254 



THE ANATOMY OF VEETEBEATED ANIMALS. 



posterior of these ossicles are stronger than the others, and 

 are closely connected with the pnbic cartilages. 



In the Crocodilian skull the following are the chief pecu- 

 liarities which are worthy of especial notice : — 



1. There is an interorbital septum, and the presphenoidal 



PN 



Fig. 77.— Longitudinal and vertical section of the hinder part of the 

 skull of a Crocodile : — Eu, Eustachian tube; F iV, posterior nares 

 P, pituitary fossa. 



and orbitosphenoidal regions remain cartilaginous, or very 

 incompletely ossified. 



2. All the bones of the skull (except the mandible, stapes, 

 and hyoid) are firmly united by sutures, which persist 

 throughout life. 



3. There are large parotic processes. Both the upper 

 and the lower temporal arcades are completely ossified, and 

 formed by postfrontal, squamosal, jugal, and quadrato-jiigal 



