108 CEBUS 



matic width, 72.3 ; median length of nasals, 28.3 ; palatal length, 32.3 ; 

 length of upper molar series, 23.9 ; length of mandible, 67 ; length of 

 lower molar series, 27.5. 



The type of this species was described from Paraguay. Not 

 having seen an example from that district of Brazil, the above descrip- 

 tion was taken from an individual obtained at Serra da Chapada, 

 Matto Grosso, to the north of Paraguay, and on the west of the River 

 Parana, and which as far as Rengger's rather insufficient description 

 enables us to ascertain, is the same as the Paraguay specimens. It is a 

 very variable species and the individual described represents as 

 nearly as possible its general appearance. But there are darker and 

 paler styles, which, while having a general resemblance, differ con- 

 siderably in their depth of coloring. Thus, in the pale style the cream 

 buff predominates over all the body and upper part of limbs, the 

 blackish hues not extending above the elbows or knees, while the 

 darker form has the entire upper parts sepia with the line in front of 

 ears beneath chin darker and more conspicuous. Ten specimens in 

 the British Museum from Chapada exhibit these different and striking 

 variations, the examples grading from nearly white to sepia. Young 

 animals are much paler than the adults. 



The type of C. elegans Geoffroy, in the Paris Museum, may also 

 be assigned to this species. It is not so dark on the back, and the 

 under parts are paler, but when we consider that the specimen has been 

 in the Museum since 1812 exposed to the light for nearly a century, 

 no surprise should be felt if it had in places become greatly faded. The 

 tail is still brownish black and dark brown at tip and the digits are 

 gray. 



Cebus azar^ pallidus Gray. 



Cebus pallidus Gray, Proc. Zool. Soc. Lond., 1865, p. 826 ; Id. Cat. 

 Monkeys, Lemurs and Fruit-eating Bats, Brit. Mus., 1870, 

 p. 49. 



Type locality. Bolivia. Type in British Museum. 



Geogr. Distr. Santa Anna, Peru, into Bolivia. Complete range 

 unknown. 



Color. Forehead and temples yellowish white, extending in a 

 narrow line on each side into the black cap, not meeting but nearly 

 forming two black patches on the head ; top of head and nape black ; 

 narrow brown line down sides of head in front of ears to chin ; dorsal 

 region between shoulders dark bistre, grading into Prout's brown on 



