STING RAYS. 



47 



species are inhabitants of fresh water. The large specimen (130) 

 in the middle of the case is Trygon sephen, from India ; near it 

 are shown the tail-spine of Tnjgon walga (132), also from India, 

 and the jaws of Trygon thalassia (131). Hanging from the side 



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Fig. 25. — A Sting Ray, Trygon uarnak. 



rail at the other end of the Gallery, opposite Wall-cases 13 and 14, 

 are two other Sting Kays, Trygon brevicaudata and Trygon 

 tuberculata. Belonging also to the family are Urogymnus asper- 

 rimus, 135, with densely crowded calcareous tubercles in the 

 middle of the back, Taniura lymrna, 137, with a row of spines 

 along the middle of the back, and the Butterfly Bay, Pteroplatea 

 micrura, 138, with a disc twice as broad as long, and with a short, 

 thin tail. 



The Trygonidse do not lay eggs as do the Skates ; the young 

 complete their early development within the body of the mother, 



