332 



CHELONIA 



region. The Chelydridae, now restricted to North and Central 

 America, occurred formerly also in Europe. The Pleurodira, in 

 Mesozoic times plentiful in Europe, India, and North America, 

 are now restricted to South America, Australia, and Africa ; the 



DERMATEMYDAE. 

 SS TESTUDINIDAE. ; 'M. CINOSTERNIDAE. SSSS CHELYDRIDAE. Bs^: PLATYSTERNIDAE. 



FIG. 70. Geographical distribution of Cryptodirous tortoises. 



Pelomedusidae to Africa, Madagascar, and South America ; the 

 Chelydidae to South America and Australia, In the latter 

 country all the Chelonians belong to the Chelydidae. The Triony- 

 choidea, occurring since the Cretaceous epoch in North America, 

 in Early and Mid-Tertiary times in Europe, are now restricted to 



^= PELOMEDUSIDAE. Illllll CHELYDIDAE. 



FIG. 71. Geographical distribution of Pleurodirous tortoises. 



North America, Asia, and Africa. The country richest in Chelo- 

 nians is America ; North and Central America together possessing 

 representatives of all the families except the Pleurodira, and 

 these we know to have died out there. The Dermatemydidae, 



