314 SAIMIRI 



12.5 ; length of mandible, 45.6 ; length of lower molar series, 14.5. Ex 

 type British Museum. 



This species resembles S. sciureus but the forearms are bluish 

 gray instead of fulvous. Several specimens were obtained by W. 

 Hoffmanns. The exact locality being about 63° West and 7° 30' South. 



Saimiri tjstus I. Geoffroy. 



Saimiri ustus I. Geoffroy, Archiv. Mus. Hist. Nat., Paris, IV, 1844, 

 p. 15, pi. I ; Reichenb., Vollstand. Naturg. Affen, 1862, p. 16, 

 fig. 40; Bartlett, Proc. Zool. Soc. Lond., 1871, p. 219; Sclat, 

 Proc. Zool. Soc. Lond., 1872, p. 688, fig. (head). 



Saimiri ustus Dahlb., Stud. Zool. Fam. Reg. Anim. Nat., fasc. I, 

 1856, pp. 157, 158. 



Chrysothrix ustus Gray, Cat. Monkeys, Lemurs and Fruit-eating 

 Bats, Brit. Mus., 1870, p. 53. 



Saimiri sciureus Schleg., Mus. Pays-Bas, Simiae, 1876, p. 242, 

 (nee Linn.). 



Chrysothrix usta Forbes, Handb. Primates, I, 1894, p. 154. 



GEOFFROY' S SQUIRREL OR TITI MONKEY. 



Type locality. Unknown. Type in Paris Museum. 



Geogr. Distr. Peruvian Amazons, Bolivia. 



Genl. Char. Ears naked save a fringe of hairs on the inside near 

 the upper edge ; general color golden yellow and black. 



Color. Upper part of head, shoulders, upper arms to elbow, and 

 hind limbs to ankles golden yellow speckled with black, the hairs being 

 golden yellow with black tips ; back from neck to rump orange red 

 and black, the latter being the tips to the orange red hairs ; face around 

 eyes and upper part of nose flesh color, muzzle black; cheeks pale 

 yellow ; sides of head and neck, throat, under parts of body and fore- 

 arms golden yellow ; hands and feet reddish brown ; tail, hairs golden 

 yellow with black tips, the tip of tail all black. Ex type Paris Museum. 



Measurements. Size about equal to S. sciurea Linn. Skull : total 

 length, 72. (Geoff. Arch. Mus.). 



The type of this form is in the Paris Museum and fairly well 

 preserved, though probably the golden yellow of the greater part of the 

 body has faded somewhat. The back, however, is conspicuous for 

 the depth of its orange red color, and more resembles the hues of the 

 Central American forms than any of the eastern South American 

 examples. With our present knowledge of this group, in spite of 

 Schlegel's unqualified statement, (1. c.) it seems best to consider 



