THE FORERUNNERS OF THE HORSE 269 



The last genus referable to the Anchitheriidce 

 appears to be Anchilophus, of the Upper Eocene 

 of Europe, which seems to connect in some 

 degree the preceding genera with the undermen- 

 tioned Packynolophus, so far at least as the cheek- 

 teeth are concerned ; the limbs being imperfectly 

 known. All the species were small. 



When Sir Richard Owen, 1 in the year 1839, 

 described the imperfect skull of a small ungulate 

 mammal, of the approximate size of a fox, from the 

 Lower Eocene London Clay of the cliffs at Studd 

 Hill, near Herne Bay, Kent, under the name of 

 Hyracotherium leporinum, he had no conception 

 of the epoch-making importance of the discovery. 

 Indeed, the serial position of the genus, which 

 is now known to be the most primitive member 

 of the horse line, could not be even approximately 

 determined, its describer believing it to be most 

 nearly related to a small Eocene pig-like animal 

 known as Cheer op otamus. Subsequently, when 

 its affinities became better known, the genus was 

 placed in the extinct family Lophiodontidce,\y\)\fadi by 

 the genus Lophiodon of the Middle Eocene of Europe. 

 The lophiodons are, however, now known to be 

 related to the tapirs, which form a line quite dis- 

 tinct from the horse-group. By Professor Osborn 

 the hyracotheres are included in the same family 



1 Trans. Geol. Soc. London, ser. 2, vol. vi. p. 203 ; see also 

 British Fossil Mammals and Birds, London, 1846, p. 419. 



