60 MAMMALIAN ANATOMY 



complete absence of a spinous process, and by the simple character 

 of the end of its transverse process. 



The laminae are still more inclined toward the middle line, and 

 their caudal margins are more arcuate. The tubercles are well 



O 



marked. The cephalic articular processes are shorter. The pedicles 

 are vertical. The neural canal is smaller and more nearly round. 

 The transverse processes have a greater cephalo-caudal diameter and 

 a more caudal direction. Their costal element is often reduced to a 

 small strip attached to the ventral edge of the transverse element. 

 The whole vertebra is longer and narrower than the fourth. 



The Second Cervical Vertebra is known as the Axis. It is recog- 

 nized at once as the longest and narrowest of all the cervicals. 



The body is rectangular, with the cephalo-caudal length twice the 

 transverse width ; it is flat from the dorsal to the ventral side. Its 

 cephalic end is prolonged, in the middle line, into a conical odontoid 

 process, which articulates with the dorsal surface of the body of the 

 first cervical, called the atlas. 



The ventral surface of the body (Fig. 32) is contracted transversely 

 at a point cephalic to the middle of the cephalo-caudal diameter. The 

 region cephalic to this contraction is flat, or slightly concave from side 



to side ; but, caudal to the contraction, 

 FIG. 33. 



the surface has a strong median keel 



flanked by decided excavations. 



The cephalic end of the body (Fig. 

 33), on each side of the odontoid pro- 

 cess, slopes in a lateral and caudal 

 direction. It is arcuate and swollen, 

 and forms the ventral part of the 

 cephalic articular process. 

 T* The odontoid process (Fig. 34) is 



Cephalic Articular Process. 



a conical mass, scarcely twice as long 



AXIS, ANTERIOR OR CEPHALIC ASPECT. 



as wide, directed toward the skull and 



dorsally from the middle line of the body. Its ventral surface is 

 occupied by a smooth, transversely convex area (sometimes a decided 

 facet concave in a cephalo-caudal line) for articulation with the dorsal 

 surface of the ventral bar of the atlas. 



Each transverse process (Fig. 34) springs from the caudal part of 

 the side of the body. It is small, simple, and sharp at the end, which 



