ON THE UAKARI MONKEYS. 125 



OuaJcaria calva, Gray, Cat. Monk. p. 62 (1870). 



Pithecia calva, Schl. Mus. P.-B. vii. p. 228 (1876). 



Pithecia alba, Schl. Mus. P.-B. vii. p. 229 (1876). 



Corpore fulvido-albicante, subtus saturatiore. 



Hob. Opposite Fonteboa (Castelnau $ Deville) ; banks of the Japura 

 delta, west of its mouth {Bates). 



According to Castelnau (I. c. p. 567), B. calvus is confined to the forests 

 lying on the north bank of the Amazons, between the rivers Putumayo 

 (or lea) and Japura. 



The locality " Para," given to the species by its discoverer M. Lisboa, 

 and also marked on the mounted specimen in the British Museum, is of 

 course a mistake, as already pointed out by Schlegel (1. c. p. 226). Mr. 

 Bates's notes on this species and the next, and their distribution, are well 

 known to naturalists. On his short description and the figure in the 

 second edition of the * Naturalist,' Prof. Schlegel has attempted to found 

 a fourth species, " Pithecia alba." But, in the first place, the short de- 

 scription given, as well as the locality, suit B. calvus quite well ; and, 

 secondly, there is a specimen in the British Museum, purchased of 

 Stevens, which in all probability was one collected by Mr. Bates himself, 

 and is quite the same as three other specimens of that species. 



3. BRACHYUBUS RUBICUNDUS. (Plates IV., V.) 



Brachyurus rubicundus, Isid. Geoffr. & Dev. C. B. xxvii.p. 498(1848); 

 Geoffr. Arch. Mus. v. p. 564, pi. 30 ; Exped. Am. Sud, Mamm. p. ] 9, 

 pi. 4. fig. 2 (head). 



OuaJcaria rubicunda, Gray, Cat. Monk. p. 62 (1870). 



Pithecia rubicunda, Schlegel, Mus. P.-B. vii. p. 228 (1876). 



Corpore castaneo-rufo, collo pallidiore. 



Hab. Forests on the north bank of the Amazons opposite Olivenca, not 

 passing eastwards of the lea (Castelnau). 



The exact westward extension of this species still remains unknown. 

 The young specimen seen at Fonteboa by Bates (I. c. p. 313) and by him 

 referred to this species, was more probably B. calvus, as we know, from 

 Geoffroy and Castelnau's account, that the young of B. rubicundus 

 resembles in coloration the adult, and is not paler. Opposite Fonteboa, p z S 1880 

 moreover, is exactly the locality where the French expedition obtained P- 647. 

 B. calvus, and is well within the limits assigned to that species by 

 Castelnau. 



B. rubicundus is the western representative of B. calvus, which it very 

 closely resembles, but can at once be distinguished by its very different 

 coloration, being nearly all over of a rich deep chestnut, only paler on 

 the neck, instead of the pale sandy- white, slightly rufous below and on the 

 inside of the limbs, of the last species. The fact of the series of individuals 

 of each of these species obtained by Castelnau and Deville differing to no 



