X Quadkumana. MAMMALIA. Quadrumana. 
rig. iv. 
Skull of Howler. 
THE BROWN HOWLER [Mycetes senimlus) 
2, fig-. 5, and described in vol i, p. 38 — is one of a group 
liaving a most remarkable development of the hyoid 
bone and the under jaw, both increased in depth to 
allow of a peculiar formation of the vocal organs ; 
their voice is thereby greatly increased in volume, 
and they have accordingly been called Howlers. Or- 
ton says, “ They are gifted with a voice of tremen- 
dous power and volume, with which they make night 
and day hideous. Gangs of these large, howling crea- 
tures often entertained us with their terrific yells 
which, in the truthful language of Bates, increased 
tenfold the feeling of inhospitable wildness which the 
forest is calculated to inspire.” He adds : “ They are 
the only Monkeys which the natives have not suc- 
ceeded in taming.” They represent the Baboons of 
the Old AVorld in facial angle (30'^) and disposition, 
and the Gibbons in their yells and gregarious habits. 
THE URSINE HOWLER [Mycetes iminm) — called 
also the Araguato — is one of the largest as w-ell as 
most abundant of the Monkeys of the New AVorld. In 
length they are nearly three feet ; the tail somewhat 
exceeding that. 'J’he color of the fur is of arich reddish- 
brown, reflecting a bright golden sheen when a strong- 
light is thrown upon it. I'here is a heavy beard, con- 
sisting of long hairs, depending from the chin, and 
cheeks of a darker hue. It is impossible to conceive 
of the intensity of the howling voice of these creatures; 
they seem to delight in imitating the sounds of other 
animals, as that of the Jaguar. They are reputed to 
hold conversations, in which each seems striving to 
outdo the rest. I'he anatomical structure of the 
throat of these animals explains readily their great 
vocal power. J'he hyoid bone, a structure quite small 
in Alan, is in the Howler much larger. In the human 
throat this bone supports the root of the tongue, and 
gives attachment to certain muscles of the neck. In 
the throat of the Howler it is developed into a drum- 
like organ, bony throughout, and communicating with 
the wind-pipe ; thus, through this mechanism, the 
wonderful resonance is produced. 
A'singular method is pursued in catching these 
Alonkeys. It is said that a certain nut of great size, 
emptied of its contents, leaves a narrow natural open- 
ing ; in this is placed a quantity of sugar ; the Alon- 
key is just enabled to put his hand into the opening, 
but cannot withdraw it without leaving his prize — that 
is, he cannot take out a handful with his paw closed. 
It is stated to be a fact that their curiosity and ac- 
quisitiveness are so great, that they can be captured 
before they will relinquish their treasure, the weight 
and bulk of the nut so embarrasses them. The flesh 
of the Howler is eaten by the natives, but is not par- 
ticularly esteemed, being quite dry. 
BLACK AND YELLOW HOWLER [Mycetes Ucolor). 
— The male has uniform rigid black hair, the sides of 
the loins varied with yellow ; hairs of this part black, 
with a broad, sub-central, reddish-yellow band. In- 
habits Brazil. 
THE SILKY HOWLER {Mycetes lamger).—T\\\s. 
species is of a reddish chestnut, with middle of back 
golden yellow ; the hairs are elongate, very soft and 
silky, dark brown at the base ; golden or chestnut at 
the tip, with a close under fur. The hair of the head 
is rather elongate. A variety is mentioned with the 
end of the tail a little paler. This species is from 
Columbia. Dr. Slack regards it as “ undoubtedly the 
same as AI. seniculus.” 
THE MANTLED HOWLER {Mycetes palliatus) is 
the Aluatta palliata of Slack (Journal of Acad. 
Mat. Sciences, Philadelphia, 1862.) It is a black- 
brown ; the hairs of the middle of the back and upper 
part of the sides yellowish-brown, with black tips ; 
of the lower, parts of the sides elongate, brownish-yel- 
low forming a kind of mantle on each side, which gives 
it the specific distinction. It is found at Caraccas. 
THE RED AND YELLOW HOWLER {Mycetes aura- 
tus) has a dark red, or chestnut-brown color, with back 
and sides golden yellow. The hairs are rather short 
and rigid, dark at the base, ll'lie beard is darker. 
THE BLACK HOWLER [Mycetes caraya) is black, 
with rather elongate and rigid hair ; the sides, especially 
at the loins, with a few interspersed reddish hairs. 
This is the male, and the AI. niger of Prince Alaximilian. 
'I’he original of the latter is in the American Aluseum, 
Central Park, N. Y. It is also the Simla caraya of 
Humboldt, and inhabits Brazil. 
THE GRAY-HANDED HOWLER [Mycetes iarbatns) 
is black, with one-colored, rather rigid, moderately long 
hair. 'I’he hands, feet, inside of thighs, circumference 
of face and end of the tail, grayish. From Brazil. 
THE YELLOW-HANDED HOWLER [Mycetes beehe- 
bul) is black, with rather soft, uniform black or reddish 
hair, with a few interspersed brown hairs on the shoul- 
ders. 'i’he feet, upper line and tijj of the tail, spot in 
front of the ear and on the knee, reddish-yellow. 
'I’his is the Simla beelzebul of Linnaeus, the M. rufima- 
nus of Kuhl. and inhabits Brazil. 
THE VILLOUS HOWLER [Mycetes villosiis) is black, 
with very long and silky hairs, uniformly black on 
the cheeks and under the ears, browmish at the base. 
Habitat Brazil. 
