HISTORY OF THE ARTIODACTYLA 



393 



already long. The teeth were present in undiminished number, 

 and the grinders, while not properly to be called hypsodont, 

 showed a decided tendency to assume that character. The 

 feet were in the same stage of development as in ^O.vydactylus, 

 that is to say, with two free digits and pointed, deer-like hoofs. 

 We have thus the remarkable and most significant fact that, 

 while the grazing and browsing camels of the lower Miocene 



Fig. 210. — Sheleton oi'^Oxydactyluslongipes. Lower Miocene. (After Peterson.) For 



restoration, see Fig. 209. 



were already distinctly separated, neither had yet attained to 

 the type of foot-structure which both of them afterwards in- 

 dependently acquired. This is a very instructive example of 

 parallel evolution in closely related series. 



Of still another phylum of the camel family, the lower Mio- 

 cene contains the only representatives yet discovered, the httle 

 '^ tgazelle-camels," as they may be called. The single known 

 genus CtStenomylus, Fig. 131, p. 242) of this series was quite a 

 small animal, much smaller than its contemporaries of the graz- 

 ing or browsing series. -\Stenomylus was an extremely slender, 



