446 THE VERTEBRATE SKELETON. 



In the RODENTIA the atlas generally has broad wing-like 

 transverse processes, and the axis a large and long neural spine, 

 while the odontoid process is much developed. In the Jerboas 

 (Dipus) all the cervical vertebrae except the atlas are fused 

 together, a condition recalling that in armadillos. 



In the CARNIVORA the wings of the atlas are well developed 

 (tig. 69, A, 1), and it is deeply cupped for articulation with 

 the condyles of the skull. The axis has a long odontoid process 

 and a high compressed neural spine (fig. 69, B, 4). The third 

 to sixth cervical vertebrae have large transverse processes with 

 prominent perforated inferior lamellae, whose ventral margins 

 in the third and fourth vertebrae diverge as they pass back- 

 wards, while in the fifth they are parallel and in the sixth 

 convergent. The transverse processes of the seventh vertebra 

 have no inferior lamellae and are not perforated. Metapo- 

 physes are often developed. 



In the INSECTIVORA the cervical vertebrae vary considerably. 

 The neural spines except in the case of the axis are generally 

 very small and in the Shrews and Moles the neural arches 

 ^re exceedingly slender. 



In the CHIROPTERA all the cervical vertebrae are broad and 

 short with slender neural' arches. 



PRIMATES. In Man the cervical vertebrae have short blunt 

 transverse processes and small often bifid neural spines. The 

 neural and vertebrarterial canals are large. The atlas forms 

 a ring surrounding a large cavity, and has a very slender 

 inferior arch and small transverse processes. Traces of a pro- 

 atlas have been described in Macacus and Cynocephalus. The 

 axis has a prominent spine and odontoid process and short 

 transverse processes. In most Primates the cervical vertebrae 

 are very similar to those of man, but the inferior lamellae of 

 the transverse processes are better developed. In the Anthro- 

 poid Apes the neural spines are as a rule much elongated. 



