THE SKULL 381 



front ; and separated by a sharp, almost transverse 

 line from the facial part of the skull. The an- 

 terior ends of the frontal bones diverge slightly 

 from each other, and allow the mesethmoid to 

 come to the surface between them. 



The facial portion of the skull lies below and in front of 

 the cranial portion, with which it is only loosely 

 connected. It consists of, (1) the olfactory capsules, 

 and the bones associated with them ; (2) the skeletal 

 elements of the jaws, and the hyoid apparatus. 



a. The olfactory capsules and associated bones. The 

 olfactory capsules themselves remain in a car- 

 tilaginous condition throughout life, and are 

 therefore absent in macerated skuUs. They are 

 separated only by a thin vertical septum, and 

 almost completely fiU the conical space which, in 

 the dried skull, hes between the anterior end of 

 the orbit and the tip of the beak. Each olfactory 

 capsule has its cavity complicated by a spirally 

 roUed lamina of cartilage, which projects inwards 

 from its outer wall. 



In relation with the olfactory capsules are the 

 following bones. 



i. The nasals are a pair of thin lamellar bones, 

 which cover the sides of the hinder ends of 

 the olfactory capsules. Behind, they are fused 

 with the anterior ends of the frontals ; while 

 their anterior borders are divided by deep 

 notches into superior and inferior processes, 

 which embrace the external narial openings, 

 and are closely connected with processes of 

 the premaxillcB. 



ii. The vomer is a slender median bony rod, which 

 lies below the hinder part of the olfactory 

 capsules, and immediately in front of the 

 para-sphenoid. It is paired in some birds. 



