ATELES. 7 
Central America, of which two just enter the subregion, and two are peculiar to it. 
These species may be thus diagnosed :— 
1. A. ater. Uniform black; face black. 
2. A. rufiventris. Black; underparts deep rufous. 
3. A. geoffroyi. Colour varying from deep red-brown to nearly white, without 
any definite line of separation between the colours of the flanks and lower 
parts. 
4. A. vellerosus. Black to red-brown above, sharply defined from the pale colour 
of the lower parts. | 
What relationship these last two forms may have with the Ateles belzebuth of 
Etienne Geoffroy*, which Humboldt identified with the “Marimonda” of the River 
Orinocof, must remain for future investigation; for the type of Geoffroy’s description 
cannot now be identified at the Jardin des Plantes, and no authentic specimens of such 
an Ateles from the Orinoco appears to exist in any European museum or menagerie. 
With reference, again, to the variation of the different species of this genus, it may 
still turn out that these so-called varieties are really restricted each one of them toa 
particular tract of forest in a way that our present rough knowledge of their distribution 
fails to discriminate; whether this is so or not can only be proved by the comparison 
of a series of specimens from carefully ascertained localities gathered from all points of 
the range of the genus. Such an examination may show, on the other hand, that some 
of the forms which I now regard as distinct grade into one another ; and if so my present 
views would require modification. But until such a series is brought together we have, 
I think, no choice but to follow the course here adopted with respect to the arrange- 
ment of the species. 
1. Ateles ater. 
Ateles ater, F. Cuvier, Mammif. i. t. 64 (39° liv. 1823, descr. orig.)’; Sclater, P. Z.S. 1872, p. 5°; 
Schlegel, Mus. Pays-Bas, vii. p. 170°. 
Hab. Panama, Colon (Dawes, Zool: Soc. Viv.2).—CoLomBia?; PERUVIAN AMazons?®. 
The range of the Black-faced Spider-Monkey extends from Eastern Peru through 
Colombia to Panama, several living specimens having been sent to the Zoological 
Society by Mr. J. B. Dawes and others from the latter State. Northwards of the 
Isthmus it has not yet been traced{. In Guiana and Brazil it is replaced by the 
closely allied Red-faced Spider-Monkey, A. paniscus (Linn.). 
* Ann. du Mus. vii. p. 272, pl. xvi. + Rec. d’Obser. de Zool. i. p. 325. 
+ Nicaragua has been assigned as a locality to some of the Zoological Society’s specimens (Rev. List Vert. 
An., 1877, p. 22); but this proves to have been an accidental error. 
