^4 



Memoirs of the Indian Museum. [Vol. II, 



Rhinobatis granulatus. 

 Rhinobatus granulatus, Gthr., of>. cit., p. 443 ; Day, op. cit., p. 42. 



Snout pointed, variable in length, as a rule from 4I to 5| times in the total length ; 

 the dorsal concavity triangular, narrow. The interval between the nostrils 

 posteriorly not or hardly greater than the length of the nostril ; the anterior nasal 

 valve variable in size, usually small, not produced inwards beyond the limits of 

 the nostril. The two dorsal fins situated considerably behind the posterior margin 

 of the pelvic fins, equal or subequal, separated by rather more than the length of 

 anterior fin. The lower lobe of the caudal rounded, not distinctly marked off 

 from the dorsal lobe. 



The back, the central ridge of the snout and the anterior part of each dorsal fin 

 covered in the adult with somewhat irregular, granular or obtusely pointed, small 

 denticles, which become smaller from the mid-dorsal line outwards. There is a dis- 

 tinct row of sharp retroverted spines extending along the mid-dorsal line from a 

 little behind the spiracles to the anterior dorsal fin, and as a rule there are several 

 similar spines on the anterior margin of the orbit. The lateral fins and the sides 

 of the snout are naked. In the young ( = Rhinobatus philippi, Müller and Henle) 

 there are two sharp, retroverted spines on either shoulder, forming with the 

 slightly enlarged denticles which surround them a line crossing the mid-dorsal 

 line at right angles. On either side of the rostral ridge there is a line of similar 

 spines; the dorsal line extends backwards between the two dorsals. 



The colour of the adult is described by Day as ' ' reddish grey superiorly, becoming dull 

 white beneath." The young is greenish grey on the back ; the snout pure white, 

 with the exception of the central ridge, which is of the same colour as the back. 



The jaws are very feebly undulated, and it is not possible to recognize definite upward 

 and downward projections and corresponding concavities in them. The teeth are 

 small, transversely rhomboid, but with the four angles somewhat rounded. The 

 transverse ridge runs across the tooth near the inner margin and is markedly con- 

 vex in its centre, so that the exposed surface of the tooth as a whole has a tuber- 

 cular appearance. There is no marked difference in the size of the teeth at 

 different points on the jaw. 

 Only one specimen of this species appears to have been taken by the ' ' Golden 



Crown," a young female from off the Orissa coast. There are, however, several other 



specimens in the Museum collection. The largest (stuffed) measures 185 cm. in total 



length. 



Rhinobatis columnœ , Bonaparte. 



Rh. columnae, Bonaparte, Fauna Italica, Pesci, No. 152, plate. 

 ? Rh. horkelii, Müller and Henle, op. cit., p. 122, pi. 41. 

 Snout sharply pointed, about 6| times in the total length ; the 'distance between 

 the outer angles of the nostrils rather more than J and less than f of that 

 between the mouth and the end of the snout. The anterior nasal valve produced 



