ON THE ARRANGEMENT OF THE SIMIADJE. 359 



affinities of the members composing it. He will meet, at the outset, with a 

 group nearer to Man, in certain structural details, than the rest; viz., the 

 Chimpanzee, the Orangs, and the Gibbons, forming three genera, obviously 

 allied to each other, and as obviously separate from all that succeed. 

 Amidst the numerous genera still remaining, he will discover that some 

 present a strange and, indeed, unexpected structure of the stomach, 

 accompanied by an exclusively frugivorous appetite. Instead of being 

 simple, the stomach is complex and sacculated ; and the molars, as if to 

 keep up the analogy to the ruminant form, are deeply indented by 

 re-entering folds of enamel ; so that, when worn, they remind us of 

 those of the deer or sheep. In addition to 'these characters, he finds 

 great elongation of the organs of prehension, and an abbreviated or 

 even rudimentary condition of the fore-thumb. 



The importance of these structural characters, accompanied, as they 

 are, by corresponding habits, and minor details of organization, will 

 indicate at once the distinctness of such a group. Hence, the genus 

 Semnopithecus of India, and, provisionally, the genus Colobus of 

 Western Africa, will constitute a second sub-family. The remaining 

 Simiadse he will find to consist of several omnivorous genera, beginning 

 with the genus Cercopithecus, and advancing gradually through a series 

 of transitions to the Baboons (Cynocephalus), which in carnivorous pro- 

 pensities, ferocity, and canine-like development of muzzle, exceed all 

 the rest ; but, as he traces the gradation of form, the manner in which the 

 Cercopitheci approximate to the Macaci, and how, again, these seem, as it 

 were, to merge into the Cynocephali, he will conclude that they form a third 

 natural group, or sub-family ; and he will perceive the discordance of the 

 divisions of Buffon with those indicated by Nature. The following repre- 

 sentations (figs. 250, 251, 252, 253) shew the transition, as far as physi- 

 ognomy and the form of the head are concerned, from the Cercopitheci, 

 through the Macaci, to the Cynocephali. Such, then, is the general 

 result of an analysis of the Simiadae. It must, indeed, be acknow- 

 ledged, that the views of many writers differ from those here expressed ; 

 for the Semnopitheci are still placed, by some, among the " long- tailed 

 Guenons," or group of which the genus Cercopithecus constitutes a 

 leading part ; while, on the contrary, the Macaques and Baboons* are 

 regarded as forming a group per se. The very remarkable and import- 

 ant structural peculiarities, however, of the Semnopitheci, separate them 

 (and their immediate allies) as distinctly from the Cercopitheci as they 

 do from the Gibbons. 



* Some writers prefer associating the Macaques with the Cercopithecine group, reserving the 

 Baboons (Cynocephalus, Cuv., and Papio, Bris.) as a sub-family by themselves. Mr. Ogilby refers the 

 long-tailed Macaci to the genus Cercopithecus, and founds a new genus, termed Papio, for the Ma- 

 caques with short or with tuberculous tails. 



