REPTILIA—TORTOISE. 687 
According to the arrangement of reptiles by M. Brogniart, and followed 
by M. Cuvier, founded upon their organization, and which is adopted in the 
following summary, they are divided as noticed above, into four orders, viz. 
Chelonian reptiles, or tortoises; Saurian reptiles, or lizards; Ophidian rep- 
tiles, or serpents; and Batrachian reptiles, or frogs. 
ORDER I.—CHELONIA. 
Reptixes of this order have a heart with two auricles ; body enveloped in 
two plates or shields formed of the ribs and sternum ; four feet. 
THE WZORTOLS SE. 
TorTotsEs are usually divided into those that live upon land, and those that 
subsist in the water ; and use has made a distinction even in the name, the one 
being called tortoises, the other turtles. However, Seba has proved that all 
tortoises are amphibious; that the land tortoise will live in the water, and 
that the sea turtle can be fed upon land. A land tortoise was brought to 
him, that was caught in one of the canals of Amsterdam, which he kept for 
half a year in his house, where it lived very well contented in both elements. 
‘When in the water, it remained with its head above the surface; when 
placed in the sun, it seemed delighted with its beams, and continued im- 
moveable while it felt their warmth. The difference, therefore, in these 
animals arises rather from their habits than their conformation ; and, upon 
examination, there will be less variety found between them than between 
birds that live upon land and those that swim upon the water. 
All tortoises, in their external form, niuch resemble each other ; their 
outward covering being composed of two great shells, the one laid upen the 
other, and only touching at the edges; however, when we come to look 
closer, we shall find that the upper shell is composed of no less than thirteen 
pieces. There are two holes at either edge of this vaulted body; one fora 
very small head, shoulders, and arms, to peep through; the other at the op- 
posite edge, for the feet and the tail. These shells the animal is never 
disengaged from; and they serve for its defence against every creature but 
man. 
