340 REPTILES. SAURIA. 



This species inhabits the rivers of Carolina and Georgia ; lies in ambush among 

 the reeds, &c. and preys on birds, the smaller reptiles, and young alligators. Its 

 flesh is eaten. 



ORDER II. SAURIA. 



Body elongated, covered with scales, generally with four feet ; 

 toes with claws, at least in part ; tail more or less long ; mouth 

 armed with teeth. 



The Saurian family (so named from 0-awgoc a lizard) have the heart composed, as 

 in the preceding order, of two auricles, and a ventricle sometimes divided by imperfect 

 partitions. Their ribs are moveable, partly attached to the sternum, and capable of 

 being elevated and depressed by respiration. Their lung extends more or less towards 

 the hinder part of the body ; it penetrates often before into the lower belly, and the 

 transverse muscles of the abdomen glide under the ribs and even towards the neck 

 to embrace it. Those species which have the lung very large possess the singular fa- 

 culty of changing the colours of their skin as they are influenced by their wants or 

 passions. 



The mouth in Saurian reptiles is always armed with teeth ; their toes have nails, 

 at least in part ; and their skin is covered with scales more or less impacted. All have 

 a tail more or less long, and almost always thick at the base. The greater number 

 have four legs ; but some have only two. Their food is chiefly animal. They also 

 deposit their eggs in places convenient for their being hatched without the care of 

 the parent ; and the animal when produced has the form which it afterwards preserves. 



The Saurian reptiles are distinguished from the Chelonian by the want of a shield 

 and by the presence of teeth ; from the Ophidians because they have eyelids and 

 the branches of the jaws united, a sternum and two lungs ; and from the Batrachians 

 by their having ribs, nails, a scaly skin, and in not undergoing a metamorphosis. 



FAMILY I. CROCODILID^E. 



Body elongated, covered with square scales, of which the upper 

 and under are the largest, and those above raised into a ridge 

 in the middle ; four feet, with five toes before, and four be- 

 hind, the three interior with nails, and all more or less united 

 by membranes ; a single row of pointed teeth in each jaw ; 

 tongue fleshy, flat, and attached almost entirely to the lower 

 jaw; tail flattened on the sides, with a strongly dentated crest. 



Crocodiles are reptiles of large size, with the body covered by square scales, of 

 which those above form projecting lines, raised into a double crest on the tail. Their 

 head is long and heavy, and their jaws are articulated behind the cranium. Their 

 nostrils form a long canal which has its origin in the throat, and terminates at the 

 point of the muzzle, where the crescent-shaped orifice opens and shuts at will. Their 

 eyes have three eyelids ; the exterior ear can be shut at pleasure by two fleshy co- 

 verings ; and under the throat are two small holes, the orifices of glands which secrete 

 a musky substance. Crocodiles are the only Saurian animals which are destitute of 

 clavicular bones ; but their cor acoid apophysis is attached to the sternum, as in all the 

 others. The eggs of crocodiles are hard and as large as those of a goose. The fe- 

 males watch the eggs, and when they are hatched take charge of the young for some 

 months. 



Gen. 1. GAVIALA, Cuv. 

 Muzzle narrow, cylindrical, and much elongated ; teeth nearly 



