SKELETON OF ARTIODACTYLA. 



4o9 



centre of motion of the trnnk. The dorsal nenrapophyses are 

 directly perforated by the spinal nerves, and a bar of bone con- 

 nects the end of the diapophysis with the hind part of the cen- 

 trum, circumscribing a vertical perforation on each side. The 

 metapophysis commences as a tuberosity upon the diapophysis of 

 the middle dorsal vertebra?, projects forward midway between the 

 di- and prozyg-apophyses in the tenth, passes upon the prozyg- 

 apophyses of the eleventh dorsal, and is continued in that position 



There are no anapophyses. 



throuo'hout the lumbar series 



307 



Dromedary. 



In the Dromedary, fig. 307, and Camel (Camelus hactrianus), 

 the vertebral formula is : — 7 cervical, 12 dorsal, 7 lumbar, 4 sacral, 

 and 18 caudal. Seven pairs of ribs articulate directly with the 

 sternum, which consists of six bones, the last being greatly ex- 

 panded and protuberant below, where it supports the pectoral 

 callosity in the living animal. The cervical region is remarkable 

 for its length and flcxuosity ; the vertebra? are opisthococlian, 

 but resemble those of Macrauchenia in the absence of the perfo- 

 ration for the vertebral artery in the transverse process, with the 

 exception of the atlas ; tliat artery, in the succeeding cervicals, 

 enters the back part of the neural canal, and perforates obliquely 



