768 



MAMMALIA. 



ivrboreal in their habits. They feed on fruits, leaves, shoots, eggs, 

 young birds, spiders, and insects. Their voice is powerful, and one 

 species (the Siamang) has a laryngeal sac. As regards teeth, the 

 gibbons are most like man. Some authorities rank the gibbons in a 

 separate family apart from the three other Anthropoids. 



The Orangs (Simia) live in swampy forests in Sumatra and Borneo. 





FIG. 375. Skull of Orang-Utan. From Edinburgh. 

 Museum of Science and Art. 



/., Parietal ; j., frontal ; sy., squamosal ; /., jugal ; ;//., maxilla. 



The males measure over 4 ft. They walk on their knuckles and 

 on the outer edges of the feet. The skull is prolonged into a vertical 

 crest. There are but slight supra-orbital ridges. The canines are very 

 large. There are twelve ribs as in man, and sixteen dorso-lumba'r 

 vertebra:. The larynx is connected with two large sacs which unite 

 ventrally. They are arboreal in their habits, and make nests in the 



