DIBRANCHUS HYSTRIX. 93 



by ridges; nostrils small, anterior with a short tube, posterior transverse 

 and larger. Eye large, as long as the snout ; length less than the inter- 

 orbital width. Crown slightly convex; interorbital space wide, concave, 

 width equal to one and two thirds times the length of the snout. Mouth 

 large, width equal to more than the distance across the 'orbits, more 

 than one third of the widtli of the head, or contained one and one half 

 times in the distance from snout to nape. Teeth in villlfonii bands 

 on jaws and tongue, absent from vomer and jialatines. Two gills, none 

 on first arch ; rakers short, rounded, tubercular, four on the first arch 

 and five in front of the second ; apertures medium, placed superiorly 

 in the axilla?. Subopercular tubercle strong, bent inward, bearing five 

 spines, end tricuspid, one of the terminal cusps extending forward, one 

 upward, and the longest one backward. Skin soft, thin ; bones less 

 firm than those of D. atlantlcus. Tubercles mostly simple with long 

 slender cusps and spreading striate bases, not closely placed, mixed with 

 comparatively few small scales. As if to aid in locomotion some of 

 the tubercles along the lower side of the edge of the disk are two 

 to three cusped. Spinules such as appear on the bases of the tubercles 

 on other species are not present. The strongest tubercles are in two 

 series on the top of the tail, and in those at the sides of the disk. 

 Small spines are loosely scattered over the ventral surface, and a few 

 are seen on the tops of the orbits. The erect spines around the edge 

 of the rostrum are comparatively large. Lateral line distinct, with deep 

 channels, agreeing with the other species of the genus in regard to 

 the forward position of the second papilla from the symphysis of the lower 

 jaws, in the dermal flaps, and in the protecting spines at the sides of 

 the papillse. 



Fins small ; dorsal origin midway from occiput to base of caudal, 

 or midway from front of orbit to end of caudal ; anal small, slender, 

 origin the length of the maxilla farther backward than the origin of the 

 dorsal ; caudal narrow, length about four fifths of the distance from snout 

 to occiput, hind margin rounded ; pectorals rounded, fringed, shorter than 

 the caudal; ventrals narrow, about as long as the maxilla. 



Color a rich dark chestnut to chocolate brown ; fins black. 



