DISCUSSION OF SPECIES \ \ I > THEIR DISTRIBUTION. 181 



half of that ni' the suniit: posterior margin of the preoperculum descending obliquely back- 

 wards; lower jaw slightly prominent; cleft of the mouth rather oblique; the maxillary 

 reaches to behind theeye, and is moderately dilated behind. < Origin of the dorsal lin aearer 

 to the extremity of the snout than to the caudal lin. and immediately behind the base of 

 the centrals; its last ray is above the anterior anal rays. Pectoral lin narrow, nearlj as 

 long as tin- head, reaching to or beyond the end of the anal tin. Black. (Qimther.) 



Radial formula: D. in, 1l': A. i, 8-9; P. 14; V. i. 7; L. hit. 28. 



The Challenger obtained one specimen, 2 inches long, from the mid-Atlantic (station 

 107) at a depth of 1,500 fathoms; another, -h inches long, oil' Pernambuco, station 120, at 

 a depth of (!7;"i fathoms. 



PLECTROMUS MI'.UALol'S, Litkex. 



itelamphaes megalops, Li'TKEX, Oversigt. K. D. Vid. Srlsk, ForhandX, 1877, 17(1, pi. v, figs. 1-3. — 

 GtJNTHBR, Challenger Report xxu, 27, pi. v, lii;. ;:. 



Height of the body one-fourth of the total length, and not quite equal to the length of 

 the head. Eye rather large, its diameter more than one-fourth the length of the head, and 

 considerably greater than that of the snout. Interorbital space in its greatest width 

 equal to about half the greatest height of the body; in its least width, one-fourth the great- 

 est height of the body. The caudal peduncle is long and slender, its length equal to the 

 distance from the posterior root of the anal to the head; its height, immediately behind the 

 dorsal and anal tins, is equal to one half the greatest height of the body; its least height, 

 about midway between the dorsal fin and the caudal, .scarcely more than one-fourth of the 

 height of the body. The anal is inserted under the last rays of the dorsal, broadly trian- 

 gular in form, and owing to the rapid diminution in the height of the body under the dorsal 

 and anal, both of these fins present the greater portion of their upper margin toward the 

 posterior portion of the fish. The pectorals are long, leaf-like, extending beyond the roots 

 of the dorsal and anal. The ventral is placed entirely in advance of the root of the pecto- 

 ral, and is very broad and stout — almost spatulate at its extremity; its length equal to 

 that of the. pectoral, and its tip overlapping the anterior portion of the anal. The head is 

 very rough, foliaceous; lower jaw prominent and projecting. Color, black. 



D. in, 11; A. I, 9; 1'. 10-11; V. i, 7; L. lat. 3i; L. trans. 9; B. 8. 



This species was described by Liitken from the Atlantic, south of the Azores. Its pro- 

 portions are so peculiar that it seems quite possible that it may not belong either to Me- 

 lamphaes or Plectronms, as now characterized. 



SCOPELOGADUS, Vaillant. 



Scopelogadus, Vaillant, Exp. Sci. Travailleu'r et Talisman, lsss, 140. 

 Melamphaes, Vaillant, loc. <//., 385. (part). 



Berycine fishes resembling Melamphaes and Plectromus, but in general form strongly 

 suggestive of Myctophum. Scales moderate and cycloid, regularly arranged. Head thick 

 and comparatively short, with deep muciferous channels. Mouth moderate, somewhat 

 oblique. Jaws nearly equal, the lower slightly more prominent. Teeth upon the inter- 

 maxillary and the mandible: palate, vomer, and tongue toothless. Eyes minute, rudiment- 

 ary. A single short dorsal of about 12 rays (number of spines not determined, possibly 

 rudimentary). Vent under the middle of the base of the dorsal; origin of the anal under 

 the posterior fourth of the dorsal. The anal tin with 8 or more rays (number of spines, if any 

 not rudimentary, not determined). Ventral tins thoracic and with ten rays. Pseudobran- 

 chiae present. No swim bladder. 



This genus, was founded by Vaillant upon the five specimens of a species described by 

 him under the name of S. coeles. The material studied by him was badly preserved, and the 

 diagnosis, especially of the vertical tins, is unsatisfactory. At first, led by superficial re- 

 semblance, the form was believed to belong close to the old genus Scopelus, and the unfortu- 

 nate name Scopelogadus is intended to describe a Scopelus-like fish with thoracic tins. In 



