102 



MASTODON AND ELEPHANT. 



INFRA-ORBITAL FORAMEN. 



External diameter transversely 



Distance from the lower edge of the orbit 



Length of the infra-orbital canal 



MASTODON. 



ELEPHANT 



Inches. 



Inches. 



If 



2 by 5 



3* 





VERTEBRAL COLUMN. 



The cervical vertebrae are, in the Mastodon, in number, seven ; the 

 dorsal, twenty ; the lumbar, three ; the caudal, twenty-two. In the Ele- 

 phant the vertebrae are as follows : Seven cervical, nineteen dorsal, three 

 lumbar, five sacral, twenty-four caudal. 



The spinous processes of the cervical vertebrae are small, and the 

 transverse processes quite indistinct. The spines of the first six dorsal 

 vertebrae are very long; thence they gradually diminish in length, and 

 increase in obliquity to the seventeenth. 



The first cervical vertebra, or atlas, transversely 



From above downwards 



In circumference 



The first dorsal. — Body including transverse processes 



From above downwards 



Spinous process 



The first lumbar transversely 



From above downwards 



Circumference 







• 





12 



32 

 11 



6 

 12 

 10 



7 

 26 





15 



8 

 34 

 13 



7 

 10 



7 



n 



22| 



The transverse processes of the lumbar vertebrae are small, and hardly 

 project beyond the bodies of the vertebrae ; while those of the large skeleton 

 have a considerable projection. 



THORAX. 



The sternum of the Mastodon is wanting; the ribs are twenty in 

 number ; they are less massive than in the other skeleton in proportion to 



