OSTEOLOGY 



27 



foramen magnum and articulates with the atlas. At the base of 

 the condyle a smaU suhcondyloid fossa receives the body of the atlas 

 during extreme flexion of the head. In the center of the lateral 

 wing of the occipital bone there is a small foramen through which 

 passes the hypoglossal nerve. Somewhat laterally from this foramen 

 there is an opening through which the vagus, or pneumogastric 



Pig. 6. — View of the frontal region of the skull of a hen. i. Parietal. 2 

 ¥io-a.taX. 3, Nasal. 4, Premaxilla. 5, Temporal. 6, Inferior"Taw. T.^JttgST] 

 bone. '~ ^ 



nerve passes. Laterally from these is the canalis carolicus et ju- 

 gularis. Between the os occipitale superius, or dorsal portion, 

 and the ossa parietalia is a space to which ligaments are attached, 

 called the fontanel. 



The Ethmoid. Location. — The ethmoid, or os ethmoidale, 

 forms the anterior wall of the cranium, and the orbital septum. 

 It is related anteriorly with the vomeral, superiorly with the nasal 



