161 



II. No large luminous mass on the snout : pectorals of moderate length or 

 very long : — 



1. The pectorals reach the middle of the ventrals : snout about half as 



long as the eye ... ... ... ... ... S. indicus. 



2. The pectorals reach the 1st anal ray : snout about half as long as the 



eye ... ... ... ... ... ... S. pterotus. 



3. The pectorals reach at least to the sixth anal ray : snout about a 



quarter as long as the eye ... ... ... ... S. pyrsobolus. 



129. Scopelns engraulis, Gthr. 



Scopelus engraulis, Giinther, Challenger Deep Sea Fishes, p. 197, pi. li. fig. C : Alcock, Ann. Mag. Nat. Hist. 

 (6) VIII. 1891, p. 129. 



D. 14. A. 14-15. P. 12. V. 9. L. lat. 38. L. tr. |. 



Height of the body about a fifth, length of the head about two-sevenths of 

 the total, without the caudal. The eye is near the extremity of the extremely 

 short snout, its diameter is about a fifth the length of the head and rather less 

 than the width of the interorbital space. 



Operculum thin and narrow, scarcely covering the gill-opening : posterior 

 margin of preoperculum oblique. 



Mouth oblique, very wide, the upper jaw overlapping the lower. The 

 maxilla extends back to the mandibular joint and is not dilated posteriorly. 



The first dorsal ray is midway between the end of the snout and the adipose 

 fin and a little in advance of the root of the ventral : the last dorsal ray is just 

 in advance of the vent. Pectoral short, not reaching to the ventral. Ventral 

 reaching to the vent. 



Scales perfectly smooth, those of the lateral fine not enlarged. 



Colour : black ; mandibles whitish, with a broad black cross-band below the 

 eyes. 



The luminous organs are arranged as follows on each side : — 



one on the preoperculum, near its lower angle : 



three between the isthmus and the root of the pectorals, and one above the 

 pectoral : 



three, in an oblique series, between the pectorals and the root of the ventral, 

 and an isolated one higher up on the side : 



three between the ventrals and the vent, and two or three higher up on the 

 side: 



three in an oblique series running from the vent towards the lateral line : 



eleven along the base of the anal and a little behind, and one higher up, 

 opposite a break in this series : 



four along the root of the lower caudal rays. 

 21 



