THE EMYDOSA.UBES OB CROCODILES. 109 



ception of a single genus_, are all characterised by pos- 

 sessing fins or paddles instead of toed- feet, — a structure 

 altogether unique in this class, except in the marine 

 turtles, by which this order is unquestionably con- 

 nected to that of the Chelonides. These aquatic turtles^ 

 in short, are chelonian reptiles, with the feet of an 

 Ichthyosaurus. But there is another form in this order, 

 which appears, at first sight, altogether anomalous, and 

 as such has been considered by all our predecessors : 

 this is the PUsiosaurus of Conybeare, an extinct reptile, 

 having the body and fins of the Ichthyosauri, but the 

 head and neck of a serpent. And thus do the two 

 extremes of the series we have been tracing, meet. 

 We began with the serpents, and have ended with the 

 Enalosaures. The Plesiosaurus unites the structure of 

 both, and thus leaves us without any further doubt on 

 the grand outlines of the reptile circle. 



CHAP, IX. 



OK THE THREE ABERRANT ORDERS, OR THE EMYDOSAURES, THE 

 CHELONIDES AND THE ELANOSAURES, OR THE CROCODILES, 

 TORTOISES, AND FISH LIZARDS. 



(113.) The first order of reptiles which meets us, 

 after leaving the amphibians, is that of the Emydo- 

 SAURES, or crocodiles. They are the most bulky and 

 voracious of all those which are now in existence ; and 

 although in outward form they have much of the ge- 

 neral aspect of lizards, they are yet very dissimilar in 

 many important points. They differ, in the first place, 

 by their tongue, which is thick, fleshy, flat, and attached 

 to the mouth so much, that the ancients believed this 

 member was altogether wanting. Being aquatic animals, 

 the power of swimming is manifested by palmated feet — 

 a structure not to be found among the lizards — and by 



