348 MAMMALIA. 



types had a very wide geographical range, and assumed con- 

 siderable importance in the mammalian fauna of the Upper 

 Eocene and the Lower Miocene. 



Among these intermediate races the family of Anthraco- 

 theriidae seems to have been the most widely distributed, 

 being represented abundantly throughout the greater part of 

 Europe, and less commonly both in India and North America. 

 These are stoutly-built animals, some probably much resembling 

 the pigs in outward aspect, others more nearly similar to the 

 hippopotamus. The dentition is complete, except that pm. 1 

 is occasionally lost ; while the cusps on the molars begin to 

 be distinctly crescent-shaped. When the upper molars are 

 complicated by a small supplementary fifth cusp, this is placed 

 between the anterior, not the posterior normal pair ; and the 

 hindermost lower molar always bears a large posterior talon 

 or third lobe. The odontoid process of the atlas vertebra is 

 still peg-shaped or slightly approaching the spout-shaped type ; 

 and all the bones of both feet, which are either four- toed or 

 five-toed, remain separate. The best-known genera are An- 

 thracotherium, Hyopotamus, and Merycopotainus. 



Anthracotherium. This animal receives its name (coal-beast) from 

 the circumstance that its remains were first discovered in the lignite 

 or brown-coal of Cadibona, Savoy. The skeleton is now almost completely 

 known from several discoveries of bones in association with the character- 

 istic jaws in the Upper Eocene and Lower Miocene of Europe. The skull 

 is depressed, with an elongated facial region, and the parietal bones meet 

 in a prominent sagittal crest. The basicranial axis is straight. The 

 orbital cavity is not completely separated by bone from the temporal 

 fossa, while the zygomatic arch is slender. The dentition forms a nearly 

 continuous series ; the upper molars are complicated by a small anterior 

 median fifth cusp ; the canines are relatively large, with conical crown, 

 and closed root ; the incisors are nearly uniform in size, also conical and 

 slightly spatulate. The angle of the mandible is not produced downwards. 

 The scapula is elongate-triangular in shape, with a robust coracoid process. 

 The radius and ulna are separate and nearly equal in stoutness ; the tibia 

 and fibula also remain separate, but the latter element is very slender. 

 The femur is longer than the-humerus. The lateral digits (nos. n and v) 

 are complete, though smaller than the middle digits (nos. in and iv) on 

 each foot ; those of the pes are relatively the smallest. The metapodial 

 bones are not keeled distally. The typical species, Anthracotherium 

 magnum, has a skull about half a metre in length, and must thus have 



