164 ALLEN'S NATURALIST'S LIBRARY. 



Distribution. Upper Amazon. Of all the species of the 

 genus, this ranges furthest to the south to 14 S. lat. 



VIII. THE BLACK-FRONTED TITI. CALLITHRIX NIGRIFRONS. 



Callithrix nigrifrons, Spix, Sim. et Vespert. Bras., p. 21, pi. 15 

 (1823); Gray, Cat. Monkeys Brit. Mus., p. 56 (1870); 

 Schl., Mus. Pays Bas, vii., p. 232 (1876). 



Characters. Nearly allied to the Masked Titi (C. personata), 

 but distinguished by the nearly white back of the head and 

 nape of the neck, and by the hairs at the base of the tail 

 being entirely red. 



Distribution. Upper Amazonia. 



IX. THE RED-BELLIED TITI. CALLITHRIX CASTANEIVENTRIS. 



Callithrix castaneoventris, Gray, Ann. and Mag. N. H., xvii., p. 



58 (1866); id., Cat. Monkeys Brit. Mus., p. 56 (1870). 

 Callithrix caligata, Wagner, Arch. f. Naturg., 1842, i., p. 454 



(ex Natterer, MSS.) ; Schl., Mus. Pays Bas, vii., p. 237 



(1876). 



Characters. Fur of the same nature as in C. cufrea, black, 

 ringed with grey ; face grizzled, whiskers, throat, chest, under 

 side of the body, and inner surface of the limbs reddish-chest- 

 nut ; outside of the limbs grizzled, washed with rufous ; fore- 

 head, hands, feet and tail black ; tip of the tail paler. 



Distribution. Paraguay and Brazil ; Borba, Rio Madeira. 



The two following species may be distinguished from those 

 already described by having their soft woolly fur entirely free 

 from the long bristly hairs, which were dispersed through the 

 fur of the others. 



