gilbert: the lantern-fishes of japan 71 



Dorsal rays 13; anal raj^s 18; ventrals with outer rudiment and 8 devel- 

 oped rays; pectoral rays 16. Scales of lateral line 36. 



Eye large, though smaller than in D. pristilepis, its upper margin but 

 little below the profile, the rounded snout protruding beyond the orbit for a 

 distance equal to half the diameter of the eye. Teeth minute, in narrow 

 bands on jaws, in two small round patches on head of vomer, the narrow band 

 on palatines separated from vomer by a very short interspace. Cleft of mouth 

 obhque; maxillary decidedly broadened at tip, extending but slightly beyond 

 vertical from hinder margin of eye. Preopercular border nearly vertical, the 

 cheeks not obliquely lengthened. Gill-rakers long and slender, the longest half 

 the diameter of the eye, 4 + 15 in number (counted in one of the cotypes). Pec- 

 torals long and slender, usually reaching the vertical from the vent and extend- 

 ing to or slightly beyond the middle supra-anal photophore. Scales firm, all sharply 

 spinous, including those of the lateral line and those on breast and belly. The 

 spines are everywhere approximately equal, not greatly lengthened along the base 

 of the anal fin as in D. spinosus. In D. pristilepis, the scales are thinner and 

 less extensively spinous, the scales of the lateral line have few spines, or none, 

 and those on breast and belly are smooth. In D. orientalis, the scales of the 

 lateral line are moderately enlarged, their vertical diameter equaling their dis- 

 tance from the base of the dorsal fin. 



Photophores. — A very faint pre-orbital immediately above nostril, and one 

 better marked under the lower anterior border of the eye. Suprapectoral 

 separated from lateral line by twice its distance from base of upper pectoral ray. 

 Infrapectorals in line with first ventral, their interspace less than that separating 

 the upper one from the suprapectoral. First pair of thoracics nearest the 

 median line, the third and fourth pairs equidistant from it, the fifth pair widely 

 divergent, inserted immediately in front of the outer ventral rays. Interval 

 between the third and fourth pairs the shortest, that between fourth and fifth 

 but Uttle longer, the second interval a little shorter than the first. Supra- 

 ventral vertically above the first ventral, very slightly nearer base of ventral 

 fin than lateral line. First pair of ventrals nearly in contact, the others a httle 

 more elevated, shghtly converging from the second to the fourth, which are at 

 the sides of the vent and a little anterior to it; first ventral interval a httle 

 longer than the second, the third the shortest. Upper supra-anal immediately 

 below but not in contact with the lateral Une, on its seventeenth or eighteenth 

 scale, in a vertical Une which traverses the base of the second or third anal ray; 

 upper and middle supra-anals in a line passing through fourth ventral, the lower 



