ANATOMICAL STRUCTURE OF ANTHROPOID APES. 57 



Figs. 15, 16). The frontal bone, which in the young 

 of both sexes is high, broad, and arched, becomes 

 depressed in the centre in the aged male. The 

 temporal ridges, thickened to a hem, pass over this to 

 the coronal crest. 



Fig. 16.— Front view of tlie skull of an aged male gorilla. 



This crest is highly characteristic. It begins in the 

 region of the frontal bone, and, rising abruptly, unites 

 itself with the transverse ocoipital crest. It is of 

 varying height,* but is rarely altogether absent in 

 an adult male animal. On the top of this coronal 



« 



The coronal oreafc haa attained to a quite unusual height in 

 the fine epecimen of the skull of an aged male gorilla, No. 92, in 

 the Natural History Museum in Paris. 



