221 
of the Bay of Bengal. 
except at the extreme anterior limit, its place being taken by 
a long elastic muscular band which extends from the tip of 
the hyoid to the inner surface of the mandibular symphysis ; 
the mouth-cleft and the gill-cleft being thus continuous 
beneath almost divide the head from the rest of the body; 
the lower jaw projects beyond the upper. Teeth, everywhere 
except in the maxilla, in the form of slender acute rigid 
fangs ; in each premaxilla laterally eight or nine, with three 
remote stouter ones at the symphysis ; in each half of the 
mandible laterally an uneven row of over twenty, with five 
(one median flanked on each side by a pair) of superior 
size at the symphysis ; in each palatine a row of seven or 
eight, increasing in size from before backwards, and a patch 
on the upper pharyngeal bones ; maxillary teeth in the form 
of even, close-set, recurved serrations, of which there are over 
thirty in each bone. 
Gill-cleft extremely wide and oblique, its antero-superior 
limit being above the middle of the eye ; gill-cover reduced 
apparently to a narrow straight preoperculum, very obliquely 
articulated, furnished with a narrow membranous fringe ; 
four branchial arches, extremely weak and flexible, bearing 
very narrow laminae ; gill-rakers rudimentary. 
Body scaleless. Skin thick, soft, velvety, and uniformly 
covered with adherent tenacious mucus ; apparently no lateral 
line. Besides the large luminous glands already described, 
there are two regular rows of minute luminous organs along 
the ventral half of the body on each side : the upper, num- 
bering about fifty, extending from the gill-opening to the base 
of the caudal ; the lower, numbering about forty, skirting the 
ventral profile from the isthmus to the fifth anal ray ; a few 
similar luminous organs on the crown of the head. 
The dorsal fin begins slightly in advance of the posterior 
fifth of the body, and is equal and opposite to the anal. The 
longest (central) anal rays are a little longer than the corre- 
sponding dorsal rays, and are equal to the depth of the tail 
at their point of origin. The caudal is deeply forked, with 
the lower lobe the broader and longer and about of the 
total length. 
Pectorals absent. The ventrals arise in the anterior half 
of the body, their point of origin being 1 J times as far from 
the vent as from the margin of the gill-cleft ; the two outer 
rays are thickened, coherent throughout, and prolonged, their 
length being two fifths of the total length including the 
caudal ; the inner rays are short and weak. 
Stomach siphonal, its cul-de-sac extending halfway along 
the abdominal cavity ; intestine straight, opening at the 
