38 



Perissodactyla — Anchilophus, Anchitherium, etc. 



Anchilo- 

 phus. 



Anchithe- 

 rium. 



Table- case, 

 No. 5. 



Hyracothe- 

 rium. 



Pier-case, 

 No. 9. 



Pliolophus. 



Pier-case, 

 No. 9. 



Pachynolo- 

 phus. 



Fig. 47.— The right upper true 

 molars of Anchitheriwm Bairdi 

 (Leidy), from the Miocene of Dakota, 

 N. America. 



Anchilophus, a small Paleeothere, is represented by jaws and 

 teetli from the Upper Eocene at Bemtnidge, Isle of Wight, and 

 from Vancluse and Caylux in France. 



The Miocene genus, Anchitherium, is interesting as presenting 

 many characters intermediate between the Pquidce and Palceo- 

 theriidce. The bones of the extremities, especially the feet, 

 resemble the corresponding parts in Hipparion ; but Anchitherium 

 was a much smaller animal. The feet had three toes ; the 

 central toe on each foot was long and strong-, and mainly sup- 

 ported the weight of the body ; the lateral toes were slender, 

 with small terminal hoofs. 



Remains of Anchitherium aure- 

 lianense are not uncommon in the 

 Miocene deposits at Sansan, Gers, 

 Trance, of which a characteristic 

 series of teeth and bones is exhibited. 

 A. Bairdi is a smaller species from the 

 White River beds (Miocene age) of 

 Nebraska territory, North America. 



Other genera of this family are 

 Hyracotherium and Pachynolophus, 

 which are very closely allied to each other. 



Hyracotherium was a small animal, about the. size of a hare, 

 principally known by its dentition. Prof. Cope states that the 

 American Orohippus is identical with Hyracotherium. Its re- 

 mains are comparatively rare, and have been found in the 

 Lower Eocene (London Clay) of Heme Bay ; in Eocene sands 

 at Hordwell, Hants ; at Kyson in Suffolk ; and also as a " de- 

 rived fossil " from an older (Eocene ?) deposit in the Suffolk 

 Crag;. 



The genus Pliolophus was founded on an entire head and 

 some bones of the extremities, embedded in a nodule of 

 " septarium," or " cement-stone," from the London Clay on the 

 coast near Harwich; it appears to be identical with Hyraco- 

 therium, and therefore with Orohippus ; a reproduction, by Prof. 

 Cope, of H. venticolum, from the Eocene of Wyoming Territory, 

 United States of North America, has been added to this case. 

 The skeleton of Phenacodus primcevus, Cope, from the same forma- 

 tion and locality, is also represented by a coloured reproduction 

 in plaster ; it possessed five toes on each foot, and is in every 

 respect the most primitive Eocene Mammal yet discovered. It 

 indicates an ancestral form allied to Hyracotherium, which is 

 generally placed in the Coxdylarthra (see fig. 36, p. 28 and 

 text p. 27). 



Pachynolophus is an allied genus of small animals, whose 

 remains are only found in Eocene deposits. Pour species are 

 represented in the collection by teeth and jaws from France 

 and Switzerland. The dentition is complete, namely : — 



Incisors -|, canines ^ premolars f, molars f X 2=44. 



