SAURIA. 
273 
the hind, of which the three inward only of each foot are furnished with claws, all of them being more 
or less connected by membrane ; a single row of pointed teeth in each jaw ; the tongue flat and 
1 fleshy, and attaehed very near to its edges, which led the ancients to believe that it was altogether 
wanting ; the penis single ; the anal orifice longitudinal ; the back and tail covered with great square 
scales of exceeding strength, having an elevated ridge along their middle ; and a deeply dentelated 
crest upon the tail, double at its base. The scales of the belly are also square, but smooth and 
■ narrow. The nostrils, opening at the tip of the muzzle by two small transverse fissures which close 
as valves, are continued by a long straight canal pierced in the palate bones and sphenoid, as far as 
the throat. 
The lower jaw is prolonged backward beyond the skull, which occasions the upper one to appear 
! moveable, as the ancients asserted to be the case : the latter can only move, however, with the 
I entire head. 
I The external ear is closed at will by two fleshy lips ; and the eye has three lids. Under the throat 
I are two small holes, the orifices of glands, where a musky pommade is secreted. 
I The vertebrae of the neck are propped together by little false ribs, which render lateral movement 
i difficult : hence these animals cannot readily change their course, and are easily avoided by turning. 
^ They are the only Saurians which have no clavicular bones ; but their coracoid apophyses are attached 
i to the sternum, as in all the others. Besides the ordinary true and false ribs, their abdomen is pro- 
I tected by others, which do not ascend to the spine, and which appear to be produced by the ossifica- 
I tion of the tendinous extremities of the straight muscles. 
Their lungs do not penetrate into the abdomen, as in other Reptiles ; and the fleshy fibres adhering 
I to the portion of peritonaeum which invests the liver, impart the appearance of a diaphragm ; cir- 
I cumstances which, conjoined to the particular of their heart being divided into three chambers, 
j wherein the blood that comes from the lungs does not mingle so completely with that of the body as 
in other Reptiles, ally these animals somewhat nearer to the warm-blooded quadrupeds. 
! Their ear-drum and pterogoid apophyses are fixed to the skull, as in the Tortoises, 
i Their eggs are hard, and the size of those of domestic Geese, whence the Crocodiles are reputed to 
I be, of all animals, those which attain the greatest dimensions considering their size at birth. The 
females guard their eggs, and continue to protect the young for some months after exclusion. 
I They inhabit fresh water, and are very carnivorous, but are unable to swallow under water ; and 
j their habit is to drown their prey, and then place it in some hole beneath the surface, where they 
! leave it to putrefy before they devour it. 
I They differ, indeed, so much from other Lizards, that several recent authors have deemed it neces- 
j sary to make of them a particular order, termed Loricata by Merrem and Fitzinger, and Emydosaura 
\ by De Blainville. 
The species, more numerous than has hitherto been supposed, fall into three distinct subgenera. 
The Gavials, Cuv., — 
Have the muzzle slender, and very much elongated; the teeth about equal ; the hmd-feet dentelated at 
their external edge, and webbed to the ends of the toes ; two great perforations in the bones of the 
skull behind the eyes, which may be discerned outside the skin. They have only been observed on 
the eastern continent. 
That of {Lac. gangetica, Gm.), which attains a large size, is remarkable, not only for the length of 
I its muzzle, but for a large cartilaginous prominence surrounding the nostrils, which throws these backwards, and 
i led iElian to assert that the Gangetic Crocodile had a horn at the tip of its snout. 
The Crocodiles, properly so called, — 
Have the muzzle oblong and flattened, the teeth unequal, but resemble the Gavials in other respects. 
Some of this form occur on both continents. 
The Caymans, or Alligators {Alligator, Cuv.) — 
Have a broad and obtuse muzzle, and uneven teeth, the fourth below entering into cavities of the 
upper jaw, and not the interstices of the upper teeth, as in the preceding ; their feet are only semi- 
palmated, and undentelated ; and the species are only known to inhabit America. 
T 
