735 



foramen rotundum is nearly midway between this and the foramen lacerum anterius. The 

 sella turcica is narrow, moderately deep, defended by anterior clinoid processes. The optic 

 foramina are approximated. The entry to the rhinencephalic fossa is much contracted by 

 the bulging prominence of the roofs of the orbits. 



4724. The mandible, or lower jaw. 



The extent of the oblique anterior division of the first premolar (p 3), which answers to 

 the third in the Dog and the second in the Spider-Monkey, gives the appearance of the ena- 

 mel being continued on the fore part of the anterior fang. 



4725. The atlas. 



4726. The seventh cervical. 



The transverse process, although consisting only of the diapophysis, is grooved on the 

 right and perforated on the left side by the vertebral artery. 



4727. The thoracic vertebrae. 



They are twelve in number. A rudimental met- and an-apophysis may be recognized in 

 all the dorsal vertebrae after the second : these processes gradually increase in size to the 

 ninth and, more suddenly, in the tenth, where the metapophysis articulates with the acces- 

 sory facet of the posterior zygapophysis of the ninth dorsal. The met-, an- and di-apophyses 

 have become quite distinct processes in the last dorsal. This is a natural skeleton, and seven 

 pairs of ribs directly articulate with the sternum, which consists of seven bones, the penulti- 

 mate one being only partially ossified. 



4728. The six lumbar vertebrae. 



They show the progressive subsidence of the anapophyses to their entire suppression in the 

 last lumbar. 



4729. The sacrum. 



It includes four anchylosed vertebrae, the fourth having the character of a caudal. 



4730. The first free caudal vertebra. 4731. The right scapula. 

 4732. The right clavicle. 4733. The right humerus. 



