CHARACTERS OF THE SOUTH AMERICAN MONKEYS. 109 



I have had no opportunity of examining the dead body of a 

 female Ateles, but in living examples the clitoris attains a quite 

 unusual size. It is pink in colour and subcylindrical in shape, 

 and so greatly exceeds in size and prominence the penis of the 

 male, that people unacquainted with the facts invariably confuse 

 the sexes of this genus. This clitoris is apparently ungrooved, 

 and its apex is truncated and not incrassate. 



The Anal and Genital Areas of the Male. 



In the Marmozet Hapale jacehus the naked circum-anal in- 

 tegument, the ischial prominences, the scrotum, and the area 

 abov^e the scrotum are studded with white glandular pustules, 

 like those of the female. The penis, which emerges from the 

 centre of the naked area of pustular skin, the lower half of which 

 is formed by the anterior surface of the scrotum, is subacuminate, 

 ending distally in a subcylindrical prominence, which lies above 

 and overhangs the transversely crescentic urino-genital orifice. 

 (Text-fig. 13, A-D.) 



In Leontocebi(,s rosalia the pustules, as in the female, are 

 absent ; and the penis differs from that of H, jacehus in ending in 

 a definite hemispherical glans, carrying on the lower half of its 

 distal surface the transversely crescentic urino-genital orifice. 

 (Text-fig. 13, E, F.) 



In Mystax ursulus the subcaudal integument is without glan- 

 dular pustules, and the penis ends in a small hemispherical glans, 

 which is described in my notes as bilabiate. That epithet might 

 also be applied to the glans of Leontocehus ; but whereas in the 

 latter the labia are apparently dorsal and ventral, in Mystax 

 they appear to be lateral and to close over the small subcentral 

 orifice of the urethra. 



Fresh ma.terial, hovi^ever, is required to substantiate these 

 apparent differences in the glans in the genera of Hapalidse. 



In the Cebidse the penis differs to a greater or less extent in 

 the genera examined. In Sa,imiris it terminates in a somewhat 

 cordate glans with longitudinally elongated orifice on its under- 

 side (text-fig. 13, G, H). In Gallicehus personatus the generative 

 area of the male closely resembles that of the female, the scrotum 

 recalling the labia of the generative orifice and the penis re- 

 sembling an enlarged clitoris. The penis, which is short, ends in 

 an ovate glans, with an elongated orifice on its inferior or pos- 

 terior side as in Saiviirls (text-fig. 12, C-F). In Callimico (text- 

 fig. 12, G), the penis has a hemispherical glans with terminal 

 orifice. 



In Ateles the penis is subcylindrical from the ba,se to the tip, 

 which is a little expanded. Its distal extremity is a nearly flat, 

 subcircular area, the orifice piercing the middle of its lower half 

 (text-fig. 13, K-M). In an immature example of Lagothrix infu- 

 matus the penis apparently difters from that of Ateles in having 

 the orifice in the middle of the terminal field. In neither of 



