LECTURE VIII. 



205 



fronted cebus belong to two different divisions of tlie genus 

 cebus. The first, according to Grirbel, belongs to the species 

 possessing five ribless lumbar vertebrae, a compact structure, 

 a thick globular head^ powerful teeth, large canines, short 

 limbs and tail ; whilst the white fronted Capuchin ape belongs 

 to the species possessing six ribless lumbar vertebrae, small 



Fig. 75. Skull of the Cebus albifrons, top view. 



canine teeth, and a slender structure. Vfe thus find here 

 more than a simple specific difference, so that some natural- 

 ists felt justified in establishing two sub-genera ; neverthe- 

 less I selected these two species simply because in the Geneva 

 Collection I found tvfo male skulls of the same age and 

 size. 



The Roll-apes {Cebus) possess a long hair}- roll-tail. The 



