate. EXPLANATION OF PLATE IV. Fig. 1. Embryo of Pteroplatea micrura, from dorso-lateral aspect; nat. size, but with only a few of the gill-filaments represented, for the sake of clearness. s, spiracle. Fig. 2. End of a gill-filament, showing the marginal capillary filled in places with blood-clot. x 42, Fig. 3, Transverse section of a gill-tilament, showing the marginal capil- lary in section and the single fold of epithelium. x 188. For the sake of clearness the blood-clot is represented in one limb of the capillary only, and the spaces between the nuclei of the surface epithelium are a little exaggerated. Fig. 4. End of a trophonema, or nursing-filament, seen as a transparent object in glycerine, showing the marginal artery and the super- ficial capillary plexus. x 42, The median vein is not seen so near the end. Fig. 5. Obliquely transverse section through a nursing-filament, showing the glands still in the form of solid bulbs lying beneath a still unbroken surface of epithelium. x 110. a, a, arteries; 2, vein ; ¢, c, superficial capillaries. * Balfour, op. et tom. cit, p. 62. On some new or little-known Fishes from Brazil. 9 IIl.—On some new or little-known Fishes obtained by Dr. J. W. Evans and Mr. Spencer Moore during their recent Hapedition to the Province of Matto Grosso, Brazil. By G. A. BOULENGER. [Plates I. & II.] Plecostomus pantherinus, Kner. Nothing could be more misleading than a division of the fishes of the genus Plecostomus according to the presence or absence of granular plates on the belly. Among the nume- rous specimens of P. bicirrhosus in the British Museum there are some with the belly partly or entirely naked (the latter being young) which are not to be otherwise distinguished from the typical form. Thus, in three specimens (one half- grown and two young) from British Guiana the belly is naked in one young, partly naked in the other, entirely granu- late in the larger specimen. It is therefore very probable that P. seminudus, Kigenmann, will turn out to be merely an individual variation of P. becerrhosus. With regard to the specimens which I refer to Kner’s P. pantherinus, described from a single young specimen from the Rio Guaporé, the much larger eye distinguishes them at once from P. bicirrhosus, their nearest ally; in Kner’s specimen, 3 inches long, the eye measures one fourth the length of the head, whereas it measures only one fifth or one sixth in P. bicirrhosus of similar size. In the adult P. pantherinus the diameter of the eye is one fifth the length of the head, against one seventh or one eighth in P. dicirrhosus. The head is besides larger in proportion to the body in the former than in the latter. ‘Two specimens were obtained by Dr. Evans in the River Jangada, close to Jangada village; the larger measures 200 millim. (to the end of the middle caudal rays), the smaller 170. Form stout. Head as long as broad, one third total length (without caudal) ; snout rounded, with a small naked space at its extremity; an obtuse ridge from the upper angle of the orbit to below the nostril, the sides of the head below it being slightly concave ; an obtuse ridge on the occiput and another on each side behind the eye; interoperculum with small spines. Diameter of orbit one fifth length of head, one third length of snout, three fifths to one half interorbital width, and equal to its distance from the posterior border of the head. Labial fold moderate, papillose, not or but slightly notched ; barbel short. Dorsal 1 7, the first ray as long as or 10 Mr. G. A. Boulenger on some a little longer than the head. Anal 5. Pectoral I 5, nearly as long as the head, and extending beyond the base of the ventral. Ventral 15. Lower caudal lobe longer than upper. Scales 25 5; lateral line 25. Breast and belly partly naked; in the smaller specimen the anterior portion of the belly is covered with granular plates extending right across, in the larger specimen these granulations are confined to the sides and a median strip; 12 scales between the anal and caudal fins. Dark olive-brown, with rather indistinct round black spots, which are smaller and closer together on the head. Plecostomus cochliodon, Kner. Of this remarkable fish, of which, like the preceding, no other but the type, preserved in the Vienna Museum, was hitherto known, a single specimen was obtained by Dr. Evans at Jangada. It measures 180 millim. Its fins are unfortunately much damaged. In every respect it agrees with Kner’s description. Lateral line 28. The difference in the dentition being merely one of degree, and the fish agreeing in other respects so closely with the other species of Plecostomus, I doubt whether it is advisable to separate it as a distinct genus ( Cochliodon). Loricaria Evansit, sp. n. (Plate I.) Teeth well developed in both jaws. Head a little longer than broad, one fourth total length (without caudal) ; snout obtusely pointed, with long bristles on the sides; three short keels on the back of the head; postorbital notch scarcely distinct; diameter of orbit one sixth length of head, two sevenths length of snout, and two thirds interorbital space, which is concave. Labial fold much developed, notched, papillose, and with long cirrhi. Dorsal I 7, the first ray two sevenths length of head, and just above the base of ventrals. Anal I 5. Pectoral I 6, a little shorter than head, extending to base of ventrals. Ventral I 5, as long as pectoral, reaching anal. Upper caudal ray produced in a long filament, half as long as head and body. Lateral scutes 29, with two spinose ridges meeting on the 19th; nuchal scutes with spinose keels ; 20 scutes between dorsal and caudal, 17 between anal and caudal; breast and belly naked, but rough with minute spines ; a series of seven or eight shields between pectoral and ventral on each side of the thorax. Olive-brown above ; a dark band across the nape, and four others between the dorsal and caudal fins ; fins with black spots. Total length 205 millim. new or little-known Fishes from Brazil. 11 A single specimen from Jangada. This fish is evidently very closely allied to L. nudiventris, known from a single specimen from the Rio San Francisco, described by Cuvier and Valenciennes. It differs, however, in having seven or eight shields on each side of the lower surface, between the pectoral and ventral fins, instead of four. Tetragonopterus Moorti, sp.n. (Pl. II. fig. 1.) Length of head 33 times in total length (without caudal), depth of body 2?. Maxillary toothless, extending to below the centre of the eye; diameter of eye 4 length of head, 14 length of snout, equal to interorbital width ; adipose eyelid short. Dorsal I 10, originating above base of ventrals. Anal II 28, originating a little behind the vertical of the base of the dorsal. Pectorals reaching base of ventrals, ventrals reaching origin of anal. Scales 37-38 =; lateral line complete. A black spot behind the shoulder; a silvery lateral stripe, turning to black on the tail and extending on the caudal. Total length 75 millim. Two specimens were collected by Mr. Moore on the Chapala plateau. The nearest ally of this new species appears to be 7. maai- mus, Stdr. (alosa, Gthr.), from the Peruvian Andes, which differs in having the interorbital region wider. BRACHYCHALCINUS, gen. nov. Intermediate between Tetragonopterus, Cuv., and Luetkenia, Stdr. Dentition as in the former, viz. two preemaxillary and one mandibular row of tri- or quinquecuspid teeth; body elevated, with sharp ventral edge. Differing from both in having a movable spine, directed forwards, in front of the dorsal fin. In one of the three specimens (probably a male) this spine is hammer-shaped, its free portion forming a longer anterior and a shorter posterior branch, both of which are sharply pointed ; in the two others (one of which I have ascertained to be a female) the posterior process is wanting and the ante- rior is more developed but not spinose, spoon- or saddle- shaped, rounded at the end, concave below, and fitting into a notch in the back in front of the dorsal fin. The differences in this curious arrangement will probably prove to be corre- lative of the sexes. In Serrasalmo the first interneural bears likewise a spine directed forwards, which is bicuspid behind and scarcely movable. 12. = On some new or little-known Fishes from Brazil. Brachychaleinus retrospina, sp.n. (Pl. IL. fig. 2.) Length of head 4 to 44 times in total length (without caudal), depth of body 14 to 13. Maxillary toothless, nearly vertical, not extending beyond the anterior border of the eye; diameter of eye half length of head, once and two thirds length of snout, equal to interorbital space; dorsal profile ascending abruptly from above centre of eye; a very short adipose eyelid in front. Dorsal I 11, just behind vertical of base of ventrals. Adipose fin well developed. Anal II 31-34. Pectorals slightly shorter than head, not quite reaching ventrals. Latter small, I 6. Scales 33-35 =; lateral line complete. A silvery lateral stripe; fins speckled with black, adipose black-edged. ‘Total length 80 millim. Three specimens, from Santa Cruz. I seize this opportunity to point out that Pseudocorynopoma Dorie, Perugia, Ann. Mus. Genova, (2) x. 1891, p. 646, fig., and Bergia altipinnis, Steindachner, Anz. Ak. Wien, 1891, p- 173, and SB. Ak. Wien, C. 1. 1891, p. 366, pl. il. fig. 2, are identical. Perugia’s description (April) has priority over Steindachner’s (July). The other species represented in Messrs. Moore and Evans’s collection are the following :— Acara viridis, Heck. Corumba. Pimelodus, sp. (young). Chapala Plateau. Macrodon trahira, Bl. Schn. Corumba. Erythrinus uniteniatus, Spix. Corumba. Pyrrhulina semifasciata, Stdr. Corumba. Leporinus megalepis, Gthr. Santa Cruz. Tetragonopterus orbicularis, C. & V. Santa Cruz. lacustris, Rhdt. Corumba. rivularis, Ltk. Chapala Plateau. Chalcinus paranensis, Gthr. Corumba. Xiphorhamphus ferox, Gthr. Santa Cruz. EXPLANATION OF THE PLATES. Prank Te Loricaria Evansii, 4 nat. size. PuateE II, Fig. 1. Tetragonopterus Moor. fig. 2. Brachychaleinus retrospina. On some Teeth of new Chimeroid Fishes. 13 IIIJ.—On some Teeth of new Chimeroid Fishes from the Oxford and Kimmeridge Clays of England. By A. Smitn Woopwarp, F.L.S., F.Z.S., of the British Museum (Natural History). [ Plate IIT.] NOTWITHSTANDING the fact that the number of forms of Chimeroid teeth known from Mesozoic formations is already large, there are still several specimens in the British Museum that cannot be assigned to the genera and species as yet described. More especially does this remark apply to the collection of Alfred N. Leeds, Esq., of Eyebury, lately received ; for if the characters of the teeth can be relied upon in generic diagnoses (as seems probable), the small series of specimens from the Oxford Clay of Peterborough, collected by Mr. Leeds, makes known the occurrence of two distinct genera hitherto unrecognized. There are also some small teeth from the Kimmeridge Clay of Weymouth, which are partly identical with one of Mr. Leeds’s fossils, and partly seem to indicate even a third genus as yet unknown in the Jurassic. It is with the systematic arrangement of these specimens that the present communication deals. A general summary of existing knowledge on the subject of the Mesozoic Chimeroid fishes will be found in the second part of the British Museum ‘ Catalogue of Fossil Fishes,’ and the following descriptions are arranged to be uniform in style with that work. Genus PACHYMYLUS, nov. Diagnosis.—Mandibular tooth massive, with a well-defined hard layer upon the outer aspect immediately below the oral margin, and a very broad symphysial facette; one median tritor forming a prominent boss; anterior and anterior-outer tritor absent ; posterior outer tritor represented by few small patches. Palatine tooth robust, with a single, large, promi- nent tritor. Remarks.—The upper and lower teeth, here placed together, have not yet been found in natural association; but they agree so closely in character that there can be no doubt as to their pertaining to one and the same fish. Regarded as Jurassic fossils they are of much interest, from the great 14 Mr. A. 8S. Woodward on some width of the mandibular symphysis, the remarkable reduction of the tritoral areas, and the prominence of the median tritor that remains. Pachymylus Leedsi, sp. n. (PI. III. figs. 1, 2.) Diagnosis.—A_ species attaining to a large size, the measurement from the middle of the symphysial border to the extremity of the post-oral margin of the type mandibular tooth being 0°14 m. Mandibular tooth with a prominent beak, and the symphysial facette occupying about one third of the inner aspect ; median tritor narrow, occupying only one sixth of the length of the oral face ; posterior outer tritor reduced to three small, round, punctated areas. Palatine tooth diverging from its fellow of the opposite side in front, and terminating anteriorly in a sharp, chisel-like edge ; median tritor occupying much less than half the width of the tooth and separated by a space equal to its own length from the anterior border. [ Vomerine tooth unknown. | Remarks.—This, the type species of the genus, is based upon the mandibular tooth and the pair of palatine teeth shown of two thirds the natural size in Pl. LL. figs. 1, 2. The state of preservation of all the specimens is good, the hinder border only of the palatine teeth being partly destroyed. Viewed from the oral aspect (fig. 1) the palatine teeth exhibit a slight want of symmetry ; and there is a marked line of weakness round the elevation on which the tritor is placed, this line being indicated by the fracture in the tooth of the left side. The inner face of each palatine tooth (fig. 1 8) exhibits the fibrous texture of the cement and exposes the base of the tritor in irregular, narrow, oblique stripes; the outer face (fig. 1 a) shows the strengthened external border, while the tritoral prominence is also conspicuous from this aspect. Seen from the inner face (fig. 2) the mandibular tooth exhibits its robust character; and a direct view of the symphysial facette (fig. 2a) shows its very broad rhomboidal form. ‘The external oral border of the mandibular tooth is strengthened, but not far beneath this border the outer face in the fossil is crushed and destroyed. Formation and Locality.—Oxford Clay, Peterborough. Genus BRACHYMYLUS, nov. Diagnosis.—Mandibular tooth short and deep, much laterally compressed, the symphysial facette narrow, and the Teeth of new Chimeroid Fishes. 15 oral border scarcely sinuous ; the symphysial, median, and posterior outer tritors deep and narrow ; anterior outer tritor absent. [Palatine and vomerine teeth unknown. | Remarks.—This genus is founded on the form of mandi- bular tooth recorded in the British Museum Catalogue (pt. ii. pp. 551, 552) as possibly referable to very young individuals of Ischyodus Beaumonti. The diminutive specimens from the Kimmeridge Clay of Weymouth noticed in that work did not seem to justify the foundation of a distinct genus and species; but a nearly similar mandibular tooth measuring 0:033 m. in length, now available in the Leeds Collection, shows that the fossils in question truly pertain to a hitherto unknown fish. In general outline they are most closely similar to the mandibular teeth of Ischyodus Dufrenoyt. Brachymylus altidens, sp. un. Diagnosis.—Mandibular tooth about as deep as long, with a regularly excavated sharp oral border and short beak ; post-oral margin parallel with the symphysial; beak-tritor and posterior outer tritor very small; median tritor occupying less than one third of the length of the oral face and situated in its hinder half. Remarks.—This_ species is known only by the left mandibular tooth, which measures 0°033 m. in length and is complete with the exception of the tip of the beak. The oral border of the tooth is very sharp and dense, but there is no conspicuous strengthening layer on the outer face. Formation and Locality.—Oxford Clay, Peterborough. Brachymylus minor, sp. n. Diagnosis.—Mandibular tooth with a very slightly exca- vated, somewhat wavy, sharp oral border and insignificant beak ; post-oral margin parallel with the symphysial, and its length much exceeding the antero-posterior measurement of the tooth ; all the tritors small, the median tritor occupying less than one third of the oral face and situated in its hinder half. Remarks.—The three teeth thus described (Brit. Mus. nos. 41866-67) differ from the corresponding tooth of the type species in the comparative straightness of the oral border and the relatively great length of the post-oral border. ‘They are also distinguished by their very small size, the antero- 16 On some Teeth of new Chimeroid Fishes. posterior measurement of the largest specimen (41866) being only 0:015 m. Formation and Locality.—Kimmeridge Clay, Weymouth. Genus ELAsMoDECTES, Newton. [Mem. Geol. Survey, iv. 1878, p. 43 (Elasmognathus). | Elasmodectes secans, sp. n. (PI. III. fig. 3.) Diagnosis.—Mandibular tooth with a moderately sinuous oral margin, and the post-oral border inclining backwards more than the symphysial border; outer tritors very small and undivided, coarsely laminated. Remarks.