90 



THE VERTEBRATE SKELETON. 



SIDE OF THE CRANIUM. 



At the posterior end is seen the basi-occipital in contact 

 above with the exoccipital, which is pierced by a prominent 



1 



10 



17 



FIG. 10. LATERAL VIEW OF 

 salar) (after PARKER). 

 Cartilage is dotted. 

 1. supra-occipital, 

 epi-otic. 

 pterotic. 

 opisthotic. 

 exoccipital. 

 basi-occipital. 

 parasphenoid. 

 sphenotic. 

 alisphenoid. 

 orbitosphenoid. 

 lateral- or ectethmoid. 



9. 

 10. 

 11. 



THE CHONDROCRANIUM OF A SALMON (SdlmO 



A few membrane bones are also shown. 



12. olfactory pit ; the vomerine 

 teeth are seen just below. 



14. pro-otic. 



15. basisphenoid. 



16. foramen for the passage of 



an artery. 



17. anterior fontanelle. 



18. posterior fontanelle. 



I. II. V. VII. IX. X. foramina 

 for the passage of cranial nerves. 



foramen for the exit of the tenth nerve. In front of this lies 

 a small foramen, sometimes double, for the ninth nerve. 



In front of the exoccipital is the large pro-otic pierced 

 by two prominent foramina. Through the more dorsal of these 

 (fig. 10, VII.) the facial nerve passes out, while the more 

 ventral (fig. 10, 16) is for the passage of an artery. Dorsal to 

 the exoccipital are the opisthotic and pterotic, and dorsal to 



