466 ORDERS OF MAMMALIA. 



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

 sometimes absent. Cheek-pouches are often present, and the 

 skin covering the tubera ischii is almost always callous and 

 destitute of hair, constituting the so-called " natal callosities." 

 With the single exception of a Monkey which inhabits the 

 Rock of Gibraltar, all the Catarhina are natives of Africa 

 and Asia. 



The earliest traces of the Catarhine Monkeys (constituting 

 the oldest known relics of the entire order of the Quadrumana) 

 appear in the Eocene Tertiary ; and they occur only in the 

 Old World, so far as is yet known. The Macacus eocanus of 

 the London Clay has now been referred to Hyracotherium ; 

 but the Ccenopithecus lenmroides of Riitimeyer, from deposits of 

 Eocene age, appears to be an undoubted Monkey. Ccenopi- 

 thecus, however, cannot be referred with any certainty to the 



Fig. 376. Lower jaw of Pliopithtcus (Pitkecvs) antiguus. Miocene. 



Catarhina, its most marked affinities being with the genus 

 Mycetes on the one hand, and the Lemuridoe on the other. In 

 the Miocene deposits of Greece occur the remains of a Macaque 

 (Mesopithecus Pentelicf); and in deposits of the same age in 

 France have been found the remains upon which have been 

 founded the genera Pliopithecus (fig. 376) and Dryopithecus. 

 The former of these appears to have been most nearly allied 

 to the recent genus Semnopithecus, in which case it must have 

 possessed a tail and cheek-pouches. The latter appears to have 

 been more nearly allied to the living Gibbons (Hylobates}, in 

 which case it must have been destitute of a tail and of cheek- 

 pouches. 



Besides the above, the Pliocene (or Miocene) deposits of 

 India have yielded the remains of Semnopithecus, Macacus, 



