ORDER QUADRUMANA. 34*7 



Magots and Cynocephala from 42° to 45°. Finally, in the 

 Mandrills and Alouattes it seldom passes 30°. 



" It has been made evident that the divisions founded 

 upon this angle are by no means contrary to the natural 

 order. For in fact, the three first species which approxi- 

 mate to man in this respect (his facial angle as is well 

 known being about 70° at least), approach him also in other 

 points more nearly than any species beside. Their hyoid 

 bone, like his, is slender, their liver divided into two lobes 

 only, and their caecum provided with a vermiform append- 

 age. 



" Moreover the organic differences are found to follow 

 pretty closely the law of this angle: for example, the Ma- 

 gots and Cynocephala have' the hyoid bone of the form of 

 a buckler with a little sac beneath. The Mandrills have 

 only a sac somewhat larger, while in the Guenons and 

 Macaques it is entirely wanting, as also in the Sapajous. 



" The Alouattes, which are completely isolated by the 

 magnitude of the palatine angle, for it is 23° in those ani- 

 mals, have likewise a structure of the larynx altogether pe- 

 culiar to themselves. 



" But it has also been sufficiently apparent to us that, 

 though this character should be considered as the principal 

 one, it ought not to be employed alone, because it would 

 not serve as a perfect division for the different families : 

 we have therefore combined with it some others, with 

 which the number of the molar teeth, and the presence or ab- 

 sence of a bony crest above the eye-brows have furnished us. 



" From these investigations have resulted seven differ- 

 ent genera, of which the following is a tabular synopsis: 



