DIVISIONS OF EEPTILIA. 



239 



thirdly, that the scapular and pelvic arches, supporting respec- 

 tively the fore and hind limbs, are situated within the carapace 

 (Fig. 118, s andjo), so that the shoulder-blade is placed inside 

 the ribs instead of outside, as is usually the case. 



Fis. 118.— Skeleton of a. Tortoise (Jlmys Ewropmi), seen from below, the plastron having 

 been removed, ca Carapace, showing the flattened and expanded ribs ; 8 Scapular 

 arch, carrying the fore-Umbs, and placed in the interior of the carapace; p Pelvic arch, 

 carrying the hind-limbs ; r Eibs. 



The Chelonia are conveniently divided into groups, accord- 

 ing as the limbs are adapted for swimming (natatory), or for 

 progression on land (terrestrial) ; or, again, enable the animal 

 to lead an amphibious life, sometimes on land and sometimes 

 in the water. Of the strictly aquatic forms the best known 

 are the edible Green Turtle ( Chelonia midas) and the Hawk's- 

 bill Turtle {Chelonia imbricatd). The former is found abun- 

 dantly jn many of the seas of warm climates, and is largely 

 imported into Europe as a delicacy. The latter (Fig. 119) is 

 truly a native of warm seas, though an occasional straggler 

 has reached the shores of Britain. It is of comparatively 

 small size — not more than about three feet in length — but is 



