xi EXTINCT PECORINES 329 



Ancodus (or Hyopotamus, as it has been called) is also Oligo- 

 cene in range, and its remains have been found in the same 

 countries as have those of Anthracotherium. Both genera are 

 indeed closely allied. Ancodus seems to be a more slightly- 

 built creature. The skull looks weaker, but presents much the 

 same features of organisation. In A. velaunus, a species found in 

 French rocks, a metacarpal of digit I. was present in the man us, 

 while A. hrachyrhynchus had a completely five-fingered manus. 



The Miocene genus Merycopotamus (from the lower layers of 

 the Siwalik formation in India) is more distinctly selenodont 

 than the forms already discussed. On this ground it has been 

 placed in a separate sub-family. As, however, in other respects 

 it does not depart from the Anthracotherian type of structure, this 

 proceeding seems to be hardly necessary. There are two species 

 known, of which one, M. nanus, is, as its name denotes, a dwarf 

 form. 



Fam. Caenotheriidae. While the last family consisted 

 of animals rather more akin to the Pigs, the present is more 

 Pecorine in its characters. The molars are selenodont ; but as in 

 the Tragulidae the premolars are more of the nature of cutting 

 teeth. The dentition, like that of so many of these early 

 Ungulates, is complete, and the canines are not prominent. The 

 feet are four-toed, the lateral toes not reaching the ground. 



The principal genus is the Eocene and Miocene Caenotherium. 

 Of this genus there were a considerable number of species all 

 European in range, and of small size not more than a foot or so 

 in length. Their small size is suggestive of the Chevrotains. 

 In the skull the orbital cavity is nearly or quite surrounded 

 by bone, and the tympanic bulla is large and inflated. A 

 common feature of Artiodactyles, a failure of the nasals and 

 maxillae to meet at the side of the face, is to be seen in this 

 ancient forerunner of the Pecora. 



Plesiomeryx, also European, and from the same geological 

 horizon, is a very closely allied form. 



Fam. Xiphodontidae. This family consists of slender, 

 small Artiodactyles which are, like the Caenotheriidae, related 

 to the Pecora. They are confined in their range to Europe. 



The type genus Ziphodon has selenodont molars and elon- 

 gated, slender, cutting premolars. The dentition was complete 

 and the canines not highly developed. Like Caenotherium, 



