WILD TARPAN AND ITS RELATIONS 95 



from the Prehistoric horse of the diluvial period, 

 which he regards as a local race of the species typi- 

 fied by domesticated horses, and therefore calls 

 Equus caballus fossilis, three other races were 

 developed in the late Stone Age. These he desig- 

 nates respectively as the desert-type [E. caballus 

 pumpellii), the steppe-type {E. c. germanicus 

 or robustus), and the forest-type {^E. c. nehringi). 



In a greater or less degree each of these, together 

 with the rather earlier type identified by Dr. Duerst 

 with E. c. fossilis, exhibits evidence of relationship 

 with the Mongolian tarpan, which is regarded by 

 the same writer as the direct descendant of the last- 

 named. 



The desert-type, as represented by the Anau 

 horse of the Prehistoric deposits of Turkestan, is 

 regarded by Dr. Duerst^ as the direct descendant 

 of E. c. fossilis. It was the smallest of all the 

 Prehistoric domesticated horses, and may never 

 have existed in a wild state. Having limbs of 

 much more slender form than those of the tarpan, 

 and very narrow hoofs, it was characterised by the 

 medium width of the forehead as compared with 

 the length of the base of the skull ; ^ some of these 

 features affiliating it to the Arab type, of which it 



^ op. cit., p. 431. 



* Eastern and western horses are distinguished by a difference 

 in the proportion of the width of the forehead to the basal length of 

 the skull. As the proportion is low in the former, they are called 

 "broad-fronted"; whereas the western horses, in which it is high, 

 are styled " narrow-fronted." 



