THE CTNOMOEPHA, 469 



being inliabitants of the old world. They fall into two very 

 distinct groups, the Cynomorpha and the Anthropomorpha. 



a. The Cynomorpha are distinguished from the other 

 group by being essentially quadi-upedal and, usually, pro- 

 vided with a tail, which is never prehensile. The femur and 

 tibia, taken together, are longer than the humerus and the 

 radius. The outer inferior incisors are not larger than the 

 inner ones, but are often smaller. The crowns of the 

 molar teeth present two transverse ridges, a third being 

 present, in some genera, on the last inferior molar. 



AH the Cynomorpha have ischial callosities, which some- 

 times attain a very large size, and are brightly coloured. 



The dorsolumbar region of the spinal column is concave 

 towards the ventral aspect, and the lumbo-sacral angle is 

 very large. The atlas has nai'row transverse processes. 

 The ordinary number of dorsolimibar vertebrae is nineteen, 

 of which twelve, or thii-teen, are dorsal ; and seven, or six, 

 lumbar. The middle cervical vertebrae have short spines, 

 which are not bifui'cated at their extremities. In the pos- 

 terior dorsal, and anterior lumbar, vertebrae, the mammillary 

 and accessory processes may be enlarged and interlock. 

 The long transverse processes of the lumbar vertebrae bend 

 forwards. The sacrum usually contains only three a,n- 

 kylosed vertebrae. The caudal vertebrae vary in number, 

 from three in Inuus (where they form little more than a 

 coccyx), to as many as thirty-one. In the anterior part of 

 the tail the vertebrae are provided with subvertebral, or 

 chevi'on, bones. 



The thorax is laterally compressed, and the manubrium 

 of the sternum is broad ; but the six or seven ste rnebrae 

 which follow it are compressed and constricted. 



The skull presents a considerable range of variation. In 

 the Semnopitheci and Colobi, the frontal region is rounded, 

 the facial angle is comparatively large, and the ascending 

 portion of the ramus of the mandible is high. In the 

 Macaci and Cynocephali, on the other hand, the supra- 

 orbital ridges become so much enlarged as to hide the 

 forehead; and the horizontal portion of the ramus of the 



