mVISIONS OF KEPTILIA. 263 



commei'cial imjjorfciuce, as it fuiiiishes the " tortoise-shell " of trade, 

 so lai'gely used in various kinds of oiiiameutal work. 



Fig. 188.-Tbe Hawk's-WU Turtle (Chelone imbrirfta). (Aftcq- Bell.) 



The Sea-tortoises or Turtles have tlie carapace niucli flattened, the 

 legs of uneciual length, in the form of solid tins or oars, the toes 

 being conjoined, and hardly distinct from one another. 



The Marsh, Pond, and River Tortoises are generally fm-nished 

 with webbed feet, and lead an ampliibioiis, send-aquatic existence. 

 The so-called "Soft Tortoises" {Trioni/eiilie) belong here, and are 

 distinguished by the imjierfect condition of the carapace, which is 

 simply covered with a leathery skin. A good example is the Soft- 

 shelled Turtle {T ferox) of the Southern States. Here also belong 

 the Snapping- turtles, so well known in the person of the conraion 

 American species {Chebidra serpentina), and the Terraj)ins (£'//(?/<7i(?<( ), 

 rjf which many forms are found in all parts of the Uniteil States. 

 In tlie curious little Box-tortoise {Cistudo Yirgiiiea) tlie jilasti'on is 

 composed of two movable portions wliicli can be brought into accu- 

 rate apposition with the carapace, thus C(jmpletel3' protecting tlie 

 animal within. 



The Land-toi'toises have slioit legs of neai'ly eipial length, tlie toes 

 little distinct, and imited into a sort of stuin[i, with indistinct, horny 

 claws. Good examples of this group are tlie common Eui-opean 

 Tortoise {Testudo Grceca) and the Tndijin Tortoise {T. Indica), the 

 last attaining a length of over tliree feet. 



