TBYGONLIXE. 55 



60. (9.) Trygon walga. 



Try gi m walga, Milll. $ Henle, Plagios. p. 159, t. li; Day, Fish. 

 India, p. 738, pi. cxciv, fig. 3 (see syncm.). 



Isacurrah tenkee, Tenkee shindraki, Tel. 



Disk about as broad as long, with the snout pointed and acutely 

 projecting, more so in some examples than in others. Eyes smaller 

 in the adult than in the young. Interorbital space concave. 

 Teeth small, having a transverse elevated ridge along each. Dental 

 laminae undulated. Fiiis no cutaneous folds on the tail, the length 

 of which is rather longer than the disk. One or two (sometimes 

 more) large serrated spines on the tail at the commencement of its 

 second third ; between this and the base of the tail exists a median 

 line of about seven short spines. Scales interorbital space, and a 

 varying width along the middle of the back and also on the tail 

 covered with numerous fine tubercles ; there are usually no larger 

 ones, but in some examples there is one larger on the centre of the 

 shoulder, in others a few more anterior to it. Neither the number, 

 size, character, nor extent of the distribution of the tubercles and 

 spines depends on age or sex, adults even may be without any of 

 either. In one example (a male) the band of tubercles along the 

 back is very narrow, a row of large ones exists in the median line 

 of the scapular region, and four along the back of the tail. This 

 would be intermediate between T. wcilya and T. polylepis. Another 

 example has a row of small spines all along the first third of the 

 back of the tail, and a moderately sized, rather compressed median 

 scapular spine with six smaller ones anterior to it ; a very wide 

 band of tubercles exists along the back. One example has the 

 smaller caudal spine very well developed, a very narrow row of 

 tubercles along the back, and a central scapular tubercle. Another 

 has only a few small tubercles and one central spine in the scapular 

 region, some between the eyes, and some fine spines between the 

 base of the tail and the two large spines. Young examples are 

 often destitute of tubercles or armature except the caudal spines, 

 and this immature character may be seen in some adults. Colour 

 dull grey or brown superiorly, white beneath. 



Blyth has observed that the males are larger than the females and 

 have proportionately longer tails ; very commonly the second caudal 

 spine (more especially of the females) does not extend beyond the 

 first one. Some have a small lauceolated tubercle on the centre of 

 the dorsal surface, others two or more, even to a series of five or 

 six along the median line. 



Hob. From the Bed Sea, through the seas of India to the Malay 

 Archipelago. 



3. Genus TJENIURA, Mull. & Henle. 



Disk oval or rhomboidal ; tail elongated and tapering. Nasal 

 valves coalescent, forming a quadrangular flap. Pectoral fins 

 united anteriorly ; tail with a broad lower cutaneous fold continued 



