FOSSIL REPTILES. 221 



The omoplate is very small in proportion to the size of the 

 animal. Its plane forms a very narrow isosceles triangle. Its 

 neck grows cylindrical, is curved internally, and widens to 

 present a face to the coraco'id bone. On the external edge of 

 this is an apophysis, which, with a corresponding apophysis of 

 the clavicle, contributes to the formation of the fossa which 

 receives the head of the humerus. 



The head and body of the coraco'id resembles in form those 

 of the omoplate. It has a thick and arched neck, and a plane 

 portion which unites with the lateral edge of the sternum. This 

 bone alone in the crocodile performs the office of buttress 

 against the sternum, for in this genus there is no true clavicle. 



The humerus, in front, behind, above, and below, is curved 

 in two directions. Its upper part is a little convex in front, 

 and the lower concave. Its upper head is compressed trans- 

 versely, so is the lower, and it is divided in front into two con- 

 dyles. 



The cubitus has no olecranon, nor sygmoid facet. Its upper 

 head is articulated to the external condyle of the humerus by 

 an oval facet wider on the radial side. Its body is narrowed 

 and compressed. The lower head is smaller, and descends a 

 little lower on the radial side. 



The radius is shorter and more slender than the cubitus, and 

 almost cylindrical. 



There are but four bones in the carpus, — a radial and a 

 cubital; a third which may be regarded as a sort of pisciform, 

 articulating to the cubital osselet and to the cubitus; and a 

 fourth of a lenticular form, between the cubital and the meta- 

 carpians of the index and the medius. 



The metacarpians pretty nearly resemble those of the mam- 

 mifera ; the differences are very minute. To the thumb are 

 two phalanges, to the index three, the medius and the annular 

 have four, and the last digitus three. 



The OS ilium is vertical, concave without and convex within, 

 where it receives the transverse apophyses of the sacral verte- 



