THE SKULL IN BIRDS. 



283 



the frontal segment varies a good deal in this respect. 

 The basisphenoid has a long rostrum, which represents 

 part of the parasphenoid of the Ichthyopsida. Large frontal 



FiK. 82. 



Finor. 



TTLSCJt.. 



x>t 



Fis. 82. — Lateral, upper, and under views of the skull of a common 

 Fov/l{Phasianus ffallvs). 7n:rp., the maxillo-palatine process. QM.,the 

 quadrate bone. The dotted line accidentally stops at the angular 

 process of the mandible. 



bones always exist, but the pre-sphenoidal and orbito- 

 sphenoidal regions are not so regularly ossified. 



The ethmoid is ossified, and frequently appears upon the, 

 surface of the skull, between the nasal and the frontal 