— The type specimen is the small left mandibular tooth shown of the natural size in Pl. III. fig. 3, from the inner (a) and outer aspect (). The beak is unfortunately broken away, revealing the small beak-tritor in section; but the tooth is in other respects complete. It is remarkable as being the most sectorial form of mandibular dentition hitherto discovered in Jurassic rocks. Though differing from the typical Cretaceous Hlasmodectes in the simple character of the outer tritors, it does not appear advisable on present evidence to refer the tooth to a distinct genus; for the normally simple outer mandibular tritors of Ischyodus are partially subdivided in some species, and such subdivision ought not thus to be always noted in generic diagnoses. When the palatine teeth of H. Willettd and of the form now described are discovered, it may be possible to determine definitely whether the two fishes in question are generically identical. Formation and Locality—Kimmeridge Clay, Weymouth. EXPLANATION OF PLATE III. Fig. 1. Pachymylus Leeds, gen. et sp. nov.; pair of palatine teeth, oral aspect, two thirds nat. size. la. Right palatine tooth, outer aspect, two thirds nat. size. 10. Left palatine tooth, inner aspect, two thirds nat. size.—Oxford Clay, Peterborough. [Leeds Collection. | Fig. 2. Ditto; right mandibular tooth, inner aspect, two thirds nat. size. 2a. View of symphysis of same specimen, two thirds nat. size.— Ibid. Fig. 3. Elasmodectes secans, sp. n.; left mandibular tooth, inner (a) and outer (6) aspects, nat. size.—Kimmeridge Clay, Weymouth. ( Brit. Mus. no. 43284. | Mr. A. G. Butler on the Genus Uypocala. F7 IV.—On the Genus Hypocala, a Group of Noctuid Moths. By Arruur G. Butter, F.L.S., F.Z.8., &e. In the seventh volume of the ‘ Illustrations of Typical Lepi- doptera Heterocera,’ p. 76, I pointed out that the species of Hypocala were trimorphic: this fact has led to so much confusion that a revision of the species has become a neces- sity. When once understood the forms of this genus are easily recognizable ; the primaries on the upper surface vary considerably, but always in the same way; the secondaries and the under surface are constant in pattern in all the modi- fications of each species. M. Guenée, who would never identify an insect from a rough figure, and yet rarely failed to describe every differing form in his possession, however bad the specimen might be, multiplied species unnecessarily. Whether from their rarity or the difficulty of capturing these moths, I do not know, but they seem to come to hand chiefly as individual specimens and at long intervals, so that of several of the species only one, or at most two, of the forms which represent the variations of each type have hitherto found their way to us. Mr. Hocking seems to have been more successful in collecting Hypocala than most men. In his Dharmsala series we obtained all three forms of H. subsatura in the following proportions :—five of the typical form, four of the variety H. aspersa, and four of the variety H. limbata (the last-mentioned having, up to that time, been unrecorded). In the following synopsis I propose to define the species hitherto described with their varieties. In order to avoid repetition in diagnosing the forms it may be premised that any good figure (such, for instance, as that given by M. Guenée, ‘Noctuélites,’ ii. pl. xii. fig. 7) will represent the general characteristics in the pattern of the genus, if one allows for the more blurred uniform character of the primaries in the variety which I regard as typical, and the sharply defined but melanic character of the form which I have characterized as var. 6. ‘The secondaries are always ochreous and black above, and the under surface is usually pale ochreous, more or less marked with blackish and greyish. The under surface gives the best characters for the differ- entiation of the species, and therefore I shall make my primary divisions on points of difference to be seen on that surface of the wings. | Ann. & Mag. N. Hist. Ser. 6. Vol. x. 2 18 Mr. A. G. Butler on the Genus Hypocala. A. Wings below pale ochreous; primaries with black discal patch divided by a band of the ground-colour ; secondaries with a black spot at end of cell and an oblique bar from anal angle to second median branch. a. Black patch on primaries broadly divided, leaving only a narrow bar of black on its inner edge; spot of secondaries small and anal bar very narrow .......... b. Black patch barely divided by a narrow central bar ; spot of secondaries elongated, anal bar broad .......... B. Wings below ochreous, greyish on costal and apical areas; primaries with a black discal patch enclosing an ovate transverse ochreous spot; secondaries with a black spot at end of cell; an irregular, partly mar- ginal, black band from anal angle to just above lower radial vein, its outer edge interrupted by two spots, that nearest anal angle small and angular C. Wings below ochreous, irrorated with purplish grey on costal and apical areas; primaries with the usual black discal patch represented by two rather broad, abbreviated, parallel, oblique bars ; secondaries with a conspicuous spot at end of cell; the usual blackish band narrow, irregularly zigzag, broadly expanded at its upper extremity and extending from close to anal angle to second subcostal branch ............ D. Primaries below almost as in B, but the black patch bounded below by the first median branch; disco- cellular spot quadrate; the blackish band zigzag, alternately narrow and broad, extending from near anal angle almost to the first subcostal branch. a, Secondaries above chiefly ochreous, much more so than in any other described species ...,...... Ss wd E. Wings below with cell of primaries and inner two thirds of secondaries bright ochreous, remainder of ground-colour paler; apical area greyish, the latter and costal border striated. with brown atoms; pri- maries with two broad black bars, converging at their lower extremities. a. Secondaries with a short, oblique, narrow, irregular black bar on the discocellulars; outer border blackish, shading into brown towards costa, becoming paler on margin towards apex and interrupted towards anal angle by an unequal, angular, ochreous, marginal patch towards ABBE ANGLO, ws cigatsts Afi. v-ale, the oc ald: chcsle attachenere amet sk b. Primaries with the black bars broader, almost touching at lower extremities ; the inner bar emitting a broad grey streak below the cell almost to the base; secondaries with the blackish portion of the outer border broader, emitting a black denticle towards the lower extremity of the discocellular bar, interrupted towards the anal angle by two separate marginal ochreous spots. Hi. clarissima. A. violacea. HH, florens. HT. deflorata. HI, guttiventris. HI, andremona. Hi, subsatura. Mr. A. G. Butler 9n the Genus Hypocala. 19 F. Wings below with costal and apical areas smoky grey, the black or blackish bars on the primaries almost united at lower extremity, the outer one diffused ; the black or blackish external belt of secondaries broad, externally and apically diffused, excepting towards anal angle, where it is interrupted by a marginal clavate streak or spot. a. Size of H. andremona, secondaries above with pale ochreous markings; external black border decreasing towards anal angle, deeply excavated just above the [TCL SoS Cp RERCIREUE ace ROR: Ee Ec HH. Mooret. b. The largest known species ; below deep ochreous, the inner black bar of primaries with an external denticle ; discocellular bar of secondaries broad and externally angular ; hind wings above with deep ochreous markings ; external black border very broad before anal angle, moderately excavated just above the angle............ HT, australia. c. Similar to 6, but with the whole under surface and the upper surface of the secondaries smoky, obscuring the markings, which are also paler and less defined in VINSTUES RYO) 2 OP nay ER ie ee ee a HT, velans. Of the above species, all of which are represented in the Museum collection, we possess all three varieties of two species only. For the convenience of students of the group I give the following arrangement of the varieties, classified according to the colouring of the primaries, whether uniform, variegated, or bicoloured :— Uniform. Variegated. Bicoloured. HT, subsatura. HT, aspersa. HT. limbata. HT, deflorata. H. plumicornis. H, rostrata, H. guttiventris. HH, lativitta. H. andremona. H, Pierrett. H. Moorez. H. australie. HH, velans. HI, velans. H. florens (Mab.). H, florens (Mab.). HT, florens (in B. M). Hi, clarissima. Hi, violacea. It seems probable that the first and second forms (which appear to be inconstant and merge into each other) are one brood, and the very distinct-looking third form another ; that they represent in fact either spring and autumn or dry- and wet-season forms of the species. Whether this is so or not can only be proved by breeding, and it is worth the con- sideration of those who have the opportunity of obtaining the eggs or larve. 9% 20 Mr. A. G. Butler on the Genus Hypocala. List of Species. Hypocala subsatura. 3. Hypocala subsatura, Guenée, Noct. iii. p. 75. n. 1419 (1852). Var. a. Hypocala aspersa, Butler, P. Z. 8. 1883, p. 164. $i Var. b. Hypocala limbata, Butler, Ill. Typ. Lep. Het. vii. p. 76, pl. exxxi. fig. 18 (1889). ; Dharmsala, Solun, and Canara. B. M. Hypocala deflorata. Noctua deflorata, Fabricius, Naturf. p. 190, pl. ii. figs. 6, 7. Var. a. Hypocala plumicornis, Guenée, Noct. iii. p. 75. n. 1420 (1852). Hypocala efflorescens, Guenée, l. c. p. 77. n. 1423 (1852). Hypocala angulipalpis, Guenée, 1. c. n. 1424 (1852), Var. b. Noctua rostrata, Fabricius, Naturf. p. 197, pl. iv. fig. 4. Madras, N. India, Dharmsala, Nilgiris, Kilima-njaro, Natal. B. M. It is a common form of superstition amongst naturalists to assume that examples of the same species cannot occur both in India and Africa; M. Guenée was evidently strongly imbued with this opinion. ‘The difference represented by the following words alone serves to separate [H. plumicornis and efiorescens : of the first it is said, “‘ Un seul g, qui m’a été envoyé comme venant de la Cafrerie: mais cette provenance me laisse quelques doutes.” Why? Because in other respects it closely resembled //. efflorescens, of which we read, “Silhet. Coll, Gn. Un @.” As for A. angulipalpis, it was based upon a single dwarfed and much rubbed example. Hypocala guttiventris. Hypocala guttiventris, Walker, Lep. Het. xiii. p. 1176. n. 10 (1857). Hypocala tryphenina, Felder, Reise der Nov., Lep. iv. pl. exii. fig. 20. Var. a. Hypocala lativitta, Walker, Lep. Het. Suppl. iii. p. 929 (1865). Moreton Bay and 8.E. Australia. Type B. M. Hypocala andremona. Phalena-Noctua andremona, Cramer, Pap. Exot. iv. p. 132, pl. ecelviii. figs. C, D (1782). Hypocala filicornis, Guenée, Noct. iii. p. 76. n. 1421, pl. xiii. fig. 7 (1852). Var. a. Hypocala Pierreti, Guenée, J. c. p. 77. n. 1425 (1852). Honduras, Amazons, Sao0 Paulo. B. M. ——S Mr. A. G. Butler on the Genus Hypocala. 21 Hypocala Mooret, sp. n. Var. a. Hypocala efflorescens, var., Walker, Lep. Het. xiii. p. 1175. n. 8 (1852) ; Moore, Lep. Ceylon, iii. p. 126, pl. clx. figs. 5, 5a. Ceylon, Canara, Old Calabar. B. M. This is quite distinct from /Z. efflorescens of Guenée. Hypocala australie, sp. n. Secondaries above most like those of H. subsatura, but deeper and brighter in colour, with marginal ochreous spot. Australia. B. M. ; Represents H. velans in Australia. Hypocala velans. Var. a. Hypocala velans, Walker, Lep. Het. xiii. p. 1177. n. 11 (1852). Hawaiian Islands. Type B. M. Hypocala florens. Hypocala florens, Mabille, Trans. Soc. Ent. Fr. 1879, p. 324. Madagascar. Bb. M. M. Mabille describes several forms of this species ; our specimen belongs to the variety with pale inner border to the primaries (var. 6 of this monograph). Hypocala clarissima, sp. n. Differs from ZH. violacea above in the greater width of its ochreous markings. Ceylon. B. M. This and H. violacea both belong to the typical form of the genus in which the primaries are of a uniform character; both agree in having these wings of a liacine rufous-brown colour. Hypocala violacea, Hypocala violacea, Butler, Trans, Ent. Soc. 1879, p. 6. Cachar and Burmah. Type B. M. Hypocala tenuis, Walk., from Sierra Leone, does not appear to me to belong to the genus; but the description is too poor to enable me to decide the point. Hypocala biarcuata, Walk., from Canara, is either a species 22 Mr. O. Thomas on a new Species of Acomys. of Audea (Catocalide) or belongs to a genus allied to Audea; it has nothing to do with Hypocala. Hypocala lativitta, Moore (said to be nearest to H. biarcu- ata), is almost certainly a species of Audea; the porrect beak-like palpi of Hypocala are not shown in the figure, which, on the other hand, gives the impression of their being formed as in Audea. V.—Description of a new Species of Acomys. By OLDFIELD THOMAS. AMONG a small collection of zoological specimens from Mombasa recently presented to the National Collection by Mr. D. J. Wilson, of the British East Africa Company’s service, there occurs a specimen of a small spiny mouse clearly representing a new species. A second specimen of the same form has also been received direct from the Com- pany, but the exact locality of this individual is unknown. I propose to call the species Acomys Wilsoni, sp. n. Most nearly allied to A. russatus, Wagn., but distinguished from that, as from every other member of the genus, by its very much smaller size, and especially by its much shorter feet. General colour orange-rufous, grizzled with black, the black predominating on the head and nape. Under surface white. Ears small, rounded, laid forward they just reach to the posterior canthus of the eye. Feet short and broad; palms and soles naked, the pads well defined. Tail short, slender, very finely haired, almost naked; darker above, whiter below ; rings of scales about seventeen to the centi- metre. Measurements of the type (an adult female in alcohol) :— Head and body 80 millim. ; tail 48 (extreme tip wanting, 55 in the other specimen); hind foot 12:2; heel to front of last foot-pad 5°8; ear, above crown, 8°4. Hab. Mombasa. Coll. D. J. Wilson. The other species of the genus are all much larger than D. Wilsoni, with hind feet measuring from 16 to 19 millim., a difference in size so great as to preclude all necessity for a detailed comparison of the new form with them. It is with much pleasure that I have named this little species in honour of its discoverer, to whose enthusiasm the British Museum is indebted for many rare and interesting specimens. Fission and Gemmation in the Animal Kingdom. 23 VI.—General Observations on Fission and Gemmation in the Animal Kingdom. By Dr. FRANZ von WAGNER, Assistant in the Zoological Institute of the University of Strassburg *. I. THE asexual reproduction of the Microstomids, as described in the foregoing pages, has been hitherto theoretically claimed by the different investigators sometimes as gemmation, some- times as fission. If we disregard CErstedt +, who probably merely observed the folding of the intestine which is connected with the formation of septa, Oscar Schmidt was the earliest investi- gator of the sinitiniodtion of the Microstomids. His diagnosis of the family ‘ Microstomex’’ states f : “ Reproduction by transverse fission.” Moreover, in his description of the reproduction Schmidt characterizes it exclu- sively as fission. But even in the same year (1848) this investigator writes as follows§:—‘“I have designated the well-known multiplication of the Naids and Microstomids simply as transverse fission, although a glance at my figures will show that with this transverse fission is combined longi- tudinal growth of the portions which are to be constricted off, That, however, a part of the parent of those Turbellarians really passes into the new animal appears to me to be indis- putable.” But immediately afterwards (loc. cit. p. 87), when discussing the reproduction of Filograna, the same author states :—“‘ If anywhere at all, it is here, at least in the case of the Filograna examined by me, that we see with especial clearness that the actual transverse fission is the least im- portant stage in the development of the new animal, and that, on the contrary, the latter grows as a true bud or sprout upon * Translated from the ‘ Zoologische Jahrbiicher—Abtheilung fiir Ana- tomie und Ontogenie der Thiere,’ 4 Bd. Heft iii. Dec. 1890, pp. 386-417: being the latter portion of a paper by Dr. Wagner, entitled “Zur Kennt- niss der ungeschlechtlichen Fortpflanzung von Microstoma, nebst allge- meinen Bemerkungen iiber Theilung und Knospung im Thierreich,” zb2d. pp- 349-423 (with four plates). aA Dn + A. S. CErstedt, ‘ Entwurf einer systematischen Eintheilung und speciellen Beschreibung der Plattwtirmer,’ Copenhagen, 1844, p. 73. ¢ O. Schmidt, ‘Die rhabdoccelen Strudelwiirmer des siissen Wassers,’ Jena, 1848, p. 22. ; i § O. Schmidt, ‘ Neue Beitrige zur Naturgeschichte der Wurmer,’ Jena, 1848, p. 36. 