ZOOLOGY. 
447 
extent of country, and never occur in such large num- 
bers as do the animals representing them in other parts 
of the world. 
Those singular creatures, the sloths, the armadilloes, 
and the ant-eaters, are very generally distributed, but 
only occur singly and sparingly. The small agoutis are 
perhaps rather more plentiful ; but almost the only ani- 
mals found in any numbers are the monkeys, which are 
abundant, both in species and individuals, and are the 
only mammalia that give some degree of life to these 
trackless forests, which seeiii peculiarly fitted for their 
development and increase. 
I met with twenty-one species of these animals, some 
of which I had no opportunity of examining. Several 
others exist ; but it is necessary to reside for some years 
in each locality, in order to meet with all the different 
kinds. I subjoin a list of the species, with the localities 
in which they were found. 
MONKEYS FOUND ON THE AMAZON AND RIO NEGRO. 
1. Mycetes seniculus, Geoff.; on the Rio Negro and 
the north bank of the Amazon. 
2. Mycetes car ay a, Gray; on the Upper Amazon. 
3. Mycetes beehehub, Br. Mus.; Para, 
4. Layothrix Humboldtii, Geoff.; Upper Amazon and 
west of Rio Negro. 
h. '^Ateles paniscuSy Geoff.; Guiana, north bank of 
Amazon and east of Rio Negro. 
6. Cebus apeltay Erxl. (?) ; Amazon and Rio Negro. 
7. Cebus gracilis y Spix; Rio Negro and Upper Amazon. 
8 . CaUitlirix sciureuSy Geoff. ; the whole Amazon valley. 
