It was not a man at all, it was a "guariba."

Of all the prehensile-tailed monkeys which haunt the forests of the
Upper Amazon--graceful sahuis, horned sapajous, gray-coated monos,
sagouins which seem to wear a mask on their grimacing faces--the
guariba is without doubt the most eccentric. Of sociable disposition,
and not very savage, differing therein very greatly from the mucura,
who is as ferocious as he is foul, he delights in company, and
generally travels in troops. It was he whose presence had been
signaled from afar by the monotonous concert of voices, so like the
psalm-singing of some church choir. But if nature has not made him
vicious, it is none the less necessary to attack him with caution,
and under any circumstances a sleeping traveler ought not to leave
himself exposed, lest a guariba should surprise him when he is not in
a position to defend himself.

This monkey, which is also known in Brazil as the "barbado," was of
large size. The suppleness and stoutness of his limbs proclaimed him
a powerful creature, as fit to fight on the ground as to leap from
branch to branch at the tops of the giants of the forest.

He advanced then cautiously, and with short steps. He glanced to the
right and to the left, and rapidly swung his tail. To these
representatives of the monkey tribe nature has not been content to
give four hands--she has shown herself more generous, and added a
fifth, for the extremity of their caudal appendage possesses a
perfect power of prehension.

The guariba noiselessly approached, brandishing a study cudgel,
which, wielded by his muscular arm, would have proved a formidable