igoç.] N. AnnandaIvE : Report on the Batoidei. 25 



Colour of the dorsal surface of the young brownish slate-colour without spots, the 

 tail being banded with black and white ; the edge of the pectorals pale. As the 

 fish grows, the colour darkens to a warm brown, and large, round, widely separated 

 cream-coloured spots appear on the posterior part of the disk and on the pelvic fins. 

 In still older specimens the ground colour darkens considerably, the cream-coloured 

 spots become obsolete, and the banding on the tail disappears. 

 The skin is tough as in T. uarnak, but the arrangement of the denticles is quite differ- 

 ent, at any rate in the adult. In the young they resemble those of the adult of 

 T. uarnak, except that none of them have stellate bases or spiny processes. In 

 adult and half-grown fish, however, they form a compact pavement-like surface, 

 which occupies the middle of the disk from the head backwards and has well- 

 defined limits, towards which they are little smaller than they are elsewhere. The 

 outline of this surface resembles a wine-glass or flower-vase with the mouth 

 directed forwards. On the tail this figure is continued, representing here the stem 

 of the vase; but it ends, in front of the serrated spine, in a point. The denticles are 

 confined to the dorsal surface of the base of the tail and do not extend either to 

 the ventral surface of the basal part or beyond the spine on the dorsal surface. 

 Mouth. — The central part of both jaws is practically straight, but on either side of it 

 on the upper jaw there is a distinct concavity, corresponding to a similar convexity 

 of the lower jaw. The teeth are nearly white ; a single stout transverse ridge 

 runs across the centre of each (unworn) tooth, separating two equal convex sur- 

 faces, each of which is strongly corrugated longitudinally. There are normally 

 four processes on the floor of the mouth as in T. uarnak, but the two central ones 

 are much stouter than the lateral ones and somewhat widely separated from them . 

 Although I have not been able to examine so large a series of this species as I have 

 been able to examine in the case of T. uarnak, I have seen a considerable number of 

 specimens. T. gerrardi is well represented in the collection of the Indian Museum and is 

 commonly sold in the Burmese coastal markets during the winter months. A consider- 

 able number of specimens was taken off the coasts of Burma , Chittagong and Orissa by 

 the ' ' Golden Crown ' ' in the late summer and autumn of last year and in the winter 

 of this. Apparently the species is only taken in shallow water, at an}^ rate in 

 winter. 



Trygon favus, sp. nov. (PI. i, fig. 3 ; pi. iii, fig. 10.) 



Closely alhed to T. uarnak , from which it may be distinguished by the following 

 characters : — 



Size moderately large (type ( 2 ) 130 cm. across the disk). 

 Disk very flat, with the pectoral fins even more broadly rounded than in T. uarnak, 



and the snout somewhat more produced ; its length about 3f in the total length 



of the disk. Eyes widely separated, small. 

 Tail rather less than twice as long as the disk. 

 Colour.— Dors2i\ surface very dark brown with a bold reticulation of dull yellow, 



which becomes less regular on the fore part of the disk than it is on the hind part. 



