1 88 THE OSTEOLOGY OF THE REPTILES 



highly speciahzed species, the astragalo-calcaneum and the large, 

 hemispherical fourth tarsale, articulating together enarthrodially, 

 around which all the short metatarsals closely articulate in two 

 groups of two and three. 



G 



Fig. 154. Limbs and feet of Chelonia. Natural size. A, Chrysemys, hind leg from post- 

 axial side. B, Chrysemys, front foot, dorsal side. C, Chelydra, hind foot, dorsal side. 

 D, Cistudo, hind foot, dorsal side. E, Podocnemys, left hind leg, postaxial side. F, 

 Podocnemys, right front forearm and foot, dorsal side. G, Trtonyx, left hind foot, 

 dorsal side. 



