SKELETON OF THE CAMEL, 175 



will show the extension of the frontal and parietal sinuses 

 into its lower fourth, the rest of the horncore being a solid 

 and dense bone. The protuberance upon the frontal and 

 contiguous parts of the nasal bones is entirely due to an 

 enlargement of those bones, and not to any distinct osse- 

 ous part : its surface is roughened by vascular impressions. 

 The lachrymal is separated from the nasal by a large va- 

 cuity intervening between those bones, the frontal and 

 the maxillary. The premaxillaries, which are of unusual 

 length, articulate with the nasals. The petrotympanic is 

 a separate bone, as in all ruminants. The symphysis of 

 the lower jaw is unusually long and slender in the giraffe. 

 In the skeleton of the Camel {Camelus hadrianus) the 

 vertebral formula is — seven cervical, twelve dorsal, seven 

 lumbar, four sacral, eighteen caudal. Seven pairs of ribs 

 articulate directly with the sternum, which consists of six 

 bones, the last being greatly expanded and protuberant 

 below, where it supports the pectoral callosity in the living 

 animal. The cervical region, though less remarkable for -^ 

 its length than in the giraffe, is longer than in ordinary 

 ruminants, and is remarkable for its flexuosity ; the ver- 

 tebrae are peculiar for the absence of the perforation for 

 the vertebral artery in the transverse process, with the 

 exception of the atlas ; that artery, in the succeeding cer- 

 vicals, enters the back part of the neural canal, and per- 

 forates obliquely the forepart of the base of the neurapo- 

 physis. The costal part of the transverse process is large 

 and lamelliform in the fourth to the sixth cervical vertebras 

 inclusive : in the seventh it is a short protuberance. The 

 spinous process of the first dorsal suddenly exceeds in 

 length that of the last cervical, and increases in length to 

 the third dorsal ; from this to the twelfth dorsal the sum- 

 mits of the spines are on almost the same horizontal line, 



