SAURIA. 13 



Linnaeus included them all in two genera^ the Dragons 

 and the Lizards : but it has been found necessary to divide 

 the latter into several, which so far differ in the number of 

 feet, &c. the shape of the tongue, tail and scales, that we are 

 even compelled to distribute them in several families. 



FAMILY L 



CROCODILIDA. 

 This family contains the single genus 



Crocodilus, Br. 



Crocodiles are large animals, with a tail flattened on the sides, 

 five toes before and four behind, of which only the three internal 

 ones on each foot are armed with nails, all more or less united by 

 membranesj a single range of pointed teeth in each jawj the tongue 

 fleshy, flat, and adhering close to its edges; a circumstance which in- 

 duced the ancients to believe that they had nonejl the back and tail 

 covered with very stout, large, square scales or plates, relieved by a 

 ridge along their middlej a deeply notched crest on the tail, which 

 is double at its base. The plates on the belly are smooth, thin, and 

 square. Their nostrils, which open on the end of the muzzle by two 

 small crescent-shaped fissures closed by valves, communicate with 

 the extremity of the hind part of the mouth, by a narrow canal which 

 traverses the palatine and sphenoidal bones. 



The lower jaw being continued behind the cranium, the upper one 

 appears to be movable, and has been so described by the ancients; 

 it only moves, however, with the entire head. 



They have the power of closing the external ear by means of two 

 fleshy lips, and there are three lids to their eyes. Six small holes, 

 orifices of as many glands, may be observed under the throat, from 

 which issues a kind of musk-scented pomatum. 



The vertebrae of the neck rest on each other through the medium 

 of small false ribs, which renders all lateral motion difficult, and does 

 not allow these animals to deviate suddenly from their course; con- 

 sequently it is easy to escape from them by pursuing a zig-zag direc- 

 tion, or by running round them. They are the only Saurians that 

 are destitute of clavicles, but their coracoid apophyses are attached 

 to the sternum, as in all the others. In addition to the common and 

 false ribs, there are others which protect the abdomen, without 



