82 APES, MONKEYS, AND LEMURS 



under parts and the inner sides of the limbs, are of a brilliant yellow, tending to 

 orange, the naked parts of the face being bluish-gray. 



These langurs inhabit the forests of the mountain region between Moupin and 

 Lake Khokonor, where snow is said to lie for a large portion of the year. They 

 are stated to live in numerous troops, always ascending the loftiest trees, and feed- 

 ing on fruits, but when pressed by hunger eating also the leaves and shoots of the 

 bamboo. 



FOSSIL L,ANGURS 



As we might naturally suppose would be the case, fossil remains of langurs 

 have been found in their native land of India. Some of these have been obtained 

 from caverns in the Madras Presidency, and do not date back much, if at all, beyond 

 the human period. Other remains occur, however, in the much older Siwalik sand- 

 stones forming the ranges on the flanks of the Himalayas, and belonging to the upper 

 part of that division of the Tertiary period known to geologists as the Pliocene. 

 This does not, however, by any means limit the range of extinct langurs, since their 

 remains have been found in the Pliocene deposits of the Val d'Arno in Tuscany, and 

 also in strata of equivalent age in the south of France. We have, therefore, evi- 

 dence that these monkeys, which are now confined to the Oriental region, were 

 formerly widely spread over the Eastern Hemisphere. 



THE PROBOSCIS MONKEY 

 Genus Nasalis 



If the physiognomy of the Tibetan langur strikes us as ludicrous, it is hard to 

 say what epithet we ought to apply to the far more grotesque-looking creature rep- 

 resented in the accompanying figure. The nose of the proboscis monkey is indeed 

 so enormous in proportion to the face that it presents the appearance of an absolute 

 deformity, and it is very hard to imagine of what possible advantage it can be to its 

 owner. 



The proboscis monkey (IV. larvatus) is an inhabitant of Borneo, and its marked 

 difference from other monkeys is one of many proofs indicating the great antiquity 

 of that island, and the long period during which it has been isolated from other 

 lands. In general structure the proboscis monkey conforms so closely to the langurs 

 that the peculiarity of its nasal organ would not alone justify its separation from 

 that group as the representative of a distinct genus, although it was on this ground 

 alone that the separation was originally made. Subsequent researches have, how- 

 ever, shown that the skull can be distinguished at a glance from that of any of the 

 langurs, and also from those of the African genus Colobus, to be mentioned immedi- 

 ately, by the form of the aperture of the nasal cavity. Thus, whereas in the latter 

 this aperture extends upwards between the sockets of the eyes, in the proboscis 

 monkey the nose bones which roof over this aperture descend considerably below 