24 Dr. F. von Wagner on the parent, and has its alimentary canal in common with it, as in the case of the old and young Hydra before separation has taken place. d In the last (1882) edition of his‘ Vergleichende Anatomie’ * Schmidt again designates the asexual reproduction of Micro- stoma (as also that of the Naide) simply as fission. In 1849 M. Schultze declared very emphatically that the multiplication of the Microstomids, like that of Nazs, ‘depends not upon a mere formation of buds, but upon a constriction of a single animal into several, progressing according to perfectly definite laws” t. Like Schmidt, Schultze also herein attached most importance to the fact that “ in this there takes place an actual separation of a portion previously belonging to the parent to form a new individual”’ (doc. cit. p. 294). Von Graff, in his ‘ Neuen Mittheilungen tiber Turbellarien ’ (1875), in which we find the first exact description of the asexual reproduction of Microstoma, regards the process as fission, without making any further observations on the pointf. Von Graft’s results were supplemented, in some cases rectified, by the important investigations of P. Hallez, in particular by the discovery that it is always the posterior third of the body of the multiplying animal which represents the rudiment of the new zooid §. Von Graff was subsequently able to confirm this discovery, but it induced him, in his great Monograph of 1882, to declare the multiplication of Microstomids to be a case of gemmation. The following sentences || convey the essence of his view :—‘‘ The . . . . asexual reproduction of Microstoma lineare is undoubtedly to be regarded as gemmation, and indeed as a terminal formation of buds, in which the posterior end of the parent ‘ grows and separates itself off as a young individual from the old,’”’ so that therefore “‘ the younger terminal bud’” is “subordinate to the older parent indi- vidual.’ ”’ “Tt was not until Hallez discovered the fact that it is always only the posterior third or fourth of the parent, there- fore that portion which we may as it were regard as the * O. Schmidt, ‘Handbuch der vergleichenden Anatomie,’ 8 Aufl, Jena, 1882, p. 107. } M. Schultze, “ Ueber die Fortpflanzung durch Theilung bei Nais proboscidea,” Arch. f. Naturgesch. 15 Jahrg. Bd. i. p. 294. } L. Graff, “Neue Mittheilungen iiber Turbellarien,” Zeitschr, f. wiss. Zool. Bd. 25, pp. 409 et sqq. § P. Hallez, ‘Contributions 4 histoire naturelle des Turbellariés,’ Lille, 1879, pp. 153 et sqq. | L. vy. Graft, ‘Monographie der Turbellarien.—I. Rhabdoccelida,’ Leipzig, 1882, p. 174. eo) Fission and Gemmation in the Animal Kingdom. 25 increase due to growth over and above the limits of the indi- vidual, which separates off from it, that the character of this reproduction as a process of terminal gemmation was made plain. That it is a case of terminal gemmation with which we have to deal is emphasized even more definitely by the fact that the parent, however many buds it may produce, never decreases in size. On the contrary, the size is always equal to that of solitary individuals, which I have observed before the appearance of any indication of budding, or at the very commencement of it... .” This view has hitherto met with much approbation. Yet opposition, though indeed more of an occasional kind, has also been meted out to von Graff’s gemmation theory. Thus Count Zeppelin, in his paper on Ctenodrilus mono- stylos * (1883), observes :—‘ ‘The erroneous view previously held, that reproduction by fission in the Worms depends upon mere gemmation, has been overthrown by O. Schmidt for the Microstomids, which belong to the Rhabdoccele Turbel- laria, since in these animals there takes place an actual sepa- ration of a portion previously belonging to the parent. The incorrectness of this theory is similarly proved by the pro- cesses of fission which are found in Nais, Chetogaster, Ctenodrilus, &c., in which the hindmost section of the body passes unchanged into the new creature. In these animals a genuine fission occurs, while in -O-pRA I EAE aig Fission and Gemmation in the Animal Kingdom. 33 so, since it does not possess any other kind. The essence of gemmation, however, lies precisely in this, that the growth peculiar to it is added as a new process to the normal pheno- menon,. Moreover, no matter what views we may hold as to the evolution of the Metazoa from the Protozoa, we are bound to recognize in the fission of the ovum a recapitulation of the typical fission of the Protozoa, which thereby passes from a form of reproduction into a mode of multiplication for tissues. The segmentation of the ovum thus teaches us that the expression fission is also applied in the same sense outside the phenomena of reproduction. For the investigation of reproduction by fission and gemma- tion in the Metazoa the course which we adopted in the case of the Protozoa is impracticable for obvious reasons. I shall therefore in the first place attempt to gain standpoints for a general consideration of the question, and in so doing briefly refer to concrete examples only where it is necessary. The cases of asexual reproduction by fission and gemmation which have so far been discovered in the domain of the higher animals admit quite well of being connected with the similar conditions which exist among the Protozoa. Firstly with regard to fission: the modifications of the original form of fission, architomy, which arise among the lower animals, undergo extensive development in the 5 re pe Metazoa. The higher stage of organization existing in these animals entails the impossibility of architomy in their case ; the processes of regeneration which are connected with almost all cases of fission among the Metazoa cause those modes of reproduction to appear rather as instances of paratomy when contrasted with what happens in the case of Stentor. In the fission of the higher animals three stages may be distinguished, which both in themselves, as also in their relation to one another within a case of paratomy, require more detailed discussion. They are, firstly regeneration, secondly separation (dissection), and thirdly growth. That the regeneration which in the case of Stentor com- bines with the separation to form an harmonious whole must in the Metazoa advance into the foreground in proportion as the organization of the proliferating animals becomes more complicated, is so natural a circumstance that we should be surprised if it were otherwise. Now as the measure of the work to be performed by regeneration in organs and parts of organs, which must necessarily be reconstructed, becomes constantly greater, it is self-evident that the process of separation will sink in the Ann. & Mag. N. Hist. Ser. 6. Vol. x. 3 34 Dr. F. von Wagner on same degree in the outward manifestation of the fission, until at last it assumes the position of a more secondary final act. There is a natural inclination on the part of the observer of this class of fission to regard the extensive reconstructions as the essence of the process, while considering as of trifling moment the uninteresting separation. It is, however, other things being equal, not so much the extent as the nature of the regenerations which causes many cases of fission to be interpreted as gemmation. Thus gem- mation is especially discovered in all kinds of worms, whereas, so far as my own conviction goes, in these animals, with perhaps the sole exception of the remarkable reproduction of Syllis ramosa, with which M‘Intosh has made us acquainted*, fission alone occurs. For, on observing the course of the regenerations, manifold features are scen, which are found in the formation of a number of organs in the ontogeny of many animals, and which we are wont to term in ordinary phraseology “sprouts” or “ buds.” Of the extent to which this outward similarity of what are at the bottom very different processes is taken as internal homogeneity, owing to the consonance of their designations, the Naids are a classic example. The gemma- tion which is alleged to exist among these worms reduces itself to the appearance of so-called ‘ zones of gemmation” in their asexual reproduction. Herein it must remain unde- cided whether this multiplication is to be regarded as ‘‘semmation,’ because “ zones of gemmation” are formed, or whether, on the contrary, these latter receive their desig- nation because the whole process is to be taken as an instance of gemmation. The “zones of gemmation” of the Naids are, however, nothing more than zones of regeneration, within which proceeds the development of organs and parts of organs, which is necessarily combined with paratomy. That the latter is an actual new formation is in accordance with the nature of the case; it is related to the fission of the Naid in precisely the same way as is the formation of peri- stome and pharynx to the reproduction of Stentor. If, there- fore, we speak of such processes as fission depending upon ‘“gemmation ” or “ processes of gemmation” +, we do not use the expression ‘‘ gemmation”’ in the sense of the mode of * “Report of the Scientific Results of the Voyage of H.M.S. ‘Chal- lenger, Zoology,” vol. xii. pp. 198 et sqq. t Thus, according to Vogt and Yung, the asexual reproduction of Microstoma consists “ of repeated transverse fissions, and proceeds from axial budding at the posterior end” (C. Vogt and E. Yung, ‘Lehrbuch der praktischen verg]. Anatomie,’ i. p. 284, Braunschweig, 1888). Fission and Gemmation in the Animal Kingdom. 35 reproduction defined thereby, and consequently are not entitled to consider the two ideas as equivalent to one another. Tt would be more correct and would help to avoid erroneous conceptions were we to abandon the word ‘“ gemmation”’ altogether in such a sense, and simply designate the new formations as what they actually are, namely regenerations. That the so-called zones of gemmation really deserve to be criticized in this way is most clearly shown by the cases in which such localized zones do not appear at all for the new formations which are necessary. This is seen in .Wicrostoma, for example ; quite peculiarly characteristic, however, is the different behaviour of the two species of Ctenodrilus, there- fore of two Annelids which are most closely allied; in the case of one of these, Ctenodrilus pardalis, fission is ushered in by the appearance of the rudiment of a zone of regenera- tion *, while in the reproduction of the other such a process is absent, and the regenerations only proceed after the zooids have attained their independencef. All these processes of new Sormation are the same in principle, no matter whether they are accompanied or not by the development of special zones of regeneration. The fission of Haplosyllis spongicola, however, which has been closely investigated by Albert, proves that the regene- rations, and therefore also the special kind of them, can in themselves in no way determine the character of a case of asexual reproduction; for in the Syllid in question the “swimming buds,” as they are called, which are detached and contain the sexual products, do not reproduce a special cephalic somite at all, but rather give rise to quite differently constituted new formations throughout their entire organiza- tion, so that the form and structure of these swimming zooids appear to diverge very considerably from that of the primary form ft. In this connexion mention must moreover be made of Clistomastus, a Capitellid in which, as Hisig has informed us, the abdomen is constricted off filled with the ripe sexual products, although in these genital zooids neither new forma- tions, as in Haplosyllis, nor regenerative processes appear, so that they represent extremely incomplete persons—so to speak * J. Kennel, “ Ueber Ctenodrilus pardalis, Clap.,” Arbeiten a. d. zool.- zoot. Inst. in Wiirzburg, Bd. 5, pp. 395 et sqq. + Graf Leppelin, “ Ueber den Bau und die Theilungsvorginge des Ctenodrilus monostylos, u. sp.,” Zeitschrift f. wiss. Zool. Bd. 89, pp. 635 et sqq- ‘oo Albert, ‘“ Ueber die Fortpflanzung von Haplosyllis spongicola, Gr.,” Mitth. a. d. zool. Stat. zu Neapel, Bd. 7, pp. 10 et sqq. és 4 we e 36 Dr. F. von Wagner on mere genital tubes*. Similar conditions are also presented by the fission of the Scyphostoma (Strobila formation), in which the fission-products which successively arise are trans- formed from the original tentacle-bearing form into the lobed stage of the Hphyra. The process of separation, as has already been stated, when contrasted with the more or less comprehensive regenerations, recedes in the same ratio into the background, especially where the paratomy is still further complicated by vigorous growth. As arule separation constitutes the conclusion of fission, so that the development of the zooids which are set free is essentially complete. Occasionally, however, it ushers it in, as is partially the case in Ctenodrilus monostylos, but is especially seen in Lumbriculus. Von Kennel has laid stress upon this condition, as he is moreover inclined to regard the fission of Lumbriculus not as a mode of reproduction, but as a simple augmentation. Nevertheless the observations which have been published by Biilow { tend in one way rather to confirm the former view, though beyond this no special importance can be attached to the occurrence of so-called raw surfaces (“f Wundfliichen ”’), since these appear, although in a limited degree, in many cases of fission, and in fact are usually quite unavoidable. In Microstoma itself, for example, it is easy to convince ourselves that not infrequently quite a considerable raw place is to be seen, so that a destruction of tissues takes place at the spot. With regard to growth it is to be remembered that it may accompany fission in so far as the growth is a property of the individual. ‘The only question to be decided therefore is whether in a particular case the growth is individual or differential. Such a distinction is at all times practicable as soon as we grasp the fact that the bud, as such, proceeds from differential growth. I make this observation in oppo- sition to the objection, improbable though it be, that the regenerations which have been discussed above arise in the same way. The essential feature of gemmation-growth lies in its pecu- liarity of producing new individuals by being added to the normal growth ; that it is also a growth which is confined to definite spots on the surface of the body of the parent form, * H. Hisig, ‘ Monographie der Capitelliden des Golfes von Neapel &c.,’ Berlin, 1887, pp. 794 et sqq. ; + J. vy. Kennel, ‘Ueber Theilung und Knospung der Thiere,’ Dorpat, 888. { C. Biilow, “Ueber Theilungs- und Regenerationsvorgiinge bei Wiirmern,” Archiv fur Naturgesch. 49 Jahrg., Bd. 1, p. 28. Fission and Gemmation in the Animal Kingdom. 37 and is therefore local, is undeniable; but dt ds not every instance of local growth that signifies gemmation. It is neces- sary to exclude, firstly those regenerations which are localized upon zones of growth, and secondly the large number of processes of growth which, whether it be in consequence of simple elongation, or whether it be due to actual increase in bulk, are hereby restricted to an axis of the body (longitu- dinal axis). ‘This course involves nothing that is arbitrary, but is rather a consequence of a logical necessity, since that increase in size represents the normal form of growth of the Metazoa in question and takes place even in those cases where no asexual reproduction tis combined with tt. As regards the mutual relations of regenerations, separa- tion, and growth in the course of a case of paratomy, I have already mentioned the variation which occurs in the time of the appearance of separation. With reference to this we might distinguish cases of paratomy with precocious regene- rations from those in which they are of subsequent occur- rence, were it not for the existence of the difficulty which is due to the fact that in many cases separation sets in when the first stages of the new formations have already com- menced. The relation in time between the regenerations and growth is here of special interest for us. In this respect the fission of the Naids is perhaps the most instructive and may serve as an example. In the first place the growth of the Naid in process of fission appears everywhere as segmental and restricted to the longitudinal axis of the body of the animal, as is typical for the segmented worms; it is therefore an individual growth. But the extent of the increase in size, which is for the time being attained by the fission- products which are in process of formation, varies greatly, owing to the fact that the regene- rations, that is the zones of regeneration, already appear before the growth of the zooids which are originated thereby has developed a trunk-section of any size (reproduction from the anal somite) ; or, in other words, that the point of time at which the rudiments of the zones of regeneration are deve- loped appears to be transferred to constantly earlier stages in the size and therefore in the development of the future zooids. In consequence of such accelerations it is easy to form the impression that the fission-product grows out as a bud from the parent form. In connexion with forms of para- tomy in the Naids which runa more regular course, however, these alterations in the order of time will become of so much 38 Dr. F. von Wagner on the less importance, since the various processes themselves are the same in all cases. This conception of the reproduction of the Naids applies in corresponding fashion to the asexual reproduction by fission not only of the Annelids, but of the Worms in general, for there is no room for doubt that those modes of propagation are essentially of the same kind. Now if an animal begins to divide and the regenerative processes in the zooids thus produced are quickly completed, and if, moreover, fission again sets in in the zooids themselves before they have attained their independence by means of the separation which is the concluding stage of the primary fission, the result naturally is a formation of temporary colonies, or, to speak more precisely, chains, since we are dealing with the transverse fission of animals which grow in their longitudinal axis. The precocious commencement and retarded conclusion of fission, concurrently with rapid growth of the dividing animals, are the circumstances which are chiefly responsible for the complicated and often very peculiar mani- festations which are exhibited in the course of the asexual reproduction of many Metazoa. It is true that secondary causes are often added to these, since reproduction by fission may combine with transformations of the fission-products (strobilation of the Medusze) or become more or less subser- vient to favourable sexual reproductive conditions; this may result in the omission of regenerative processes and the occur- ° rence of effective new formations which did not belong to the original animal, but are of great service for the special pur- poses of the fission-products. An example of this is presented by, among others, the swimming zooids of the already mentioned Faplosyllis, which, in order to ensure the widest possible distribution of the sexual products, have equipped themselves with an exquisite locomotor apparatus *. With regard to gemmation a few words only are necessary, for its character lies exclusively in the peculiarity of differen- tial growth, so that all instances of gemmation, no matter whether we have to deal with a Polype, a Bryozoon, ora Salp, agree in this, though diverging widely in the details of the process. It is in consequence of this simplicity in the nature of gemmation as opposed to fission, which in many respects 1s subject to manifold changes, that the very different phases of development in which gemmation confronts us nevertheless invariably exhibit the same characteristic of special growth. * FB Albert, “Ueber die Fortpflanzung yon Haplosyllis spongicola, Gy.,” Mitth. a. d. zool. Stat. zu Neapel, Bd. 7, pp. 12 et sqq. Lawl Pe” ee ~ tS ap eee Fission and Gemmation in the Animal Kingdom. 