porn ier er eves i fe ‘ Cle) her a sachet Renate vir > revit) ae ee as acenk > oe Se ra jalsael etal ce alu bs gates Vea peck aby tom # Satie its ata ecre ita sicatee ss Racaice getehh 26a StS) areata stay UR As arene) NOY eirsseita br hatbberdenipsae eles & nee) BUS itteaabtaralatbeataret seta heaty . elt Shen s eh iat ener eas tips ts CT eet ts of Stns Ma Sadtacscaeecels eee ees eet Gerreronsid Hn ey a ea Piet Maree . { PA oa?) pereis eithase penne he Aesragtebinee 9m, . Ve miplnidsicde pear a rtienah ot escalated ARH acarbe ue Mens He ata msaeeh ietrAeeet eerie) let eee? esctss 5 ; ny: wets erage gat aS gree nari teee = h aaa MT by bole a8 85 aun hewn) nate mi . aes yet: detet , raiibensetet a ’ presi Nit care Ses thioia osm beth oA Gl) abst ne tabad fet el PN be it er aay Batee thon eth ay RASA ith e ph AM , pAb neater tage Citas wiet ot Nicdbe waders 4 Ss iswstbents Calton a's a dimare hale ae oT sees } * i SHA ity $Hae'ts They pad) deen, rahy. ah 24st a terech ie fate hd feet thie ‘ ine ape bebines SR fet eae at ap tha lsige@ite NS aah, ae tye ea! Engh a ae hand yt ties eeieatetae ede te Vater DPE ey mee tha oe tive tat ah EAT tieteed eet ete ) nicest Reh openies “a Davee * sets intl aes Chest bedcea at 343 pe hauat fi tabny et Sebrtl def nA Vipveentte bos 25 9) Ty eb ete at ” tes wh ait © ty ae ' Crome ed bes oe Morar oneee sf Amie tetris ge ieenyenfiter es ee Mrecp pecies bobertt fesaarer Ds Ls A ahie le fs pei Wolorarl acon Esrae thet aS cattantet pesrisetes dept bra (nat dif Oot aan inte, PS Ae ee it tela he POW 6 Gt Ome DEO i aye Sib: Merah epee ot vend pees 0 pt Bey’ aeeesi theres ® Te oe aT hada hyeheke tty pete, + mews ane oe a pes pbdest ea tele) eae Berto Maietinek ect tte 4 VIET Sos natanahdineete! PLE hemp bir Hele Hae eee” se FT Roe res handaded Setebnar! oni, ap let net ee a8 eres eh os Leah rN MP ton meer ce prewpenoare sya: tether o orn tieets war Ay Cer bon wah ow iS we EN ee en eh Peeecbe os pervopeme ten ieteT ntlet ele SIMs eae ene atateas Stienertit Chere etde iw on rr onc ame Sa Newnan tian 8 ole babes Porn oey ran bape: a attwe ia hae ~ r ivi Fe = at 7B" Later y ue bpane grb. oir e in Tepe e pee - 5% Py Pecteete ten oe tie RS he cee nek rea ees arm ao ae es Pers at Ther wre wren aoe oe we oie bak nybg nie we PW Piles a get oa A ao, Lotsa Hoh [Rtas Gepiaca ooh wee i renew TM ON 1a Beta te cocern ay eld cere oun eb won a fork ® wamena tha ht Jer eo ie pie Ea Tae le te ro oe ae Save erres 2 ot Fale mnachs dub pw awetarnapen orb * oe Bir tao ey epee nlite ewer Pete lag anal fe eae aye vere Siena wePeh es # Bay vm there we pyys ses Vmun Vie me wn sepa eenetict sie ete ei ert See IE) Pose dene gage od aw mee oR Per Og TN NEY ST ets fered ag vet ts tere ches wee pean bie bee SSP etal irs eaeacey arco 9 he mee oe A OO S| ee Loe vorpancore or roves pevkeartotee as gtias ees ENO are wene ase peer ie it) baat Chace ott le eas rsepeterets rites : bate . error ieiren nas Lr ecetacer sips rere ia rs oe Te rm a ord - a L dbeaabeke ee Pre ceeaEm ht pment amity Pe tie ar tessa Catania re deeds bothbane a tA, eure res Pe fee tbe dns te pia eaeereee Ms COT sin i p 5 He 8 ea ck , OE POOR > oe re Sent etageterp ie tes See oteaee a Ce traricineo es - oeries or x we) Rt ee ee aad etre a sameee ssh ape pm Peters bedstehe bd ee sed . bd ten ope 7 fo! Seat alee oie oe rere, oa (i - os a A Fleece wi po nen ve somwcnsets Repti hela tnel sonnei eet Ieewersesrataes Urbl ewoesace pwromeert + oieteae 0-0 SF Syicreeete nee (Drtieccd sevteats z aaa - r : Pigre Seemewspee MOP LTTe=h BV rea ore-o apron steno 219 789 eagles a beeatippetiperpees Seren eee + rep tnabe or eb itesvees eer Lae esha penton niskphoeremnenymtoner penenereanyyet ~ arses eat rreatagearemcmre renee rene moan re renee can eer boo ee RET. yeh races ba : SS ee afer ree a eranennante nas borer e: cans eves Serie een nye pcan rth ters corteh eo Dee Sey eicess Ay Mabel ice meres pee Neen tenes son a re gone poseeteerer Detrtaskict heeled deaeanraie tent aeeensemaenl ap gv ovenst in ave xin” esmnb be roves “ peda aek tyrant athe cron ben cates cee setae beste ent ate ties eLiageer Peete rete iteeteet ho meelintespsesecetelim rahvtug nae) Saar he pppoe net Diirevgt Labebortepbornesins maleyaneerpeney ; Pepe gee epep ie pins enpem deayeepine aide wa npler jana eleo nie sper ge ole deep yes preverosennsnss nearest aces Bgs0i8 106 Seerese 080 0 PORTS EE Be ates tel ies cated eroperstoneyeep ess ar ee mar trer feetette BAA I Ee rersses woe prasomenia bmioriprin eter 9 1019 F529 OF NO rt Te panies Saale ot sagly eesiatyoanssnted poepmnprye tata ae ‘ RS ee yet ree seated tee stelerateates itd Xetots scars rsinguherenenieen se alginate pate ity or brthce mm es i cprorbem ponegesye: ork ge reiaad an bebpeane eon ese. 4 4.004 peg ubys: RSS altnnt ak owe he era eer gala ned eli Bay ES ote Ron owisie ei ew on ne ene ere erie # eee aga sed ¢ 5) Theat Mo wk be suri ry ae bestest rosie viata get ene LM nT LS A mad phovaapgmseae tt facts Pye oy © iq A j i ult | ? oS macy 1 %, 1. tk ul y, i} al Gil a os oe pith 4 il ct. ee * Sew as —— = as CO” “vi Sy es 7 oho Ce Tt eames, a: lai Gat\ wv ( ty, x ‘i Wey 0 im a ~ ss “> 2 Le Ny So : > rs { \ I No | ite Sy WH, il Wa | FHE VOYAGE OF H.M.S. CHALLENGER. ZOOLOGY-VOL.722ain t 90 G-4'1r ROESE OF 7b 1837 FISH ON THE SCLEMEYEEC RESULTS VOYAGE OF H.M.s. CHALLENGER MUPReING THE: YEARS 18%#3>76 UNDER THE COMMAND OF Captain GEORGE S. NARES, R.N., F.R.S. AND THE LATE Carrain FRANK TOURLE THOMSON, R.N. PREPARED UNDER THE SUPERINTENDENCE OF THE LATE Sip Caywyy UE IE AO M SON: alent PR Se cce: REGIUS PROFESSOR OF NATURAL HISTORY IN THE UNIVERSITY OF EDINBURGH DIRECTOR OF THE CIVILIAN SCIENTIFIC STAFF ON BOARD AND NOW OF JOHN MURRAY ONE OF THE NATURALISTS OF THE EXPEDITION ZOOLOGY—VOL. XXL JOublished pp Order of Her Majesty's Government PRINTED FOR HER MAJESTY’S STATIONERY OFFICE AND SOLD BY LONDON :—EYRE & SPOTTISWOODE, EAST HARDING STREET, FETTER LANE EDINBURGH :—ADAM & CHARLES BLACK DUBLIN :—HODGES, FIGGIS, & CO. 1887 Price Fifty Shillings. SS aD NRE PRINTED BY NEILL AND COMPANY, EDINBURGH, — FOR HER MAJESTY'S STATIONERY OFFICE. : / a ’ ’ IO RTT j FOUN SA MOIT AL, VW , | Ory ATi, y 0 : 7 Cid CONTENTS. Report onithe Derp-Sza Fisues collected by H.M.S. CHALLENGER during the years 1873-1876. By ALBERT GuyTHEr, M.A., M.D., Ph.D., F.R.S., Keeper of the Department of Zoology in the British Museum. EDITORIAL NOTE. Tue Report on the Drzp-Sza Fisuzs, by Dr. Albert Giinther, F.R.S., occupies the whole of the present Volume. This Report, which forms Part LVII. of the Zoological Series of Reports on the Scientific Results of the Expedition, extends to nearly 400 pages, with 73 Lithographic Plates and several woodcuts. The Report comprises two Appendices, the first by Professor H. N. Moseley, F.R.S., on the structure of the Pscuniarn Orcans on THE Heap or Ipnops, the second by R. von Lendenfeld, Ph.D., on the structure of the PuosPHORESCENT ORGANS oF Fisuus. With reference to the depths at which the specimens of Deep-Sea fish were captured I desire to repeat here a statement so frequently made in connection with these publications. During the cruise the naturalists recorded in each case, as faithfully as possible, the depth to which the dredge or trawl was sent down. The animals may have been captured at the bottom, or in any of the intermediate layers between surface and bottom ; in many cases the structure, colour, or modifications of organs, and the contents of the stomach, furnish clear indications as to whether the animal lived at the bottom or on the surface, and on such matters the specialists in each group are the best judges. In this Report, therefore, the depths given for the specimens show that Dr. Giinther regards the specimens, with a few exceptions which are mentioned in the body of his Report, as having been captured at the recorded depth. This exceedingly valuable and comprehensive Report does not refer to Vili THE VOYAGE OF H.M.S. CHALLENGER. the immature and larval specimens or pelagic fish captured at the surface of the sea during the Expedition. It is hoped that Dr. Giinther may prepare a short Report on these forms during the coming year. The Manuscript was received by me in instalments between the 9th September 1886 and the 28th June 1887. Joun Murray. CHALLENGER OFFICE, 32 QUEEN STREET, Epinsuren, lst August 1887. THE VOYAGE OF H.M.S. CHALLENGER. ZLOOLOGY. REPORT on the Deep-Sea Fisuzs collected by H.M.S. Challenger during the Years 1873-76. By Dr. Atsert Ginruer, M.A., M.D., Ph.D., F.R.S., Keeper of the Department of Zoology in the British Museum. PREFACE. AurHoucH the collection of Deep-Sea Fishes which was made by the naturalists of H.M.S. Challenger was entrusted to me for investigation nearly ten years ago, the preparation of this Report was delayed by the pressure of other engagements, especially an increase of official duties. Only during the last two years I was able to steadily apply myself in my leisure hours to the work of re-examining the specimens and of preparing the present Report for press. This delay appeared to be the less a matter of regret as it was known that deep-sea explorations were being actively carried on by two Institutions of the United States of America, and by the Norwegian, Italian and French Governments. As these expeditions had the great advantage of profiting by the experiences of the Challenger, and were likely to materially increase our knowledge of bathybial fishes, and to elucidate points which the Challenger with its initial apparatus had left obscure (such as the vertical range of pelagic forms), it seemed advantageous, in order to produce a complete account of the fish fauna of the deep sea, to await the publication of the results of those explorations. The hope, however, of utilizing those results for the present work became fainter, as in the succeeding years only more or less fragmentary and preliminary notices appeared, with one exception, viz., that of the valuable Report on the Fishes of the Norwegian North Atlantic Expedition. (ZOOL. CHALL, EXP.—PART LV1I.—1887.) Lil a > a +a il THE VOYAGE OF H.M.S. CHALLENGER. : One of the instructions given to me by the late Sir Wyville Thomson was, to include in my Report not only the species collected by the Challenger, but also those which from other sources are known to inhabit the deep sea. He agreed with me in the conclusion I arrived at from the materials then available, that a depth of 300 or 350 fathoms should be _ considered the boundary between the surface and deep-sea fishes, the fishes above that level belonging principally to littoral genera, whilst those specially organized for bathybial life appeared at or below that depth. Accordingly, almost all fishes captured by the Challenger at a less depth than 350 fathoms were included in my Report on the Shore Fishes. However, the subsequent Norwegian and North American explorations brought to light instances of fishes with an unmistakably bathybial organisation occurring at a much shallower depth than the forms discovered by the Challenger, or, on the other hand, showed that certain littoral forms descend not only to 100, but even to beyond 300 fathoms. It consequently seemed advisable to abandon the intention of limiting this Report to fishes occurring below 300 fathoms, and to adopt instead the 100-fathom line as the boundary at which, with the extinction of sun-lght, the bathybial fauna commences, sporadically at first and largely mixed with surface forms. This line does not express a sharply defined boundary any more than any other depth, but it is chosen for the purposes of the present Report, in which a certain upper limit of the deep-sea fauna had to be fixed. In employing it I intend only to express the fact, that no fish not, known at present to have occurred beyond the 100-fathom line, is admitted in the present Report; and, further, that no truly bathybial fish is known to live habitually above that line. TABLE OF CONTENTS PLATE PREFACE, INTRODUCTION, History of our Knowledge of the Fish-Fauna of the Deep Sea, Characteristics of Deep-Sea Fishes, ; Vertical and Horizontal Distribution of Deep-Sea icles; : The Constitution of the Fish-Fauna of the Deep Sea, Table showing the Vertical Range of Distribution of Species, Gaisee and amiliess DESCRIPTION OF GENERA AND SPECIES. Chondropterysgii. \ PLaGIosTOMATA. Selachoidea—Sharks, Seylhidee. Scyllium, M. and H. canescens, Gthr., . . : é . ; ial Pristiurus, Bonap. melanostomus, Raf., Notidanide. Chlamydoselache, Garman. anguinea, Garman, : ; . P ; *) xv Spinacide. _ Spinaw, M. and H. spinax, L. granulosus, Gthr., Centrophorus, M. and i. foliaceus, Gthr., . . : : ¢ é a ie celolepis, Bocage, squamulosus, Gthr., Centroscyllium, M. and H. fabricti, Ruhrdt., granulatum, Gthr., Lemargus, M. and H. borealis, Scoresby, Batoidea—Rays. Raja, Cuv. isotrachys, Gthr., circularis, Couch, il. FIG. PAGE 1 xix Xxiv . XxXxill .. XXXVii oon xl A 1 bo —— Lo A 5 bo | ~~ THE VOYAGE OF H.M.S. CHALLENGER. Batoidea—Rays—continued. PLATE FIG. PAGE Raja radiata, Donov., : ; ; : . =i Re Ae 8 hyperborea, Collett, z : : . : see oo 8 plutonia, Garman, . : : . . tote 10 batis, L., : : : 3 : : apse ae He il vomer, Fries, ’ : : : . : toe ooo il Sullonica, L., F : ; 5 : : sae ooo 11 nidrosiensis, Collett, : : : : 5 a3 es 11 Urolophus, M. and H. kaianus, Gthr., . j 2 : : : Seles bs 12 HoLocrPHata. Chimera, L. monstrosa, L., . - ; 3 5 : pepe: He 12 affints, Capello, . ; : : ; : Pvt Ane Bas 13 Acanthopterygii. Percidie. Anthias, Cuy. megalepis, Gthr., j 3 : . : aes at 13 Centropristis, Cuv. Val. pleurospilus, Gthr., d ; 3 : : iS 43 ei 13 Scombrops, Schleg. chilodipteroides, Blkr., . ‘ Z ; y oe Sates a 14 Acropoma, Schleg. philippinense, Gthr., . : ; i 3 WANA. a 15 Propoma, Gthr. roseum, Gthr., . : : : P : Sagiens ere 15 Malacichthys, Déderlein. griseus, Dod., —. ; ; 5 é ; ee ie 15 Synagrops, Gthr. japonicus, Déderlein, : : ; : ; eee te 16 Polyprion, Cuv. cernium, Val., . : : ; : ; os. xx, 268 Scorpzenidee. Scorpxna, Gthr. percoides, Solander, : : ; 2 5 S Plage 5x 17 dactyloptera, de la Roche, Bib aie kuhlit, Bowd, X1x Sebastes, Gthr. marinus, L., . : ; ; : ¢ aise ae 17 viviparus, Kroy., : : ; : : ces <7 18 macrochir, Gthr., 3 ; : 3 . ges Sst 18 hexanema, Gthr., : : : ; ‘ ae ae 18 oculatus, Gthr., 18 Setarches, Johnson. Jidjiensis, Gthr., . I C 19 Bathysebastes, Steind. and Doderl. albescens, St.and D., : ; 4 : sbettiee sie 2 Iioscorpius, Gthr. longiceps, Gthr., . REPORT ON THE DEEP-SEA FISHES. ¥ Berycide. PLATE FIG. PAGE Hoplostethus, C. V. mediterrancum, C.V., . : : : fot ere eb ie Pe 21 Trachichthys, Shaw. australis, Shaw, . : : 3 F é aay se, ek 22 jacksoniensis, Macleay, . t ’ : eee ot 22 elongatus, Gthr., . 