MARSH TORTOISES. 



149 



beak is notched with a strong tooth on each side, producing the 

 appearance of a beak closely resembling that of birds of prey. 



The Mud Tortoises (Cistudo europcea, Fig. 34), sometimes called 

 the Yellow Tortoises, are very abundant in Europe. They are found 

 in Greece, Italy, Spain, Portugal, and in the southern provinces of 

 France ; also in Hungary, Germany, and as far north as Prussia. 

 They inhabit lakes, marshes, and ponds, at the bottom of which they 

 bury themselves in the mud. They live principally upon insects, 

 molluscs, aquatic worms, and small fishes. Although the flesh of 



Fig. 35. — Box Tortoise. 



the Mud Tortoise is far from being palatable, it is nevertheless eaten 

 in countries where they are common. 



The Emydes are divided into four considerable groups — namely, 

 the European group, of which the Box Tortoise (Fig. 35) is typical; 

 the American group, containing twelve or fourteen species, of which 

 the justly celebrated Diamond-backed Terrapin is one ; the African, 

 seven species ; and Oriental group, about twelve species. 



The Plenroderes have the neck retractile on one side of the 

 carapace, without their having the power of drawing it between their 

 fore feet, and under the buckler and plastron, like the Cryptoderes. 

 The Bearded Tortoise ( Chdys \niatamata, Fig. 36), belongs to this 



