498 



THE VERTEBRATE SKELETON. 



the scapula is elongated and curved backwards, and has a very 

 concave glenoid border. In the Eared Seals (Otariidae) the 

 scapula is proportionally much larger and wider, the pre- 

 scapular fossa being specially large, and being traversed by a 

 ridge, which converges to meet the spine. 



FIG. 104. DORSAL VIEW OF THE STERNUM AND RIGHT HALF OF THE 

 SHOULDER-GIRDLE OF Mus sylvaticus x 4. (After PARKER.) 



1. postscapular fossa. 



2. prescapular fossa. 



3. spine. 



4. suprascapular border unossi- 



fied. 



5. coracoid process. 



6. acromion. 



7. cartilaginous vestige of pre- 



coracoid at scapular end of 

 clavicle. 



8. clavicle. 



9. cartilaginous vestige of pre- 



coracoid at sternal end of 

 clavicle. 



10. omosternum. 



11. epicoracoid. 



12. presternum. 



13. first segment of mesosternnm. 



14. xiphisternum. 



15. cartilaginous termination of 



xiphisternum. 



16. 2nd sternal rib. 



17. 1st vertebral rib. 



