zoo ANIMAL LIFE PAST AND PRESENT. 



Tortoises and turtles, or, as it is frequently con- 

 venient to call them, Chelonians (from the Greek name 

 of one species), are, however, in reality a very remark- 

 able group, or order, of the great class of Eeptiles ; 

 and their structure is so peculiar and interesting that 

 a short glance at some of their chief features cannot 

 fail to be instructive. We are, indeed, accustomed to 

 regard many extinct groups of reptiles, like the Fish- 

 Lizards,* as more bizarre and strange than any which 

 now inhabit the globe ; but if we were to be made 

 acquainted for the first time with tortoises from their 

 fossil remains, we should certainly consider them as 

 far more extraordinary than any other types; and it 

 is highly probable that the palaeontologist who first 

 made known such a remarkable type of reptilian 

 structure would be charged with* having created a 

 totally impossible monster. 



The most striking and peculiar feature about tortoises 

 and turtles is the more or less complete bony shell 

 with which their body is protected, on, account of 

 which they are noticed in the chapter on " Mail- Clad 

 Animals." The accompanying woodcut (Fig. 27) ex- 

 hibits a typical Chelonian, as exemplified by a land- 

 tortoise. In this creature we see a fully developed 

 bony shell, within which the head, limbs, and tail can 

 be retracted, so as to afford a perfect protection for 

 the entire animal. We have said that the shell of the 

 tortoise is a bony one ; but it will probably be at once 

 objected that the " tortoise-shell " of commerce is about 



* See Chapter V. 