39 It follows as a matter of course from what has been stated that gemmation by no means excludes the direct transition of a portion of the parent into the rudiment of the bud. Asa matter of fact this actually occurs in the reproduction of certain Stony Corals, for an account of which we are indebted to the beautiful investigations of von Koch *. In the foregoing statements as to fission and gemmation [ have, in order to avoid too great complication of the progress of the discussion, disregarded a circumstance which never- theless requires to be shortly considered in order to complete the views which we have gained, ¢. e. the question of indi- viduality. Heckel was probably the first to establish the fact that, contrary to what happens in the case of fission, which disposes of the original parent-form, the individuality of the bud-producing animal is preserved unaltered. The general truth of this proposition is beyond question; in the case of gemmation it is proved by experience, in that of fission it 1s @ prior? a logical necessity. Nevertheless it appears to me to be desirable to trace the change of individuality, at least in the case of those ‘ successive” fissions (strobilation-form of fission sensi latiori) which are of such frequent occur- rence. In so doing I have no intention of entering at length into the theory of animal individuality; on the contrary, it is sufficient for our purpose to proceed from more general experience and considerations. Starting from the fact that in many animals ‘the single individual can be split up by means of artificial division into several individuals which continue an uninterrupted exist- ence,”’ it was shown by Geette “that this divisibility is neither unlimited nor unconditional, but is without exception accom- panied by the fact that the parts possess the structural con- ditions of the whole, and moreover the power of preserving them in integral continuity—that, in other words, they are capable of providing in themselves a complete repetition of the original whole ; ‘ individuality’ of organisms therefore does not signify absolutely an indivisibility, but rather only such as maintains the integrity of a vital unit or of a common life, and at the same time the possibility of an independent existence” +. Goette therefore sees in individuality the ‘ condition of * G. v. Koch, “ Die ungeschl. Vermehrung einiger paliozoischer Koral- len vergleichend betrachtet,” Paliontographica, Bd. 29, pp. 341 eé sqq. + A. Goette, ‘Ueber den Ursprung des Todes,’ Leipzig, 1883, pp. 12 et sqq. 40 Dr. F. von Wagner on certain relations of the parts to the whole ;”’ this corresponds, however, to the stage which the organization has attained at the time, and is therefore “ moreover dependent upon the origin and progress, in short the development of the organi- zation.” This conception applies in the same degree to embryonic development as to reproduction of animals by fission or gemmation. In both cases the individuality of the animal which is coming into existence shows itself dependent upon the progress of the organic development, as a cohesion of definite relations of the parts to the whole, which becomes ever more and more consolidated concurrently with the organiza- tion. But naturally it is impossible that this cohesion should be a rigid one, the same for all animals—this is proved at once by the exceedingly variable degree to which the regene- rative capacity is expressed; it .will, on the contrary, be extensible within narrower or wider limits. Herein lies the & priort difference between fission and gemmation, as well as every other mode of reproduction, since the former neces- sarily postulates a loose arrangement of that cohesion, more readily dissoluble without injury to the common life; for were this not so the power of fission would be altogether suspended. ‘The individuality of animals undergoing fission must therefore be of a fusible kind, so fusible that a con- tinual change in the cohesion of the parts which form a whole is rendered possible, without occasioning disturbance to the common life. Eixperience proves that in all cases of fission a portion of the original relations existing in the parent form is dissolved, and combines with those which now appear for the first time and which result from the development of new organs by regeneration to form a new unit ; while the remnant of the old relations which is left behind either manifests by itself a unity which is viable or replaces the relations which have been lost by equivalent new formations. Thus, in Microstoma an animal divides in the first place into two individuals, whereby the original individuality is destroyed and superseded by the two new ones. The latter soon experience the like fate, and with the destruction of their individualities four fresh ones are constituted, and so on. It is impossible to raise the objection that perhaps they are quite unimportant and trivial portions which are taken from the original animal and applied to the formation of one of the new individuals, and that therefore the individuality of the other zooid is essentially unchanged, since, indeed, it remains pasties ies, Fission and Gemmation in the Animal Kingdom. 41 in possession of the most important primary organs (central organ of the nervous system &c.) ; for the proportion of the original relations which are dissoluble is indeed limited by the conditions of the permanence of the common life, but within these limits is free, now greater, now smaller. Whether the posterior half or the posterior quarter or eighth of a Microstoma forms a new individual of itself is a matter of complete indifference for the character of the entire process. In other words, the division of a J/icrostoma into two equal halves is fundamentally the same process as its fission into two products, one of which consists of three quarters and the other of one quarter of the original animal, and so on. A series of separate acts of fission, as exhibited by the species of Microstoma for instance, is in ordinary terminology usually referred to one animal as the mother-individual (“ancestress” (“ Stammmutter”) of von Graff); and if a number of units has been developed we are accustomed to say that the “ ancestress ” has given rise to so many daughter individuals. We are the more inclined to do this since separation sets in very late, so that the zooids remain for a time in connexion with one another and form temporary chains of individuals, This view is, however, strictly speaking erroneous, for the ostensible “ ancestress ”’ is destroyed by the very first fission, and for the following one the two zooids which resulted from the first paratomy behave to their products as “ ancestresses,”’ precisely in the same way as their parent form did to them, and so on. If therefore we say that the Microstoma-chains have arisen simply through fission we must be understood only to mean that these chains owe their origin to a series of paratomies, in which the final acts, the separations, appear postponed in regular sequence to relatively late periods. ‘The reproduction ot Microstoma therefore represents a combination of successive acts of fission, each separate one of which constitutes a para~ tomy. From the standpoints which have been developed in the foregoing paragraphs, I would define fission and gemmation in the Metazoa as follows :— Fission ts a process of separation of parts which originally belonged to an integral whole, and have arisen or are tn process of origin by normal growth, wherein new individuals are Sormed by supplementary new formations, with destruction of the original unit. Gemmation, on the contrary, is a process of new formation 42 Dr. F. von Wagner on of entire individuals, depending exclusively on a peculiar (differential) growth, which differs from the normal ; herein the budding vital unit is wswally preserved unchanged. III. I have no intention of here discussing separately the cases of reproduction by fission and gemmation which have been discovered up to the present time among the Metazoa. After what has been stated in the previous section there can scarcely be any necessity to do so, more especially since a series of instances of asexual reproduction, like that of the Tunicates, Bryozoa, and most of the Ccelenterates, is universally and without contradiction regarded as gemmation. It is true that the case is different as regards the so-called terminal gemmation (formation of buds at the end, strobilation sensi latiori=axtal gemmation of von Kennel*), under which are included the formation of Hphyre in the Medusee (originally strobilation sens@ stricto), certain forms of repro- duction in the Stony Corals, more closely characterized by Semper f, the formation of chains in the Microstomids (Microstoma and Stenostoma), and lastly the majority of modes of reproduction in the Annelids ¢. Nevertheless even in these cases there is no further need for any detailed statements if affirm that the above processes of asexual reproduction are instances of fission. For as regards the strobilation of the Meduse, in the first place, the two latest and most exhaustive investigators of the subject, Claus and Goette, have conclusively proved that herein, even according to the customary method of representa- tion, fission, and not gemmation, takes place. “For the proper comprehension of the phenomena of strobilation,” writes Claus §, “it is before all things neces- * J.v. porn ‘Ueber Theilung und Knospung der Thiere,’ Dorpat, 1888, p. 17. ? es Semper, “Ueber Generationswechsel bei Steinkorallen &c.,” Zeitschr. f. wiss. Zool. Bd. 22, pp. 285 et sqq. } The formation of proglottides in the Cestodes, which is included here by certain investigators as being likewise a case of “axial gemma- tion,” may well be neglected, for the justification for considering the proglottides as a special generation of sexual animals, developing asexually from the Scolex, and therefore regarding the tapeworm as a dimorphic colony, as was persistently maintained by Leuckart (‘Die Parasiten des Menschen,’ Bd. 1, 2 Autl., Leipzig, 1879-1886, p. 342), whose latest disciple is von Kennel (op. czt. p. 16), is still very doubtful. § C. Claus, ‘Untersuchungen iiber die Organisation und Entwicklung der Medusen,’ Leipzig, 1883, p. 16. Even to these statements of Claus I am able to attach but little weight, after what has been already men- Fission and Gemmation in the Animal Kingdom. 43 sary to bear in mind the fact that the regeneration of an Ephyra on the oral disk of the Seyphostoma, within the circlet of tentacles belonging thereto, has in no single case been proved. There is no terminal gemmation of Ephyre on the oral disk of the Scyphostoma-polype ; on the contrary, the rudiments of the disks of the Ephyre are segments of the actual body of the Seyphostoma, which are marked off outside the circlet of tentacles by constriction of the wall of the cup, and are set free as sections of the body.” In opposition to Heckel Claus insists * that ‘ as a matter of fact the terminal portion of the Strobila which becomes the Ephyra—and for the sake of simplicity we will commence with the simplest and most typical form, that of the mono- discous Strobila—is no product of subsequent growth on the part of the Scyphostoma, but rather the anterior half of the body of the latter, which after previous uniform growth of the trunk of the Scyphostoma has marked itself off by con- striction and proceeds to attain its liberty as a segment. Moreover, with the separation of the latter the primary indi- vidual, as such, is destroyed and split up into two new individuals, since the posterior individual also represents only a segment of the parent form. Both fission-products are coordinated to one another, for the basal stump, with or without a circlet of tentacles, nevertheless essentially corre- sponds to a Polype which is equivalent to a Medusa. Both Ephyra and Polype are consequently in their mutual rela- tions comparable to an Infusorian in process of fission, of which only the one segment possesses a mouth and adoral zone of cilia, while the other is as yet without these struc- tures or only exhibits them in course of formation. But should we wish to consider one segment as older than the other, and to subordinate the latter to the former, it would be more just to regard the hinder and less perfect segment as the younger portion, which would then be comparable to a terminal bud. In truth, however, from the point of view of ontogeny, they are both of the same age and equivalent to one another; yet the anterior segment differentiates sooner into a form which becomes free as a Medusa, while the poste- rior one subsequently undergoes regeneration and comple- tion. tioned (cf. note a, p. 26); I quote them, however, in order to show that even those investigators who consider it superfluous to discuss whether we are dealing with fission or gemmation, nevertheless in a given case exert themselves diligently to answer the question. * Op. cit, p. 17. 44 Dr. F. von Wagner on Goette * expresses himself in a precisely similar fashion :— “Since the first Ephyra-disk is only the further developed oral segment of the Scyphostoma, it naturally follows that it can in no way be regarded asa bud. That which reminds us of gemmation in it, e. g. the outgrowth of the circlet of lobes, belongs, just as does the previous outgrowth of the tentacles of the Scyphostoma—both of which processes are indeed termed ‘ sprouting’ (‘ Hervorknospen’) in looser phraseology—simply to the progressing development of the entire segment, which preserves its identity. It follows that the liberation of the first Ephyra can also be nothing else than the separation of two segments of an organism, both of which are in process of development, but were already in existence before—or, in other words, simple fission, On the abandoned peduncle of the monodiscous larve, however, the new Ephyra arises in precisely the same way as the first, by a transformation of what is originally its oral section into the disk of a Scyphostoma, which develops only secondarily into the disk of an Ephyra. For the formation of Kphyre in the case of the monodiscous larvee gemmation is therefore entirely out of the question. But owing to the agreement of this process in the case of the mono- and polydiscous larvee this necessarily applies to the latter just as much as to the former. The disk of the Ephyra therefore never arises by gemmation, and thus strobilation is in all cases a simple fission of larvee in process of development.” With regard to the phenomena which immediately succeed the actual separation of the Ephyra from the Scyphostoma, both in the case of the liberated Kphyra-Medusa as also in that of the Polype which is left behind, Goette | remarks that “therein is repeated merely a process of regeneration analo- gous to that in the development of any other organism with terminal mouth—be it a Worm, Infusorian, or anything else —whereby the general import of the previous or simultaneous process of fission is in no way prejudiced. It is likewise clear that in this respect the regeneration of the proboscis can be of no greater account than that at the gaping crown of the previously liberated Ephyra: both phenomena are inevit- able accompaniments of fission, which the development of the first and all subsequent Ephyre of a polydiscous Strobila cannot exhibit in materially different guise.” With reference to the supposed instances of gemmation * A, Goette, ‘ Entwicklungsgeschichte der Aurelia aurita und Cotylo- rhiza tuberculata, Leipzig, 1887, p. 50. t+ Op. cit. p. 46. Fission and Gemmation in the Animal Kingdom. 