PEEISSODACTYLA. 



313 



recent species of the E/mlthc the number is reduced to six. but then- is a small 

 tooth in front of the first praemolai 1 which soon falls out (Wolfszahn, liojaini- ). 

 Fossil 1'nniis Mi-st appear in the eocene \ < >ri>]ii/>j/i/x still with a rudimentary 

 fifth digit, as well as the three other digits which rested on the Around, and 

 A nrlii/ In-riiini). Thej' persisted in the miocene and pliocene (Jliji/m r'mn) and 

 then pas? into the diluvial genus /;,/// ///,-. id whieli the domestic horses of the 

 present day belong. Am-hiHn'riinn IliimnxiJ (ierv. Feet with three dibits, middle 



FIG. 690. IVilu: skeleton of different genera of Equkhe (after Harsh). <t, Foot of Qroh 



(Eocene); b. Foot of Aiickitherium (Lower Miocene ; e, Foot of Hipparlon (Pliocene); J, 

 Foot of the recent genus Equits. 



digit large, remains of fifth metacarpal on the anterior limbs. The grinders are 



7 F" 4'i 3'3 ~~\ 



-z I P- '" .. '- '-j. I Ilipparion iji'in-ilr Kp., miocene. Of the seven grinders, 



the anterior is a simple prism with a semilunar transverse section : it is In-i 

 with the milk dentition. Eyian* ciiliallux. Foot composed of one digit, with 

 remains of metatarsals (metacarpals) of second and fourth digits (splint 



FIG. 091. Skull of Ki 



bones): grinders arc P- m. _ . 



remains of an anterior .-eveiith 



grinder in the milk dentition. This genus is only known in the donp 

 state, but is probably descended from one or several of the species of hdi--.--; 

 ^hich lived in the diluvial period. Axinii* tanlnpux Heugl.. the wild ass of 

 South-Ea^t Asia, the ancestral form of the domestic ass (E. <ixinux): 

 A. hennoiius Pall.. Dziguetai ; A, una/ier Pall.. Kulan. Mongolia. The African 