7g Se aa 2 : aA C 22 fernandezianus, Gthr., 4 : : ; Dy tice Pe 23 traillii, Hutton, . 2 : : : : pe LY. A 23 macleayt, Johnston, : 5 : : ; fee a Ras 24 intermedius, Hector, : : : 2 : APN B 24 _ darwinii, Johnson, 24 Anoplogaster, Gthr. cornutus, C. V., . : . ‘ : F eee a 25 Caulolepis, Gill. longidens, Gill, . : / ; : ; Bebe aS 26 Melamphaés, Gthr. microps, Gthr., . F , F : : ye es of. 26 typhlops, Lowe, . : : : : : ae Ve A 27 megalops, Ltkn., . F : : : ; apne B 27 crassiceps, Gthr., . : : : , 2 WILT. B 28 mizolepis, Gthr., . : : : : : by, Meee as 28 robustus, Gthr., . , : ! : : abies Be 29 beanti, Gthr., . : : : : : Pa ee res 29 suborbitalis, Gill, . . : : - . Sartace Wie 30 Malacosarcus, Gthr. macrostoma, Gthr., : : . , E sabes ae 30 Stephanoberyx, Gill. mone, Gill, F : 2 : . 7 Be bot 31 Beryx, Cuv. decadactylus, C. V. ; : ; : : aioe SEX Oe splendens, Lowe, . ; : : : 3 tee Boban p Polymixia, Lowe. ; nobilis, Lowe, . : ‘ : . 2 Se B 34 Poromitra, Goode and Bean. capito, G. and B., : j : : ‘ et He SP 35 Myripristis, Cuv. kaianus, Gthr., . : f , : Shea S25 35 Trichiuride. Nealotus, Johnson. tripes, Johns.,_—. é : 2 : j 5 eth a 35 Aphanopus, Lowe. carbo, Lowe, ‘ : , 2 : : are We A 36 Nesiarchus, Johnson. nasutus, Johuns., . F é : : . Pardes She 37 Lepidopus, Gouan. caudatus, Euphrasen, . : ; : : ba fee Ba: 37 tenwis, Gthr., : : : : : ; ~ Vile B 37 elongatus, Clarke, 3 é : : : a eRe fe 38 vi THE VOYAGE OF H.M:S. CHALLENGER. Trichiuridee—continued. PLATE FIG. PAGE Trichiurus, L. lepturus, L. ; : : : . sae + 39 Euoxymetopon, Poey. txniatus, Poey, . : f ; : 3 2 area: es 39 poeyt, Gthr., : : : : 7 i > jMEOOLL, 83 39 Thyrsites, C. V. pretiosus, Cocco, . ; ; : : : CG xix, 268 prometheus, C. V., 3 : s ‘ ; wobate xx, 268 Gempylus, Cuy. Val. serpens, C. V., . : : : ? : AS cee 41 Carangidee. Anomalops, Kner. palpebratus, Boddert, . : : : ; AU i as 4] Cyttide. Cyttus, Gthy. abbreviatus, Hector, A . : . 4 me eroK B 42 Antigonia, Lowe. capros, Lowe, . ; : ; : } gee a a 44 Diretmus, Johnson. argenteus, Johns., : : : ‘ : sae $ ats 45 aureus, Campbell, ; : ‘ : } zw me 45 Coryphenide. Schedophilus, Cocco. medusophagus, Cocco, : : : ; ater teee >. 46 lockingtontz, Jordan and Gilbert, . , : : iy ae ae 46 enigmaticus, Lockington, : : Sek . .. | XLV. ee 46 Trachinide, Bathydraco, Gthr. antarticus, Gthr., : A : : : a VARI A 48 Aphritis, C. V. gobio, Gthr., , ; : : ; ‘ dasha te Ks! 48 Acanthaphritis, Gthr. grandisquamis, Gthr., — . ; : ; : Sete aa: 49 Champsodon, Gthy, vorax, Gthr., : : ‘ : : Pe Nits + 49 Uranoscopus, L. kaianus, Gthr., . : : : i : eee nA 49 Notothenia, Rich. mizops, Gthr., . : ‘ ; ; ; ai DOGS Pediculati. Lophius, Art. piscatorius, L., . ; : : ; mas, ee aa 49 naresii, Gthr., ; i ; : , i im 49 Himantolophus, Rhdt., : 2 : ; : by eae ave 50 groenlandicus, Rhat., : : . ’ \ eit 5 re, 51 reinhardti, Ltk., . : . ‘ P a yy 51 Aegaxonichthys, Clarke. appelit, Clarke, . : : ; } ie . 2 REPORT ON THE DEEP-SEA FISHES. vil Pediculati—continued. PLATE FIG. PAGE Ceratias, Kroyer. bispinosus, Gthr., ya pa 4 . a yee o5 B 53 holbilli, Kroy., . , ; . : . st a 53 wranoscopus, Murr., ; ; : : : a I C 54 shufeldti, Gill, . : ; : : ; ae Be 54 carunculatus, Gthr., t : : 3 : te Xt D DD Cryptopsaras, Gill. couesii, Gill., : 2 , ; : P Ear a. 55 Oneirodes, Liitken. eschrichtt, Ltk., . ; : : ¢ : 4 GRRE fe 56 Melanocetus, Gthr. Johnsonit, Gthr., . : : ; > : SNe ee 56 murrayt, Gthr., . ‘ ; : é , dese A 57 Linophryne, Collett. lucifer, Coll, : ; ; ; , : = ie 57 Chaunax, Lowe. pictus, Lowe, : ¢ g : : ; eho x A 58 Halieutxa, C. V. ' senticosa, Goode, . : : : : ‘ La one hee 59 Dibranchus, Ptvrs. atlanticus,! Ptrs., f : : . : Bases nee 59 Cottidee. Cottunculus, Collett. microps, Coll., . : : : ; p a2 0.0 A 60 thomsonii, Gthr., . ‘ : ; : : Says B 61 Cottus, Art. bathybius, Gthr., . : : : : : by Ss C 62 Centridermichthys, Richards. uncinatus, Rhdt., ; ; ; F ; et Raa as 62 Icelus, Kroy. hamatus, Kroy., . : : ‘ . ‘ pete. a, 63 Triglops, Reinhardt. A pingelii, Rhdt., . : : : : : Mo ee se 63 Trigla, Art. leptacanthus, Gthr., 5 : : ; . eecaee Ee 63 Lepidotrigla, Gthr. spiloptera, Gthr., : : : : ; nN trae Be 64 Cataphracti. Peristethus, Lacép. miniatum, Goode, : , 3 ; : eas ae 64 moluccense, Blkr., : ! : ; : ae sas ae 64 murrayt, Gthr., . : ; : ; ; Un SS ee 65 liorhynchus, Gthr., é ; ; . : aes een “et 65 micronema, Poey, : : 4 : d a eS ee 65 truncatum, Gthr., : : ; . ‘ ee: at? 65 Agonus, Bl. Schn. decagonus, Bl... : : : : : uens oo 65 1 This fish was obtained at 360 fathoms, not at 3600 fathoms, as stated in the description. ead a et * es OF ou a . ’ ie. sp cae -— Gobiide, —— Callionymus, L. — Blenniide, | -_Trachypteride, : ‘ Stylophorus, Shaw, . ) uxt. A 248 ee og AD LXI. C 249 LI. B 250 252 252 ona ape kets LXIU. A 253 253 Xv1 THE VOYAGE OF H.M.S. CHALLENGER. Synaphobranchina, Synaphobranchus, Johns. pinnatus, Gronov., : : bathybius, Gthr., . : 5 : : : . LXIT. infernalis, Gill, . 3 , brevidorsalis, Gthr., : : 4 : 3 Seep aie Saccopharyngina. ‘ Saccopharynx, Mitchill. ampullaceus, Harwood, . : - : ; . LXVI pelecanoides, Vaill., bairdii, Gill and Ryder, . Nemichthyina. Nemichthys, Rich. scolopacea, Rich., avocetta, Jord. and Gilb., yee bas infans, Gthr., . é : 5 : : = WAI B Cyema, Gthr. atrum, Gthr., . : ; : : 4 paLive D LXIl. oo Q: Plectognathi. Triacanthodes, Bik. anomalus, Schleg., Monacanthus, Cuv. tessellatus, Gthr., Cyclostomata. Myzxine, L. glutinosa, L., australis, Jen., APPENDIX A., : 5 ; 5 0 : E ; 5 : Report on the Structure of the Peculiar Organs in the Head of Ipnops. By Professor H. N. Moseley, F.R.S. APPENDIX B., 5 : : A : < 5 3 5 : : Report on the Structure of the Phosphorescent Organs of Fishes. By R. von Lendenfeld, Ph.D., F.LS. PLATE FIG. INTRODUCTION. The materials which form the subject of this Report consisted of 794 specimens, of which 610 were obtained during the voyage of the Challenger, 88 on the cruises of the “Knight Errant” and “Triton,” and 96 from various other sources. These specimens are referred to 266 species, 177 falling to the share of the Challenger, and 14 being due to the exploration of the Ferée Channel, The number of new forms discovered by the Challenger amounts to 144, whilst by the deep-sea exploration of the Ferée Channel ten species were added to the fauna of the British Seas. The latter possess, perhaps, the greatest interest to the student of the British marine fauna; they verified the supposition which had been entertained for some time, viz., that fishes distinct from those of the littoral fauna inhabit the depths of the ocean surrounding the British Islands. At a time when so much attention is paid to the investigation of the marine products of the British Seas, it may be hoped that the hitherto intermittent efforts of exploring the deeper parts of this ocean may be prosecuted in as systematic a manner as the explorations carried on on the American side of the Atlantic, where the United States Government has spared no expense to secure the rich harvest that was to be expected not only for the advancement of knowledge, but also for the direct benefit to the country. The majority of the Challenger specimens were at least externally in a very good state of preservation; those fishes only which possess bones, integuments, or fin-rays of a soft or delicate texture, and thin deciduous scales, naturally suffered more or less through being dragged to the surface from a depth of 1000 and more fathoms. Such specimens can reach the surface in perfect condition only under exceptional circumstances. However, with few exceptions, even the specimens of delicate structure were sufficiently well preserved to enable us to recognise their original shape and the arrangement of their scales, and to reproduce them in what are believed to be tolerably accurate figures. Unfortunately the abdominal organs were only too frequently found to be destroyed, or had suffered too much by laceration and decomposition to admit of examination. This was especially the case in those provided with an air-bladder, which was almost invariably torn into mere shreds. The stomach was nearly always empty. This condition of the specimens, combined with the circumstance that many of the new types were represented (ZOOL, CHALL, EXP,—PART Ly,—1887.) Lile xviii THE VOYAGE OF H.M.S. CHALLENGER. only by one or two examples, which have to be kept intact for the use of future investi- gators, must account for the scanty information which I am able to give with regard to their internal structure. In some of the specimens the so-called phosphorescent organs were well enough preserved for microscopical examination, and having always held the opinion that the function of all these organs was to produce light, an opinion which has been partly or wholly opposed by Leuckart, Ussow and Leydig, I was particularly anxious that as much as possible of the materials of the Challenger should be utilized for a thorough histological investigation of these organs by zoologists thoroughly versed in the method of histological research. Mr. Murray acceded without hesitation to this proposal, and it was hoped that Professor Moseley would undertake the whole of this investigation ; but as he was compelled by other duties to limit himself to the examination of the remarkable organs in the genus Jpnops, the remainder were entrusted to Dr. von Lendenfeld. The reports of both these gentlemen will be found in the Appendices to the descriptive report. My technical descriptions of the Challenger fishes will be found to be much more concise than those given by some recent writers on similar subjects, and will appear to some to be too short. In my own experience, the practice of circumstantially describing every minute detail of the surface of a fish, repeating every point of structure common to all ‘the species of the genus or family, and indiscriminately mixing individual features with specific, not only renders the use of these lengthy descriptions a laborious and thankless task, but actually leads to misunderstandings not less frequently than insufficient short diagnoses prepared by inexperienced describers. In fact, in several instances I have found that the descriptions which I published some ten years ago as “preliminary diagnoses,” express so fully the specific characters of the fishes as to render any additions to them superfluous. REPORT ON THE DEEP-SEA FISHES. xix HISTORY OF OUR KNOWLEDGE OF THE FISH-FAUNA OF THE DEEP SEA. Isolated examples of Deep-Sea Fishes had fallen into the hands of zoologists at an early period of systematic ichthyology ; thus, specimens of Trachypterus, Regalecus, Saccopteryx, Stylophorus, Plagyodus, and other genera were known to and described by zoologists of the last century. But, having been captured whilst floating on the surface or near to the coast, they were regarded merely as extremely scarce creatures, without any clear idea being entertained that they were stray individuals from the unknown depths of the ocean. Russo was the first to distinguish a bathybial fish-fauna, assigning to it certain fishes and stating the depths