TRIONYCHOIDEA 



411 



and below, in younger specimens with conspicuous, large, yellow- 

 spots on the sides of the head. The young are ornamented with 



Fig. 94. — Trionyx formosa (young). x 1. 



two or three pairs of large round spots on the back, and the 

 same applies to the Ijeautiful young of the Burmese, T. formosa. 

 The three genera, Cycloderma and Cyclanor'bis of Tropical 

 Africa, and Emyda of India, have a pair of cutaneous femoral 

 valves or flaps on the plastron, beneath which the hind-limbs 

 are withdrawn. 



