TURTLES AND TORTOISES 5 



Family Chelonidw. Sea Turtles. 



Genus C'helonia; 2 species; tropical and semi-tropical seas. 

 Genus ThalassocheUjs ; 3 species; tropical and semi-tropical seas. 



Superfamily Pleurodira. 

 Family Pelomedusida;. Fresh-water Turtles. Old and New World. 

 Genus Sternothcerus; 6 species; semi-aquatic; Africa. 

 Genus Pelomednsa; 1 species; semi-aquatic; Africa. 

 Genus Podocnemis; 7 species; semi-aquatic; South America — 6; 

 Madagascar — 1. 



Family Chelydklw. Fresh-water Turtles. Old and New World. 



Genus Bydromedusa; 2 species; semi-aquatic; South America. 



Genus Chclodina; 4 species; semi-aquatic; Australia; New Guinea. 



Genus Bhineinys; 1 species; semi-aquatic; South America. 



Genus Hydraspis; 7 species; semi-aquatic; South America. 



Genus Platemys; 3 species; semi-aquatic; South America. 



Genus Emydura; 7 species; semi-aquatic; Australia; New Guinea. 



Genus Elyseya; 1 species; semi-aquatic; Australia. 

 Family Carettochelydidce. 



Genus Carettochelys; 1 species; thoroughly aquatic; New Guinea. 



Superfamily Trionychoidea. The Soft-shelled Turtles. Old and New 

 World. 

 Family Trionychidce. All of the species are persistently aquatic. 

 Genus Trionyx; 15 species; No. America; Africa and Asia. 

 Genus Pelochelys; 1 species; East Indies. 

 Genus Chitra; 1 species; East Indies. 

 Genus Cycloderma; 2 species; Africa. 

 Genus Emyda; 3 species; East Indies. 

 Genus Cyclanorbisj 2 species; Africa. 

 Besiime: 



Number of Families 11 



Number of Genera 52 



Number of Species 224 



Family Sphargidcc: The sole representative of this 

 famity, the Leathery Turtle, Luth, or Trunk Tur- 

 tle, Sphargis coiiacea, a strictly marine animal, seems 

 to be the survivor of an ancient group. Externallj^ it 

 differs from the few other marine turtles by the tough, 

 leathery covering of the carapace and plastron in place 

 of hornjr shields ; from this fleshy integument rise seven 

 heavy and bony keels (on the carapace). The reason 



