158 CHELONIANS. 



Museum Catalogue, who makes them the third order of Eeptiles 

 in his arrangement as follows : — 



I. TESTTJDmiDiE. 



Testudo, Chersina, Kinixys, Pyxis. 



II. Emydid^. 



Geoemyda, Emys, Cyclemys, Malaclemys, Cistudo, Kinosternon, 

 Chelydra, Platystemum. 



in. CHELYDID-a:. 



Sternotlierus, Pelomedusa, Hydraspis, Chelymys, Phiynops, Chelodina, 

 Hydromedusa, Chelys, Peltocephalus, Padocnemis. 



rV. TEiONYCin^. 

 Trionyx, Emyda. 



V. Cheloniad^. 

 Sphargis, Chelonia, Caretta, Casuana. 



In the valuable " Erpetologie " of Messrs. Dumeril and BIbron, 

 the Chelonians are divided into — 1, Land Tortoises, Chersites ; 2, 

 Marsh Tortoises, Elodites ; 3, River Tortoises, Potamites ; 4, Sea 

 Tortoises, or Turtles, Tkalassites. 



This arrangement being the most simple, is adopted as best 

 adapted to our purpose.] 



Lakd Tortoises. 



Terrestrial Tortoises are distinguished by their short, oval, and 

 convex bodies, covered by carapace and plastron ; four feet, and 

 the absence .of teeth ; short, stumpy, unshapely legs ; nearly equal 

 toes, armed with claws, united by a thick skin, so as to form a 

 clumsy foot, the periphery of which forms a sort of hoof, which 

 seems adapted for the land. 



In this group the carapace is very convex, its height sometimes 

 exceeding its breadth ; it forms a solid, generally an immovable, 

 arch, under which the animal can completely conceal its feet and 

 tail. This buckler is covered with large horny plates or scales. 



Land Tortoises have been known from the earliest times, repre- 

 sentations of them being found on numerous monuments of anti- 

 quity, the product of ancient art. Moreover, ancient writers tell 