45 which some years ago were stated by Semper to occur in certain Stony Corals*, it is to be remarked that some of them, in so far as the facts, which were principally derived from the skeletons, admit of such an interpretation at all, must be referred to processes conformable to the Strobila- formation of the Meduse, ¢. e. must be regarded as cases of fission. This applies especially to Flabellum variabile and Placotrochus levis. But as to Semper’s statements about the asexual reproduction of his species of Hungta (which are not more closely specified), they have so little to do with adequate observations that a close investigation, particularly of the processes of growth as they occur in these forms, will have to be undertaken afresh before a satisfactory insight will be possible. ‘The numerous modes of reproduction in the Annelids, some of which are more thoroughly, but the greater portion only very superficially, known +, cannot be here discussed. Thus much, however, may be affirmed without immediate proof, that, so far as regards observations and not theories, gemma- tion has hitherto not been shown to exist with certainty in the segmented worms, with the exception of the peculiar budding form of Syllis ramosa. ‘The pretended lateral gem- mation of certain Annelids, which Pagenstecher{ believed he had observed, has already been rejected by Ehlers § as erro- neous. It is true that the asexual reproduction of Autolytus prolifer, which was observed years ago by Frey and * C. Semper, “Ueber Generationswechsel bei Steinkorallen &c.,” Zeitschr. f. wiss. Zool. Bd. 22, pp. 235 et sqq. + This applies especially to the reproduction of Myrianida (Myria- dina) described by Milne-Edwards (“ Recherches zoologiques faites pen- dant un voyage sur les cétes de la Sicile,” Ann, Sc. Natur. (sér. 3), Zool. t. iii. pp. 170 et sqq). With regard to this M. Schultze says, “As a matter of fact, as is evident from his description, Milne-Edwards observed only a single specimen, which consisted of a series of seven individuals adhering to one another. From the series in question this investigator formulated his views as to the nature of the fission, which he supposed to be based upon a true formation of buds. But how difficult it is to decide from such scanty material, and without the closest microscopical inves- tigation, whether a segment of the parent-form does or does not pass into the young, will be admitted by every one who has occupied himself with similar observations” (M. Schultze, “ Ueber die Fortpflanzung durch Theilung bei Nats proboscidea,’ Arch. f. Naturgesch. 15 Jahrg., Bd. 1, p. 802). The numerous and scattered statements as to cases of asexual reproduction in Annelids altogether urgently need a critical sifting, in order to separate the observations from the speculations. t A. Pagenstecher, “ Untersuchungen iiber niedere Seethiere aus Cette,” Zeitschr. f. wiss. Zool. Bd. 12, p. 267. § E. Ehlers, ‘ Die Borstenwiirmer,’ Leipzig, 1864-1868, pp. 211 e¢ sqq. 46 Dr. F. von Wagner on Leuckart *, but has not since been investigated again, seems to a certain extent to present the appearance of gemmation ; yet when considered in connexion with similar processes in the forms most closely allied (Auwtolytus cornutus and the true Syllide) it will certainly require another interpretation. Indeed it has been stated by Ehlers precisely with regard to the asexual reproduction of the Syllide (including Autolytus) “that there is here no question of fundamental differences, but that there merely takes place a development of the same process differing in degree” f. Asa matter of fact we ought certainly not to perceive gemmation in the asexual reproduc- tion of Autolytus prolifer, but merely an extreme one-sided development of the usual simpler mode of reproduction of the segmented worms. It is evident from what has been stated that the asexual multiplication of M/crostoma, which has the chief claim upon our attention in the present investigation, represents fission. That which was demonstrated by Claus and Goette for the formation of Ephyre is perfectly applicable in all essential points to the fission of the Microstomids also, and it is suffi- cient to refer the reader to what has been quoted above from the writings of the investigators in question. Since all forms of reproduction which have been regarded as instances of terminal gemmation thus prove to be cases of fission, we arrive at the result that a formation of terminal buds in the customary sense has no existence whatever. LV. I have yet to allude to the statements of earlier investi- gators. If we may neglect the more incidental assertions of older authors, E. Heckel was the first who, although a long time ago, attempted systematically to establish the theory of fission and gemmation. In his classic ‘ Generelle Morphologie,’ so rich in fresh points of view, this investigator wrote (1866) : ‘‘ Tn self-fission the growth of the individual which ushers in reproduction is total, and in the act of fission is destroyed in its totality, so that the products of fission are equivalent to one another. In the formation of buds, on the contrary, it is an isolated portion of the body of the individual which, by means of special growth, leads to the formation of a new indi- * H. Frey and R. Leuckart, “ Beitrage zur Kenntniss wirbelloser Thiere &c., Braunschweig, 1847, pp. 91 et sqq. + E. Ehlers, op, cit. p. 208. | ; Fission and Gemmation in the Animal Kingdom. 47 viduality (bud), and this then separates completely or incom- pletely from the parent individual without the latter’s own individuality being thereby destroyed. ‘Therefore in this case the two products of fission are of unequal value.” Heckel further proceeds to show that fission produces indi- viduals of the same age, whereby the original animal as such is abolished, while the products of gemmation are of different ages, and the budding animal continues to exist unaltered as the parent form *. These assertions, the artificial construction of which is unmistakable, met with just contradiction on the extension of our knowledge of the processes in question. Thus Goette took the special case of the strobilation of Aurelia aurita as the starting-point of a critical excursus, in which he in the first place alludes to the fact that the products of gemmation resemble the parent form far more often than do those of fission. He then goes on to say: ‘‘ What Heckel moreover means by the unequal age of the products of gemmation is shown by the application to the case of Strobila which follows upon the heels of the definition ; for he says that the disks of the Strobila arise one after the other, and so possess that inequality of age which is the characteristic of gemmation. He therefore refers in this case not to the difference in age between the products of division due to one individual process of gemmation, but rather to the different age of the disks which follow one another in succession. Precisely the same difference of age exists, however, in all successive fissions of the same animal, such as, for instance, appear so conspicu- ously in MWicrostoma ; it is therefore quite useless as a distine- tive characteristic of gemmation. “ Just as untrustworthy is, lastly, the characteristic of growth, in the one case total (fission), in the other only partial (gemmation) ; for, apart from the frequent difficulty of such a distinction, we are in no wise justified by expe- rience in declaring a growth at all to be the necessary cause of every division.” Goette, therefore, is unable to recognize as applicable and sufficient the distinguishing characters of fission and gemma- tion laid down by Heckel, and for his part defines fission as a “separation of connected parts, which were therefore already present in a fully developed state,” but gemmation as a ‘new formation of parts by the method of a local growth, which become more or less independent ” f. * E. Heckel, ‘ Generelle Morphologie der Organismen,’ Bd. 2, Berlin, 1866, pp. 37 et sqq. + A. Goette, op. cit. pp. 47 et sqq. 48 Dr. F. von Wagner on Very recently the customary views upon fission and gem- mation, which conform more or less to Heckel’s statements, have also been criticized and rejected by von Kennel, who in so doing arrives at the conclusion “ that neither equality or inequality of the products of division, nor difference or agree- ment of age, nor even the possibility of distinguishing between the original and the new individual, furnish us with the means of separating fission and gemmation ” *, It appears to me to be superfluous to add anything further to the critical statements of Goette and von Kennel, with the results of which I am in accord. As regards Goette’s defini- tions of fission and gemmation which are quoted above, they confine themselves too strictly to conditions which are of importance for the special question of the interpretation of strobilation to suffice for a more general application. I there- fore turn to the definitions of the conception of fission and gemmation which have lately been developed in comprehen- sive fashion by von Kennel. “If we compare all reproductive processes with one another,” says von Kennel, “ we find that in one group the mass of the products proceeding from the reproduction, when taken together, is equal to the mass of the original individual before the commencement of the visible changes by which the process was ushered in. In all other cases reproduction is introduced by the appearance of new portions, which have nothing to do with the individual, through an accession of organized substance, so that the sections, after becoming independent, represent in their entirety more mass than was possessed by the original animal before the appearance of the reproductive phenomena. We may term the former class fission, the latter gemmation ” f. It follows from this that von Kennel regards the presence or absence of growth as the sole criterion of gemmation or fission respectively. ‘That in the case of the latter at any rate von Kennel’s definition betokens an artificial and arbi- trary limitation is manifest without further comment. But if we follow out von Kennel’s assertions to their logical conclusion we arrive at the result that no instances whatever of fission occur within the limits of the Metazoa., For it is impossible to mention any case of asexual reproduc- tion in these animals in which “the mass of the products proceeding from the reproduction when taken together is equal * J. v. Kennel, ‘Ueber ‘theilung und Knospung der Thiere,’ Dorpat, 1888, p. 14. + J. v. Kennel, op. et. pp. 14 et sqq. Ne » Fission and Gemmation in the Animal Kingdom. 49 to the mass of the original individual’ before the commence- ment of the visible changes by which the process was ushered in;”’ because every instance of fission in the Metazoa is, and must be, inevitably combined with regenerations or new formations of another kind, But these just as necessarily entail an increase in organic substance. Now it is certainly no reason for claiming a process as an instance of fission to say that if we did not fission would entirely disappear as a method of reproduction in the Metazoa. But von Kennel himself designates as fission the asexual reproduction of Planaria subtentaculata, which has been described, it is true only imperfectly, by Zacharias *, and has moreover acquainted us with the interesting multiplica- tion of a freshwater Triclad, which he terms “ transverse fission,” although in both cases, having regard to the regene- rative processes which ensue, an increase in organic substance is undeniable +. Fundamentally von Kennel’s conception of fission is exhausted with the bare process of separation, therefore with that which I have termed “ dissection’? within a case of paratomy. It is therefore postulated by this investigator that, when we would speak of fission in animals, the process in question must be identical with the splitting of a block of stone. This, however, according to animal organization is impossible, + Von Kennel’s conception of gemmation is in no better case. If, as we have seen, practically nothing remained for fission, gemmation, according to von Kennel, includes all instances of asexual reproduction in which any sort of growth appears. It is consequently a matter of complete indifference whether the particular process of growth takes place in the animal as a speciality, leaving the individual manifestation thereof unaffected, or whether it coincides with the normal increase in size of the creature, as we also meet with it in the animal’s nearest allies, which, however, lack the faculty of asexual reproduction. The gemmation of a Salp or Bryozoon, the formation of Ephyre in the Meduse, the processes of strobilation in the Worms, the gemmation of Hydroids and Corals, &c., are accordingly the same in principle, so much so indeed that, as v. Kennel { in the first instance, and, independently of him, * O. Zacharias, “ Ergebnisse einer zoolog. Excursion in das Glatzer-, Iser-, und Riesengebirge,” Zeitschr. f. wiss. Zool. Bd. 43, pp. 271 et sqq. + J. Kennel, “ Untersuchungen an neuen Turbellarien,” Zool, Jahrb, Bd. 3, Abth, f. Anat. u. Ont. der Thiere, pp. 407 et sqyq. }{ J. v, Kennel, ‘ Ueber Theilung und Knospung der Thiere,’ pp. 17 e¢ sgq. Ann. & Mag. N. Hist. Ser. 6. Vol. x. 4 50 Dr. F. von Wagner on Lang *, almost simultaneously endeavoured to render probable, all these processes are referable to one and the same starting- point—the regenerative faculty of animals {. Nothing appears to me to be so characteristic of von Kennel’s view of gemmation as the following statements by him t:—“ There appear .... in many Annelids, such as Nais, Cheetogaster, Atolosoma, Syllis, &c., new structures nearly in the middle of the segmented body, owing to which the anterior and posterior halves of the body are pushed away from one another. If this newly intercalated region of the body differentiates into a larger number of young segments, which further develop partly into new cephalic somites for the section of the body which lies behind them, and partly into new trunk-segments for that which lies in front—it is manifest that a formation of buds is thereby constituted, for in the original individual a new formation has appeared which is at first small, but is nourished by the original form and increases in size. If this bud subsequently constricts more and more about at its middle until complete separation takes place, we can scarcely be contradicted if we term it a case of reproduction by gemmation.”’ Here, therefore, v. Kennel designates as a bud the “ new formation, which is at first small, but is nourished by the original form, and increases in size.” ‘This supposed bud, which in truth represents nothing else than the so-called zone of gemmation (zone of regeneration), is no individual at all, no organic person, but a mixtum compositum, formed from the posterior and anterior halves of two different animals, attached together by their opposite ends ; and for the origin of these two there finally remains no other method after all, except—fission. Moreover it is at once evident that v. Kennel is here con- sidering cases of fission which, as we are wont to express it, depend upon processes of gemmation, and, designating the special kind of definite regenerative processes as processes of * A. Lang, ‘ Ueber den Einfluss der festsitzenden Lebensweise auf die Thiere &c.,' Jena, 1888, pp. 108 et sqq. + From my standpoint I am naturally unable to assent to this view, especially in this generalization. The faculty of reproduction by gemmation and fission and the power of regeneration may certainly depend upon the same general primary causes ; but with this nothing is stated as to the special causes, in consequence of which fission has been developed in one case and gemmation in another. The cutting off of a tentacle is, it is true, the external stimulus for its regeneration, but it is not the cause of the power to replace the lost part. } Op. eit. p. 13. Fission and Gemmation in the Animal Kingdom. 51 gemmation, interprets the whole mode of reproduction simply as gemmation. When v. Kennel further divides the manifold forms of gemmation into aaial (strobilation sens@ latiore) and lateral*, this distribution is also of little value, since it is based solely upon the difference in the direction of the growth, and there- fore a similarity of the processes in question in other respects is tacitly affirmed, which is by no means the case. Besides it is in many instances a matter of purely personal interpre- tation whether the actual bud is regarded as lateral or ter- minal (origin of many Hydromedusz by gemmation). In other words, whether an animal, as such, grows, and during the growth or subsequently divides itself into a number of individuals, or whether an animal by a special growth upon itself produces new zooids, are two entirely different pro- cesses; at any rate their difference is far greater than that between the questions whether the buds arrive at their deve- lopment upon an animal at the side, in front, or behind, pro- vided only that their formation agrees in other respects. I am therefore not in a position to recognize as really well- grounded the distinguishing characteristics of fission and gemmation which are laid down by v. Kennel, apart from the fact that they also convey no advantage for the praxis of a simpler discrimination between the two modes of repro- duction. Vi On referring to the foregoing statements it may be asserted that fission and gemmation can well be distinguished from one another. While all forms of reproduction which were referable to the natural conception of fission were brought into one division, a general characteristic was disclosed for those methods also which remained outside that series, in the special character‘of the growth which appears in connexion with them. ‘This separation of two widely distributed forms of asexual reproduction is, however, not to be maintained merely from the practical point of view of facility of syste- matic survey ; but it is also not devoid of a deeper meaning : the intimate relation between fission and gemmation is, at least to the extent to which it is nowadays so frequently accepted, a fiction. Without of course wishing to deny all connexion between * Op. eit. p. 17. 