454 THE VERTEBRATE SKELETON. 



Elephant. The tail is exceedingly long in Anoplotherium and 

 in Phenacodus, in which there are thirty caudal vertebrae. 



In RODENTIA the tail is variable. In the Hares, Guinea 

 pig (Cavia) and Capybara it is very small, in Pedetes and the 

 Beaver it is very long and has well-developed chevron bones. 



Most of the CARNIVORA except the Bears and Seals have 

 very long tails, the greatest number of vertebrae, thirty-six, 

 being met with in Paradoxurus. Bears have only eight to 

 ten caudal vertebrae. Chevron bones are not often much 

 developed. 



In INSECTIVORA the tail is very variable as regards length, 

 the number of vertebrae varying from eight in Centetes to 

 forty-three in Microgale. 



In CHIROPTERA the tail is sometimes quite rudimentary, 

 and as in Pteropus, composed of a few coalesced vertebrae, 

 sometimes it is formed of a large number of slender ver- 

 tebrae. 



In PRIMATES also the tail is very variable. In Man all 

 the four caudal vertebrae are rudimentary and are fused 

 together, forming the coccyx. In the Anthropoid apes, too, 

 there are only four or five caudal vertebrae. In many 

 monkeys of both the eastern and western hemispheres the 

 tail is very long, having thirty-three vertebrae in Ateles, in 

 which genus it is also prehensile. Chevron bones are present 

 in all Primates with well-developed tails. In the Lemuroidea 

 the number of caudal vertebrae varies from seven to twenty- 

 nine. 



