SKELETAL SYSTEM. 



615 



dentaries, are lodged in distinct cavities ; beside and eventually beneath 

 the teeth lie reserve " germs " of others. 



Each ramus of the mandible consists, as in most Reptiles, of a cartilage- 

 bone the articular working on the quadrate, and five membrane bones 

 dentary, splenial, coronoid, angular, and surangular. 



-p.mx 



FIG. 303. Crocodile's skull from dorsal surface. 



p.inx., Premaxilla ; iii.v., maxilla; /., lachrymal : pr.f., prefron- 

 tal ; j., jugal ; p.f., postfrontal ; q.j., quadrato-jugal ; g., 

 quadrate ; sq. , squamosal ; pa., parietal ; e.pt., epipterygoid ; 

 _/., frontal; pt., pterygoid (on lower surface); <?./., os trans- 

 versum (on lower surface) ; ., nasal. 



The hyoid region is very simple. 



The pectoral arch includes a dorsal scapula and a ventral coracoid 

 (with a characteristic foramen) ; there are no clavicles nor epicoracoids, 

 but there is a sternum and a so-called interclavicle or episternum ; the 

 fore-limb is well though not strongly developed ; there are live digits, 

 webbed and clawed. 



In the pelvic arch, large ilia are united to the strong ribs of the two 



