DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 181 



half of that of the suout; posterior margin of the preopercuhim descending- obliquely back- 

 wards; lower jaw slightly i)roininont; eleft of the mouth rather ol)li(iue; the maxillary 

 reaches to behind the eye, and is moderately dilated behind. Origin of the dorsal fin nearer 

 to the extremity of the snout than to the caudal fin, and immediately behind the base of 

 the ventrals; its last ray is above the anterior anal rays. Pectoral fin narrow, nearly as 

 long as the head, reaching to or beyond the end of the anal fin. Black. {GUnther.) 



Radial formula: 1). in, 12; A. i, 8-9; T. U; Y. i, 7; L. lat. US. 



The Challenger obtained one specimen, 2 inches long, from the mid-^Vtlanti*- (station 

 107) at a depth of 1,500 fathoms; another, 2 J inches long, off Pernambuco, station 120, at 

 a depth of 675 fathoms. 



PLECTROMUS MEGALOPS, Lutken. 



Melamphaes megalops, Li'TKEN, Oversigt. K. D. Vid. Selsk, Forbanill., 1877, 17G, pi. V, figs. 1-3. — 

 CtOnther, Challenger Report xxil, 27, pi. V, fig. 3. 



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 

 con.siderably 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 tlie posterior root of the anal to the head; its height, immediately behind the 

 dorsal and anal fins, 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 tlie rapid diminution in the height of the body under the dorsal 

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

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

 of tlie 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. Ill, 11; A. I, 9; P. 10-11; V. i, 7; L. lat. 34; 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 Plectromiis, as now characterized. 



SCOPELOGADUS, Vaillant. 



Scopelogadiis, Vaillant, Exp. Sci. Travailleur et Talisman, 1888, 1-tO. 

 MelampluieK, Vaillant, loc. cit., 38.5. (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 fin with 8 or more rays (number of spines, if any 

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

 chiai present. No swim bladder. 



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

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

 diagnosis, especially of the vertical fins, is unsatisfactory. At first, led by sni)erficial re- 

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

 nate name Scopeloyadus is intended to describe a Scopelus-like fish with thoracic fins. In 