at which they habitually live. In enumerating?! the various regions of the Gulf of Genoa he states—‘ Les grands abimes de la mer ne sont fréquentés que par les alépocéphales, les pomatomes, les chiméres et les lépidolépres. Les profondeurs moindres sont la demeure habituelle des merlans, des molves, des phycis, des soldados, des citules, des serioles, des tétragonures, des castagnolles, ete.” He states exactly the depths inhabited by several fishes: thus Alepocephalus rostratus occurs at a depth of 2000 feet or more (350 fathoms), Trachyrhynchus trachyrhynchus and Macrurus celorhynchus at a depth of 1500 or 1800 feet (250 or 300 fathoms) “ou parait constamment régner une température de dix degrés,” Uraleptus maraldi at a depth of 1000 feet (170 fathoms), and Gadus minutus (Morua capelanus) at a depth of 300 metres (150 fathoms). é During his numerous and prolonged visits to the Island of Madeira the Rev. R. T. Lowe’ paid special attention to the wonderful variety of the fishes of the sea surrounding that island. He.discovered a number of new forms, the bathybial habits of which were ascertained, either by himself at the time of their discovery, or subsequently by others who studied the subject after him. In his History of the Fishes of Madeira, the five parts of which appeared at irregular intervals between the years 1843 and 1860, and which unfortunately remained unfinished, he gives the precise depths at which several species occur, viz., Beryx splendens, ‘which begins to be met with, of small size, at a depth of 150 or 200 fathoms, but is scarcely ever taken in full size and abundance, except with its congener, Beryx decadactylus, the Alfonsin a caste larga, at the enormous depth of from 300 to 400 fathoms, and from one to two leagues from shore”; Scorpena kuhli, the “ Requeime,” which is “caught with lines of from 100 to 250 fathoms”; Thyrsites ' Histoire naturelle des principales productions de l'Europe méridionale, vol. ‘iii, Paris, 1826 ; Introduction, page x. 2 He left England with his wife in April 1874 for his last journey to Madeira, which he never reached again. The steamer “Liberia,” in which he had taken his passage, foundered in the Bay of Biscay, not a soul being saved of the passengers and crew. To him and to his successor in the field of Madeiran ichthyology, Mr. J. Y. Johnson, I owe a debt of gratitude for the encouragement and help they gave me at an early period of my ichthyological studies. xx THE VOYAGE OF H.M.S. CHALLENGER. pretiosus, the “ Escolar,” which “is taken with an ordinary bait at a depth (the fishermen affirm) of from twelve to fourteen linhas (= 300-400 fathoms), living habitually near the bottom, in company with the Cherne (Polyprion cernium), Coelho (Thyrsites prometheus or Prometheus atlanticus), ete.” ; Thyrsites prometheus, which “lives habitually at the bottom, and is taken at most seasons in a depth of from 100 to 300 or 400 fathoms”; Scorpena dactyloptera, from 250 to 400 fathoms. Especially instructive is Lowe’s account of the capture and occurrence of Polyprion cerniwm; he says :— “The Sherny in Madeira is only captured by the hook; and though shoals of small fishes, weighing from five to twenty pounds, and called Chernotta, are said to be often taken near the surface, in the neighbourhood of floating wreck or logs of wood, the proper habitat of the full-sized fish, weighing from thirty to one hundred pounds, is from one to two or three leagues from shore, and at the enormous depth of from twelve to fifteen or sixteen linhas, or from three hundred to four hundred fathoms. With a strong line’ of this length, to the bottom of which is tied a stone (called the ‘ pendula’) of three or four pounds’ weight, and having attached immediately above the stone, at intervals of eighteen inches, from twelve to fifteen strong hooks, baited with pieces of Cavallo [Mackerel] or Chicharro [Madeiran’ Horse-Mackerel], I have been frequently assisting at their capture. Coming up from these enormous depths, the fish becomes so distended with gas, expanding upon the removal of the vast pressure below, that it rises to the surface, not indeed entirely dead, but wholly powerless, and in a sort of rigid cataleptic spasm ; the stomach is usually inverted, and protruded into the mouth; and the eyes in general are forced so completely from their sockets, sticking out often like two horns, that ‘eyes like a Cherne’ is a common phrase amongst the fishermen for a prominent-eyed person. Sometimes, from the same cause, it rises faster as it approaches the surface than the line can be hauled in, shooting quite out of the water at some distance from the boat upon its first emergence, like a cork or bladder, from the lightness caused by its great distension. The usual size of these was from two and a half to three and a half feet long, weighing from twenty-five to forty or fifty pounds.” The discovery that some fishes live, at an early period of their existence, at or near the surface, and in the course of their growth retire into the depths of the ocean, is due to Lowe. The study of the fishes of Madeira was continued by Mr. J. Y. Jonson, who, between the years 1862 and 1866, made some of the most interesting additions to ichthyology ; he discovered important bathybial types, such as Chiasmodus, Melano- cetus, Halosaurus, Synaphobranchus, the Saccopharyn« of Mitchell, and others, but he treated them like any other rare surface-fishes, without taking note of their pertinence to a distinct fauna. Each boat is generally furnished with two such lines, each worked by a single fisherman, who is, however, assisted by others in the labour of hauling in the line, which takes from twenty to thirty minutes. REPORT ON THE DEEP-SEA FISHES. xxi Lowe as.well as Johnson deposited their treasures in the British Museum, and from these materials chiefly I formed the idea of a special adaptation of the ichthyic type to bathybial life. The comparison of fishes so widely different as Plagyodus (Alepido- saurus), Regalecus, Trachypterus, Stylophorus, Saccopharynx, Chiasmodus, Melano- cetus, showed nevertheless a singular agreement in important points of organisation, and even in the circumstances under which their capture took place. And having recognised that the diminished amount of earthy matter in the osseous system, the extreme thinness of the muscular layers of the trunk and tail, the easily ruptured connective ligaments and tissues of the muscles and bones, the increase in size or degradation of the organ of sight, the distensibility of the stomach, the shrinking of the gills, the development of the muciferous system with or without special organs of "luminosity, the black coloration of the pharynx and peritoneum, were peculiarities which, either singly or combined, either by themselves or in connection with other evidence, indicated the bathybial nature of the fish, I relegated to the deep-sea fauna Plagyodus in 1860, the Trachypteridee and Lophotide in 1861, Halargyreus and Saccopharynx in 1862, Melamphaés, Melanocetus, Chiasmodus, a part of the Sternopty- chidee, Scopelidee and Stomiatidze in 1864, the Halosauride in 1866, Pseudophycis in 1867, and Synaphobranchus in 1870." I had no definite information at the time with regard to the depth at which these types habitually live, but I thought it probable that some of them descend to much greater depths than were recorded hitherto, and that the degree of adaptation to a bathybial life increased with the depth reached by the fish ; in fact, that the successive vertical zones of the deep sea were inhabited by fishes of a different and peculiar organisation, This last surmise has not been verified by the facts obtained during the Challenger and subsequent expeditions. But I ascertained, at a time previous to the British Deep-Sea expeditions,’ that deep-sea fishes must have a wide horizontal range, and that consequently the physical conditions of the depths of the ocean must be the same or nearly the same over the whole globe,—a fact already recognised by Risso, though his observations were limited to the district of the Gulf of Genoa (vide supra, 1h xe The materials brought home by the Challenger laid abroad and sure foundation of our knowledge of the abyssal fish-fauna, and the preliminary notices of the new and remarkable forms which were published in the years 1877 and 1878° could not fail to draw the attention of the succeeding explorers of the deep sea to this class of animals. 1. Of the three Norwegian North Atlantic expeditions undertaken in the years 1876, 1877, and 1878, the last furnished much information as regards the deep-sea 1 See Cat. Fish., under the headings of the genera enumerated ; Proc. Zool. Soc. Lond., 1864, p. 301 (Melanocetus) ; Proc. Zool. Soc. Lond., 1866, p. 336 (Ausonia). 2 Cat. Fish., vol. v. p. 420, 1864. 3 Ann. and Mag. Nat. Hist., 1877, vol. xx., and 1878, vol. ii. XXil . THE VOYAGE OF H.M.S. CHALLENGER. fishes of the Polar Sea. The sea between Hammerfest and Varanger Fjord, that extending towards Novaja Zemlja and Jan Mayen, and northwards to the north-western extremity of Spitzbergen, were explored. The greatest depth reached by the trawl was nearly 1400 fathoms. About thirty species were collected, of which those of the genera Lycodes and Liparis, and the genus Rhodichthys are of particular interest. In an elaborate Report by Robert Collett these fishes are described in detail and well ficured.* 2. Thanks to the exertions of Professor A. Agassiz and Dr. Spencer Baird, the Government of the United States provided, at first by the loan of ships, and later through the organisation of the U.S. Commission of Fish and Fisheries, for a syste- matic exploration of the depths of the Western Atlantic. Omitting the earliest opera- tions, in which no special attention was paid to deep-sea fishes, we have to mention, in* the first place, the successful trips of the U.S. steamer “ Blake,” under the command of Lieut.-Com. C. D. Sigsbee and Commander J. N. Bartlett, in the years 1878 to 1880, to the Gulf of Mexico and the Caribbean Sea. The dredging and trawling apparatus used by the Challenger was improved, and in order to ascertain the nature of the fauna at any given depth intermediate between the surface and bottom, Com- mander Sigsbee introduced an apparatus, which works in a vertical, instead of hori- zontal, direction, and which admits animals only at a desired depth. Whatever importance may be attached to the results obtained by it with retard to the distribution of the lower animals, the fact that this apparatus failed to capture any fishes in mid- water is evidence of but negative value. The investigation of the bottom revealed areas devoid of and others rich in animal life, and the causes of such abundance or poverty were approximately ascertained. The operations of the U.S. Fish Commission had to be conducted chiefly with the direct object of developing the commercial resources of the country, but as this object goes hand in hand with, and as its attainment is in great measure dependent on, strictly scientific research, the work of the Commission was carried on in both directions. From the year 1877 the Commission was enabled, by the possession of a suitable steamer, the “ Fish-Hawk,” to engage in deep-sea operations, chiefly in parts of the Atlantic north of the area surveyed by the “ Blake,” but occasionally extending southwards into the West Indian Sea, as, for instance, those of 1884 by the U.S. steamer “ Albatross.” These explora- tions, which were systematically carried out with sound judgment and intimate knowledge of the requirements for deep-sea operations, yielded adequate results; no other part of the ocean is now better known, with regard to its marine products, than the Atlantic coasts of the United States and the deep water outside the littoral zone. The contributions to the fauna of deep-sea fishes were numerous and of great interest, and have been described chiefly by Messrs. Brown Goode and ‘Den Norske Nordhays-Expedition, Zoologie. Fiske. Christiania, 1880, 4°. REPORT ON THE DEEP-SEA FISHES. Xxil Bean, whose publications will be duly referred to in the descriptive part of this Report, So far as the materials have been worked out, they show that fishes recorded by the Challenger from great depths live in much shallower water in other parts of the | ocean, and that, on the other hand, many littoral forms descend to within the vertical — limits of the deep-sea fauna. The greatest depth from which the capture of fishes is reported was 2900 fathoms, nearly the same as that stated by the Challenger. 8. By the explorations of the Ferde Channel, in H.M.SS. “Knight Errant” and “Triton,” in the years 1880 and 1882, our knowledge of the deep-sea fishes between the British Islands and the Polar Sea was much advanced; in fact, nothing was known previously about this district. The trawl was used in from 200 to 640 fathoms.’ All the species collected are embodied in the present Report; they proved to be partly identical with those collected by the Norwegian expedition, and partly closely allied to types which were previously known from the Mediterranean. 4, The deep-sea explorations undertaken by the French Government, and entrusted to a commission under the presidency of Professor Milne-Edwards, began in the year 1880. A vessel, “ Le Travailleur,” was employed for short periods in three consecutive years, and replaced by the larger ‘‘ Talisman” in 1883. ‘The field of operations was in the first years the Bay of Biscay, and extended to the Mediterranean and the Canary Islands, but still more work was done in the “Talisman,” in which the expedition made a series of observations off the coast of Morocco southward to Cape Verde Islands and the Sargasso Sea, and westward to the Azores. From the general reports published it would appear that the materials collected contain important contributions to our knowledge of deep-sea fishes, but no authentic information has been published, with the exception of a supposed new genus, Hurypharynax. 5. The Italian Government despatched a ship of the Royal Navy, the “ Washington,” in three consecutive years (1881-3) for the exploration of the depths of the Mediterranean. With regard to abyssal fishes, these expeditions were somewhat barren in results. 1 Staff Commander Tizard, R.N., and John Murray, Exploration of the Ferée Channel, during the summer of neu in H.M.’s hired ship “ Knight Brant; ” Proc. Roy. Soc. Hdin., 1882. XXIV THE VOYAGE OF H.M.S. CHALLENGER. CHARACTERISTICS OF DEEP-SEA FISHES.* The physical conditions under which fishes live at a depth of 100 and more fathoms affect certain parts of their organisation. We know now, chiefly from the Norwegian and North America explorations, that many littoral fishes descend within the limits of the truly abyssal fauna. These descents, however, are not permanent removals from the littoral zone, but, at the most, periodical; and therefore no conspicuous change in— any of the organs of these fishes has taken place. But already, in many fishes which permanently reside at from 80 to 120 fathoms, we find indications of their habitat in the black coloration of their pharynx and in the size of their eye, which is proportionally larger than in their representatives at the surface. In the true deep-sea fishes certain organs are so conspicuously modified that every one of these fishes may be recognised as a deep-sea fish, without accompanying positive evidence of its capture at a great depth ; and vice versa, fishes reputed to have been obtained at a great depth, and not having any of the characteristics of the dwellers of the deep sea, must be regarded as surface fishes. The question whether the amount of modification is proportioned to the depth, must be negatived from the evidence at present available, inasmuch as deep-sea fishes caught at depths of between 300 and 400 fathoms may show a much more con- spicuous development of abyssal peculiarities than those from 2000 and more fathoms. The tremendous pressure under which deep-sea fishes live must be one of the primary causes affecting their organisation. The pressure of the atmosphere at the level of the sea amounts to fifteen pounds per square inch of the surface of the body of an animal ; but below the surface of the ocean the pressure is increased to a ton weight for every 1000 fathoms of depth. In many deep-sea fishes we find, then, that the osseous or muscular systems, or both, are, as compared with the same parts of surface fishes, very feebly developed, as for instance in the Trachypteride, Melanocetus, Chiasmodus, Plagyodus, Omosudis, Saccopharynx. The bones have a fibrous, fissured and cavernous texture, are light, with scarcely any calcareous matter, so that the point of a fine needle will readily penetrate them without breaking. In some the primordial cartilage is persistent in a degree rarely met with in surface fishes, and the membrane bones remain more or less membranous or are reduced in extent, like the operculum, which frequently is too small to cover the gills. When the fish is brought to the surface, all the bones, and more particularly the vertebrae, are most loosely connected with one another. Likewise the muscles, especially the great lateral muscles of the trunk and tail, are thin; the fascicles can be readily separated or torn, the connective tissue being extremely loose and ‘ The contents of this chapter formed the subject of a lecture delivered at Cambridge in 1874, and of the notes published in Introduction to a Study of Fishes, 1880, p. 296. REPORT ON THE DEEP-SEA FISHES. _ XXV feeble, so that the specimens require the most careful handling to prevent their breaking up into fragments. This condition appears to obtain in the highest degree in a fish allied to Plagyodus, and occurring in the Madeiran Sea, of which Lowe succeeded in obtaining fragments only. Specimens of this fish are sometimes caught on long lines at great depths, but before they can be hauled to the surface, the body breaks away, leaving fragments only on the hook.t We cannot assume that this loose connection of the osseous and muscular systems obtains whilst those fishes remain under the normal physical conditions of their abyssal abode. All are carnivorous, and some of them most rapacious creatures, which must be able to execute rapid and powerful movements to catch and overpower their prey ; and for that object their muscular system, thin as its layers may be, must be as strong, and the chain of the segments of their vertebral column as firmly linked together, as in surface fishes. In coming to the surface their body has undergone a change which is merely due to their rapid withdrawal from the pressure under which they-lived ; it is a much ageravated form of the affection that is experienced by persons reaching great altitudes in a balloon, or by the ascent of a mountain. In every living organism with an intestinal tract there are accumulations of free gases; and, moreover, the blood and other fluids, which permeate every part of the body, contain gases in solution. Under greatly diminished pressure these gases expand, so that, if the with- drawal from a depth is not an extremely slow and gradual process, the various tissues must be distended, loosened and ruptured ; and what is a vigorous fish at a depth of 500 or more fathoms, appears at the surface as a loosely-jointed body, which, if the skin is not of sufficient toughness, can only be kept together with difficulty. At great depths a fibrous osseous structure and a thin layer of muscles suffice to obtain the same results for which, at the surface, thickness of muscle and firm osseous tissue are necessary. The singular circumstance that the first two specimens known of Saccopteryx, two of Chiasmodus, and one of Omosudis were picked up floating on the surface, dead or in a dying condition, with their stomach distended by a large recently swallowed prey, can be easily explained by the aid of those physiological facts. If, during the struggle which must take place between the attacking fish and its prey, the fishes are carried out of their depth into a somewhat higher stratum, the expansion of the gases will cause both to ascend towards the surface, especially if one of them be provided with an air-bladder, and the rate of speed of the ascent will increase the nearer they approach the surface, which they reach dead or in a dying condition, as witnessed and described by Lowe (vide supra, p. xx.). Occurrences of this kind must happen very often, as, of course, comparatively few can by accident fall under the observation of naturalists. In a slight degree the phenomenon described is a matter of every day occurrence, well known to fishermen who fish at depths of from 40 to 80 fathoms. The fishes with- drawn from that depth come up more or less distended, if they possess a closed air-bladder. 1Wregm. Arch., 1860, p. 123. (ZOOL, CHALL. BXP,—PART LyII.—1887.) Lil d XXxvi THE VOYAGE OF H.M.S. CHALLENGER. By the expansion of the air-bladder the cesophagus and stomach are pressed out of the mouth and the eyes out of their sockets. Cod-fishers are therefore in the habit of puncturing the air-bladder, in order to keep the fish alive. Every larger collection possesses specimens showing the inverted stomach and cesophagus ; and they may be safely assumed to have been captured at some distance from the surface. . We might expect that the air-bladder of deep-sea fishes would offer special modi- fications ; and, indeed, there is sufficient evidence that in many a special muscular apparatus is developed for the compression or expansion of its contents, to enable the fish to rise into a higher, or descend into a lower stratum. But, unfortunately, in all the specimens examined by me the air-bladder was more or less ruptured and broken up, and destroyed by subsequent decomposition. One point only seems to be clearly made out, viz., that abyssal life has exercised no influence on the development of an air- bladder, that is, deep-sea fishes whose nearest surface-relations possess an air-bladder, are provided with this organ also, and vice versa. In none of the abyssal forms examined by me have I found an open communication between the air-bladder and the cesophagus, not even in those which are referred to the Physostomous division. The branches of the muciferous system are dilated in many deep-sea fishes to an extraordinary degree. Sometimes it is only the lateral line which is conspicuously wider than in the allied surface forms (Lepidopus tenwis, many Scorpzenide), but in many others, as in Berycide, Macruridee, Ophidiidee, and Scopelidee, the branches on the head are enlarged into wide cavities, the walls of which are supported by high ridges of the superficial bones. Frequently the membranes investing these cavities are very thin and after the death of the fish liable to be destroyed, so as to leave bare the deeply sculptured surface of the skull; in other fishes the outer membranes collapse in consequence of the shrinking of the mucous contents of the cavities, so that the surface of the head appears to be extremely uneven; whilst again in others, as in the majority of the genus Macrurus, the integument is sufiiciently tough to maintain the natural contours of the head. The arrangement of the cephalic branches is the same as in Teleosteous fishes generally : the rostral branches bifurcate into the frontal and infraorbital, and pass into the scapulary branch which is the commencement of the lateral line; and the mandi- bulary and preeopercular branches are likewise invariably present. All these cavities and canals are filled with an immense quantity of mucus, which, in specimens that have not been too long preserved in spirits, swells by immersion in water, and can be pressed out of the apertures of the canals. These apertures may be wide slits, or more or less open, or minute pores with or without a tubule. The physiological use of this secretion, as, indeed, the function of the whole system, is not known. Whether it be regarded as an excretory or as a sensory organ, it is clear that its extraordinary development in so many deep-sea fishes must stand in relation to some one of the abyssal conditions under which they live ; and it is very probable that some special function or functions are superadded REPORT ON THE DEEP-SEA FISHES. XXVIL to the original one which the muciferous system fulfils in the ordinary type of surface fishes. Considering that the majority of the localised and more highly specialised luminous organs are situated within the area of, and stand in relation to, the muciferous system, we may be justified in assuming that one of those additional functions is to surround the fish with luminosity, the more so as the mucus has been actually observed to have phosphorescent properties in newly caught specimens. The so-called phosphorescent organs or luminous bodies have been noticed ever since the first species of Scopelus and other pelagic genera were described; but they were regarded as peculiar pigment spots or modified portions of the scales. Many species of Scopelus possess, beside the round mother-of-pearl-coloured spots, a pair of whitish gland- like bodies on the upper side of the snout; and it seems that Cocco was the first to assert that these bodies have phosphorescent properties. He mentions’ these organs as ‘‘apparecchio lucido,” and one of the species possessing them he named ‘“ Nychtophus metopoclampus.” Bonaparte copied Cocco’s accounts, and Valenciennes’ adopted his views as to the function of these organs. In 1864, when engaged in the systematic arrangement of the fishes of the families Sternoptychide, Scopelidee, and Stomiatide, I ascribed phosphorescent properties to all these organs, whilst from their histological examinations Leuckart® and Ussow* declared them, or at least part of them, to be accessory eyes. Leydig’ holds the opinion that they are “ pseudo-electric” organs, which sometimes may have the function of emitting light; Emery’ adopts the view of their phosphorescent nature in Scopelus. As these organs occur, not only in deep-sea fishes, but also in nocturnal pelagic forms, their function might have been expected to be readily ascertained by actual observation ; however, so far as I am aware, this has been done twice only, viz., by myself, when I happened to notice distinct flashes of light to issue from a dying specimen of Scopelus floating on the surface in the British Channel; and by Dr. Guppy,’ who examined some freshly caught specimens of the same genus. During my examination of the Challenger fishes I found the luminous organs widely distributed over the various organs of the body, and discovered especially their presence, in a unique modification, in a genus of Alepocephalid fishes (Xenodermichthys), as well as in the Halosauride, in which their relation to the muciferous system is undeniable. Finally, Liitken*® suggested that the white terminations of the dorsal tentacle of Himanto- lophus reinhardti may be phosphorescent during life, which undoubtedly they are. Luminous organs are not equally distributed among the various families of deep-sea 1 Nuovi Ann. d. Sct. Nat., 1838, tom. ii. p. 184. 