218 Mr. A. Alcock on the Bathylial Fishes 



less than a diameter of the eye in width anteriorly, more pos- 

 teriorly. Mouth large, moderately oblique ; the jaws perfectly 

 equal in repose ; the maxilla reaches the preopercular angle 

 and is dilated at its hinder end ; no vomerine teeth. Opercles 

 large; the operculum produced into a membranous spur 

 behind ; the vertical border of the preoperculum very obliquely 

 recurrent. 



Scales extremely deciduous, smooth, cycloid, their average 

 diameter one twelfth of an inch. 



The dorsal fin begins nearer to the tip of the snout than to 

 the base of the caudal, but behind the bases of the ventrals, 

 which are much advanced, its last ray falls in the vertical 

 through the first or second anal ray ; adipose dorsal entire. 

 Pectorals long, extending to the first or second anal ray. 



Luminous organs : — A lateral series extending close to the 

 mid-ventral line from the isthmus to the base of the caudal, 

 and numbering four to base of ventral, three more to origin 

 of anal, ten more to hinder end of anal, and one more at base 

 of caudal; above this rectilinear series are the following, 

 rather more diffused — one at the angle of the preoperculum, 

 two along the edge of the gill-opening, one on the base of the 

 pectoral, two on the base of the ventral, three in a straight 

 line along the middle of the flank, and three along the middle 

 of the tail ; no luminous organ on the back of the tail. 



Nine pyloric cseca. A well-developed air-bladder. 



Colours in the fresh state : — Uniform silvery, with thickly 

 scattered black specks ; opercles, iris, and first branchial arch 

 burnished silver. 



Total length 1| inch. 



Hob. Vide Station 96. About sixty specimens, many of 

 them being mature females. 



20. Scopelus pyrsobolus, sp. n. (PI. VIII. fig. 3.) 

 D. 12. A. 13. P. 12. V. 8. 



Head large ; body compressed. 



Length of the head, not including a membranous expansion 

 of the suboperculum which reaches considerably beyond the 

 root of the pectoral fin, 2f in the total without the caudal. 

 Greatest height of the body or of the head not quite one 

 fourth of the same standard, its least height behind the adipose 

 dorsal 2^ in the greatest. 



Snout almost obliterated by the encroachment of the large 

 eye; it is rounded, with the jaws exactly equal and opposed 

 throughout ; its length is one fourth the diameter of the eye. 



