26 Memoirs of the Indian Museum. [Vol II 



A yellow spot or streak in the middle of most of the meshes of the reticula- 

 tion. Ventral surface white. 

 Skin devoid of denticles with stellate bases. 



Mouth large. Jaws as in T. gerrardii. Teeth white ; the transverse ridge feeble even 

 on the unworn teeth. On the floor of the mouth there are two bluntly triangular 

 processes with irregularly serrated margins and joined together by a similarly 

 serrated ridge. 



I have only seen two specimens of this species, both females. They were taken 

 together oft" the coast of Orissa in October by the " Golden Crown." In spite ol 

 their striking coloration I was inclined to regard them as representing a variety of 

 T. uaniak, until I came to examine the interior of their mouths and to analyse the 

 measurements of both forms. Unfortunately only the two mouths and the skin of the 

 back of one specimen could be preserved. One of the mouths, and this piece of skin, 

 therefore, constitute the " type," which is numbered F --f-^ in the registers of the 

 Museum. 



A good photograph of the specimen of which these relics have been kept is given 

 on pi. i, fig. 3. 



Trygon bleekeri, Blyth. (PI. iii, fig. g.) 



T. bleekeri, Day, Fishes of India, vol. ii, p. 738, pi. cxcv, fig. 3 ; Faun. Brit. 

 I lid.. Fishes, p. 54. 



Size fairly large (adults 112 — 119 cm. across the disk). 



Disk slightly broader than long. The snout narrow, acutely pointed, strongly pro- 

 duced, measuring more than 1- of the total length of the disk and twice as long as 

 the distance between the eyes. 

 Colour. — Dorsal surface dark brown, unspotted. \'entral surface in young white with 

 a broad margin of dark brown. As the fish grows, this margin becomes broader 

 and finally occupies nearly the whole of the disk. In some adult specimens a dis- 

 tinct streak remains in the middle of the disk ; in others this is more or less 

 obscured by dark blotches or disappears almost completeh'. There are no pale 

 rings on the tail. 

 Skin. — The scales closely resemble those of T. gerrardii in structure and arrangement. 

 Mouth. — Jaws distinctly undulated, the central part of the upper jaw forming a 

 narrow, conical downward projection, and the lower jaw having a corresponding 

 concavity in the middle. Teeth dark reddish brown, having a single transverse 

 ridge, which is very distinct on the unworn teeth and divides them into two 

 equal convex surfaces marked with longitudinal corrugations. On the floor of 

 the mouth there are two long finger-like processes nearer one another than either 

 is to the angle of the mouth but rather widely separated (pi. iii, fig. Q)- 

 This species is allied to T. gerrardii (which it resembles in the nature and arrange- 

 ments of its denticles very closely) even more nearly than it is to T. uaniak. As re- 

 gards the processes in the mouth the latter species seems to be at one extreme of a 

 series of which T. bteckeri is at the other. 



