DIVISION'S OF i;epttlia. 



275 



were gigantic niEirine Reptilts, cliiefly characteristic of the lormatioiis known 

 as the Lias and Oolites. As regards tlie liabits of the l^lesio^aurifs, hr Cony- 

 teare concludes : " That it was aquatic is evi<lent from the form of its paddles ; 

 that it was marine is almost eipially so from the remains with which it is uni- 

 versally associated ; that it may have occasionally visited the shore, the resem- 

 blance of its extremities to those of the Turtle may lead us to conjecture ; its 

 movements, however, must liave been very awkward on land ; and its long neck 

 must have impeded its progress through the water, presenting a striking con- 

 trast to the organisation wliich so admirably lits the Ichthyosaurus to cut 



through the waves." As its breathing-organs are such that it must of neces- 

 sity have required to obtain air frequently, it may be inferred " that it swam 

 upon or near the surface, arching back its long neck like a ^wan, and occasiun- 

 ally darting it down at the fish wliich hapjiened to lloat witliin its reach. It 

 may perhaps have lurked in shoal-water along the coast, cuncealed amongst 

 the sea-weed, and, raising its nostrils to a level with the suiiaee from a con- 

 siderable depth, may have found a secure retreat fn.nn the assaults of powerful 

 enemies; whilst the length and flexibility of its neck Jiiay have compensated 

 for the want of strength in its jaws and its incaitacity foi- swilt motion through 

 the water." 



(JRDEII VII. PtERoSAURIA. 



The Reptiles of this order are all extinct, and, like those of the preceding 

 orders, are exclusively contined to the Secondary period of geology. The most 

 familiar examples are the so-called Pterodactijles, and the distinguishing char- 

 acters of the order have reference to the fact that they \\'ere all adapted for an 

 aerial life. They present, in fact, an extraordinary combination of the charac- 

 ters of Birds and Reptiles, and they make also some approach to the Mammalian 

 order of the Bats. In the presence of teeth in distinct sockets, and, as we shall 

 see hereafter, in the structure of the fore-limbs, the Pterodactyles ditfer alto- 

 gether from all living birds; and there can be little doubt as to their being 



