LECTURE VII. 
7 
improper one, though liable to some criticisms. I 
should observe that Linnajus, from a mistaken 
idea, relative to the structure of their gills, which 
he conceived to be accompanied by a kind of 
lungs, admitted into the Amphibia several of the 
Fish tribe, as the Lampreys, the Rays, the Sharks 
and many others, which the more accurate re- 
searches of later naturalists have restored to their 
proper situation. The particular reasons for the 
Linnaean arrangement of them will be explained 
when we arrive at that tribe of animals : at pre- 
sent we . shall confine ourselves to the genuine 
Amphibia. 
Of these the first genus or Tortoise, (Testudo,) 
is characterized by having the body defended by a 
strong bony or horny comring : the mouth without 
teeth, the upper jaw closing over the edges of the 
lower. Tortoises are divided into the land and 
sea-Tortoises, which latter are termed Turtles, 
and have the feet so formed as to bear a sort of 
resemblance to fins : there are also riv-er or fresh- 
water Tortoises. All the land Tortoises have the 
feet divided into toes and furnished with claws ; 
and the river or fresh-water Tortoises have their 
feet more or less webbed. Of the land Tortoises. 
