70 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



Tliis species is uaiued in lioiior of the late Dr. David Ilumplireys Storer, in token of 

 our appreciation of tlie distiuguislied services of tbis pioueer of American ichthyology. 



Family MYCTOPHID^E. 



Seopelini, Miiller, 1843.— Jordajj &GiLiiKRT, Bull., xvi, U. S. Nat. Mus., 279. 



ScopelUlw, OiKARD, Rep. P. R. R. Survey, x, 1858, 328.— Gunther, Cat. Fish. Brit. Mus., v., 1867,328. 



MyctujMda; Gill, MS. 



Body oblong or moderately elongate, compressed (except in Scopelosai(nts), covered 

 with scales, which are usually cycloid. Mouth wide, the entire margin of the upper jaw 

 formed by the long and .slender premaxillaries, closely adherent to which are the slender 

 maxillaries. Teeth various, mostly villiform, and in bauds in the jaw; also pterygoids, 

 palatines, and tongue; also on vomer in adults. No barbels. Gill membranes separate, 

 Iree. Branchiostegals, 8-10. Pseudobranchia', well developed. Gill rakers long and 

 slender. Lateral line present, the scales prominent and often enlarged. Cheeks and 

 opercles scaly. Adipose fin present. Dorsal fin short, median, of soft rays. Pectorals 

 and ventrals present. Anal tin moderate. Caudal forked. Air bladder small. Intestinal 

 canal short. Sides scaly, with phosphorescent spots. 



For convenience of study and comparison, it would seem somewhat desirable that the 

 forms now usually grouped under the great polymorphous genus Scopclus, should be divided 

 into minor groups. We have, therefore, proposed the provisional plan formulated in the 

 accompanying key. Some of the groups are probably of subgeneric value. 



Since the completion of our study of this family, two important papers have appeared: 

 the first by Dr. Fed. Kaffaele, i>ublished in tlie " Mittheilungeu " of the Zoiilogical Station 

 at Naples in 1889, and secondly, Dr. Liitkeu's masterly and exhaustive paper on the Scope- 

 lids of the Zoological Museum of the University of Copenhagen, forming part 2 of "Spolia 

 Atlautica," printed in the Memoirs of the Royal Academy of Sciences and Letters of Den- 

 mark, sixth series. Vol. vii, part C, Copenhagen, 1892. 



The first of these papers announced an important new system of discriminating between 

 the species of fishes formerly grouped in the genus Seopelus, based upon the arrangement 

 of the luminous spots, which were classified by the author in eight groups. 



At the time when Dr. Raffaele's paper was brought to our attention, our book was being 

 put in type, so that, beyond reference to it in tlie synonymy, it was impossible to utilize the 

 work of the author, for it became evident that if his plan were adopted it would necessitate 

 an entire revision of our plan of classification, and while it seemed to be full of suggestions 

 we were not yet satisfied as to the extent of the usefulness of the proposed new plan. 



The publication of Liitkeu's work has, however, rendered it necessary to completely 

 revise our opinions upon the relations of the species. A review of the group in the light 

 of Liitkeu's conclusions convinced us that the arrangement of the luminous spots is of the 

 greatest value in the classification of these fishes. 



MYCTOPHUM, Rafinesque. 



Myctophum, RxFiKEsqvE, Indice (Vlttiologia Siciliana, 1810, 56; type, Myctophum pitnclalum, Raf. — Bona- 

 parte, Fauu. Ital., Pesci, fasc. xxvii. 



Nyctoplms, Cocco, Giorn. Sicil. 1829, 44 (iucl. M. mctopoclampus) Lett, su Salmon, (iut-l. 1. X. linjinesquei; 2. 

 N, Metopoclampus ; 3. X. Gemclarii; X, lionapartii) . 



Scopelm, CuviEK, Rfcgne Animal, ed. 2d, 1817, II, 169 (type, .S'. lIumboUlti).—GvfiTn¥.R, Cat. Fish. Brit. Mus., 

 V. 404 (-part). 



Body oblong, compressed, covered with cycloid scales, those in the lateral line not much 

 enlarged. Head short, compressed, with limb of preoperculum nearly vertical. Mouth 

 large, the jaws about equal; premaxillaries long and slender; maxillaries well developed. 

 Snout more or less blunt and declivous. Teeth in villiform bands on jaws, palatines, ptery- 

 goids and tongue. Eye large. Gill rakers long and slender. Branchiostegals, 7-16. Air- 

 bladdei', small. Pyloric cseca, few. Pseudobrauchife, large. Dorsal fin entirely in front 



