118 CLASSIFICATION OP AMPHIBIANS. 



inch long ; yet the toes^ the claws^ and the shelly resem- 

 ble those of the Chelidridcs. Such are the prominent 

 distinctions of the families of chelonian reptiles ; to enter 

 into the different generic characters wUl in this place be 

 unnecessary^ since they will be found in the systematic 

 arrangement of the work. 



(120.) The analogies resulting from the series in 

 which we have aiTanged these animals are highly curious, 

 since we thus find representations not only of the pri- 

 mary divisions of the whole class^ but of many other 

 groups of animals^ whose affinities are yet regulated by the 

 same laws. Some of these we shall now glance at. The 

 Testudinidce, or land tortoises^ from the peculiar shape^ 

 hardness^ beautiful regularity, and highly-finished work- 

 manship of their shells, evince the greatest perfection 

 of that structure which nature has given to this order 

 o/ reptiles. Like all other typical groups of animals, 

 they are completely terrestrial, and in their slowness of 

 motion, powers of abstinence, and tenacity of life, 

 show the least affinity of aU others of their race to 

 the neighbouring groups. "We look, therefore, upon 

 this family as the most typical of the chelonians ; and 

 we place them opposite to the Ophides, or serpents, 

 these latter being unquestionably typical of the entire 

 class of Reptilia. The Emydce, or freshwater tortoises, 

 stand next in the series : these, like the lizards, are 

 remarkably active in their movements, and it is in these 

 two analogous groups, also, that the greatest variations, 

 or, in other words, the greatest nmnber of genera, are 

 to be found. The long-tailed, or alligator-tortoises, 

 forming om- Chelidridce, have hitherto been classed 

 with the Emydce, just in the same manner as many 

 authors, even to this day, continue to unite the crocodiles 



sembling those of a carp, but stronger and thicker ; yet that the under 

 parts are soft and smooth. Bontius says he had two of these animals, one 

 of which he kept for some time in water ; that it inhabits the rivers of 

 Java, and burrows in its banks to deposit its eggs. The head is small like 

 that of a snake, with small moveable eyes and sharp teeth. I have no 

 doubt but that this refers to some animal still more closely connecting the 

 tortoises to the crocodiles than even the Chelidra serpentina. 



