1909-] ^- Annandai^e : Report on the Batoidei. 31 



Mouth rather small ; the lower jaw more distinctly undulated than the upper, which 

 is nearly straight. Teeth faintly tinged with brown. The unworn teeth are dis- 

 tinctly but minutely ridged longitudinally ; the transverse ridge is strong, and 

 there is a well-marked concavity on the surface in front of it. There are two 

 short processes on the floor of the mouth, one situated near each angle. 



Skin. — The skin is delicate, but not so soft as in T. microps. The head and the centre 

 of the back are covered with closely set, rounded, almost fiat denticles, which 

 on the tail are intermixed with stellate spines. On the back the denticles become 



Fig. 5. — Trygon marginatus , d, x c. ■^\. (From stuffed specimen.) 



gradually smaller from the middle outwards and do not form a clearly defined figure 

 on the area they occupy. Externally, on either side, some of them have stellate 

 bases — a character which becomes more marked as regards those that occur on 

 the pectoral fins, on which they show a tendency to be arranged in longitudinal 

 lines. They extend to the margin and sometimes over it on to the ventral surface. 

 This description is based on a large male taken by the ' ' Golden Crown ' ' in Octo- 

 ber off the coast of Burma and a still larger female captured in March off the coast of 



