96 DEEP SEA FISHES. 



is a considerable amount of individual variation in the number of spines on 

 each tubercle ; this aside, however, the tubercles are of much assistance in 

 the determination of the species of this genus and of allied genera. 



Width of disk equal to the distance from the snout to the gill openings, 

 that is, a little less than twice the length from snout to nape. Crown flat- 

 tened. Snout short, with a deep naked cavity on the top, hardly pro- 

 truding beyond the lower jaws, with a series of five erect tubercles around 

 the outer edge, with a strong antrorse tubercle above the inner edge of 

 each nasal sac, subrostral area deeply excavated for the trilobed protractile 

 illicium, rostrum separated by a very shallow notch from the preorbital 

 ridge. Eyes large, length equal to the widtli of the interorbital space, 

 longer than the snout, orbits convergent forward. Mouth medium, width 

 about four fifths of the distance from snout to nape. Teeth in villiform 

 bands on jaws and tongue, absent from palatines and vomer. Gills two, 

 absent from first and fourth arches ; openings small, placed superiorly in 

 the axillae. Branchiostegal rays six, outer stronger and joined to the 

 opercular bones. Subopercular tubercles strong, with four spines; the 

 anterior pair on the stem, one of them directed obliquely outward and 

 somewhat upward, the other out and downward ; the terminal pair blade- 

 like, one of them directed outward, the other in toward the gill oj^ening. 

 Spines tubercular, strong, unequal, with sharp cusps and broad striate bases, 

 largest on the top and the sides of the tail and along the edges of the di;-k 

 where some have two spines and others three, very small and more separ- 

 ated on the lower surfaces. 



Fins small ; dorsal origin behind the midlength of the disk ; anal origin 

 little backward of the end of the base of the dorsal, fin reaching backward 

 of the bases of the caudal rays ; caudal nearly as long as the skull to the 

 nape, somewhat pointed ; pectorals medium, less than twice as long as the 

 ventrals, fringed. 



Blackish externally and on the linings of the body cavity. 



station. Latitude. Longitude. Depth. Temperature. Bottom. 



3418 ; 16° 33' N. ; 99° 52' 30" W. ; 660 fathoms ; 39° F. ; Br. S. bk. Sp. 



DiBRANCiioPSis gen. n. 



A Dibranchoid in which the skeleton has degenerated to become semi- 

 cartilaginous, in which the subopercular process and spines and those of the 

 rosti'al angle are obsolescent or obsolete, obsolescent in young, obsolete in 