2 Cuv. Val., vol. xxii. pp. 443, 444, 445. 3 Ueber muthmassliche Nebenaugen bei einem Fische, Bericht wé. d. Versamml. deutsch. Naturf., 1864. 4 Bull. Soc. imp. des Nat. Moscou, 1879, vol. liv. p. 79. 5 Die augenihnlichen Organe der Fische, 1881, 8°, Bonn. 8 Mittheil. Zool. Stat. Neapel, vol. v., 1884, p. 471. 7 Ann. and Mag. Nat. Hist., vol. ix., 1882, p. 202. 8 Vidensk. Selsk. Skriv., vol. xi., 1878, p. 341. XXV1ll THE VOYAGE OF H.M.S. CHALLENGER. fishes: and it is a remarkable fact that they are almost entirely absent in those which have the muciferous system most developed ; thus, neither the Macruride nor the Ophidiidee possess specialised luminous organs, probably beeee the mucus, pas is so abundantly secreted, supplies a sufficient amount of luminosity. In the Berycide and Gadidz we find only isolated instances, which remind us of the preeocular or rostral organ of certain Scopeli. On the other hand, the Halosaurt possess a wide lateral-line system with well differentiated luminous organs superimposed on it. In each of the families of Carangidee and Alepocephalidze one species only is provided with them. In the Pediculati luminous organs are of common occurrence and serve as lures to attract other fishes ; they are most common in the Sternoptychidz, Scopelide, and Stomiatidee, in which they have principally the function of enabling these fishes to illuminate their surroundings, more rarely of alluring other fishes. In the Mureenidz no luminous organs have been found ; but in some of them the muciferous system is enlarged. - The luminous organs present many modifications as regards their seat, appearance and structure. 1. In their most primitive condition they appear as innumerable minute tubercles more or less raised above the surface of the skin, and covering the sides of the body ; they are crowded together in transverse bands corresponding to the segments of the muscular system. This form occurs in Echiostoma, Opostomias, Pachystomias, Photo- nectes, Malacosteus. I suppose that the pores scattered over the skin of some species of Ceratias (Ceratias wranoscopus, Ceratias carunculatus) are apertures of follicles in which luminous mucus is secreted. 2. Larger in size, less numerous and more projecting beyond the surface, are the small nodules in the skin of Xenodermichthys; they are distributed over the head as well as the body, and follow, on the former, the muciferous ducts, whilst they are arranged i a quincuncial fashion on the body, and are wanting along the tract of the lateral line. 3. More differentiated are the eye-like spots, of a white colour in preserved specimens, and red or green during life, which are arranged at regular intervals in two series on the lower side of the body of the fish, and which occur also on the head, at the base of the branchiostegals and on the gill-cover. Their arrangement 1s constant within the limits of a species, and to judge from their external appearance they gradually pass into the next form. They occur in numerous genera :—Gonostoma (some species), Chauliodus, Astronesthes, Stonias, Echiostoma, Opostomias, Pach ystomias, Photonectes, and Idiacanthus. 4, Still more differentiated are large round flat organs of a peculiar mother-of-pearl brightness, arranged like the former in rows on the lower side of the body and head, with isolated ones on the sides and on the opercles, and frequently with the addition of a short dorsal and yentral series on the peduncle of the tail. They are found in the REPORT ON THE DEEP-SEA FISHES. 9.0 B.¢ families Sternoptychide and Scopelide only, viz., Gonostoma (Gonostoma denudatum), Argyropelecus, Sternoptyx, Polyipnus, Photichthys, Scopelus and Nannobrachium. 5. More or less diffuse patches of a white glandular substance of varying thickness are found. a. On the side of the trunk in Astronesthes. b. On the dorsal or ventral sides of the caudal peduncle in Gonostoma and Nanno- brachiwm. c. On or near the clavicle and more or less within the gill-cavity in Sternoptyz, Opostonuias and Halosaurus. d. Above the maxillary in the infraorbital region in Gonostoma and Photichthys. e. On the top of the snout or in front of the eye in species of Melamphaés, Melanonus and Scopelus. Jf. On barbels in Linophryne, Stomias, Opostonias and Idiacanthus. g. On fin rays in Melanocetus, Chaunax, and Himantolophus reinhardtii. 6. In this group these large glandular masses are differentiated, forming a rounded, more or less oval mass lodged in a cavity of the infraorbital region (as in 5, d), viz., in Anomalops, Echiostoma, Opostomias, Pachystomias, Photonectes, Malacosteus, Idia- canthus, Astronesthes. . 7. The luminous apparatus of the dorsal fin is differentiated, representing a cavity with an aperture from which a tentacle or filament may be exserted. This form is found in Pediculates only, such as Himantolophus, Aegxonichthys, some species of Ceratias, Onewrodes and Linophryie. 8. The luminous organs of Halosaurus differ from all those enumerated, inasmuch as they are arranged on the body in a single series which is lodged on the scales of the lateral line ; on the head they follow the lower branches of the muciferous canals; in fact, they are situated in them. The organs have also ‘a peculiar diamond-shape, and nearly all lie below, but free from, the semitransparent integument of the body. 9. The cephalic organ of Zpnops, the genetic relations of which are still obscure, although there can be no, doubt as to its function. The disposition of all these organs will be more fully noticed in the following pages, and a complete account of the histology of the more important forms will be given by Professor Moseley and Dr. von Lendenfeld in the Appendices at the end of the Report. / Light-producing organs are very generally distributed in the abyssal fauna, and those parts of the depths of the ocean in which phosphorescent animals are abundant must be sufficiently illuminated to enable such of them as are provided with well-developed eyes to perceive objects with as much distinctness as do the pelagic forms which sport at the surface at night, and are dependent on the light of the moon and stars and the general phosphorescent light around them. There is no doubt that fishes contribute XXX THE VOYAGE OF H.M.S, CHALLENGER. a considerable amount of this luminosity of the abyssal depths; but the various degrees of differentiation of the luminous organs, as well as their location on very different parts of the fish, prove that the production of light is dependent on a variety of circumstances and subserves different purposes. 1. Light may be produced by the luminous organ to enable its possessor to see. In fishes which secrete merely a large quantity of luminous mucus without specially developed organs (Macruridee), or in which innumerable minute organs are disseminated over the greater part of the body, the luminosity proceeds from the general surface of the fish whenever the animal is active, and probably ceases whilst it is asleep or at rest. But in those fishes in which the organs are highly developed and specialised, the production of light is evidently subject to the will of the fish. Only thus can the luminous apparatus be of advantage to the fish; if the production of light were constant, or could not be suppressed instantaneously, the fish would be a most conspicuous object and fall a ready prey to its enemies. The high degree of development of the luminous organs on the side of the head, in close proximity to the eye, as it is found in Anomalops and the Stomiatide, can be accounted for only by assuming that these fishes are able at will to shoot rays of light in the direction which they want to explore for the purpose of discovering their prey, or for some other object. In fact these organs are used by them as we would use a“ bulls-eye.” The circumstance that some of the organs are lodged below membranes or even in the cavities of the gills or within the mouth, cannot be regarded as an objection to this explanation of their function, as the membranes as well as the bones are semi-transparent, and would not much interfere with the effect. No doubt the intensity of light produced by the various organs is not the same, and it is probably least in those least specialised: perhaps no more than the glimmer produced by a number of minute particles of phosphorus ; but the light which issues from the large pearly organs of the Scopelidee, the infraorbital organs of the Stomiatide, and from the lenticular organs of the Halosauride, must be intense and penetrate to a considerable distance. 2. The luminous organs which are placed on barbels, filamentous fin-rays, or tentacles have evidently the function of attracting other animals and of serving as lures. It is a matter of common observation that aquatic animals are in the dark attracted by a light ; and therefore these appendages will prove most efficient lures in the abyssal darkness, when, with one or several bright phosphorescent spots at the end of the tentacle, they are played about by the fish. Thus, whilst the appendages retain the original function which they have to perform in surface fishes like Lophius, Antennarius, ete., in which they simulate » worm or other similar creature, the means by which the final end is attained is changed in accordance with abyssal conditions. Their luminous property could not be of any other use to these fishes, many of which, as, for instance, the deep-sea Pediculates, have their eye in a most rudimentary condition. REPORT ON THE DEEP-SEA FISHES. XXXI I am also of opinion that the highly specialised organs which are placed on the dorsal and ventral sides of the caudal peduncle of many Scopelids and Sternoptychids, have the function of attracting prey, and not of enabling their possessors to see. Situated at the posterior extremity of the body, they would be in a most unfavourable position to throw the light within the area of vision by the eye. On the other hand, when we recollect the peculiar motion of a Scopelus, which darts rapidly in short curves to'the right and left, upwards and downwards, we can understand that these posterior organs are of great assistance to the fish m picking up any creatures which, attracted by the gleam of light issuing from its tail, are lured into too near a proximity. The explanation that these caudal organs shoot out rays of hght to frighten away a pursuer, does not seem to me a happy idea. ‘They are, as I assume, subject to the will of the fish, which when pursued would simply extinguish its lantern and escape into darkness ; light would not frighten, but rather attract a pursuer. Special organs of touch are not more generally developed in deep-sea fishes than in the littoral fauna. As such may be considered the ventral filaments of the Ophidiide, the more or less detached rays of the pectoral fin of Pteroidonus, Microlene and Mixonus, and especially of Bathypterois which possesses but rudimentary eyes, and the pectoral filaments of which remind one of those of the Polynemidee. Indeed, the comparatively rare occurrence of special organs of touch in deep-sea fishes may be used as evidence that the majority depend on the sense of sight for the perception of surrounding objects, and that therefore a large amount of light must be distributed, at least locally, in depths to which the surface light does not penetrate. The excessively elongate