THE OWL MONKEY. 
18£ 
with a large round head, short face, and very large eyes ; their fur is kept close; they have a tail of some 
length, but it can only curl around objects without holding on. The body is short, and greatly resembling 
that of the Squirrel Monkey in some points. They are distinguished as follows : — The two middle 
upper front teeth (incisors) are broad, and the lower ones project in a slanting direction ; the canines, 
are moderately long. The ears are partly hidden amongst the hair of the head, and the eyes are large. 
There is a curious condition of the upper arm-bone (humerus) of these Monkeys, which they have in 
common with the different kinds of Cebus, the Squirrel Monkeys, and the little Ouistitis about to be 
mentioned. It is, moreover, seen in the Carnivora, or the flesh-eating animals. The lower part of the 
bone, where it is jointed to the two bones of the fore-arm, at the elbow, has one of its projections there 
(the inner condyle) perforated by a hole. This gives passage to the main artery of the limb and 
the main nerve, and the use of it appears to be to prevent the contracting muscles of the arm pressing 
upon these important structures. They resemble some of the lower animals, especially one of the 
Lemuroida, of the genus Stenops, in the length of the loin back- 
bones ; and, indeed, relatively this lumbar region is longer in them 
than in any other Monkey. The rib-bearing back-bones are more 
numerous than in other Monkeys, and there are either fourteen or 
fifteen of them, and, moreover, their spines are much prolonged 
forwards, as in carnivorous quadrupeds. 
THE THREE-STEIPED OWL MONKEY .* 
This is another of the interesting objects first made known to 
us by the researches of M. Humboldt, who described it as one 
of the most remarkable Monkeys of South America. According 
to the account of this well-known traveller, its habits are com- 
pletely nocturnal, as it wanders about only during the night, and 
retires into hollow trees, or rather recesses, to sleep away the day. In captivity it generally 
composes itself to rest at nine in the morning, and continues in that state until seven in 
the evening ; if, during this period, it is awakened, it becomes melancholy, listless, and stupid, 
and seems to have much difficulty in opening its large, owl-like eyes. M. Humboldt’s 
figure represents the animal dormant. No sooner, however, does the setting sun bring the return 
of twilight, which to him is his “ opening day,” than our little Monkey becomes all life and 
impetuosity. Pie then commences his hunt (if unconfined) after small birds, insects, and probably 
fruits, since he shows no objection to the latter aliment when in captivity. This carnivorous 
disposition may probably account for the extreme difficulty with which this species is tamed. An 
individual in the possession of the traveller, and which he kept for nearly five months, could not be 
reconciled to captivity. It slept during the day, hiding itself in the darkest recess it could find. It 
seldom played with its master, but showed particular cleverness in capturing flies, and, if irritated, 
it hissed and struck with its paw like a Cat, the throat being at the same time inflated. Its voice, 
for so small an animal, is extremely powerful ; at times it is described as faintly resembling the 
howl of the American Tiger, or Jaguar ; and at others to be a kind of mew, accompanied by 
a disagreeable guttural sound. The hair is grey, mixed with white, and glossed with a silvery 
lustre. The centre of the back is marked by a brown line, and on the head and forehead are three 
others, diverging, and of a black colour. The chest, belly, and under surface of the limbs are yellowish- 
orange. The face resembles that of a Cat, and is covered with blackish hail’s. The eyes are very 
large, and the ridges of a bright yellow. The tail is bushy, and half as long again as the body, which 
measures nine inches and a half. 
Mr. Bates is quoted in the following passages with reference to this and other kinds of Nyctipi- 
theci, and their resemblances : — 
“ An interesting genus of Monkeys, found near Ega, are the Nyctipitlieci, or Night Apes, called 
Ei-d by the Indians. Of these I found two species, closely related to each other, but nevertheless quite- 
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* Nyctipithecus trivirgatus. 
