TURTLES AND TORTOISES 5 



Family Ch.elonid.ee. Sea Turtles. 

 Genus Chelonia; 2 species; tropical and semi-tropical seas. 

 Genus Thalassochelys; 2 species; tropical and semi-tropical seas. 



Superfamily Pleurodira. 



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



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



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

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

 Madagascar — 1. 



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

 — jGenus Hydromedusa; 2 species; semi-aquatic; South America. 

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

 -» Genus Rhinemys; 1 species; semi-aquatic; South America. 

 _^» Genus Hydrastis; 7 species; semi-aquatic; South America. 

 ^Genus Platemys; 2 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 Cyclanorbis; 2 species; Africa. 



Resume": 



Number of Families 11 



Number of Genera 52 



Number of Species 224 



Family Sphargidce: The sole representative of this 

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

 tle, Sphargis coriacea, a strictly marine animal, seems 

 to be the survivor of an ancient group. Externally, it 

 differs from the few other marine turtles by the tough, 

 leathery covering of the carapace and plastron in place 

 of horny shields ; from this fleshy integument rise seven 

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