fin-rays of young Trachypteride are evidently not organs of touch; it is difficult to explain their use in those young fishes; it might be imagined that they would be rather disadvantageous to them by attracting other fishes of prey, unless they afford protection by their resemblance to delicate fronds of fucus floatmg in the water or gradually settling towards the bottom. Such delicate filaments can only be developed in fishes sojourning in water which is not subject to violent agitation. In the subsequent descriptions of deep-sea fishes frequent mention is made of the reduction in size and length of the gill-laminz. These organs appear short and shrunken ; it is possible that they are longer during life, ending in delicate points, and shrunken only in consequence of the action of the spirit, but the horny rods which support the plaits of the mucous membrane are also wanting in firmness, like the parts of the skeleton, and are much shorter than in the ordinary Teleostean type. The laminz are also reduced in number, and the gill does not possess the same extent of respiratory surface, so that the intensity of the respiratory process seems to be more diminished than in surface fishes. We can hardly doubt that the sojourn in the low temperature of the abyssal depths must have some effect upon circulation, respiration, assimilation of food XXXII ; THE VOYAGE OF H.M.S. CHALLENGER. and secretion ; but we cannot hazard a conjecture as to the manner and degree in which those physiological functions may differ from those of surface fishes. I may here also shortly refer to a subject in regard to which very few facts are known, and which therefore offers wide scope for speculation. It is the fact that the spawn of some deep-sea fishes (as for instance Polyprion cernium), is developed at the surface, whilst mature individuals of the species reside at more or less considerable depths. It is not probable that these fishes rise to the surface at the season of propagation ; we may rather suppose that the spawn is deposited at a depth of several hundred fathoms and gradually rises to the surface, the young fish, after a short pelagic surface existence, returning to the depths inhabited by their progenitors. This, however, is certainly not the case with all deep-sea fishes; of many the spawn will not only be deposited at the bottom of the ocean, but also remain there throughout the period of its development. But when we consider the immense difference of the conditions under which the development of the ova of these two kinds of fishes pro- ceeds—the one under the accelerating influences of light, warmth, and a constant supply of oxygen, the other under the retarding conditions of darkness, cold, and a minimum amount of oxygen—we cannot help thinking that the one series supplies the deep sea with the forms which retain the organisation of the surface fishes, whilst the other develops into those degraded forms, of which the families Ophididee and Mureenidee offer the most striking examples. The colours of deep-sea fishes are extremely simple, their bodies being either black, pink, or silvery; however, some of the fishes which now are black are described as having been of a bluish colour when they were brought to the surface. In a few only are some filaments or the fin-rays of a bright scarlet colour; black spots on the fins or dark cross-bars on the body are of very rare occurrence. An extremely common, almost general characteristic of deep-sea fishes is the black coloration of some of the body-cavities ; this is limited to the pharynx in many of the fishes which live about the 100-fathoms limit, but the colour is more intense, and spread all over the oral, branchial, and peritoneal cavities in strictly typical deep-sea forms. The highly specialised luminous organs on the head of the Stomiatidee are green or pink during life, whilst they fade into white after the immersion of the fishes in spirit. Among the black-coloured deep-sea fishes albinos are not scarce. REPORT ON THE DEEP-SEA FISHES. XXXIiil VERTICAL AND HORIZONTAL DISTRIBUTION OF DEEP-SEA FISHES. Before the voyage of the Challenger scarcely thirty deep-sea fishes were known; this number is now increased to about 370, if we include a few species which are, in fact, surface fishes, but descend occasionally or regularly to or even beyond the 100-fathoms limit. In a table appended to these introductory remarks, I have endeavoured to show in a graphic manner the bathymetrical range of each species, so far as it has been ascertained at present. Unfortunately, some uncertainty prevails as regards the depth at which certain specimens were obtained. I formerly. assumed that the fishes of the open sea were living either near to the surface or at the bottom, but I think now that Mr. Murray is right in supposing that certain fishes live habitually in intermediate strata, without ever coming to the surface or descending to the bottom.’ The function of the pneumatic apparatus with which many deep-sea fishes are provided is to regulate their specific gravity, so that a fish is able to maintain its position at a certain depth, which would vary only within certain limits, comparable to those which we observe in surface fishes. As the mouth of the dredges or trawls used by the Challenger was open during their descent or ascent, it is within the limits of proba- bility that sometimes fishes were accidentally enclosed whilst the apparatus was traversing the strata intermediate between the surface and bottom. And this has actually happened more than once; for it is quite certain that common surface fishes, like Sternoptyx and Astronesthes, never ranged to the depth of 2500 fathoms, the depth to which the dredge had descended on the occasion of the capture of these specimens. On the other hand, many of the fishes obtained by the Challenger offer sufficient evidence, from their own organisation, that they live at the bottom, and are unable to maintain themselves suspended in the water; and, consequently, that they actually were obtained at the depth to which the dredge descended. Besides, the statements of the depths of the Challenger fishes have been confirmed in many instances by the observations made during the more recent deep-sea explorations. However, it may be assumed that of those md-water fishes, as the forms may be ealled which inhabit intermediate strata, comparatively much fewer specimens are captured than of the bottom fishes. It must be of rare occurrence that fishes accidentally enter the narrow mouth of the dredge whilst it is passing to the bottom or to the surface, and it is more likely to happen when the larger trawl is used. But such free-swimming fishes are much more agile in their movements, and escape more easily on perceiving the 1 The habit of some fishes of living at a distance from the surface and bottom is a fact which has been known for along time among fresh-water fishes. Salmo lacustris, of the Lake of Constance, has received its vernacular name from this habit ; it is called “Schwebe-forelle,” that is, the trout which is suspended in mid-water. (ZOOL, CHALL. EXP.—PART LvII.—1887.) Lile XXxiv THE VOYAGE OF H.M.S. CHALLENGER. approach of the dredge than bottom fishes, which are generally of a more sluggish nature, and which, seeking safety by burying themselves in the ooze, would: be readily enclosed in the dredge. So far as the observations go at present, no distinct bathymetrical zones, characterised by peculiar forms, can be defined. As the transition from the organisation of the typical surface fish to that of the most highly specialised deep-sea form is gradual, so the passage from the littoral to the abyssal fauna is continuous and not marked by a sudden change. The limits between the two faunz are still more obscured by the remarkable manner in which they overlap each other owing to the wide bathymetrical range of certain species of either fauna. I need only mention such common littoral forms as Lophius piscatorius, Merluccius vulgaris, and Pleuronectes cynoglossus, which descend to depths of from 300 to 700 fathoms, thus living in the same areas which are inhabited by the most highly specialised abyssal forms like Chiasmodus, T'rachypterus, and Alepocephalus. Also the temperature of the water clearly interferes with a uniform bathymetrical dis- tribution of fishes, as many species, which in low latitudes are found at considerable depths, often ascend into the cold surface strata of high latitudes.’ Further, nocturnal pelagic surface fishes seek, during the day-time, the darkness of greater depths. The instances of the wide bathymetrical range of deep-sea species are numerous: some may range from a depth of some 300 fathoms down to one of 2000 fathoms; or, in other words, a fish which has once attained in its organisation to that modification by which it is enabled to exist under the pressure of half a ton, can easily accommodate itself to one of two tons or more. But if there are serious obstacles to a division of the deep-sea fish-fauna into vertical zones characterised by the presence of peculiar forms, there are less objections to an attempt to show to what limits the families of fishes descend which are represented in the deep-sea by surface-forms or their modifications. As far as our present knowledge goes, we find— 1. That at a depth of 400 fathoms the Gobiide, Trachinidee (with the exception of Bathydraco), Blenniide, Percidee, Scorpxnide, Trichiuride, Cyttide, Cataphracti, Bathythrisside cease to exist. 2. Ata depth of 500 fathoms two important types, viz., the Sharks and Rays, and the Flat-fishes cease to flourish, only one isolated example of each descending beyond that hmit. 3. At 700 fathoms several other families, which are characteristic forms of the littoral fauna of the cold and temperate zones disappear, viz., the Cottids, Discoboli, and Lycodidz (with one exception); there is also no evidence of the Trachypteride and Myxine extending beyond this depth. 4 The depth of 1200 fathoms seems to be the limit of the Holocephali. * This fact was first expressed in Introduction to the Study of Fishes, p. 305. REPORT ON THE DEEP-SEA FISHES. XXXV 5. Beyond 2000 fathoms neither Gadide nor Salmonide nor Notacanthi have been found. 6. The families which descend to the greatest depth at which fishes have been obtained, viz., 2900 fathoms, are Berycidee, Pediculati, Ophidiidee, Macruride, Sternopty- chide, Scopelidee, Stomiatidee, Murzenidee ; also two families which have no representa- tives in the surface-fauna, viz., the Alepocephalide and Halosauride, extend to the same enormous depth; and there is no reason why all those deep-sea forms, which are known to live at a depth of nearly 3000 fathoms, should not occur in the greatest abyss of the ocean. The abundance and variety of fish life decreases with the depth, as is obvious from the following table, which expresses our present knowledge of the subject. There have been found between 100— 300 fathoms 232 species. loo emai ) Sue eeNeen Ie area i O02 700" © 2 TG Sree 8 A MOO2THOO. 56s es -OnlH00=2000 -. 