84 Lloyd's natural history. 



ternally their digestive organs differ from those of the Cerco- 

 pethecifice, the stomach being three times as large as that organ 

 in any Guenon of the same size. Instead of being a simple 

 rounded sac, it is elongate and composed of several pouches. 

 These compartments are quite different, however, from those 

 seen in a Ruminant's stomach, such as that of the Ox. In the 

 latter, each of the various divisions is differently constructed, 

 and its mucous membrane is peculiarly modified; in the 

 Guenon it is divided into two portions, the left of which forms 

 a very considerable cavity, while the right is long and narrow. 

 Two great, strong, muscular bands run along its entire length, 

 one along the greater, the other along the lesser, curvature, like 

 the muscles of the great intestine, forming a series of large 

 cells. (Otto.) In addition to this, the whole organ is twisted 

 upon itself, so that the entrance and exit regions come to be 

 close together. Its mucous membrane is throughout of the 

 same character and form. The caecum has no appe?idix veinni- 

 fori7iis^ or worm-shaped tube, which is the representative (as in 

 Man) of the elongate caecum found among the Lemuroids, as 

 among most of the Mammals. The muzzle in this Sub-family 

 is very short, and the nose is generally, but slightly, prominent. 

 There are ischial callosities, but no cheek-pouches among the 

 Langurs, tho-igh small ones have been described in certain 

 of the Guerezas {Colohus). When laryngeal sacs are present 

 they are formed of a single sac with a median aperture into the 

 windpipe, in the space below its superior opening ; it may have 

 large prolongations down the front of the neck, as far indeed as 

 the arm-pits. 



The frontal region of the skull is rounded, and the facial 

 angle is comparatively large. The ascending portion of rhe 

 hinder part of each half of the lower jaw is high, and its hind- 



