CHAPTER III 



TORTOISES, TURTLES, AND PLESIOSAURS 

 ORDERS CHELONIA AND SAUROPTERYGIA 



AMONG all existing reptiles the most easily defined are those commonly known 

 as tortoises and turtles, and technically as Chelonians, since the presence of a more 

 or less fully-developed bony shell investing the body, and containing within it the 

 upper portions of the limbs, at once separates them from all other members of the 

 class. Indeed, so utterly strange is the confirmation of these extraordinary 



UPPER SHEI.I, OF THE CHAIBASSA TERRAPIN, AND A FOSSII< SPECIMEN OF THE SAME IN WHICH 

 THE HORNY SHIELDS ARE WANTING. 



reptiles, that if they were met with only in the fossil state they would inevitably be 

 regarded as among the most marvelous of all creatures. Here however, as else- 

 where, the time-honored proverb holds good, and our very familiarity from child- 

 hood, with the common European land tortoise undoubtedly tends to render us 

 inappreciative of the marvelous bodily confirmation of this group of reptiles. 



Although the presence of a bony shell is of itself sufficient to distinguish the 

 group from other living reptiles, it is necessary to add somewhat to this in order to 



(2399) 