2 Diliios as » 2000-2900 ,, AD 6 pp Of those found between 100 and 300 fathoms 108 also occur above the 100-fathoms limit. This decrease in the number of species, as shown in this table, is no doubt partly owing to the difficulty of capturing fishes at great depths, a difficulty which increases in proportion to the depth at which the dredge is worked. But it must also be regarded as evidence of the actually diminished variety of fishes. Fishes may be, and no doubt are, locally abundant at the bottom of the ocean; but this abundance is probably one of individuals rather than of distinct forms. We may safely assume, that as the majority of deep-sea fishes are modifications and derivatives of surface forms, they are fewer in number than the latter, especially when we consider that the physical conditions of the abyss are of a very uniform character, and therefore cannot have given rise to the development of numerous specific and generic forms. This uniformity of the physical character of the lowermost strata of the ocean is also the cause of the almost unlimited horizontal distribution of deep-sea fishes, Pelagic surface-fishes have already a wide range, but are more or less influenced in their distribution by climatic conditions. Deep-sea fishes are no longer subject to this cause of limitation when they have reached a depth of 500 fathoms, where the temperature of the water is as low as 40° F., and perfectly independent of that of the surface water. Therefore, the instances already known of the same genera, and even of the same species occurring in the depths of the eastern and western, northern and southern XXxvi THE VOYAGE OF H.M.S. CHALLENGER. hemispheres are numerous, and will be still more increased by future investigations. A certain number of the species are no doubt more localised; those will be chiefly such as have been derived, and are not yet far removed in their organization, from littoral forms. Others, which may be supposed to have been derived from pelagic surface fish, may have been as widely distributed, almost from the beginning of their existence, as their ancestors. At present, however, our knowledge of the actual distribution of deep-sea fishes is much too imperfect to be used as a safe basis for further generalisations. REPORT ON THE DEEP-SEA FISHES. XXXVIi THE CONSTITUTION OF THE FISH-FAUNA OF THE DEEP SEA. If, as has been done in the present Report, all species which hitherto have been found at a depth of 100 fathoms are included in the deep-sea fauna, so great an admixture of surface forms is admitted, that the characteristic features of abyssal fauna are obscured. We obtain a more correct idea of its constitution if we take into consideration only such forms as have been found from 300 fathoms downwards; eliminating from the total number of 385 species enumerated in this Report all which do not descend to 300 fathoms, 155 in number. This leaves 230 true abyssal forms. Of this number the Chondropterygians furnish 8 species or 33 per cent. Holocephali A a ee 1 ” Acanthopterygians GA tt 26 e Berycidee ide) aa LSD eee Pediculati aS ct as, Trachypteridz a BO ce Scorpzenidee > Saas Discoboli “= 5 Percidee a Be cinta, Trichiuridee i 4 Ness Cottidee a 3 Cataphracti 33 Fos Cyttidee a3 Es Trachinidee 33 Ls Lophotidee >> te aes Anacanthini i le ee 40 im Lycodidee 5th Ee tas Gadidee NG meee 9 Pe Ophidiidze Ste ADE Ris 9 %3 Macruridee Was iy ae 16 9 Pleuronectidee s es a Physostomi Gomes 26 s Scopelidze aie Le Geass Murzenidee lee. sy Stomiatidee ital 0 Seta Alepocephalidee Sy aa ; ‘THE “VOYAGE OF H.M.S. CHALLENGER. -——- Halosauridee furnish 5 species. : on eas we mteroptychide 14 4,1 4 4, Se a IETS a Oe a Ber ee " Notacanthi ; ae ee ts, ; — Bathythrissidee ae “eee - Cyclostomi The ak » 2 y orl percent. nid a 2 las regards the abundance of individuals the Macruridze seem to surpass all the ¢ . forms then follow the Ophidiidee and Gadidz. Scopelidee and Stomiatidee are likewi _ numerous, much more s0 than the Borycider, although these latter are represented by air M gh reeds how: + ive “he “eo I egere ggtde span | J ee eee en a SHARKS— Scyllium canescens, Pristiurus melanostomus, Spinax spinasx, Spinax granulosus, Centrophorus foliaceus, Centrophorus celolepis, Centrophorus squamadosus, Centroscyllium fabrictt, Centroscyllium granulatum, Lzmargus borealis, Rays— Raja isotrachys, Raja circularis, Raja radiata, . Raja hyperborea, Raja plutonia, . Raja batis, Raja vomer, Raja fullonica, Raja nidrosiensis, Urolophus kaianus, HoLocEPHALA— Chimera monstrosa, Chimera affinis, . ACANTHOPTERYGII— Percide— Anthias megalepis, Centropristis plewrospilus, Scombrops chilodipteroides, Aoropoma philippinense, Propoma rosewm, THE VOYAGE OF H.M.S. CHALLENGER. Vertical Range of Distribution 0-100} 100-300 300-500 500-700 700-1000 eee ee | | | wow ww o oo nv o 21 22 £9) 00) ST Oa. SOY ie 1000 IRS) aed — Oo REPORT ON THE DEEP-SEA FISHES. of Species, Genera, and Families. 1000-1500 1500-2000 2000-2900 (ZOOL, CHALL, EXP.— PART LVII,—1887,) xli Lu; xlii THE VOYAGE OF H.M.S. CHALLENGER. Vertical Range of Distribution 0-100} 100-300 300-500 500-700 700-1000 Malacichthys griseus, . : ; ; . solegieisorce as : Ma 28 Synagrops japonicus, . : : : : Ea tinal Simca cael = 2 q 29 Polyprion cernium, . ; : : ee erie ef Seeded 30 Scorpenide— Scorpena percoides, . 7 ¢ . a 5 : 31 Scorpxna dactyloptera, —_—=— C 5 2 ¢ 32 Scorpxena kuhlii (see Lowe), 3 eee a 33 Sebastes marinus, : : 3 —— epee Atlee < Pa toa | 84 Sebastes viviparus, —— ee ° 5 5 35 Sebastes macrochir, a — 36 Sebastes hexanema, . 2 4 : : —— i 4 4 ‘ . 0 : 37 7 Sebastes oculatus, 5 : d 4 ee a 5 F 3 5 38 Setarches fidjiensis, . 5 é 7 2 ¢ : _ a 2 : ° . 39 Setarches parmatus, . : 5 ; : —— . 3 : > . 5 5 40 Setarches guntheri, . 3 : a a ee 6 “ 6 A : c E 41 Bathysebastes albescens, P 0 : . a es . 5 : - 5 : . 42 Lioscorpius longiceps, . . : : 4 a ° 0 - 2 . a 43 Berycide— Hoplostethus mediterraneum, . - : - é ----)---- 2 5 . . | 44 Trachichthys australis, = : ; 5 wa------ : 4 4 ; 45 Trachichthys jacksoniensis, Z ; 6 F -------- : . : ° : 46 Trachichthys elongatus, 5 5 , d Z ----|---- A 3 ) F 47 Trachichthys fernandezianus, . - ' , wo----- : A : “. 48 Trachichthys traillii, . : 5 » : : ---|---- ¥ - . 49 5 Trachichthys macleayi, ° . . 2 ; ----/----- ‘ : 3 a 50 t) Trachichthys intermedius, A 5 : é -_———— Raleiare : : ; 51 : Trachichthys darwinii, : : : : 2 w------- r : ° : c 52 . Anoplogaster cornutus, : ; - == : ; 5 - : : : 9 5 53 TS Caulolepis longidens, . ; : : ; 5 4 3 - & . : : 54 ng Melamphaés microps, . . : 5 5 , , : 2 5 3 : : ‘i : 55 atlamphads tuuhlonsy 2" 2h ay loin Beal eM) oh had eatedl ayia ee are ae 56 Hi Gamnnliads megatops, |, 0° \ RB BM Beas | ie bel ae ae aL 8) [hace tall ee 57 Melamphaés crassiceps, |_| 53 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 |} 57 58 REPORT ON THE DEEP-SEA FISHES. of Species, Genera, and Families. 1000-1500 1500-2000 2000-2900 xlili xliv Melamphaés mizolepis, Melamphaés robustus, Melamphaés beanti, Melamphaés suborbitalis, Malacosarcus macrostoma, Stephanoberyx mone, . Beryx decadactylus, Beryx splendens, Polymixia nobilis, Poromitra capito, Myripristis kaianus, Trichiuride— Nealotus tripes, Aphanopus carbo, Nesiarchus nasutus, Lepidopus caudatus, Lepidopus tenuis, Lepidopus elongatus, Trichiurus leptwrus, Euoxymetopon teniatus, Euoxymetopon poeyi, Thyrsites pretiosus, Thyrsites prometheus, . Gempylus serpens, Carangide— Anomalops palpebratus, Cyttidae— Cyttus abbreviatus, Antigonia capros, Coryphenide— Diretmus argenteus, Diretmus aureus, Schedophilus medusophagus, Vertical Range of Distribution 0-100} 100-200 THE VOYAGE OF H.M.S, CHALLENGER. 300-500 59. 790 81 82 83 | 84 85 86 79a 81 82 83 84 85 86 REPORT ON THE DEEP-SEA FISHES. xlv of Species, Genera, and Families. 1000-1500 1500-2000 2000-2900 Se ee ee es Re es ee xvi THE VOYAGE OF H.M.S. CHALLENGER. Vertical Range of Distribution 0-100} 100-300 300-500 500-700 700-1000 Schedophilus lockingtonti, : : ; -----(!) 87 Schedophilus enigmaticus, 5 3 ; 4 ------(?) A F ae ‘i 3 : 88 Trachinidee— Bathydraco antarcticus, ‘ i ‘A : : , 4 : 4 4 2 ; : 89 Aphritis gobio, DEN hae a ; 6 — c 5 a 3 z 4 4 90 Acanthaphritis grandisquamis, : ; ; i ante tg te: in 91 Champsodon voraz, . 5 : a —_— ‘ 5 a : 5 5 A 92. Uranoscopus kaianus, . Re 5 < 5 = ‘ ; : Fi 5 ; : 93 Notothenia mizops, . bs A F ; ---— : zy a : 4 4 5 93a Pediculati— Lophius piscatorius, . : 5 . —_—_—_—_—_—_—_— 5 5 A “ cd 94 Lophius naresii, 5 6 + 2 2 — ketal shee, ; 3 5 : s 95 Himantolophus groenlandicus, 3 6 5 -----(!) : fs 3 4 : > 2 96 Himantolophus reinhardti, . } ele aie jae iy sctiat Ce ak Aegeonichthys appelii, a 5 F -----(%) A 0 cl cl . é 98 Ceratias bispinosus, . 2 rea 6 5 A 2 c — 3 : 4 5 : 99 Ceratias holbolli, 0 3 : ¢ 5 -----(?) a : . 3 . . 5 100 Ceratias wranoscopus, . 1 Ceratias carunculatus, : 5 & ‘ 5 4 3 — 3 : 7 : A 2 Onetrodes eschrichtii, . s 4 2 A -----(?) 8 Melanocetus johnsonii, . 5 4 : ; . | -2--- 4 Melanocetus murrayi, . 5 Liinophryne lucifer, , . ° F a (2) 6 Chaunax pictus, a : x ; - . —EEE 7 Halieutza senticosa, — Fe 8 Dibranchus atlanticus, , : Suet oe : : 3 —= 9 Cottide— ig Cottunculus microps, . ’ A ‘ : seat eee Sea TEV |e P| a hie? 10 re Cottunculus thomsoniti, 5 f , " a : eer — 4 » 11 el Cottus bathybius, : : F ; : ; a ea lly O\) BESS —- are hu? 12 Centridermichthys uncinatus, . 4 e — = 0 “ : . . 13 Icelus hamatus, 6 5 : é ee ; 4 ks 2 5 : 2 14 Triglops pingelii, ‘ o : | — 15 REPORT ON THE DEEP-SEA FISHES. xlvii of Species, Genera, and Families. 1000-1500 1500-2000 2000-2900 87 88 89 —_— 90 91 92 93 93a, 100 . 3 xlvili THE VOYAGE OF H.M.S. CHALLENGER. Vertical Range of Distribution 0-100 100-860 300-500 500-700 Trigla leptacanthus, Lepidotrigla spiloptera, Cataphracti— Peristethus miniatum, . Peristethus moluccense, Peristethus murrayi, Peristethus liorhynchus, Peristethus micronema, Peristethus truncatum, Agonus decagonus, Diseoboli— Cyclopterus spinosus, Liparis fabricit, Liparis micropus, Liparis gelatinosus, Paraliparis bathybius, Paraliparis liparinus, Paraliparis membranaceus, Gobiide— Callionymus kaianus, . Callionymus calawrspomus, Blenniide— Anarrhichas minor, Anarrhichas latifrons, Blenniops ascanii, Trachypteride— Trachypterus, . Stylophorus, . Regalecus, Lophotidea— Lophotes, (?) 700-1000 116 32 33 34 35 36 37 38 39 40 116 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 REPORT ON THE DEEP-SEA FISHES. of Species, Genera, and Families. 1000-1500 1500-2000 xlix 2000-2900 (ZOOL, CHALL. EXP.—PART Ly1I.—1887.) Lil g THE VOYAGE OF H.M.S. CHALLENGER. Vertical Range of Distribution 0-100; 100-300 300-500 500-700 700-1000 PHARYNGOGNATHI— Feliastes roseus, ANACANTHINI — Lycodide— LIycodes esmarkit, Lycodes reticulatus, Lycodes frigidus, Lycodes pallidus, Lycodes seminudus, Lycodes murena, Lycodes sarsii, Lycodes verrilli, Lycodes paxitlus, Lycodes paxilloides, Lycodonus mirabilis, . Gymnelis viridis, Melanostigma gelatinosum, Gadidee — Gadus morrhua, Gadus poutassou, Gadus argenteus, Gadus minutus (see Risso), Mora mediterranea, Halargyreus johnsonii, Melanonus gracilis, Merluccius vulgaris, Hypsicometes gobioides, Lotella marginata, Uraleptus maraldi (see Risso), Physiculus dalwighii, Physiculus kaupi, Physiculus peregrinus, Phycis blennioides, 141 141 REPORT ON THE DEEP-SEA FISHES. of Species, Genera, and Families. 1000-1500 1500-2000 li 2000-2900 hi THE VOYAGE OF H.M.S. CHALLENGER. 0-100 100-300 Vertical Range of Distribution 300-500 500-700 700-1000 Phycis chesteri, Phycis regius, . Phycis americanus, Phyeis tenuis, « Lemonema barbatulum, Haloporphyrus guentheri, Haloporphyrus lepidion, Haloporphyrus eques, . Haloporphyrus tnosime, Haloporphyrus ensiferus, Antimora rostrata, Antimora viola, Molva molva, . Molva abyssorum, Onus macrophthalmus, Onus carpenteri, A Onus reinhardti, 5 Onus septentrionalis, Onus ensis, Onus cimbrius, Brosmius brosme, Chiasmodus niger, Ophidiide— Barathrodemus manatinus, Neobythites grandis, Neobythites macrops, Jeobythites ocellatus, Neobythites gillii, Catxtyx messieri, Pteridium atrum, Pteroidonus quinguarius, Dicrolene intronigra, . Mixonus laticeps, ee Se ee ee a ee ee ee Ie 170 REPORT ON THE DEEP-SEA FISHES. liii of Species, Genera, and Families. 1000-1500 1500-2000 2000-2900 170 eee ee ee liv THE VOYAGE OF H.M.S. CHALLENGER. Vertical Range of Distribution 0-100} 100-300 300-500 500-700 700-1000 Bathyonus compressus, ° 5 - - 202 Bathyonus tenia, 3 Bathyonus catena, 4 Porogadus gracilis, . % é : 3 2 5 5 Porogadus miles, 6 Porogadus rostratus, 7 Nematonus pectoralis, . —----|---------|------------- 8 Diplacanthopoma brachysoma, : - - - : : — A 9 Acanthonus armatus, . 10 Typhionus nasus, < c : 3 5 - 5 . 2 11 Aphyonus gelatinosus, 12 Ophidium murexnolepis, : ; 5 : —— 3 Q ¢ 2 : : : 13 Rhodichthys regina, . c 2 R 4 a } a ; : ¢ 4 r F 14 Macruride— Macrurus parallelus, . 5 . - é : 5 5 ee ; : 5 15 Macrurus japonicus, == 16 Macrurus australis, . c a 5 = —----- 2 4 5 : : : ili Macrurus caelorhynchus, —_ 18 Macrwrus carminatus, 5 : | ee ‘ 0 3 & a 19 Macrurus fasciatus, See 20 Macrurus fabricti, 3 5 4 . eo a 5 é 5 : 6 21 Macrurus rudis, Seeman 22 Macrurus nesutus, S c 5 : 5 5 4 c oe ee . . 7 23 Macrurus serrulatus, . | —— 24 Macrurus sclerorhynchus, : . : : : ‘ 5 2 m We eo séeace [=a = ee mnie 25 Macrurus xqualis, - - : : - A 5 2 : — ¢ 5 : 26 Macrurus bairdii, c 4 5 . 5 a 27 Macrurus goodii, . : - : - : : jee fee eeenn|---- ee 28 Macrurus holotrachys, : 5 c A : F ; . — 5 : ; 29 Macrurus asper, 3 ; : : 5 3 6 : 5 : 5 : : 7 . 30 Macrurus carinatus, . by eg : 4 : ¥ , 4 — fs 5 4 . 5 31 Macrurus rupestris, . ; : ; 3 [me en : 5 5 . - 32 Macrurus altipinnis, . meee ioe See 33 REPORT ON THE DEEP-SEA FISHES. of Species, Genera, and Families. lv 1000-1500 1500-2000 2000-2900 lvi THE VOYAGE OF H.M.S. CHALLENGER. 0-100 Vertical Range of Distribution 100-300 300-500 yess 500-700 700-1000 Macrurus longibarbis, Macrurus italicus, Macrurus filicauda, Macrurus microlepis, . Macrurus villosus, Macrurus crassiceps, . Macrurus leptolepis, Macrurus simulus, Macrurus fernandexianus, Macrwrus liocephalus, Macrurus murrayi, Macrurus denticulatus, Macrurus levis, Macrurus macrochir, . Macrurus sulcatus, Macrurus armatus, Macrurus affinis, Macrurus longifilis, Trachyrhynchus trachyrhynchus, Trachyrhynchus longirostris, . Trachyrhynchus murrayi, Bathygadus cottoides, . Bathygadus multifilis, Bathygadus cavernosus, Bathygadus macrops, . Bathygadus longifilis, Macruronus nove-xelandiz, Ateleopodide— Ateleopus japonicus, Pleuronectidee— Hippoglossus pinguis, . Hippoglossoides platessoides ? Poecilopsetta colorata, . ~---=-(") 234 61 62 63 64 REPORT ON THE DEEP-SEA FISHES. lvii of Species, Genera, and Families. 