FOSSIL REPTILES. 299 



birds, but is easily distinguished from it by not being hollow, 

 or pierced with holes for the admission of air. 



The cubitus is compressed, and trenchant on its radial edge. 

 Its olecranon projects but little. 



The radius is slender ; the femur much resembles that of the 

 crocodile. The rotula is very small, and often scarcely visible. 



The leg is always composed of two bones, of which the tibia 

 is the most bulky, and the peroneum or fibula is flatted and 

 widened in the lower part, and united to the tarsus by a narrow 

 line. 



The carpus is composed of nine bones, like that of tortoises, 

 and its composition will also bear a comparison with that of the 

 simise. The tarsus has but four bones, like that of the crocodile. 



The first four metatarsians are slender, and nearly straight. 

 There are two phalanges to the thumb, three to the second 

 toe, four to the third, and five to the fourth. The latter is the 

 longest toe, and gives the peculiarly elongated and unequal 

 form characteristic of this family. The unguical phalanges 

 of all the toes are trenchant, hooked, and pointed. 



In the cameleon, the toes are grouped in an inverse manner. 

 The thumb and first toe are together, and directed inwards ; 

 the three others are together^ and directed outwards. Aristotle 

 has remarked this singular conformation. 



Having thus prepared ourselves for the investigation, we 

 now proceed to the remains of 



Fossil Saurians. 



The Saurians, indeed, constitute in the ^' Animal Kingdom " 

 an entire order of the class reptiha, and include the crocodiles 

 and gavials. The rest of the order consists of the lizards which 

 we have been now describing, and which, in the Regne animal, 

 are divided into different families. But it is more convenient 

 to consider their fossil remains under this general title ; and we 

 have, therefore, adopted M. Cuvier's arrangement in the 



