THE SAPAJOUS. 211 



very abundant, and in all the sonorous voice is con- 

 spicuous. 



The next group which occurs is 



THE SAPAJOUS, 



Containing animals of a more slender form ; milder 

 dispositions ; the face rather flat ; the tail very long, 

 and the whole form in the general contour allied to 

 the Guenons of the Old World. The first genus to be 

 mentioned is Ateles of Geoffroy, so named from the 

 imperfect structure of the fore extremities, which want 

 the thumbs, and thus bear analogy to those of Colobus 

 in the first geographical division. It may be charac- 

 terised by a facial angle of about 60 ; by the extre- 

 mities being very long and slender; the fore 

 hands destitute of a thumb, or having that member 

 supplied by a rudiment ; the tail very long, covered 

 at the tip with a delicate skin, strongly prehensile ; 

 the os hyoides large, but not apparent on the outside. 



By Geoifroy, two species, which have a rudimentary 

 thumb, are generally placed at the commencement of 

 this genus the A. hypoxanthus and Subpentadactytus ; 

 but the form is well represented by 



