V.] DISTINCTIVE MAMMALS. l8l 



pithecus, from the French Pliocene, has a longer muzzle; while 

 Oreopithecus, from the Italian Miocene, seems to connect the 

 CercopitheddcB with the Simiida. 



It is thus evident that during the latter portion of the Tertiary 

 epoch monkeys and apes were spread over the greater part of 

 Eastern Arctogaea; and their extensive diffusion is a proof that 

 this half of the realm could only have been connected with North 

 America by land situated so far north that it formed an impass- 

 able barrier to these animals. Although the smaller extinct 

 European monkeys do not necessarily indicate a very high 

 temperature in the regions they inhabited, there can be little doubt 

 that at the era when Dryopithecus flourished southern Europe at 

 least enjoyed a moist tropical climate. 



Not less characteristic of Eastern Arctogaea are the existing 

 lemuroids, of which there are three families ; the largest (Lemurida) 

 ranging over the Oriental, Ethiopian, and Malagasy regions, the 

 Tarsiidce, with a single genus, being exclusively Oriental, while 

 the sole representative of the Ckiromyida is Malagasy. The 

 numerous existing members of the Lemuridce. are all characterised 

 by the first of the three lower premolar teeth assuming the form 

 and functions of a canine; and as this feature is unknown in 

 any of the Tertiary representatives of the sub-order, this family 

 appears to be exclusively confined to the area under consideration. 

 For the most part, the Oligocene lemuroids of Europe seem 

 likewise to have been markedly distinct from those of North 

 America. Microchcerus^ , for instance, which is represented both 

 in France and England, indicates a family characterised, among 

 other features, by the general presence of only three pairs of 

 premolar teeth in each jaw ; and Adapts, which is likewise 

 common to the same two countries, has four such teeth. 



Although there are several families of Insectivora peculiar to 

 the eastern hemisphere, the only one of these with a wide distri- 

 bution is that of the hedgehogs and their allies (Erinaceida), which 

 has representatives in the eastern Holarctic, Oriental, and Ethiopian 

 regions. Although none are known from America, extinct repre- 

 sentatives of this family are common in the European Oligocene. 



1 Teeth figured on p. 156. 



