LAttt) TORTOISES. 145 



In the valuable " Erpetologie " of Messrs. Dume'ril and Bibron 

 the Chelonians are divided into i. Land Tortoises, Chersites. 2. 

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

 Tortoises, or Turtles, Thalassites. 



This arrangement being the most simple, is employed as being 

 best adapted to our purpose. 



LAND 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. 



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

 sentations of them being found on numerous monuments of anti- 

 quity. Moreover, ancient writers tell us that the carapace of the 

 tortoise contributed its substance to the formation of the first lyre \ 

 it was consequently sacred to Mercury as the deity of music and 

 inventor of that instrument. 



The Land Tortoises are divided into four genera, which Dume'ril 

 and Bibron again divide into three sub-genera and thirty species. 

 The most interesting species, however, to which we must limit 

 our remarks are the Marginate Tortoise, Testudo marginata; the 

 Moorish Tortoise, Testudo mauritanica ; the Greek Tortoise, Testudo 

 : and the Elephantine Tortoise, Testudo elephantina. 



The Marginate Tortoise, which was long confounded with the 

 Greek Tortoise, is found abundantly in Egypt. The carapace is 

 oval in form, oblong, convex, and much dilated at the posterior 

 margin, and nearly horizontal ; the plastron is movable behind, which 

 is its chief sub-generic character ; the tail is thick, conical, and 

 scarcely issues from the carapace. The plates of the disc are of a 

 blackish-brown, presenting towards the centre certain spots of a 

 beautiful yellow colour ; the marginal plates are habitually orna- 

 mented with two triangular spots, one yellow, the other black. The 

 under part of the body is of a dirty yellow, with one large triangular 

 black spot upon six or eight of the sternal scales. This Tortoise 

 is of a medium size. 



