First we have the Sakis, which have a bushy tail and usually very long
and thick hair, something like that of a bear. Sometimes the tail is
very short, appearing like a rounded tuft of hair; many of the species
have fine bushy whiskers, which meet under the chin, and appear as if
they had been dressed and trimmed by a barber, and the head is often
covered with thick curly hair, looking like a wig. Others, again, have
the face quite red, and one has the head nearly bald, a most remarkable
peculiarity among monkeys. This latter species was met with by Mr. Bates
on the Upper Amazon, and he describes the face as being of a vivid
scarlet, the body clothed from neck to tail with very long, straight,
and shining white hair, while the head was nearly bald, owing to the
very short crop of thin gray hairs. As a finish to their striking
physiognomy these monkeys have bushy whiskers of a sandy color meeting
under the chin, and yellowish gray eyes. The color of the face is so
vivid that it looks as if covered with a thick coat of bright scarlet
paint. These creatures are very delicate, and have never reached Europe
alive, although several of the allied forms have lived some time in our
Zoological Gardens.

An allied group consists of the elegant squirrel monkeys, with long,
straight, hairy tails, and often adorned with pretty variegated colors.
They are usually small animals; some have the face marked with black and
white, others have curious whiskers, and their nails are rather sharp
and claw like. They have large round heads, and their fur is more glossy
and smooth than in most other American monkeys, so that they more
resemble some of the smaller monkeys of Africa. These little creatures
are very active, running about the trees like squirrels, and feeding
largely on insects as well as on fruit.

Closely allied to these are the small group of night monkeys, which have