20 Memoirs of the Indian Museum. [Vol. II, 



individuals. The adults of the other species included in Section I of my key grow over 

 2 feet (60 cm.) in diameter, but T. gerrardii does not greatly exceed this limit. 



Trygon microps, Annandale. (PI. iv, fig. i ; pi. ii, figs. 3, ^a; pi. iii, fig. i.) 

 T. microps, Annandale, Rec. Ind. Mus., ii, p. 393, pi. xxvii. 

 Size large {large female over 222 cm. across the disk, large male over igo cm.). 

 Colour white ; the dorsal surface of the disk suffused with rose-pink, without definite 



markings ; tail grey above, becoming darker distally. 

 Disk rhombic, wider than long by more than one-quarter of the width ; the pectoral 

 angles rather greater than right angles. Snout rounded as a whole, but with a 

 small terminal projection which is covered with enlarged denticles. Distance from 

 eyes to tip of snout greater than that from eye to eye ; length of snout 3^^ to 4^ 

 in length of disk. 

 Eyes very small, dark in colour, little prominent ; spiracles large, without dorsal flaps, 



their area more than eight times that of the eyes. 

 Tail without cutaneous fins, not longer than disk, consisting of a broad, flat, proximal 

 part about half as long as the disk, and a slender, cylindrical distal part of ap- 

 proximately the same length, a single massive spine borne at the junction of the 

 two parts ; a very low ridge on the ventral surface of the distal part. 

 Skin soft and delicate, without enlarged tubercles on the disk, bearing numerous 

 minute, spiu}^ denticles (pi. ii, figs. 3, 3«), all of which have stellate bases. The 

 denticles larger on the tip of the snout and the region surrounding the eyes and 

 spiracles than elsewhere, sometimes extending to the ventral surface at the edge 

 of the pectoral fins. The proximal part of the tail armed with much larger 

 denticles, which are largest on the sides and only bear very short stellate spines on 

 the ventral surface ; distal part densely clothed with denticles similar to but 

 smaller than those on the sides of the proximal part. 

 Mouth large ; upper jaw undulating slightly, lower jaw practically without undula- 

 tion ; a coarsely digitate cutaneous flap hanging down from the roof of the mouth ; 

 usually five short finger-Hke processes on the floor of the mouth, three in the 

 centre joined together at the base and one at either side (pi. iii, fig. i). Teeth 

 white ; the transverse ridge very conspicuous in the unworn teeth, the part an- 

 terior to it being slightly concave and considerably greater in area than that pos- 

 terior to it, which is convex. 



Two specimens, both females, have been taken by the " Golden Crown," one 

 (the type) off the coast of Chittagong in 17 fathoms in August, and a second, larger 

 specimen off the coast of Orissa in October. In all the specimens examined, the tail 

 looks as though it had been mutilated, but I cannot be quite sure that it is not in its 

 normal condition. The larger specimen gave birth to a young one on board the 

 trawler, but the young one was unfortunately thrown overboard. Owing to a clerical 

 error, which I have been able to rectify by measuring a cast of the type specimen, the 

 tail was represented in my original description of the species as being two feet longer 

 than was actually the case. 



