348 UNGULATA. 



name Pclonax has been applied erroneously to some of the 

 American forms ; but the specimens on which it was based 

 clearly belong to Elotherimn. This genus affords another 

 example of the aberrant Suilline offshoots, already mentioned. 

 Some of the species were nearly as large as a Ehinoceros, 

 and in all there were but two serviceable toes, the outer 

 digits, seen in liviug animals of this group, being represented 

 only by small rudiments concealed beneath the skin. In 

 the Upper Miocene of Oregon, Suillines are abundant, and 

 almost all belong to the genus Thinoliyus, a near ally of the 

 modern Peccary {Dicotylcs), but having a greater number of 

 teeth, and a few other distinguishing characters. In the 

 Pliocene, Suillines are still numerous, and all the American 

 forms yet discovered are closely related to Dicotyles. The 

 genus Platygonus is represented by several species, one of 

 which was very abundant in the Post-Tertiary of North 

 America, and is apparently the last example of a side branch 

 before tlie American Suillines culminate in the existing 

 Peccaries. The feet in this species are more specialised 

 than in the living forms, and approach some of the peculiar 

 features of tlie Kuminants ; as, for example, a strong tend- 

 ency to coalesce in the metapodial bones. The genus Platy- 

 gonus became extinct in the Post-Tertiary, and the later and 

 existing species are all true Peccaries." 



Leaving the typical Svida, we must next glance at a group, 

 or several groups, of Tertiary Mammals, which have strong 

 Suilline affinities, but which have a more or less distinctly 

 selenodont type of dentition, thougli in a generalised form, 

 and which thus conduct us from the Suida to the true 

 Ruminants. 



Among the more pig -like of these transitional forms 

 Anthracotherium and Chmropotamus may be specially singled 

 out. In Anthracothcrmm are included a number of Miocene 

 Suillines — all European — in which the dentition is complete, 

 the incisors being strong, the canines moderately large, and 

 the molars (fig. 643, a) having the two transverse lobes 

 which characterise their crowns broken up into four tubercles, 

 while the last molar has an accessory fifth tubercle. Tlie 

 ChceroiMamus of the Eocene Tertiary shows points of resem- 



