444 



ANATOMY OF VERTEBRATES. 



fibula, 67, retains its distinctness from end to end in the Probos- 

 cidian Ungulates. The patella, 66^ is slightly convex lengthwise, 

 and concaA-e transversely at its articular surface. The bones of 

 the foot are described at p. 309, fig. 193. 



§187. Skeleton of Peris sodactyla. — A. Vertebral Column. All 

 the existing, and so far as is known the extinct, species of this 

 order have more than nineteen dorso-lumbar vertebrae. The 

 Tapir ( Ttf/?z>?z5 america7ius, fig. 299) has 7 cervical, 18 dorsal, 

 5 lumbar, 6 sacral, and 13 caudal vertebrae. The pleurapophysial 

 part of the transverse process extends forward in the third cer- 

 vical, and underlaps that of the second : the corresponding part 

 of the transverse process progressively expands in tlie succeeding 



299 



American Tapir (Tapirus americanus). 



vertebrpe to the sixth, where it forms a broad hatchet- shaped plate 

 of bone directed downward and a little outward. In the seventh 

 cervical the transverse process consists of a diapophysis only, and 

 is therefore imperforate. In the anterior dorsal vertebrae the 

 base of the neural arch is perforated on each side by the spinal 

 nerve. In both these and the cervical vertebrae the fore part of 

 the centrum is convex, the hind part concave. 



The neural spines gain rapidly in height to the third dorsal, and 

 gradually shorten to the eleventh ; after which, they increase in 

 fore-and-aft extent, and, from slightly inclining backward, be- 

 come vertical. Eight pairs of ribs directly join the sternum, 

 which consists of seven bones, with the xij)hoid cartilage. The 

 transverse processes of the last two lumbar and first sacral vertebrae 



