420 



ORDERS OF MAMMALIA. 



the septum narium is narrow. The thumbs of all the feet 

 are opposable, so that the animal is strictly quadrumanous. 

 In Colobus alone the anterior thumbs (pollex) are wanting. 

 The dental formula is the same as in man, viz. — 



2 — 2 ' 



1—1 

 1—1 



2 2 



pm 



2—2 ' 3—3 



32. 



Tire incisors, however, are projecting and prominent, and 

 the canines — especially in the males — are large and pointed. 

 Moreover, the teeth form an uneven series, interrupted by a 

 diastema or interval. The tail is never prehensile, and is 

 sometimes absent. Cheek-pouches are often present, and 

 the skin covering the tiibera iscliii is almost always callous 

 and destitute of hair, constituting the so-called "natal 

 callosities." "With the single exception of a monkey which 

 inhabits the Eock of Gibraltar, all the Catarhina are natives 

 of Africa and Asia. 



The earliest traces of the Catarhine Monkeys appear in 

 the Miocene Tertiary ; and they occur only in the Old 



World, so far as is 

 yet known. In the 

 Miocene deposits of 

 France and Italy oc- 

 cur the remains of 

 various genera which 

 are referable to the 

 Catarhines. Of these, 

 the genus Pliopithe- 

 cus (fig. 690) appears 

 to have relationships 

 Ijotli with the living 

 Scmnopithecus and the 

 Anthropoid Apes, but 

 its precise position among the Catarhines is uncertain. The 

 Dryopithecus, of the Miocene of France, was an Anthropoid 

 Ape of large size, possessing large and pointed canine teeth, 

 and apparently closely related to the existing Gibbons 

 [Hylohatcs). It must therefore have been destitute of 

 cheek -pouches, and its tail must have been rudimentary. 



Fig. O'jO.— Lower jaw of I'liopi'thecus (PUhecus) antiquus. 

 Miocene. 