1000-1500 1500-2000 2000-2900 234 35 36 a ee ee 37 38 39 40 41 |---------- — 42 — 43 5 : : : C : —_———'___ 45 46 47 48 49 |----------- a es eS 50 : : z : . ae 51 52 53 54 55 56 57 58 59 60 |, 61 62 63 64 (Z00L. CHALL. EXP.—PaRT LYU.—1887.) Lik lviii THE VOYAGE OF H.M.S. CHALLENGER. Vertical Range of Distribution 0-100 100-300 300-500 500-700 700-1000 Anticitharus polyspilus, Samaris maculatus, Lepidopsetta maculata, Pseudorhombus hectoris, Pseudorhombus boops, . Pseudorhombus oblongus, Pseudorhombus ocellatus, Monolene sessilicauda, Citharichthys wretifrons, Citharichthys unicornis, Pleuronectes beanii, Plewronectes cynoglossus, « Nematops microstoma, Solea kaiana, . Aphoristia nebulosa, PHYsosTOMI— Sternoptychide— Argyropelecus hemigymnus, Argyropelecus olfersti, Sternoptyx diaphana, . Polyipnus spinosus, Gonostoma denudatum, Gonostoma elongatum, Gonostoma gracile, Gonostoma microdon, Photichthys argenteus, Chauliodus sloanii, Scopelide— Saurus kaianus, Huarpodon microchir, Bathysaurus ferox, Bathysaurus agassizii, Bathysaurus mollis, --(! 265 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 ee ‘oie wore le ed wo i. 1 265 REPORT ON THE DEEP-SEA FISHES. lix of Species, Genera, and Families. 1000-1500 1500-2000 | 2000-2900 a ee ee ee Re ee ee eee ree eS SS en SS ee ee Ix THE VOYAGE OF H.M.8. CHALLENGER, Vertical Range of Distribution 0-100} 100-300 300-500 500-700 700-1000 Bathypterois longifilis, —— : , , 295 Bathypterois longipes, . 96 Bathypterois longicauda, : 5 : - < 3 : ; 5 E A 3 y A 97 Bathypterois quadrifilis, eee ee 98 Tpnops murray, : 5 ‘ : : : ; : : : 2 A . 5 99 Chlorophthalmus agassizit, . i : 2 —_— 5 " 5 5 5 2 ; 300 Chlorophthalmus productus, . ; : ; 3 ; 5 — 1 Chlorophthalmus nigripinnis, : : : —— 2 Chlorophthalmus gracilis, 3 Scopelus nacrolepidotus, _—_ 4 Scopelus glacialis, A : : : 0 ee eee ee Scopelus engraulis, . . : : - : od 6 Scopelus dumerilii, . : : 7 - ooo a 7 Nannobrachium nigrum, : é 5 5 : 5 : - é — 8 Odontostomus hyalinus, : d . ; . |eee------- 9 Omosudis lowit, c < : ; : : 3 : — 10 Plagyodus ferox, : soe ; ; : ssdseie WW Stomiatide— Astronesthes niger, : : : |e : : c a ' 6 5 12 Stomias boa, . . 5 : : ; 2 ene mn 2 =] 13 Stomias affinis, ; . : ; 4 5 , : — cs - - : 5 14 Stomias ferox, : ; 2 ' ; or ee é 5 6 5 . 15 Echiostoma barbatun, : : . : F eee | Cee , m : 1 ‘ 16 Opostomias micripnus, rs : : : ms : : : 5 5 P : ; . 17 Pachystomias microdon, : : : , f , ; é : : ; : 2 : 18 Photonectes albipinnis, ‘ 3 : . ealewee j ; i Malacosteus niger, ° : 5 c : 3 : » | seee=- (2) R ; c 5 a 20 Malacosteus indicus, . - 5 ; 3 : ; : =—— - : : a ; 21 Bathophilus nigerrimus, : : : : » | meee (2) ; ; 0 e : 4 ; 22 Idiacanthus fasciola, . ‘ ; 5 ee oo --(?) A 2 F Fi 4 ; : 23 Idiacanthus ferox, : : . ; : , - : : A : f 6 : 24 Salmonide— Argentina silus, A ; : : A = 25 alas i I 295 £5 SOO NT ob) Ot ue Db. - OS 12 13 14 15 16 17 18 19 20 21 22 23 24 25 REPORT ON THE DEEP-SEA FISHES. of Species, Genera, and Families. 1000-1500 lxi 1500-2000 2000-2900 Argentina Vioglossa, . Argentina elongata, . Bathylagus atlanticus, Bathylagus antarcticus, 7 Bathythrisside— Bathythrissa dorsalis, Alepocephalides— Alepocephalus rostratus, Alepocephalus agassizii, Alepocephalus productus, * Alepocephalus bairdii, Alepocephalus niger, Bathytroctes macrolepis, Bathytroctes micralepis, Bathytroctes rostratus, Platytroctes apus, “ Xenodermichthys nodulosus, Halosauride— Halosaurus owenti, . 5 Halosaurus macrochir, Haloswurus mediorostris, Halosaurus rostratus, . Halosaurus afinis, Notacanthi— Notacanthus sewpinis, . Notacanthus nasus, Notacanthus phasganorus, Notacanthus bonapartii, Notacanthus rissoanus, Murenide— Congromurena guttulata, Simenchelys parasiticus, Netiastoma melanurum, THE VOYAGE OF H.M.S. CHALLENGER. 0-100 100-300 u Vertical Range of Distribution ~ 300-500 500-700 , granular mass of ganglion cells, with distinct nuclei; ¢, phosphorescent cells; d, reflecting layer of spicules; e, blood-vessels extending up into the masses of phosphorescent cells; /, nerves extending downwards from the external ganglion cell layer ; g, layer of tissue with numerous blood-vessels; 4, pigment coat. - of H.M.S Challenger” Deep-sea Fishes. Pl. LXXI. 37: 3th eee ws ee cpneroes — = F. Huth, Lith? aint Rv. Lendenfeld del. SCOPELUS. OPOSTOMIAS MICRIPNUS. ECHIOSTOMA BARBATUM. j—LiL (ZOOL, CHALL, EXP.—PART Lyu.—1887. Fig. 46. Fig. 47 Fig. 48. Fig. 49. Fig. 50. Fig. 51. Fig. 52. Fig. 53. Fig. 54. Fig. 55 Fig. 56. Fig. 57. Fig. 58. Fig. 59. Fig. 60. Fig. 61. I lor) bo Fig. 64 - PLATE LXXIII. Figs. 45-48. Halosaurus macrochir. 5. ‘Transverse vertical section of the glandular phosphorescent organ below the gill-cover. x 15. a, Granular substance ; b, vertical threads ; ¢, structureless reflecting cuticular membrane ; d, pigment- layer. Transverse vertical section of the same organ. x 250. a, Granular substance; }, vertical threads, consisting of blood-vessels, nerves, and a cartilaginous support ; c, structureless reflecting cuticular basal membrane ; d, pigment-layer; ¢, outer pavement epithelium. Tripolar cell from the granular substance. x 600. Bipolar cell from the same. x 600. Figs. 49-53. Xenodermichthys nodulosus. Transverse vertical section of the ducts of the slime-glands in the sides of the body. x 100. a, Outer pavement epithelium with scattered pigment; , proximal end of efferent duct; ¢, thick pig- ment-layer of the dermis ; d, transparent fibrous tissue. Axial section of a projecting ocellar phosphorescent organ, from the side of the body. x 100. a, Thick pigment-layer of the dermis ; 4, outer pavement epithelium, with scattered pigment ; ¢, thick pigment-layer covering the upper proximal portion of the organ; d, internal crest dividing the organ into a proximal and a distal portion ; ¢, limit of the pigment cover ; 7, nerve passing into the organ ; g, thick pigment-layer on the proximal side ; 4, proximal granular portion, with large nuclei; i, typical phosphorescent clavate cells ; /, pigment patches ; 7, transparent epithelium. Bipolar cell from the distal portion of the same organ. x 800. Typical phosphorescent clavate cells, from the same. x 800. a, Light-refracting vesicle ; b, nucleus ; ¢, peduncle. A similar clavate cell with abnormal refractive vesicle, from the same. x 800. a, Two light-refracting vesicles ; 6, nucleus ; v, peduncle. Figs. 54-64. Halosawrus macrochir. Surface view of the reflecting membrane, clothing the spaces between the modified scales of the lateral line. x 1400. Transverse section of the large lateral slime-canal. x 150. a, Phosphorescent tissue overlying the slime-canal ; 4, gland-tubes; ¢, short cylindrical longitudinally situated cells, with well-defined cell-wall, occupying the lower portions of the slime-canal ; d, irre- gular cells surrounding the lumen of the slime-canal ; ¢, lumen of the slime-canal ; 7, muscular fibres. Tripolar cell, from the slime-canal; adjacent to the lumen. x 400. Bipolar cell, from the same situation. x 400. Group of cells, from the slime-canal ; adjacent to the outer wall, in transverse section. x 500. Coiled gland-tubes, from the vicinity of the slime-canal. x 300. Longitudinal section of the tissue occupying the spaces below the large modified scales of the lateral line. x 500. a, Lenticular yellow bodies ; », intervening fibrous tissue. Longitudinal section through the slime-canal, showing the phosphorescent organs, in the modi- fied lateral line. x 150. a, Muscular fibres ; }, inner portion of the tissue filling the slime-canal ; c, lumen of the slime-canal ; d, extensions of the lumen below the inner margin of each scale ; ¢, extension of the roof of the slime- canal along the outer side of the proximal portion of each modified scale ; f, tissue covering the slime-canal ; g, tissue between the modified scales of the lateral line ; 2, roof of the slime-canal ; i, modified scales of the lateral line; %, posterior margin of the scale; 7, pigmented membrane covering the outer surface of the modified scales ; m, pigmented membrane covering the inner surface of the modified scales ; 2, reflecting membrane on the inner side of the modified scales ; o, reflecting membrane on the outer side of the modified scales ; p, phosphorescent organ on the outer side of the scale ; g, tranSverse ridge of the scale ; 7, inner membrane ; s, outer membrane ; t, canal passing through the scale and leading to the phosphorescent organ. 2. Longitudinal section of a portion of the lateral line, near the proximal end of one of the modified scales. x 400. a, Phosphorescent tissue overlying the slime-canal ; b, reflecting membrane ; c, pigmented membrane below the scale; d, scale; ¢, pigmented membrane; /, reflecting membrane above the scale ; g, extension of the roof of the slime-canal along the outer side of the proximal portion of the scale ; h, fibrous tissue ; 7, lenticular yellow bodies of the tissue between the scales. Longitudinal section of the slime-canal, showing the phosphorescent organs in the modified lateral line. x 60. a, Lumen of the slime-canal ; b, tissue of the slime-canal ; c, tissue between adjacent modified scales ; d, scales and their membranes (compare fig. 62). . Transverse section of a phosphorescent organ attached to the outer side of the scale. x 400, w, Blood-vessels ; b, ganglion cells ; c, phosphorescent spindle cells ; 7, granular superficial layer. The Voyage of HM.S Challenger’ wits Sy fe Ry.Lendenfeld del HALOSAURUS XENODERMICHTHYS. Deep-sea Fishes. PLUXXI ectaiiess Sans * } “tt D fee (we> an yt. ( ) Y 4 x , : bs um cS — ( 4 ' > a2 f Os, 4 a b \ we BN — My a aes) mie ac wow cae one ogee. wean he 9088 00035 9315 mM Uh SMITHSONIAN INST; UTION LIBRARIES sinew w. ccegcachan Guveidep ar keder tacbiaae Ms calietye ry aie WP ae pee wee . h hy caida wreteoe fe Sie Aen! was ; : ‘ Pe tauryce toe we 4m ie ¢ cererr ane het hh ‘ tee toe etdioAl he Aiorkseh to ¢ ' : “ oe as pt ages rs . ‘ ‘ Shuchieeg eis shi cf ; . eo i . mlaeNn steed ened ‘ vr NTA haat : . SU madetnsayer! weestas ‘ ‘ 4 hopiaee date iy rene k : . PeReyy ¢ \ ‘ eee ‘ * . + ‘ + ‘ bie be ; > » rs * Vine 4 ‘. a Ly eS Bs ee i icao 4 iY ib eit) al ‘ Sou 4 i Seer} bib rae ‘ * > het Rh ae > : ' 7 Lys ris é ‘ 5 Ce Tick Oe sme ie Pies ip i ( + “ = biebie ait - est A ‘ Luster ‘ : ¥ thai g? _ r ; ne ¢ Ete Tae teary aed oky SEE SEES RES age i . Pie entre EM a han chem a bain se ' thier tia in y z bbAlehite icin da Skat “ : ib PERE OE HG Beets Ne Ge « Sehite: \ tac ; SON eee Were santa, Pe seers ty > Onde as oaks tome was ‘ a ‘ Tht we At teh ont pi My Shee OH ee “y xa " ‘ wee See penreriy . SSireeeyaans prunqcuryity rerneepeae. to Eira br ocrng sm tesa mea renin tech pat hy isa Semi aay-eomepmapiragn tne tame any pegs hab inant bed me hundew en gure Cee ak ar apt Sg he maiapeie \votitwe florets Tegierits Br ah Tee astarn ty prtts aerate Mints easy State ae) Inara vane ee SB aTHY mee Ph Ren é oie Semaine Eynigie Me tng yar ae c Use mirigy ot Sena spewed A Re Ut teria WigeesUners eg yma, nesta } ART wena pines Ay Nyman) Ae wary) wegen 9 oh iste SRG. hay Pl Sane NY Soltotinipieliitintts Hark teheietintcies santos Minit nee yt % ei ime ma ee hang net HMA IAeTE NOTA “we dey MyLI NU ueronr ee Ss Perera: (enue hslabatetnla lataaryiatheta oteoa be hee Meek Dea ern Nn Ray: Bete Te Sbehtanconr ania iate in| 2 Ac tiasbac eine atyrectiopmlchthe wae Soke fataena art rae mut Suenalsdtwebe fo Mc toyed psy YE pene laden heey Sou ctraser-yer year ma CMON Gea) ree tat ate Ato Moeapiayy re thane LOMn OVE Be meMae one Uwe kare ath yess Ln mnvere ni sabe e een ee roe 0 wa pat sy ioe tetarmas eee Spates horses Wnavengeniowe:Umeeuedtace scales SSystinsyss Sweqal sete ra Cea? Treas tceetegat me neayay saene al Whi etry Sennen esovesteetes Meche sia tion mee ty eas ipeumesnenenrarteacee eo atone tarred tele es aitevnetstectnnraanenapiee nt ian is cusses eT EATEN tee sions Westy tg’ HEP ae te be ischial sey sane iayelseracgertney ge nsonsen twegestecana ty hate, Dee te Tibeimev asian Ost cerw me Ta CO OCraNT Widnes TOUT i x casechitratvon wil yper vutct sown ese: . anaberet tent Ret TN gec wae Denteeu tart naeamcueesice dnb orarere UNicibudten, i tel we tb aga CE MS Wet Goh a Na 0 ot G8 Setanr bisth bee mu .rd Oryith tas Nepaaisesy tates eae rae earn sear Pee cine dade g wine tow Ge elie naa teres pees tTa bees wigee tafe oS mn REM ot OAHU ober fon heh Ua eye st Ou Ubwe sk o woot har © we ah We eu OC tan erie} piste tet eek Eo (A DE “r aan. sbseebrte bse tee ee Mo OO) mt ie )= rays ‘ (Tas beet HN TUT Ee by OA an NM Te OR A TM We Dee ew yy la ie ge Wr proade rh meg dey daybed le ty wee pels : , WAL 4 Sean Wweestie se Sibiathtatetuwtritanatp etna at PLM dh lina tad yh hes pasctavansiats = ‘ eh ta ; setecacaSptatgaaa’stoerata spesneceteyeretyea Ot) Mdaa treet SONCMarA ro Na esheaiehcteerrnseciretc nati ira eueh A bla weit re rctim boa be beth rater breietametcent ateetetnt “ Jt Ai cere rt the Ob be bh he ee et ie