94 DEEP SEA FISHES. 
Dibranchus scaber sp. n. 
Plate XXIV. 
Br. 163 D.G; As 4s VEG Bs 135.C. 9. 
This species resembles Dibranchus hystrix, Pl. XXIII., more than any 
other of the known species of the genus, yet the differences are so marked 
as to render it an easy matter to distinguish the one from the other. 
D. scaber has more uniform, smaller sized, shorter cusped, and more numer- 
ous tubercles on the back, the rostrum is shorter and the notches are not so 
deeply incised above the nostrils, and the spines on its extremity are differ- 
ently arranged, and the snout and the anteorbital space are broader. Body 
and head depressed, together forming a disk nearly as wide and one third as 
deep as long, narrower forward. Head as wide as long, slightly convex 
behind the eyes on the crown, concave forward; interorbital width nearly 
twice the length of the snout. Tail narrow, round, slender, tapering. 
Snout short, two thirds as long as the orbit, blunt, extending little forward 
of the lower jaw; rostrum broad, concave on the top with a strong ridge 
around the upper edge, separated from the supranarial prominence by 
a shallow notch from which a groove extends backward, excavated below 
in a recess for the trilobed protractile illicium. Nostrils small; anterior 
smaller with a short tube; posterior transversely oblong. Eye large, 
orbital length and width of interorbital space equal. Mouth hardly as wide 
as that of Dibranchus hystrix, oblique, width equal to three fifths of the 
distance from snout to nape. Teeth in villiform bands on jaws and tongue, 
absent from vomer and palatines. Two gills, none on the first arch; rakers 
very short, thick, blunt, six on the first arch and the same number on the 
front edge of the second; openings medium, situated superiorly in the 
axilla, near the hind edge of the disk. Subopercular tubercle with four 
spines, the compressed hinder portion of the tubercle having only two, the 
anterior one of which is directed inward and very little forward and the 
posterior one backward and very little outward. This process makes 
a ready mark of distinction from D. hystrix or any other species of the 
genus. The skin is more firm than that of D. hystrix and the bones are 
more rigid. The tubercles on the skin are rather small, close together, and 
have short cusps and spreading striate bases; those of the tail are larger, as 
also those at the edges of the disk where, along the operculum, some 
