1354 



CLASS MAMMALIA. 



tible of modification than the Bunodont type upon which the Artio- 

 dactylate molar is constructed, but this is really a pure assumption. 

 Family Tapirid^e. — This family is represented by the single 

 existing genus Tapirus, now found in the widely separated areas of 

 the Malay Peninsula and South America, and thus affording an 

 excellent example of what is termed discontinuous distribution. The 



dental formula is /. 



C. -, Pm. 



M. 



the cheek-teeth are 



3 i 3 3 



brachydont, and of the simple Lophodont type ; the hinder pre- 

 molars being as complex as the true molars, and the last lower 

 molar having no third lobe. The first upper premolar has a decid- 

 uous predecessor ; and in the existing forms there are four digits 

 in the anterior (fig. 1225, a), and three in the hind foot. The 

 cranium (fig. 1227) has its cerebral portion much vaulted, and the 



Fig. 1227. — Side view of the skull of Tapirus americanus. Reduced. (After Giebel.) 



nasals short and arched ; in one American species (which on this 

 account is regarded by some authors as generically distinct under 

 the name of Elasmognathus) the narial septum is largely ossified ; 

 and there is a short proboscis. In Europe this genus is found in 

 the Middle Miocene of France (T. Poirrieri), and continues to the 

 Upper Pliocene ( T. arvernensis) ; it also occurs in the Pliocene of 

 China (T. sinensis), and in the Pleistocene cave-deposits of Brazil, 

 one of the forms from the latter being indistinguishable from the 

 living T. americanus. The North American Miocene forms named 

 Tapiravus are probably not generically distinct. An imperfectly 

 known form from the Middle Eocene of France, described as 

 Paiceotapirus, is referred by Dr Filhol to this family. 



Family Lophiodontid^. — This Eocene family presents char- 

 acters allying it very closely with the Tapiridtz, Palceotheriidce, and 

 Rhinocerotidce, and probably contains ancestral forms of all those 

 families. The upper true molars (fig. 1228) are brachydont, and 

 always more complex than the premolars ; the last lower true molar 



