ANTHROPOMORPHlDsE. 



789 



wards, those of the forearm upwards ; except the plantigrade 

 gibbons, the apes tend to walk on the edges of their feet ; 

 there are no cheek-pouches ; there are no ischial callosities 

 except in gibbons ; the caecum has a vermiform appendix. 



The Gibbons (Hylobates] live in S.-E. Asia, especially in the Malayan 

 region. The largest attains a height of 3 ft. They walk erect with 



FIG. 418. Skull of Orang-Utan. 

 /., Parietal ;/., frontal ; j^., squamosal ; /., jugal ; m., maxilla. 



the hands reaching the ground. The skull is not prolonged into a 

 vertical crest. There is an os centrale in the carpus. The hallux is 

 well developed. The only flat nails are those of pollex and hallux. 

 There are 13 ribs and 18 dorso-lumbar vertebrae. There are small 

 ischial callosities, the only instance in Anthropoids. They are mainly 

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