4* 52 Dr. F. von Wagner on fission and gemmation*, that conception nevertheless could well have its foundation only in the supposition that not merely do fission and gemmation merge into one another through unequivocal intermediate forms, but that also there is justification for venturing to speak of both modes of repro- duction in the general sense; for only on such hypotheses would it be permissible to extend to all cases definite results of the facts found in one or more, and to elevate them into a principle of general applicability. The conditions alluded to, however, by no means occur. As regards possible transitional forms, in the first place it certainly appears to be beyond doubt that, especially among the Cnidaria, the existence of such intermediate modes of reproduction cannot be gainsaid. Yet these supposed inter- mediate forms assume this aspect solely in consequence of the faulty and indefinite character of the views which have hitherto been held. Intermediate forms of this kind occur in the Cnidaria just as little as in the Worms or any other Metazoa. Von Koch was entirely in the right when, on the basis of his minute investigation of the conditions of asexual reproduction, which were, it is true, chiefly those of the Paleozoic Corals, he was induced to create a ‘ fission-gemma- tion” (“ Theilungsknospung’”’), and included it, as well as his “ septal gemmation,” under fission, according to custo- mary views +. Yet, according to the aspects which influence me, it is no less clear that, in the forms of gemmation alluded to, | am bound to recognize real gemmation and not fission. The instances of asexual reproduction in the Worms, in spite of all differences of detail, nevertheless exhibit so uni- form a general character as to necessitate similar interpre- tation. In contrast to these conditions the remarkable gemmation of Syllis ramosat} appears completely isolated ; as yet this represents the sole case of gemmation in the Anne- lids, and is probably a purely personal acquisition on the part of this Syllid, which has been gained in adaptation to the fundamentally altered mode of life. * By this I allude not merely to the connexion which is entailed by the community of the same primary causes (cf. last note), but also to that which would, as it were, be implied by the proof that a particular case of fission could, in its origin, be traced to a particular case of gemmation, or vice versd (e.g. origin of strobilation, according to Claus—‘ Unter- suchungen tber die Organisation und Entwicklung der Medusen,’ Leipzig, 1883, p. 18). - + G. y. Koch, “Die ungeschl. Vermehrung einiger paliozoischer Korallen vergleichend betrachtet,” Paliontographica, Bd. 29, p. 89. } “ Report of the Scientific Results of the Voyage of H.M.S, ‘ Chal- lenger, Zoology,” vol. xii. pp. 198 et sqq. Fission and Gemmation in the Animal Kingdom. 538 The second point, whether fission and gemmation may be conceived in a general sense, is in no better case. Noone will wish to maintain that the various kinds of fission as well as the manifold cases of gemmation have been inherited through the animal series from their first appearance, and should consequently be regarded as phyletic units. But also as regards their origin fission and gemmation cannot have proceeded from the same causative conditions. From the facts which we have before us an origin of the same kind cannot be exhibited for the series of those modes of reproduction which are to be designated as cases of gemma- tion; on the contrary, it is in the highest degree probable that the gemmation of the Salps and that of the Bryozoa represent specific acquisitions within the respective phyla. Although at the present time no certain decision is possible as to the way in which these acquisitions were developed, nevertheless the wide-reaching investigations of Seeliger have sufficiently demonstrated that the formative laws of gemmation in the Bryozoa are of an entirely different character from those which have had effect among the Tunicata *, With reference to the quite aberrant gemmation of Sy/lis ramosa, I have already remarked above that the active causes of its origin may well be sought without hesitation in the specialities of its peculiar mode of life. The cases of gemmation among the Cnidaria are in no way lacking, as it appears, in a more homogeneous character, which may well indicate a common originating cause. Although it follows that the conditions under which the manifold instances of gemmation may have arisen in the various animal phyla are at present in a great measure still an object of pure conjecture, nevertheless that which is actually known about them in the several cases or series presents results of so heterogeneous a nature that the justification for generalizing about gemmation is at least not proved, The same applies to fission. The strobilation-forms of this process in the Cnidaria and Worms, which are usually selected for comparison, have in truth a mere external similarity only. Owing to the great agreement which is exhibited in essential features by all cases of fission in the Worms, we shall have to consider them as a development pointing to a common basis; for this deve- lopment the conditions of the origin of those modes of repro- * O. Seeliger, “Die ungeschlechtliche Vermehrung der endoprocten Bryozoén,” Zeitschr, f. wiss. Zool. Bd, 49, p. 204. 54 Mr. W. L. Distant on duction were supplied within the phylum of these animals themselves and their peculiar circumstances. In the same way, too, this point of view may well be adopted for the Medusan Strobila also, no matter whether we would derive it with Claus * from the gemmation of stolons or not. We thus arrive at the final result, that the customary idea of the intimate relationship between fission and gemmation has no justification in facts, but rather that the separation of the asexual reproductions of the Metazoa possesses not only a notional meaning, but also a real foundation. The cases of asexual reproduction in the various animal phyla have proceeded independently of one another from con- ditions existing within these phyla, so that that which, it may be, can be rendered probable for a single case of reproduction or for a congeries of similar cases, includes no binding force for other instances of multiplication by fission or gemmation. It will be the task of future investigation, in determining the originating causes which have decided the character of each form of reproduction belonging to the present category, to separate chaff from wheat, so to speak, 7. e. to eliminate from the series of propagations those modes of multiplication which represent mere augmentations. Merit is due to von Kennel for having emphatically drawn attention to this important difference fT. VII.—On some undescribed Cicadidee, with Synonymical Notes. By W. L. Distant. It has been urged, and with some reason, that descriptive papers should, where possible, be confined to the diagnoses of members of some particular zoological region; and if this course could always be pursued the convenience it would afford to purely faunistic workers would doubtless be great. But the formulation of rules and theories is often a very special gift of a very few, and is sometimes in an inverse ratio to possibili- ties and experience. ‘There is, however, a course which will enable the descriptions of widely distributed insects to be faunistically apprehended, and that is by geographically tabulating the species described in some manner similar to the following, which applies to the present paper. * C. Claus, ‘ Untersuchungen iiber die Organisation und Entwicklung der Medusen,’ Leipzig, 1888, p. 18. + J. v. Kennel, ‘ Ueber Theilung und Knospung der Thiere,’ p. 8. i ia a ii i a a in i eee some undescribed Cicadide. 55 _ All the species described are contained in my own collec- tion. ErHioP1an REGION, Cicada madagascariensis, sp. n. Madagascar. NEorropicaL REGION, Fidicina amazona, sp. 0. Kea. bogotana, sp. n. Bogota. —— rubricata, sp. n. Brazil. Tympanoterpes colombia, sp. n. Colombia. -—— Bergt, sp. n. Argentine Republic, Dorachosa (gen. noy.) erplicata, sp. n. Panama. Tibicen ege. Kga. Tettigades parva. Argentine Republic. AUSTRALIAN REGION, Psaltoda flavescens, sp. n. Australia. Cicada extrema, sp. 0. Australia. Melampsalta labeculata, sp. n. Australia. PactFric REGION. Kanakia (gen. nov.) typica, sp. n. New Caledonia. Tibicen pumilus, sp. n. New Caledonia. CrcaDINZ. Psaltoda flavescens, sp. n. 3. Head ochraceous ; the base and lateral areas of front, the area of the ocelli, a broad fascia between the eyes, a central basal fascia, and a linear spot near anterior angles of vertex, black. Pronotum with the disk castaneous, the lateral and posterior margins and a central fascia ochraceous ; inner edge of lateral and posterior margins, a central spot on posterior margin, the fissures, and the margins of the central fascia, black. Mesonotum castaneous, with four obconical black spots, the central pair shortest, the outer pair sometimes broken, and a spot in front of the basal cruciform elevation, black. Abdomen above pale castaneous, the anterior margins of the segments broadly blackish, especially on the basal segments, where the markings are centrally macular. Tym- panal coverings, excluding anterior margins, blackish. Head beneath, sternum, legs, and opercula ochraceous ; the central suleation and transverse striations to face, space between face and eyes, rostrum (excluding base), coxal streaks, ante- rior tibie, apical halves of intermediate tibie, the anterior 56 Mr. W. L. Distant on and intermediate tarsi, and the inner margin of the opercula, blackish. Abdomen pale castaneous, with the base narrowly black, enclosing two small ochraceous spots. Tegmina and wings pale hyaline, the venation castaneous. Tegmina with the costal membrane and basal cell pale casta- neous; the transverse veins at the bases of the second and third apical areas narrowly infuscated, and a series of small and somewhat indistinct fuscous marginal spots on the apices of the longitudinal veins to the apical areas. Wings with the margins of the claval areas infuscated. The face is very globose; the opercula do not meet centrally ; the rostrum reaches the posterior coxe. Long., excl. tegm., ¢ 40, 9 30 millim.; exp. tegm., g 107, 2 90 millim. Hab. Australia (no precise locality). This species is allied to P. argentata, Germ., from which it differs by the shape and colour of the opercula, the more globose face, the different colour-markings, &c. I long possessed an unlocalized female specimen of this species, and have lately acquired a male example from Australia (no definite locality), which has enabled me to describe it. Cicada extrema, sp. n. &. Head and thorax brownish ochraceous. Pronotum with the lateral and posterior margins pale ochraceous. Abdomen above castaneous, the posterior segmental margins paler in hue; apical half of the last segment and the anal appendage ochraceous; tympanal coverings obscure ochra- ceous. Head beneath and sternum brownish ochraceous ; the face, space between face and eyes, lateral margins of prosternum, legs, and opercula, pale ochraceous ; femora and tibie streaked with castaneous. Abdomen beneath casta- neous, the apex pale ochraceous as above. Tegmina and wings pale hyaline, the venation fuscous, ochraceous at basal area; tegmina with the costal membrane and upper part of basal cell ochraceous. The face is very globose, centrally suleated (excepting at base), and obliquely striated ; the rostrum reaches the inter- mediate coxe; the opercula are short, not extending beyond the basal segment, are convexly rounded, and overlap at their inner margins. ?. Head and thorax above pale greenish ochraceous and unicolorous. some undescribed Cicadide. 57 Long., excl. tegm., ¢ 34, 9 30 millim.; exp. tegm. & @ 90 millim. Hab. Australia, Swan River. Coll. Dist. This somewhat large species of Cicada is allied to C. inter- secta, Walk., and like that species has the pale apex to the abdomen; but C. extrema may be at once recognized by the more robust and less symmetrical body, the head and thorax being relatively wider, the unspotted head and thorax, the longer second apical area to the tegmina, &e. Cicada madagascariensis, sp. 0. &. Body above dull ochraceous. Head with the margins of front, fascia to lateral areas of vertex, and the area of the ocelli, black. Pronotum with a central longitudinal fascia margined with black (these black edges sometimes obsolete). Mesonotum with four obconical dull castaneous spots, the central pair shortest and somewhat fused, a similarly coloured spot in front of the basal cruciform elevation. Body beneath and legs pale ochraceous; central area of face and a fascia between base of face and eyes black. Tegmina and wings pale greyish, semihyaline and talc- like, the venation ochraceous, inclining to fuscous towards apical areas ; tegmina with the costal membrane ochraceous, the transverse veins at the bases of the second and third apical areas narrowly infuscated, and a submarginal series of small fuscous spots placed on the longitudinal veins to the apical areas. The eyes are large, prominent, and subsessile ; the ros- trum reaches the posterior coxe ; the opercula are about the length of the posterior tibiz, oblong, just or almost meeting at their inner basal margins, their apices convexly rounded but not extending beyond the basal abdominal segment. Long., excl. tegm., g 13-15 millim.; exp. tegm. 40 millim. Hab. North Madagascar. A very small species of the genus; its principal charac- teristics are its pale greyish semihyaline tegmina, with the darker venation and submarginal spots, the large and promi- nent eyes, and the well-developed opercula. It is allied to C. maculigena, Sign., but differs from the description of that species by the smaller expansion of the tegmina, with the small submarginal fuscous spots to same ; the markings of the pro- and mesonotum appear to be also altogether different. 58 Mr. W. L. Distant on TIBICENINZ. Fidicina amazona, sp. n. &. Body above olivaceous, inclining to ochraceous. Head with a central fascia to front and an irregular transverse fascia between the eyes (enclosing the ocelli) black. Pro- notum with the anterior margin, the fissures, and a central transverse spot on the inner edge of posterior margin, black. Mesonotum with four obconical black spots, the central pair shortest ; the anterior margin of the basal cruciform elevation and a small spot in front of each of its anterior angles black. Abdomen much shaded with black ; the black markings are situate on the abdominal segments, narrowing to apex and again obliquely branching off from near base to lateral margins ; the inner areas of the tympana and four longitu- dinal stripes on anal appendage—the central pair short— black. Body beneath and legs olivaceous; the central sulca- tion (partly) and transverse striations to face, margins of face, coxal spots, femoral shadings, apices of anterior and inter- mediate tibie and the tarsi, base, lateral margins, and apex of abdomen, black; abdomen with the anal appendage and a large spot on apical lateral margins ochraceous, and with a central series of blackish spots; opercula olivaceous, with their bases and margins black. Tegmina and wings pale hyaline, the venation fuscous; tegmina with the costal membrane and basal cell olivaceous ; bases of both tegmina and wings narrowly blackish. The front has a distinct central sulcation ; the face is pro- foundly suleated and striated; the head beneath, sternum, and legs strongly pilose ; the rostrum reaches the posterior coxe and has its apex black; the opercula are small, just meeting at their inner basal angles, their posterior margins sinuated. The first and third apical areas of the tegmina are equal in length. Long., excl. tegm., ¢ 25 millim.; exp. tegm. 87 millim. Hab, Kuga, on the Amazons. A strikingly marked species, to be easily recognized by the black fasciated abdomen. Fidicina bogotana, sp. n. Body above brownish ochraceous; the eyes, lateral and posterior margins to pronotum, and the posterior margins of the abdominal segments pale ochraceous. Head with the anterior margin of front, a transverse fascia between the eyes, some undescribed Cicadide. 