xxvi INTRODUCTION 



species of Lasiopyga. The Langurs, as they are called, are rarely seen 

 in Zoological Gardens as their delicate constitutions cause them easily 

 to succumb when held in captivity. 



Rhinopithecus is the second genus with three species, large 

 animals with the nasal portion of the face depressed, the nose very 

 small and the end turned upward giving a very bizarre expression to 

 the countenance. One species has bright colors, roxellan^e, the others 

 are garbed in more sober hues, but their size makes them imposing, and 

 to rank among the finest species of the Primates in the Family to which 

 they belong. The next genus Simias contains but one species, a 

 curious creature apparently, a connecting link between Rhinopithecus 

 and Nasalis as it possesses characters peculiar to each. Thus, it has 

 the upturned nose of the members of the first genus, and also similar 

 teeth, with cranial characters resembling those of the Proboscis 

 monkey. It is altogether, considering the above mentioned peculiarities 

 and its short naked tail with the terminal tuft, not comparable with any 

 species of the Order; a very remarkable animal. 



Nasalis is the fourth genus with an equally extraordinary species, 

 its greatly lengthened nose turned downward. This organ has a 

 depression in the center and is capable of being dilated. The laryngeal 

 sac is large, and there is a beard on the chin. There is but one species 

 known. The last genus of the Family is Colobus containing the 

 Guerezas of which there are thirty species, composed of the red and 

 black Guerezas, the former constituting about two thirds the entire 

 number. These animals have the thumb absent or rudimentary. They 

 are large in size, and the black Guerezas are ornamented on different 

 parts of the body, with long white hairs falling like a fringe, and the 

 tails are more or less tufted with white. The fourth Family is Hylo- 

 bathxe containing the Gibbons, with two genera, Hylobates with 

 twelve species, and Symphalangia with one species and two sub- 

 species, one of which, continentis is somewhat doubtful. These flying 

 Apes are, among other characters, remarkable for the length of their 

 arms, which, when the animal is erect, permit the hands to reach the 

 ground. They walk erect, balancing themselves somewhat awkwardly 

 by holding the arms, crooked at the elbow, over the head. The ischial 

 callosities are small and they are the last of the large Ape-like species to 

 possess them. The species and subspecies of Symphalangia are the 

 largest in size, and differ from those of Hylobates in having the second 

 and third toes united by skin up to their last joint, and the skin of the 

 throat is distensible and overlies the laryngeal sac by the thyro-hyoid 

 membrane. 



