Cuap. VI. MONKEYS. 125 
the inhabitants are obliged to close the doors and windows of their 
sleeping apartments ; and it is singular that this simple means of keeping 
out the pests seems to be pretty successful. On the Upper Amazons 
the precaution is of no use, and every one is obliged to sling his 
hammock under a mosquito tent. The whole of this coast, as well 
as the banks of the many inlets which intersect it, is inhabited by 
scattered settlers. The population of the municipal district of Obydos, 
which comprises about twenty miles of river frontage, is estimated at 
12,000 souls. 
I made a large collection in the neighbourhood of Obydos, chiefly of 
insects. The forest is more varied than it is in the Amazons region 
generally. There is only one path leading into it for any considerable 
distance. It ascends first the rising ground behind the town, and then 
leads down through a broad alley where the trees arch overhead, to the 
sandy margins of a small lake choked up with aquatic plants, on the 
opposite bank of which rises the wooded hill before mentioned. Passing 
a swampy tract at the head of the lake, the road continues for three or 
four miles along the slopes of a ravine, after which it dwindles into a 
mere picada or hunters’ track, and finally ceases altogether. Another 
shorter road runs along the top of the cliff westward, and terminates at 
a second small lake which fills a basin-shaped depression between 
the hills, and is called Jauareté-patia, or the Jaguar’s Mud-hole. The 
vegetation on this rising ground is, of course, different from that of 
the low land. The trees, however, grow to an immense height. Those 
plants, such as the Heliconiz and Marantacez, which have large, broad 
and glossy leaves, and which give so luxuriant a character to the moister 
areas, are absent; but in their stead is an immense diversity of plants 
of the Bromeliaceous or pine-apple order, which grow in masses amongst 
the underwood, and make the forest in many places utterly impene- 
trable. Cacti also, which are peculiar to the drier soils, are very 
numerous, some of them growing to an unwieldy size, and resembling 
in shape huge candelabra. 
The forest seemed to abound in monkeys, for I rarely passed a day 
without seeing several. I noticed four species: the Coaita (Ateles 
paniscus), the Chrysothrix sciureus, the Callithrix torquatus, and our 
old Para friend, Midas ursulus. The Coaita is a large black monkey 
covered with coarse hair, and having the prominent parts of the face of 
a tawny flesh-coloured hue. It is the largest of the Amazonian monkeys 
in stature, but is excelled in bulk by the “ Barrigudo” (Lagothrix 
Humboldtii) of the Upper Amazons. It occurs throughout the low 
lands of the Lower and Upper Amazons, but does not range to the 
south beyond the limits. of the river plains. At that point an allied 
species, the White-whiskered Coaita (Ateles marginatus) takes its place. 
The Coaitas are called by some French zoologists spider monkeys, on 
account of the length and slenderness of their body and limbs. In 
these apes the tail, as a prehensile organ, reaches its highest degree of 
perfection; and on this account it would, perhaps, be correct to con- 
sider the Coaitas as the extreme development of the American type of 