59 the posterior margin of eyes, and a spot at anterior angles of vertex, black. Pronotum with the anterior margin and a transverse central spot on inner edge of posterior margin black. Mesonotum with two short, central, angulated black fasciee at anterior margin, with a shorter and more obliterated spot on each side, a lineate spot on hinder portion of disk, a spot on each side of the cruciform elevation, the anterior margin of same, and a small spot in front of its anterior angles, black. Abdomen with the basal segmental margins narrowly blackish. Body beneath and legs ochraceous ; the central sulcation (partly) and the transverse striations to face, margins of face, fascia between face and eyes, apices of ante- rior and intermediate tarsi, apex of rostrum, and the basal margins of opercula, black. Tegmina and wings pale hyaline, the venation ochraceous or fuscous, their extreme bases narrowly ochraceous, streaked with black; tegmina with the costal membrane and upper art of basal cell ochraceous, the postcostal area fuscous. The front has an obscure central sulcation, the face is profoundly sulcated and striated; the body beneath is slightly pilose ; the rostrum reaches the posterior coxe; the opercula are small, not quite meeting at their inner basal angles, their posterior margins sinuated. Long., excl. tegm., ¢ 25 millim.; exp. tegm. 93 millim. Hab. Bogota. This species is closely allied to the preceding, F. amazona, although of very different coloration and markings. It differs also from /. amazona by the broader and less ante- riorly produced head, the much less pilose body, the narrower central sulcation to the face, and by the shorter upper apical area to the tegmina, which is not equal to the third area in length. Fidicina rubricata, sp. n. 2. Body above brownish ochraceous. Head with the area of the ocelli and the hinder margin of the eyes broadly black. Pronotum with the anterior margin and a central transverse spot on inner edge of posterior margin black. Mesonotum with two central curved fasciate lines on anterior margin, a small spot in front of the anterior angles of the cruciform elevation, the anterior margin, and a large spot on each side of same, blackish; the posterior lateral margins blackish, narrowly edged with ochraceous. Abdomen reddish ochraceous (excluding central base), much shaded with black, and very strongly pilose, the hairs being distinctly ochraceous 60 Mr. W. L. Distant on on the lateral areas ; anal appendage with an irregular black fascia on each side. Body beneath and legs ochraceous and thickly pilose. ! Tegmina and wings pale hyaline, the venation ochraceous ; tegmina with the costal membrane, postcostal area, and basal cell ochraceous, the extreme base also narrowly ochraceous ; wings with the base narrowly pale ochraceous and the upper half of the abdominal area pale sanguineous. The head is broad, with a profound central suleation to front, the face is also profoundly suleated and striated ; the anterior angles of the cruciform elevation are very ill-defined ; the rostrum only just passes the intermediate coxe. Long., excl. tegm., 9 30 millim.; exp. tegm. 100 millim. Hab. Brazil (sic). A species to be recognized by the ochraceous and sanguine- ous base of the wings and the obsolete nature of the anterior angles of the cruciform elevation. Tympanoterpes colombice, sp. n. &. Body above brownish ochraceous. Head with the front black, its base and a central longitudinal fascia ochra- ceous ; a broad irregular fascia between the eyes and enclosing the ocelli, anterior angles of vertex, and inner and posterior margins of eyes, black. Pronotum with two central longitu- dinal fasciz (united posteriorly) and the fissures black, the posterior margin pale greenish or ochraceous, its inner edge and a spot near lateral angles black. Mesonotum with four large obconical spots (the central pair shortest), a large trian- eulated spot in front of cruciform elevation, and a transverse waved spot on each side of same, black. Abdomen with central transverse segmental fasciz, narrowing and becoming obsolete towards apex. Body beneath and legs pale ochra- ceous ; the opercula and the margins of the sternum greyishly tomentose ; discal portion of the transverse striations to face, a large spot at inner margin of eyes, and the apex of the rostrum, black. Tegmina and wings pale hyaline, the venation ochraceous or fuscous ; tegmina with the costal membrane and upper half of basal cell greenish or ochraceous, the postcostal area fuscous ; extreme bases of both tegmina and wings narrowly pale fuscous, the wings with a pale fuscous streak on basal half of abdominal area. The costal edge of the tegmina is finely serrated, with the teeth minute and fuscous in hue; the face is globose, sul- cated and striate; the rostrum just passes the posterior cox ; ee or some undescribed Cicadide. 61 the opercula are small, slightly sinuated on their posterior and lateral margins. Long., excl. tegm., g¢ 29, 2 27-29 millim.; exp. tegm., 3 94, 2 85 millim. Hab. Colombia, Manaure (/. Simons) ; Bogota.—Vene- zuela. Tympanoterpes Bergi, sp. nu. Head and thorax above thickly covered with ochraceous pile and wholly ochraceous, excepting a few lineate marks at base of head; the fissures, a central spot near the base of the pronotum, a spot at angles of the posterior margin to same, and a central spot to the cruciform elevation, black. Abdomen dark castaneous, the rudimentary tympanal coverings black. Head beneath, sternum, opercula, and legs thickly pilose and ochraceous in hue; coxal spots, apices of the femora, basal annulation to the fore and intermediate tibie, bases of the tarsi, and margins of the opercula paler in hue; apices of the tarsi fuscous; abdomen castaneous, anal appendage ochraceous on each lateral area. Tegmina and wings pale hyaline, the venation ochra- ceous, inclining to fuscous. Tegmina with the costal mem- brane ochraceous, containing a black central line; base of the upper vein and the terminal vein to basal cell, basal claval margin, outer edge of terminal vein to radial area, and spots on the longitudinal veins to the second, third, and fourth ulnar areas, black ; transverse veins at the bases of the first, second, third, fourth, fifth, and seventh apical areas very darkly infuscated; a series of longitudinal fuscous lines in some of the apical areas and a marginal row of very dark fuscous spots; wings with the abdominal area margined with fuscous and with its base ochraceous, containing a black line. The transverse vein at the base of the second apical area to the tegmina is only moderately oblique; the rostrum reaches the posterior coxee; the opercula are wide apart at their inner basal angles, but almost meet at their inner apical angles, their outer margins are moderately convex, and their lateral margins slightly sinuate. Long., excl. tegm., ¢ 24 millim.; exp. tegm. 72 millim. Hab. Argentine Republic (Berg). A species to be recognized by the ochraceously pilose head and thorax and by the well-marked tegmina, 62 Mr. W. L. Distant on KANAKIA, gen. nov. Head somewhat convexly produced in front, about equal in length to the space between the eyes, including outer margins of eyes about equal in width to base of mesonotum ; eyes large, obliquely directed backwardly ; ocelli about equally wide apart from eyes as from each other; a distinct broad central sulcation from between ocelli to base. Pronotum more than twice as broad as long, with the lateral margins prominently and somewhat acutely angulated, the lateral posterior angles moderately ampliated. Mesonotum large, with the cruciform elevation well developed. Tympana totally exposed and uncovered. Abdomen jin the male mode- rately inflated, beneath grooved before the lateral margins ; the opercula small ; anterior femora armed with four spines, the one near base and one near centre longest and very promi- nent, remaining two small, situate about apex, and the apical one minute. Face long and somewhat depressed. Tegmina and wings hyaline. Tegmina with eight apical areas; the interior ulnar area with its anterior margin convex, and with its base and apex subequal in breadth ; ulnar veins well sepa- rated ; basal cell twice as long as broad. Wings with six apical areas. Kanakia may be placed near the Madagascar genus Malagasia, Dist. is ; Sure Kanakia typica, sp. n. 3. Body above ochraceous. Head with two castaneous spots at base of front; a spot at anterior angles of vertex, base and area of ocelli (excluding central sulcation), and pos- terior margins of eyes, black. Pronotum with the interior margins, two central oblique fasciz which are narrowed and convexly united posteriorly, the fissures, and two angular spots, black. Mesonotum with four large obconical casta- neous spots, all of which are united to a large castaneous spot in front of the basal cruciform elevation, which is also castaneous. Abdomen with a series of small central spots, a series of larger lateral spots more or less continued inwardly, and a subapical transverse fascia, black. - Body beneath and legs ochraceous; anterior and intermediate tibie and tarsi, longitudinal fasciz to femora, and coxal streaks castancous. Face with a broad central fascia (containing a triangular spot at base), the posterior margins, and a linear spot near base of antennee, very dark castaneous. some undescribed Cicadide. 63 Tegmina and wings pale hyaline, the venation ochraceous. ‘Tegmina with the transverse veins at the bases of the second and third apical areas darkly infuscated ; the costal membrane ochraceous, with its outer edge fuscous, the postcostal area fuscous. Wings with the margins of the abdominal area narrowly infuscated. @. The body above darker in hue than in the male; the spots of the abdomen fused and fasciate-like in appearance and distinctly greyishly tomentose ; anal appendage with two oblique black fascize. The rostrum reaches the posterior coxe ; the face is faintly suleated on its posterior half and is somewhat ebscurely transversely striate. Long., excl. tegm., ¢ 9 37 millim.; exp. tegin., ¢ 100, @ 107 millim. Hab. New Caledonia. DORACHOSA, gen. nov. Head about twice as long as the breadth between the eyes ; the front somewhat broad and prominent ; ocelli about as far apart from the eyes as from each other; lateral margins of the vertex somewhat convex; eyes very long, directed obliquely backwardly, their inner margins ampliated and laminately produced inwardly. Pronotum rather more than twice as broad as long, the lateral margins straight and trun- cate, the posterior lateral angles moderately ampliated. Mesonotum with the cruciform elevation well developed, with its anterior margin slightly gibbous, and its anterior angles very slender. ‘Tympanal coverings absent, the tympana altogether exposed and uncovered. Face very broad, globose, and prominent. Anterior femora armed beneath with three large spines, one at base, one at centre, and one near apex. Rostrum with the apex rather broad and reaching the inter- mediate coxee. Opercula very small and slender. Abdomen grooved beneath on each side before the lateral margins. Tegmina and wings hyaline. Tegmina with eight apical areas, the ulnar veins well divided, the basal cell much longer than broad and wider at base than at apex; the interior ulnar area about as broad at base as at apex. Wings with six apical areas. This genus is allied to 7ibicen, from which it may at once be distinguished by the remarkable structure of the eyes ; the structure of the front and face and the strongly spined anterior femora are also distinctive characters. 64 Mr. W. L. Distant on Dorachosa explicata, sp. n. &g. Body above with the head and pronotum ochraceous, the mesonotum greenish ochraceous, and the abdomen casta- neous. Head with a slender oblique black fascia between the eyes and the ocelli, a dark linear transverse fascia on anterior margin of vertex, and with some irregular castaneous marks at the region of the ocelli. Mesonotum with four subobsolete obconical dark spots, the central pair smallest. Head beneath, sternum, legs, and opercula pale ochraceous, the abdomen beneath castaneous ; apices of the femoral spines and ‘apex of the rostrum castaneous. Tegmina and wings pale hyaline, the venation ochraceous, inclining to fuscous; tegmina with the costal membrane and postcostal area ochraceous. The front has a short central apical sulcation; the face is very distinctly centrally sulcated and obscurely transversely striate; the opercula are slender, transverse, and attenuated at the apices, which are well separated from each other. Long., excl. tegm., g 12 millim.; exp. tegm. 37 millim. Hab, Panama, Matachin. Tibicen egw, sp. n. g. Body above dull dark ochraceous. Head with the lateral margins of the vertex and the inner margins of the eyes darker in hue. Pronotum with the margins dark fuscous, a central transverse fuscous spot on anterior and _ posterior margins, and with two faint central, linear, sinuated, fuscous fascie. Mesonotum with four faint darker obconical spots, the central pair shortest, a lateral fascia and a spot in front of the cruciform elevation of the same colour. Abdomen with the basal area somewhat darker in hue. Body beneath and legs dull dark ochraceous. Tegmina and wings pale hyaline, the venation ochraceous, inclining to fuscous; tegmina with the costal membrane ochraceous, the postcostal area fuscous; the transverse vein at the base of the second apical area and the apical margin of the first apical area infuscated. The face is very strongly transversely striate and the central sulcation is very narrow. ‘The opercula are very small, with their basal margins somewhat darker in hue. Long., excl. tegm., ¢ 14 millim.; exp. tegm. 42 millim. Hab, liga, on the Amazons. A small and obscurely marked species, in coloration allied to T. guatemalanus, Dist. some undescribed Cicadidee. 65 Tibicen pumilus, sp. n. 3d. Body above dull dark ochraceous. Head with the interior margins of eyes, lateral margins of vertex, and the area of the ocelli black. Pronotum with a pale ochraceous central fascia, the fissures and a spot on each side of disk black. Mesonotum witlt four obconical black spots, the central pair shortest, and a black spot in front of the anterior angles of the basal cruciform elevation. Abdomen greyishly tomentose, the basal segmental margins blackish, the apical segmental margins pale ochraceous, excepting the two basal segments, which are almost uniformly greyishly tomentose ; the lateral margins of the last four segments are also dis- tinctly blackish, and the base of the anal appendage is of the same colour. Head beneath black, the margins of the face ochraceous. Sternum, legs, opercula, and abdomen beneath ochraceous ; sternal spots, coxal streaks, longitudinal fasciee to anterior femora, the intermediate and posterior femora (excluding bases and apices), apices of anterior and inter- mediate tibie and tarsi, the rostrum, the margins of the sonorous orifices, and the apical segment of the abdomen, dark castaneous or blackish. Tegmina and wings pale hyaline, the venation fuscous ; tegmina with the costal membrane ochraceous, its base fuscous. The rostrum just passes the intermediate coxe ; the oper- cula are small and convexly rounded. Long., excl. tegm., ¢ 9-10 millim.; exp. tegm. 27-30 millim. Hab. New Caledonia. A small species of the genus, in size somewhat allied to the Australian 7. Gregory, Dist., and to be recognized by its very distinctive coloration and markings. Tettigades parva, sp. n. ?. Body above black; the eyes, the anterior and posterior margins of the pronotum, lateral and posterior margins of the mesonotum, anterior angles of the cruciform elevation, and posterior margins of the last two abdominal segments and of the anal appendage, ochraceous. Body beneath black and pilose; lateral margins of the face, sternal spots, coxal streaks and apices, bases and apices of the femora, posterior tibiz and tarsi (¢ntermediate tibiw mutilated), disk ef the abdomen, and lateral margins of the anal appendage, ochraceous. Tegmina and wings pale hyaline and tale-like. Tegmina Ann. & Mag. N. Hist. Ser. 6. Vol. x. o) 66 On some undescribed Cicadide. with the venation fuscous ; the extreme base, the costal mem- brane (excluding inner margin), the basal cell, the basal and apical veins of the lower ulnar area, the transverse veins at the bases of the three upper ulnar areas, and a spot on thie lower vein of the third ulnar area, ochraceous. Wings with the venation of the basal area ochraceous, remainder fuscous. The rostrum reaches the intermediate coxee; the face is distinctly suleate, but obscurely striate. af Long., excl. tegm., 9 14 millim.; exp. tegm. 45 millim, Hab. Argentine Republic (Berg). A small species allied to 7. chilensis, A. & S., from which it differs by its smaller size, the black lateral margins to the pronotum, the black centre of the cruciform elevation, the much less pilose surface of the body beneath, the less broadly sulcated face, &c. Melampsalta lubeculata, sp. n. @. Head and thorax above ochraceous; head with the margins of front, a lineate spot near anterior angles of vertex, and a very broad fascia between the eyes, enclosing the ocelli, black. Pronotum with two central fascize rounded and joined posteriorly, a spot on each side, and the fissures, black; a black spot on posterior margin at the lateral angles. Meso- notum with four large obconical spots (the central pair shortest), a central lanceolate fascia, anterior margin of cruci- form elevation, a spot on its anterior angles, and a small spot in front of the same, and the posterior lateral margins, black. Abdomen black, moderately pilose, the posterior segmental margins very narrowly ochraceous; a spot on each side of the last dorsal segment, two large lateral spots (basal and apical), and two central lines to anal appendage, ochra- ceous. Body beneath and legs ochraceous; a broad central fascia to face on each side of the sulcation, base and apex of rostrum, sternal spots, longitudinal streaks to femora, anterior tibia (excluding bases), bases and apices of intermediate tibie, apices of the tarsi, a broad central fascia to abdomen, and anal appendage (the last centrally united with the dark coloration above), black. Tegmina and wings pale hyaline: tegmina with the vena- tion fuscous, the costal membrane ochraceous, and with a large blackish spot on the transverse veins at the bases of the second and third apical areas; wings with the venation ochraceous and fuscous. Long., excl. tegm., 2 20 millim.; exp. tegm. 62 millim. Hab. Australia (no precise locality). Mr. H. M. Bernard on the Apodemes of Apus ke. 67 This species cannot well be confused with any other of the Australian Delampsalte. By the prominent subapical spotting of the tegmina it is somewhat allied to J. wmbri- margo, Walk., and M. convergens, Walk., but with both these species it has nothing else in common. SYNONYMICAL NOTES. Tympanoterpes sodalis. Cicada sodalis, Walk. List Hom. i. p. 108. n. 9 (1850), = Fidicina vultur, Walk. Ins, Saund. Hom. p. 10 (1858). Melampsalta mangu, B. White, Ent. Month. Mag. vol. xv. p. 214. n. 63 (1879),=JMelampsalta nervosa, Walk. List Hom. 1, p. 213. n. 166 (1850). Tibicina lactetpennis, Puton, Rev. d’Ent. il. p. 45 (1883). N. Persia, This name is already preoccupied in the genus Tibicen by T. (Cephaloxys) lacteipennis, Walk. List Hom. i. p. 237. n. 8 (1850), described trom North India. I therefore propose to rename the Persian species as 7. Putoni. VUI.