LAND TORTOISES. 33 



17. Tortoises lay eggs with a hard shell, which they deposit 

 in the sand or earth, in some situation exposed to the sun, to 

 cause them to be hatched. The males are generally smaller than 

 the females, and are ordinarily recognised by the plastrum which 

 is slightly concave. The duration of life in these animals is very 

 great : authentic instances are known of land Tortoises that have 

 lived a hundred and twenty years, even two hundred years, and 

 some cases of a still greater age are related. 



18. The habits af these animals vary, and these differences, 

 which coincide with the modifications of their structure, has 

 caused them to be divided into four principal families. Their 

 chief characters may be seen in the following table: 



(Families.) 



f largo, truncate at the end, and formed for "1 

 walking only, and having the toes united in a } LAND TORTOISES. 

 common mass as far as the nails. 



(incomplete. Cara- ") 

 pax furnished with V POND TORTOISES. 

 scales. j 



complete. Carapax 



covered by a soft skin 



M 



RIVER TORTOISES. 



flattened, in the form of large swimming 



paddles, and not having the toes externally }- SEA TORTOISES. 



distinct. 



19. The LAND TORTOISES, Teshido, ( Plate I, fig. 1, and 2.) 

 have feet formed for walking only ; their legs are, as it were, 

 truncate, and their toes are short, and united to the nails ; their 

 number is five in front, and four behind. The carapax is very 

 much vaulted, and they can draw the head, tail, and extremities, 

 completely within their shell. They live in the woods, or in 

 places well furnished with herbage : they never go into the water, 

 but often inhabit its neighborhood. Most of them feed chiefly on 

 vegetables, and terrestrial mollusks. They make a kind of bur- 

 row, and in temperate climates pass the winter in a state of 

 hibernation. Their eggs are generally spherical and furnished 

 with a hard shell ; the female deposites her eggs in a hole, and 

 seems to take no care of her young. The most common Euro- 

 pean species is the Greek Tortoise, Testudo grceca, which is 



17. By what agency are the eggs of Tortoises hatched ? How does the 

 male differ from the female? What is the duration of life in Tortoises ? 



18. How is the order of Tortoises divided? 



19. How is the family of Land Tortoises charade- ised ? What are the 

 habits of Land Tortoises ? Where is the Greek Tortoise found ? 



