206 ALLEN'S NATURALIST'S LIBRARY. 



ever, are not yet numerous enough, nor exact enough, to enable 

 those who have only studied the species alive in Europe, or had 

 skins, to decide with such imperfect data as to their sex, age, 

 and habitat. Not until some naturalist has made a prolonged 

 study of these animals in their native country, and watched 

 their conduct and relations in the living state, can we hope to 

 attain to any certain knowledge of how many species the genus 

 contains ; and of the differences between the old and young of 

 both sexes at different periods from youth to age. 



I. THE WHITE-THROATED CAPUCHIN. CEBUS HYPOLEUCUS. 



Sat d gorge blanche, Buffon, Hist. Nat. Mamm., p. 64, pi. 15, 



fig. 9 (1767); Fr.Cuv., Hist. Nat. Mamm., livr. xvi.; Audeb. ; 



Hist. Nat. Singes, fam. v., sect. 2, pi. 5 (1797). 

 Si in ia hypokuca, Humb., Obs. Zool., i., p. 337 (1811); Pucher., 



Rev. et Mag. de Zool. (2), 1857, p. 348. 

 Cebus hypoleucus, Geoffr., Ann. Mus., xix., p. 111(1812); Gray, 



Cat. Monkeys Brit. Mus., p. 50 (1870); Schl., Mus. Pays 



Bas, vii., p. 190 (1876). 

 Cebus leucocephalus, Gray. P. Z. S., 1865, p. 827, fig. 4; Sclater, 



P. Z. S., 1872, p. 4 ; Alston in Godman and Salvin, Biol. 



Centr. Am. Mamm., p. 13 (1879). 



Characters. Hair very silky, smooth and stiff, and thicker 

 above than below. Face and forehead nude, flesh-coloured; 

 hands and feet nude, of a violet hue, as also the thinly- 

 haired skin of the under side of the body. The tip of the tail 

 fora short distance being naked, distinguishes this species from 

 all others. Shoulders, arms, and sides of the head behind the 

 ears pure white ; chest and throat yellowish ; rest of the body 

 deep black. 