— The Apodemes of Apus and the Endophragmal System of Astacus. By Henry M. Bernarp, M.A. Cantab. [Plate V.] THE endophragmal system of Astacus has been a considerable puzzle to all who have studied the subject. Though the elements of which it is made up are clearly seen to be folds of the outer skin, in some way connected with segmental con- strictions, it has never been understood how they arose. No muscles are apparent which could have drawn them in; indeed, some of those attached to them, e. g. the coxal muscles, pull in the opposite direction, ¢. e. tend to straighten the skin and not to draw it into folds. When attempting lately to show * that Apwus is a primitive Crustacean nearly related to the Annelids, 1 was many times struck with the close resemblance between it and the Ma- crurous Decapod Crustaceans, and could not refrain from * “The Apodide.” Macmillan, 1892. ee 68 Mr. H. M. Bernard on the Apodemes of Apus hoping that some one would attempt a detailed deduction of Astacus from the Apodide. As a contribution to such an attempt, I propose here to show how Apus supplies us witha full explanation of the endophragmal system of A stacus. Apodemes, or inward foldings of the skin, are very plenti- ul in Apus, and their origin is in all cases clear. We have, first of all, the segmental constrictions, which are naturally obliterated in the stretched regions of the body, but very marked in longitudinally compressed regions. For our present purpose we confine our attention to the con- strictions on the ventral surface anteriorly. In some speci- mens, according to the state of contraction at death, these are very deep and throw the ventral cord into a series of waves (Cjpele Westie), In Astacus the moving forward of the anterior trunk-limbs to function as mouth-parts or maxillipedes, and the conse- quent longitudinal compression of this region of the body, necessarily caused these constrictions to form high fixed barriers across the inner ventral surface. Over these barriers the ventral cord had at first either to stretch, or to form a series of arches. Each barrier has, however, in time been cut down in the middle line, so that the cord has come to lie in a groove along the ventral surface, known as the sternal canal. ‘The subsequent arching over of the canal by sinewy matter is a secondary arrangement which also receives its explanation in Apus, as we shall presently see. So far, this explanation of the origin of the endosternites (as the two halves of these constrictions are called) is simple enough. ‘The origin of the endopleurites (or endotergites as they are sometimes called) is not quite so evident. Taking first the endopleurites between the trunk-limbs, we find that in Apus, in the anterior part of the body, where the limbs are developed, the two ventral longitudinal muscle- bands are attached to the segmental folds between the limbs. These points of attachment naturally tend to be drawn in- wards by the action of these muscle-bands. Further, as the pulls of the muscles are in the longitudinal direction, the folds naturally acquire the diamond-shape shown in the tangential sections (figs. 5,6). In these apodemes the dorso- ventral diagonal is the natural direction of the segmental constriction ; the longitudinal diagonal is due to the pulls of the muscle-bands. By comparing the sections we find that each of these apodemes in Apus is pulled backwards as far as the segmental constriction posterior to that to which it really belongs. This is easy to understand; the length of the posterior region in Apus and the use made of it for sudden and the Endophragmal System of Astacus. 69 diving movements make it probable that the prevailing pulls of these muscle-bands are for the bending of the abdominal region. But although the greater part of the apodeme thus slopes backwards, there are indications of a slight anterior pull in its diamond form. Turning now to Astacus, we find very pronounced apo- demes dorsally to the limbs, and in the line between them. These are clearly homologous with the apodemes of Apus, and originate as part of the segmental constriction between the limbs. How they came to be drawn in we have learnt from Apus; they were originally the points of attachment of the segmental constrictions to the ventral longitudinal muscle- bands inherited from the original Chetopod Annelid, and retained in Apus. This origin is no longer apparent in Astacus. Internally these endopleurites give off two branches, one running posteriorly to the endosternite belonging to the next posterior constriction, and one running in “towards its own endosternite. The former alone of these is, as above described, developed in Apus, and has been handed on to Astacus ; but whence came the anterior branch ? A trace of this anterior branch is, as we have seen, present in Apus, and might be easily developed if it were to be sub- mitted to any strong anterior pulls of the longitudinal muscle- bands. ‘This is clearly what has happened in Astacus, and we have abundant evidence of such persistent anterior pulls in the compression of the anterior ventral region. The effort to bring forward the four anterior pairs of legs as maxilli- pedes and forceps must have meant, for many generations, a strong contraction of the ventral longitudinal muscles con- necting the somites to which these limbs belong. ‘To this, then, I attribute the development of the anterior branch of the endopleurite. The parallel between Apus and Astacus is, however, by no means complete. ‘The most anterior of the folds forming the endophragmal system of Astacus cannot be called either an endopleurite or an endosternite, because it is one deep con- tinuous furrow only interrupted by the sternal canal. It occurs between the 2nd maxille posteriorly and the para- gnatha and mandibles anteriorly. So capacious is it that the Ist maxille: may be said almost to spring from the bottom of it. It is, in fact, nothing more than the sinking in of the region of insertion of these limbs. Apus again supplies us with a complete explanation of this phenomenon. ‘lhe Sections 1-7 show us a very deep fold behind the underlip, which runs in above the insertion of the Ist maxilla, It 1s so pronounced that it forms one of 70 Mr. H. M. Bernard on the Apodemes of Apus the principal supports of the “ sternal plate” *. It runs in further than any of the other lateral apodemes of Apus. I consider the fold of some importance, and due not so much to the bending round of the five annelidan segments to form the crustacean head +, as to the forcing back of the underlip in order to bring the mandibles in front of it. The counterpart of this fold may be seen in a small apodeme in front of the mandible, due to the forcing forward of the latter in front of the underlip (fig. 2 a). This very pronounced fold behind the underlip in Apus very nearly coalesces with another less pronounced apodeme between the Ist and 2nd maxilla. The fold between these limbs is very deep, as is also that between the 1st trunk-limb and the 2nd maxilla (Section 1). I am inclined to attribute these to the bending round of the segments to form the head. It is clear, therefore, that we have in Apus, just behind the underlip around the insertion of the 1st maxilla, an area of subsidence, which, if it sank, would infallibly draw this limb down with it, so that it would then spring from the base of the fold. In Astacus this subsidence has actually taken place, and the cause of it is not far to seek. The bringing forward of the anterior trunk-limbs as maxillipedes necessarily com- pressed the region of the body between these limbs and the mouth, with the natural result that any tendency of the skin to form folds in this region would at once be taken advantage of, and the fold would become deeper. That this is the true account of the origin of this fold in Astacus can still be made out from an examination of its structure. It shows its com- position out of two apodemes, the anterior of which, as in Apus, is much the more pronounced, bending forward at its proximal end into a strong horn-like prolongation, which is clearly the homologue of the stout apodeme marked 6 in the sections. If this is the case, then the sinewy tissue joining the folds of the two sides across the middle line and thus bridging over the sternal canal is the rudiment of a sternal plate like that of Apus and Limulus. Following on this first fold of the endophragmal system of Astacus is a somewhat complicated arrangement of folds and ridges. The chief complication seems to be due to the fact that the endopleurite between the first and second trunk-legs (or * This is commonly called the endosternite, but, having already (following Huxley) used that term for the ventral apodemes, I here use an alternative term for the sinewy mass to which the ventral longitudinal bands are attached anteriorly. + Vide ‘The Apodide,’ pp. 10 et seq. LL. at at ois Taciby aitetietahs SDS) 10) 79) ‘TL [OF] ——— SO OIRO HTS) ‘O ve) “esoq 1 WO Cur mod SDS ‘0 9) ‘eqBUIO “* uputtony ‘snytitds stsfm0ystqag 8) ¢) @ 10) ee lere (« ve 5 SDR Oye) “BInAM ONT "'* Sus. °C HY “BouRTIeyIpeTt mosereess BID CO “xD “eyeiies he] eleereke ts. = SIDS “°C ro) ‘suesata ayypry ‘sTuLTeuL —— "8 Sune ‘CG ‘4D ‘eqoo;seu “ots danny “esonxay sishukg wag un ‘“Waqqeig stsdorevyy "*-Yono) ‘RULOURT SISATUTUIA FT SMX "OC “4 ‘stptoRts sisXu0ydary UDULLOAT “BOTULOQ TY m8 supe "C *y) “eysn.cue —— * unuswon ‘sXydpeprp sisdoprisAqy "sung (OQ “yy Suseox sdoawyy AIT YRuUgy *T “6 “VsoULIOF stsKTMO0.10JO FT ‘GE ‘IS ‘OS ‘6G | "8G “LG ‘9G GG ‘PG ‘SG ‘CE “IG ‘0G ‘OL ‘81 a ‘OL ‘GT TL +51 ‘EL ane | 146 Rev. Canon A. M. Norman on British Myside. Professor G. O. Sars has recorded forty-five species of Schizopoda from Norway (including Finmark). Of these the following have not yet been found in our seas :— . Euphausia pellucida, Dana. Oceanic. Boreomysis arctica, Kroyer. 200-400 fath. tridens, G. O. Sars. 200-400 fath. megalops, G. O. Sars. 80-200 fath. . Erythrops microphthalma, G. O. Sars. 100-500 fath. abyssorum, G. O. Sars. 150-230 fath. . Pseudomma roseum, G. O. Sars. 200-300 fath. 8. affine, G. O. Sars. 200 fath. 9. —— truncatum, Smith. 150 fath. 10. Parerythrops obesa, G. O. Sars. 80-800 fath. abyssicola, G. O. Sars. 100-300 fath. robusta, Smith. 60-150 fath. 13. Amblyops abbreviata, G. O. Sars. 150-300 fath. 14, Mysidets insignis, G. O. Sars. 100-300 fath. grandis, Goés. 30-100 fath. 16. Hemimysis abyssicola, G. O. Sars. 150-300 fath. 17. Mysidella typica, G. O. Sars. 50-150 fath. typhlops, G. O. Sars. 150-200 fath. 19. Mysis oculata, Fabr. 20. mixta, Lilljeborg. It will be observed that with the exception of the last two species, which are arctic forms not likely to occur in our seas, all the species in the preceding list are deep-water species, which may be found when the deep-water auna to the west of our islands shall have been properly investigated. Sars’s work on the Mediterranean Myside contains twenty- one species, and of these fifteen are here recorded as British, together with one not in Sars’s list—Hemimysis lamorne. That such a percentage of Mediterranean forms should also be known in our northern seas is quite at variance with the distribution of other orders of the Crustacea, or, indeed, of any class of the Invertebrata. The wider yange of the Schizopoda is probably due to their more active and swimming habits. ‘Thus likewise from the north vast shoals of Huphau- siidee appear to come southwards and make their appearance in the winter months on our eastern coast—and probably on our western also, though as yet they have only been observed off our eastern shores. Rev. Canon A. M. Norman on British Myside. 147 Fam. Myside. Mazillipeds stoutly built ; exopodite natatory, multiarticu- late ; epipodite lanceolate and projected into the branchial cavity. irst limbs of the trunk (here called the gnatho- pods) are generally like in the general aspect of the endo- podite to the maxillipeds*, and differ totally from the following six pairs of /egs, which are all developed and have their distal portion (here called tarsus) in most cases divided into numerous setiferous articulations. Nail generally feeble or absent, more rarely well developed. No true branchie present. Marsupial pouch composed of two or three (in Boreomysis of seven) pairs of leaf-like processes springing from the bases of the posterior legs. Pleopods in female small and rudimentary, in male much more developed f ; sometimes in that sex all except the first are biramose and all multiarticulate and natatory; in other genera they are variously modified and the third or fourth pair, or both these pairs, are specially developed to subserve sexual functions. Inner uropods with acoustic organ at their base. No phos- phorescent organs. Telson very variable in form, but never as in the Euphausiide. Synopsis of Subfamilies. A. Outer uropods two-jointed, outer margin of the first joint spined. Telson entire. Tarsus of legs with only one or two joints, with a two-jointed Badd rays ceo! ¢ Sao erctid apes Sviapane aye cleus Spake, eve ledere ct sone Cynthiline. B. Outer uropods one-jointed, their outer margin spined, Telson entire. Tarsus of legs muitiarti- PPAR ga oc) cote ein siete beets, cates a Fa enys Weare werere cary Gastrosaccine. C, Outer uropods one-jointed, their outer margin setose. 1. Gnathopods conforming in general character of endopodite to the maxillipeds, 2. Gnathopods conforming in general character to the first legs. 1.—a, First legs greatly developed, very strong, and much larger than the following, their tarsus * In Mysidella the gnathopods are quite different from the maxillipeds and very like the first legs. + But in the genera Heteromysis and Mysidella the pleopods of the two sexes are of similar character. 148 Rev. Canon A. M. Norman on British Myside. two-jointed—first joint very large, spined, second minute; nail strong. Tarsus of remaining five feet multiarticulate. An- tennal scale ovate, shorter than peduncle of antenne. Pleopods simple in both sexes .. Heteromysine. b. First legs not unlike the following in general character. Male with all the pleopods greatly developed and adapted for swimming, second to fifth pairs biramose, all branches multi- articulate and setose, the outer branch of fourth and sometimes also of third modified for sexual purposes, but the modification only extending to a slight lengthening of the limb and a change in the character of the sete of theterminal joints: 7.0). c/a. velo ee wie .. Leptomysine. ce. First legs not unlike the following in general character. Male with first, second, and fifth* pleopods as in female; third consisting of a basal joint and two short branches}; fourth of basal joint and two branches, inner minute, outer styliform and generally of great length. Mysine. d. First lees not unlike the following in general character. Male with first, second, and fifth pleopods as in female, third and fourth with a basal joint and two branches, the inner minute, one-jointed, the outer in both pairs styliform, but longer in fourth than in third. . Stelomysine (not British). Genus Stilomysis, gen. nov. : type Mysis grandis, Goés, = Mysidets grandis, G. O. Sars. 2, Pleopods of male all rudimentary, as in female. Maxillipeds strongly built, differing widely in cha- racter from those of other Myside ; last joint with- out sete, terminating in a very long spine and three or more shorter spines. Gnathopods re- sembling in general character the following legs. Myszdelline (nov British). Genus Mysidella, G. O. Sars f. * Hemimysis is an exception; in it the fifth pleopods are greatly deve- loped into swimming-organs, and consist of a large basal joint and two multiarticulate strongly setose branches. + But Neomysis and Diamysis, Czerniavsky (type Mysis bahirensis, G. O. Sars), have third pleopod simple, as in female. { I have brought Stelomysis and Mysidella into this table, because those genera may occur in our seas. Rev. Canon A. M. Norman on British Myside. 149 Subfam. I. Cywrarrrr 2. Genus 1. CynTHinia, J. EK. Gray, 1850 *. = Cynthia, J. VY. Thompson (non Fabr., nec Sav., nec Latr.). =Siriella, Dana, 1852. Rostrum produced, pointed, sometimes of great size.