RHINOBATUS BLOCHII. 271 



opposite the orbits about 61°, length two and two thirds times the width of the 

 mouth. Rostral cartilage strong, ridges nearly parallel from the fontanel, where 

 the convergence is slight. No fold above the tip of the snout. Nostrils wide, 

 two thirds of the width of the mouth, or one and one half times that of the inter- 

 narial space; anterior valve feebly developed not extending half way from the 

 lobe to the inner edge of the nostril, lobe narrow, pointed; posterior valve about 

 two thirds the width of the nostril, lobe well developed, outer and inner sect inns 

 narrow. Mouth nearly straight, width equal three eighths of the snout length. 

 Spiracle as large as the eye, a prominent outer fold, inner rudimentary. Dorsals 

 small, equal, pointed, concave on the hind margins; base of first less than one 

 third of its distance from the bases of the ventrals, two fifths of that from the 

 second dorsal. Caudal narrow, elongate. From the snout to the axils of the 

 pectorals is about two fifths of the entire length. 



Scales minute, very sharp, smoother and more closely set below the disk. 

 Strong compressed and depressed tubercles in a dorsal row, to the second dorsal, 

 in a pair on each shoulder, outer smaller, in a pair in front of each eye, in a row 

 of smaller ones on each rostral ridge, and in a pair above the end of the snout as 

 in R. lentiginosus. A row of small tubercles above each orbit ends in a larger 

 one above the spiracle. 



Light brownish on the back, lighter at each side of the rostrum, lighter on 

 the lower surface. A blackish blotch beneath the end of the snout. 



Specimen described from Akkra, Ashanti. 



RHINOBATUS BLOCHII. 



Rhinobaius (Syrrhina) blochii Muller & Henle, 1841, Plagios., p. 115, pi. 37, f. 1; Dumeril, 1865, 



Elasm., p. 488. 

 Rhinobaius blochii Gunth., 1S70, Cat. fishes Brit, mus., 8, p. 447. 



Disk subtriangular, snout to ends of bases of pectorals about one third of 

 the total length, nearly as broad as long, margins rounded anteriorly, slightly 

 concave opposite the gill openings. Snout short, blunt, angle from the orbits 

 about 88°, length more than twice the width of the mouth, four times the inter- 

 narial space. Rostral cartilage short, broad at the base; ridges widely sepa- 

 rated, converging regularly. Nostrils as wide as the interspace, more than half 

 as wide as the mouth; outer section of anterior valve feebly developed, lobe 

 short, inner section extended upon the internarial space but not reaching the 

 median line by a distance of half the length of the eye; posterior valve with a 

 small outer section, extended outward beyond the nostril, an elongate lobe and a 



