S6 LLOYD^S NAttrkAL IIISTORV. 



tinguishes them from the Langurs, which (with the exception 

 of the monotypic Nosed Monkeys of Borneo) form the re- 

 maining members of the Sub-family, is the condition of their 

 thumbs. In these animals the thumb is practically absent, 

 being either quite invisible externally, or presenting merely a 

 tubercle, which may or may not have a nail upon it. The 

 hands are long and straight, and the nails of the fingers are 

 compressed and pointed. In these animals the body is slender, 

 though somewhat more robust than in Semnopithecus. The 

 face is naked or covered only with a sparse and soft down, 

 the nostrils being separated by a wide division. From this 

 feature these Monkeys have been described by some naturalists 

 as Platyrrhine or Megarrhine. The ears are rounded above, with 

 the posterior upper angle pointed or square, and generally 

 naked, but they are sometimes haired or tufted inside. All the 

 Guerezas have a specially elongated tail, which is often tufted 

 at the end. Their fur is long and slightly harsher than that of 

 the Langurs, but it is not ringed with differently coloured 

 bands. Their callosities are large and naked. 



The skulls in Colobus and Semnopithecus are very similar in 

 shape ; but those of the former are often longer, larger, and 

 have a greater cranial capacity than those of the Senuiopitheci, 

 The muzzle is short, and the hind molar of the lower jaw has 

 five tubercles. The thumbs, even when apparently absent, 

 are represented under the skin by a single bone, the ungual 

 phalanx, which articulates directly with the metacarpal bone. 

 The Guerezas differ from the Guenons in having very small 

 cheek-pouches and no laryngeal sacs. Their stomach is trans- 

 versely sacculated like the upper part of the great intestine in 

 the human body. 



The Guerezas, which represent the Langurs in Asia, inhabit 



