ORDER Aai 



CEOCODILIA 



219 



Bo 



Fig. 321. 

 Gavialis gangeticus, Geoffr. 



The under side of the skull is characterised by a great development of the 

 secondary palate, formed by horizontal expansions of the premaxillae, maxillae, 

 palatines, and pterygoids, and pierced by a moderate or large-sized infraorbital 

 vacuity. This extensive roofing of the buccal cavity conceals the vomers and 

 causes the internal opening of the nasal passage to be displaced far backwards, 

 at the posterior border of the pterygoids, whereas in 

 the Mesosuchia the opening is never further remote 

 than the hinder margin of the palatine plates (cf. 

 Fig. 313 with Fig. 321). A transverse bone (ecto- 

 pterygoid) is present, connecting the jDterygoids 

 with the maxillae and jugal (Fig. 321, T). Modern 

 gavials exhibit in the adult a pair of bulbous out- 

 growths {hu) of the palatines which communicate 

 with the nasal passage and function as air-reservoirs. 



The mandibular ramus is composed of the usual 

 six pieces, one of which, the articular, is pneumatic. 

 A large foramen communicating with the inner 

 cavity of the jaw is almost invariably present 

 between the angular, surangular, and dentary. 

 The symphysis is formed by the latter element decent ; inciia. ' orai aspect of 



•i \ " TCI 11 1 posterior half of skull, showing 



alone m the broad-nosed forms, by the dentary and eusuchian secondary palate. &o, 



1.1, .1 ,^ ^ • 1 , • Basiocclpital ; &«, Ossified air- 



Splenial together among the longU^OStrate species. chambers ; c\ Posterior nares ; j, 



Numerous conical teeth of oval or circular cross- pf ® pterygoid -^^gM ' QuatoteT^^' 

 section, smooth or striated, and frequently carinated, Bctopterygoid ; a;, Opening of eusta- 



-,,■,•-, ITT ,1 • c chian canals. 



are implanted in deep alveoli along the margin of 



the jaws. They are often irregular in form and size, but their number remains 



constant for particular 

 species, and in many cases 

 also for the genus. 



In the pectoral arch 

 clavicles are wanting. The 

 scapula is elongated and 

 expanded at either end, 

 as is also the coracoid. 

 The latter is thickened in 

 its proximal portion, and 

 pierced by a round fora- 

 men. The humerus is 

 stout, slightly curved, and 

 exhibits near the head a 

 conspicuous process as 

 well as a deltoid crest. Its distal end is furnished with two 

 facettes for the bones of the second segment, of which the 

 ulna is generally somewhat the longer (Fig. 323). The 

 proximal row of the carpus contains two elongated elements 

 (radiale and ulnare, both constricted in the middle), and a Ciocodi"ie.'" 4 Radius; 

 small pisiforme to which the fifth metacarpal is attached by caVpaisT V/pisiforme^; 

 ligaments. The two radial digits are slightly stouter than jij^-^'^^l^u's "' ^^^"^^'*" 

 the three ulnar. 



Of the three elements of the pelvic arch (Fig. 322), the pubis is excluded 



Fig. 322. 



Pelvis of Crocodile. 

 il. Ilium ; is, Ischium ; yu, Pubis. 



Fig. 323. 

 Right fore -limb of 



