48 CHONDKOPTERYGII. BATOTDEI. 



Family V. TRYGONID^E. 



Disk wide ; the pectorals continued to the extremity of the 

 snout, where they become confluent. Tail long and slender, without 

 any lateral folds. Vertical fins, if present, imperfectly developed, 

 or they may be modified into a serrated spine. 



The forms with armed tails, generally termed " sting rays," 

 occasion exceedingly dangerous injuries, not merely owing to the 

 jagged nature of the caudal spines, but apparently also to the 

 presence of some irritating foreign substance, which is carried into 

 the wound. 



Geographical Distribution. Tropical and temperate seas. 



Synopsis of Indian Genera. 



Tail long and spineless. Body densely covered with 



tubercles 1. UROGYMNUS. 



Tail long, armed with a serrated spine. Teeth flattened 2. TRYGON. 



Tail long, armed with a serrated spine, and having a 

 broad lower cutaneous fold continued to its termi- 

 nation 3. T^ENIURA. 



Body very broad, tail very short and armed with a 

 serrated spine. Teeth with from one to three 

 cusps 4. PTEROPLATEA. 



1. Genus UROGYMNUS, Miiller & Henle. 

 Syn. Anacanthus, Ehren. ; Rhachinotus, Cantor. 



Disk subcircular ; tail long and distinct, destitute of any spine, 

 but with a narrow inferior fold ; pectorals united anteriorly. Teeth 

 flattened. Body covered with osseous tubercles, amongst which 

 are sharp conical spines. 



Geoywipliical Distribution. From the Red Sea and east coast of 

 Africa, throughout the seas of India to the Malay Archipelago. 



51. (1.) Urogymmis asperrimus. 



Raja asperrima, Bl. Schn. Syst. Ich. p. 307. 



Urogymnus asperrimus, -Day, Fish. India, p. 730, pi. cxcv, fig. 1 (see 

 synon.). 



Moollan tiriki, Tarn. 



Disk nearly as wide as long ; snout scarcely projecting. Body 

 densely covered with small heart-shaped scales, between which are 

 numerous thorns which are generally erect, and are continued pos- 

 teriorly to the first fifth of the tail, where they cease. On the 

 pectoral fins are numerous small conical spines, irrespective of 

 those over the body amongst the tubercles. Colour greenish 

 above, white beneath. 



