THE UAKARI MONKEYS. 177 



along the hind border of the thigh and leg. (IF. A. Forbes). 

 Between the thigh and the lower part of the leg there is a wide 

 expansion of the skin behind the knee. 



The thumb is in the same plane with the other digits and not 

 opposable ; digits with compressed and rather elongated nails ; 

 the nail of the thumb and the great-toe shorter and more 

 " nail "-like ; upper surface of the hands and feet haired, on to 

 the fingers. The caecum (6 inches) and intestines (22 inches) 

 are absolutely and relatively longer than in any other New 

 World Monkey. 



Length of the body, 27-28 inches; of the tail, 6^ 



Distribution. — Forests on the north bank of the Amazons, 

 opposite 01iven9a, not passing eastwards of Iga on the Iga 

 river. The exact westward extension of this species still 

 remains unknown. The young specimen seen at Fonteboa by 

 Bates, and by him referred to this species, was more probably 

 B. calvus, as we know from the account given by Geoffrey 

 St. Hilaire and Castelnau, tl at the young of B. ruhicundus 

 resembles in coloration the adult, and is 7iot paler. 



Habits. — Gregarious and diurnal ; living in the high trees, 

 and feeding on fruits, probably exclusively, the length of its 

 intestines seeming to indicate that it is more of a vegetarian 

 than its allies. 



111. THE BALD UAKArI. BRACHYURUS CALVUS. 



Brachyurus calvus^ Is. Geoffr., C. R., xxiv., p. 576 (1847); id., 

 Arch. Mus., v., p. 560 (1845) ; Castelnau, Exped. Amer. 

 Sud, Mammif, p. 17, pi. 4, fig. i (1855); W. A. Forbes, 

 P. Z. S., 1880, p. 646; Beddard, P. Z. S., 1887, p. 119, 

 pi. xii. 



3— V. I. N 



