ARTIODACTLAY, HIPPOPOTAMIDAE. 



583 



liberienaia is a small species with only two incisors in the lower jaw, Liberia 

 (formerly called choeropsis} ; extinct species from all over the Old World, 

 including Madagascar (not in Australia), Pliocene and Pleistocene. 



All the above families 

 have tuberculated mo- 

 lars. 



We now come to 

 a number of extinct 

 forms in which the 

 tubercles of the molars 

 are connected by low 

 ridges, so that they 

 may be called buno- 

 lophodont. They are 

 intermediate forms 

 leading to the Rumi- 

 nantia. The Caeno- 

 theridae and Xiphodon- 

 tidae show affinities to 

 living groups. The 

 others though inter- 

 mediate between Suidae 

 and Ruminantia show 

 no special affinity to 

 any living group 



Fam. 4. Anthracoth- 

 eriidae. * Extinct forms, 

 Eocene and Miocene. 

 i f c \ p i ra | ; u. 

 molars with 4 tubercles 

 and an intermediate 

 tubercle in the anterior 

 half of the tooth, molars tending to selenodonty ; tetradactyle limbs, 

 inner and outer toes rather smaller than the middle, metacarpals and 



/?" r m* B 



FIG. 304. Hyopotamus velaumts Cuv. Skull, A from below. 

 B from the side {after Kowalevsky, from Zittel). 



FIG. 304 bis. Anoplotherium latipes Gerv., Upper Eocene. A the two hinder upper pre- 

 molars and the anterior molar. B the two hinder lower molars. The cusps are lettered 

 as follows : a antero-external, b antero-internal, 6 1 antero-intermediate, c postero- 

 external, d postero-internal ; a antero-internal, p antero-external, y postero-external ; 

 /3', *, y 1 the three inner tubercles (nat. size, from Zittel). 



metatarsals not fused (Fig. 303) ; ungual phalanges pointed. Anthra- 

 coiherium Cuv., Hyopotamus Ow. (Ancodus Pomel), Merycopotamus 

 Falconer, u. molars with 4 tubercles only. 



Fam. 5. Anoplotheriidae.f Extinct, Eocene and Miocene ; i f c 1 

 p | m f ; teeth in a continuous row, without gaps as in man ; molars 

 seleno-bunodont, u. molars with an intermediate tubercle (Fig. 304 bis, A, b) 



* W. Kowalevsky, On the Osteology of the Hyopotamidae, Phil. Trans., 

 1873. t Cuvior," Ossem. Foss., 3, 1812. 



