170 REFT1LIA. 



but little nourishment, and can pass whole months and even years without 

 eating. 



The chelonia were all united in the genus- 



TKSTUDO, Linnaeus. 



They have since been divided into five subgenera, chiefly from the forms 

 and teguments of their shell and of their feet. 



TESTUDO, Brongniart. 



The Land Tortoises have the shell arched and supported by a solid bony 

 frame, most of its lateral edges being soldered to the 

 sternum ; the legs, as if truncated, with very short toes, 

 which are closely joined as far as the nails, all susceptible 

 of being withdrawn between the bucklers ; there are five 

 nails to the fore feet, the hind ones have four, all stout 

 and conical. Several species live on vegetable food. 



K.MYS, Brongniart. 



The Fresh-water Tortoises have no other constant characters by which 

 they can be distinguished from the preceding ones, than the greater sepa- 

 ration of the toes, which are terminated by longer nails, and the intervals 

 occupied by membranes ; even in this respect there are shades of difference. 

 They likewise have five nails before and four behind. The form of their 

 feet renders their habits more aquatic. Most of them feed on insects, small 

 fishes, &c. Their envelope is generally more flattened than that of the land 

 tortoises. 



Among the fresh-water Tortoises we should remark THE BOX-TORTOISES, 

 the sternum of which is divided by a moveable articulation into two lids, 

 which, when the head and limbs are withdrawn, completely encase the animal 

 in its shell 



CHELONIA, Brongniart. 



The envelope of the Sea Tortoises is too small to receive their head, and 

 particularly their feet, which are very long (the anterior 

 ones most so), and flattened into fins. The toes are all 

 closely united in the same membrane, the two first ones of 

 each being alone furnished with pointed nails, one or other 

 of which at a certain age is usually lost The pieces of 

 their sternum do not form a continuous plate, but are variously notched, leaving 

 considerable intervals which are filled with cartilage only. The ribs are 

 narrowed and separated from each other at their external extremities; the 

 circumference of the shell, however, is surrounded with a circle of pieces cor- 

 responding to the ribs of the sternum. 



Test, mydas, Lin. (The' Green Tortoise.) Is distinguished by its greenish 

 plates, thirteen in number, which are not arranged like tiles ; those of the 

 middle range are almost regular hexagons. It is found from six to seven feet 



