94 DEEP SEA FISHES. 



Dibranchus scaber sp. n. 



Plate XXIV. 



Br. r. 6; D. 6; A. 4; V. 6; P. 13; C. 9. 



This species resembles Dibranchus hyslrir, PI. 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 bi'oader. 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 

 axilloB, 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. hjstrix or any other species of the 

 geniis. The skin is more firm than that of D. hi/strix 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 



