Remarkable Variations in Certain Monkeys. 195 
can reach tlie brandies of a tree. Except at da.y1»reak, one never lieara 
their very peculiar rattling note. The flesh of the older birds can only 
be chewed and enjoyed when they have been killed with urari poison 
which renders it quite delicate and tender. 
442. The Cchiis mentioned above differs not only in size, but also in 
its longer hair from Cebus capncinus and apclla: it might be almost 
taken for the capncinus. The dorsal surface of its body and of the 
extremities with the exception of the shoulder?, snd uppei' arms tliat are 
straw yellow is of a dark olive colour: on the skull is to be seen a black 
three cornered spot which in front is sharply defined and is continued 
to the root of the snout, and l)ehind is lost in the dark colouring of the 
nape of the neck: tlie scanty hairs on tho dorsaf surface are walnut- 
coloured, and ]ial(> golden yellow towards tbo tail-tip A\ hirh, however, is 
black. Forehead, clieeks and throat are walnut yellow, liaiiy, and the 
face l)lackish. The ventral surface of the body is coloured similarly to 
the upper, except that on account of the thinner hair, it appears some- 
what lighter. Hands and feet, like tlie inner sides of the forearms and 
legs are lilack. The tail, which is thick and long-haired, is longer than 
head and trunk taken together; its dorsal surface tallies with the 
colour of 'the dorsum of the body, the ventral surface and the tip on the 
other hand being black. The male exceeds the female not only in size 
but particularly also in the hair of the tail being considerably longer. 
The trunk and head of a full grown female measures IG, her tail 181, and 
hind-limbs lOi Paris inches. 
443. ISTo genus of monkey shows more variation in size, colour, and 
growth of hair than does the genus Crhus, in consequence of which a 
number of new species have been called into existence that are rea'lly 
nothing more than varieties that have arisen through the mixing of 
C capuchms with apclla. I have never met a troup of C. capnciiiii<i 
without finding some specimens of P. apclla in it. This continual 
association of the two species seems to have bi^ought about a mixture 
from which have arisen the very many differences relative to hair and 
colouring that have puzzled the zoologists. It is only in the Canuku 
Kanges that I can call to mind having met troo]is of monkeys that 
consisted solely of Cchus apclla: their haunts seem generallv limited to 
particular localities because, except in the Ranges just mentioned, I have 
only seen them on the coast and then always among C. capncinus witli 
which the neat little Callithrl.r sciurca had also often associated itself. 
I invariably found Mifcctcs, 'Atclcs, Pithccia and TTapalc absolutely 
separate from one another, and even among Piiliccla Icucoccphala never 
a specimen of Pithccia cliiropofcs. 
444. But however easily one could fall into error in the identification 
of a Cchus by mistaking a mere variety for a new species, it nevertheless 
seemed that the size, the long hair, and its very restricted area of distribu- 
tion in which I had never noted the ordinaiw Cchus capncinus and apclla, 
together with the fact of the Macusis having no knowledge of the animal, 
vindicated the statement that in it I had found a new species to which 
the name Cchus cMvaceus Schomb. might well be applied : it is never met 
below 3,000 feet. The Cchus are pets of the Indians and thus one finds 
M 2 
