RHINOBATUS ACUTUS. 273 



Rhinobatus granulalus Cuv., 1829, Reg. anim., 2, p. 396; Muller & Henle, 1841, Plagios., p. 117, 

 pi. 38; Blyth, 1860, Journ. Asiat. soc. Bengal, 29, p. 36; Dum^ril, 1865, Elasm., p. 493; GilNTH., 

 1870, Cat. fishes Brit, mus., 8, p. 443 (part); Day, 1878, Ind. fishes, p. 732 (part), pi. 192, f. 2; 

 Annandale, 1909, Mem. Ind. mus., 2, p. 14. 



Rhinobatus typus E. T. Bennett, 1830, Mem. Raffles, p. 694. 



Snout long, pointed, length more than half the length of the disk, or about 

 two thirds of the width of the latter, angled from the orbits in about 50°. Crown 

 flattened, width one fourth of the distance from the mouth to the end of the 

 snout. Rostral cartilage strong, tapering, slender forward; ridges narrowly 

 separated by the fontanel and confluent in the anterior half of their length. Nos- 

 trils of greater width than the internarial space. Width of mouth two fifths 

 of length of snout. Spiracles with two folds. Dorsals sharp angled above, con- 

 cave behind; base of first dorsal two fifths of its distance from the bases of the 

 ventrals, or half the distance from the second dorsal. Second dorsal Uttle longer. 

 Middle of back and top of head with enlarged, coarse, rough scales. Compressed, 

 backward-directed tubercles in a vertebral series, on the shoulders and around 

 the orbits. 



Greenish gray; lower surfaces, and sides of snout, white. 



Off coasts of India. 



Rhinobatus acutus. 



Plate 17b, fig. 1-2. 

 Rhinobatus acutus Garman, 1908, Bull. M. C. Z., 51, p. 253. 



In a fifteen inch specimen the length of the snout is contained twice in the 

 length of the disk, and one and two sevenths times in the width. Crown con- 

 vex across the middle, edges slightly prominent. Snout long, slender, pointed, 

 angled from opposite the orbits about 45°. Rostral cartilage strong, tapering to 

 the end; rostral ridges moderately separated by the fontanel, confluent and 

 straighter forward. Width of nostril three fourths of that of the internarial 

 space; anterior nasal valve feebly developed, inner section hardly reaching one 

 third of the distance from the lobe to the inner edge of the nostril, end very 

 slightly turned forward; posterior valve with slight expanse in either outer or 

 inner sections. Mouth nearly straight, in width about one third of the length 

 of the snout. Eyes small. Spiracles as large as the eyes, with two rudimentary 

 folds. Dorsals subequal, posterior borders concave, base of first dorsal one 

 third of its distance from the bases of the ventrals, or less than half of the dis- 

 tance between it and the second dorsal. Scales minute on the fins, larger on 



