DICROLENE NIGRA. 151 
Snout short, as long as the eye, thick, broad, blunt, scarcely projecting 
beyond the mouth. Hinder nostril near the eye; anterior as near the lip, 
with a groove down and forward. Mouth large; maxillary not in contact, 
half as long as the head, becoming wider than the eye backward, with 
upper, lower, and hinder edges concave. Teeth sinall, in villiform bands on 
the jaws, in narrower bands which make a short curve inward at the forward 
ends on the palatines, and ina small group below the forward end of the 
vomer. Eye of medium size, as long as the snout or the width of the inter- 
orbital space, two ninths of the head. Gills four, a slit behind the fourth; 
laminz short; rakers stout, longest two thirds as long as the eye, four on 
the upper and ten to twelve on the lower section of the first arch. Gill 
openings wide; membranes not united, free from the isthmus. Eight 
branchidstegal rays. No pseudobranchiz. No barbels. Opercle with a 
slender horizontal spine at the upper angle, three fourths as long as the 
eye; preopercle with three rather short spines, the median little longer, the 
spaces separating them about equal. A small spine above the hinder border 
of each eye. Membranes of dorsal and anal continuous with the base of the 
caudal. Anterior rays of the dorsal a little longer than those of the anal, 
longest ray more than one third of the length of the head, first a trifle back- 
ward of the axil of the pectoral, twentieth nearly above the first anal ray. 
Each ventral of two rays, which are bound together for a short distance at 
the base. Caudal of six rays, slender, acuminate, free from dorsal and anal 
in greater portion of the length. Upper portion of pectorals as long as the 
head ; lower part with six free rays, rarely seven, the longest of which is one 
half longer than those in the fin web, or less than one and one half times as 
long as the head. Scales small, thin, flexible, five or six rows between the 
lateral line and the dorsal fin. Lateral line near the base of the dorsal, dis- 
tinct in the anterior two thirds of the length. In specimens of eighteen 
inches the snout is longer than the eye; the eye is about one fifth of the 
length of the head; the maxillary extends backward of the orbit nearly two 
thirds of the orbital diameter, the hind margin equalling the length of the 
eye, and the lower angle being acute. Five or six pyloric ceca, short and 
thick. Air bladder large. 
Coloration of large individuals black. On the younger ones the bases of 
the fins appear whitish and the muscular tracts reddish brown. 
Readily distinguished from D. jilamentosa by the small number of free 
rays in the pectorals. 
