Chapter VI: The Mantled Howler. Alouatta Palliata

_Mycetes palliatus_, Gray, P. Z. S., 1848, p. 138, pl. vi.; Frantz.,
Wiegm. Arch., xxxv., p. 254 (1869); Gray, Cat. Monkeys Brit. Mus., p. 40
(1870); Scl., P. Z. S., 1872, p. 7; Schl., Mus. Pays Bas, vii., p. 152
(1876); Alston, in Godm. and Salvin, Biol. Centr. Am. Mamm., p. 4 (1879).

_Aluatta palliata_, Slack, Proc. Acad. Nat. Sci. Philad., 1862, p. 519.

CHARACTERS.--Face naked; hair of forehead short, reflexed, forming a slight crest across the middle of the head; hairs of the back of the head rather longer; those of the cheeks few, short and grey; those of the fore neck lengthening into a short beard. General colour brownish-black; middle of back and {203}upper part of sides, yellowish-brown; lower part of sides brownish-yellow, lengthened into a mantle; arms, legs, and tail black. Length, 19½ inches; tail, 20¾.

The late Mr. Alston, in describing the Mammals of Central America, in Messrs. Godman and Salvin's monumental work, "Biologia Centrali-Americana," observes that "this Howler presents considerable variety in the depth of the black or brown-black ground-colour, and in the extent of the fulvous tints of the flanks and loins. Dr. v. Frantzius states that the Howlers which he saw in Costa Rica were darker than is indicated by Dr. Gray's description; and in several of the Panama examples the light markings are much reduced, but in others they are quite as conspicuous as in the Nicaraguan types." Mr. Alston, therefore, agrees with Prof. Schlegel, that the variation does not depend on locality.

DISTRIBUTION.--Shores and islands of the lake of Nicaragua; Costa Rica; Panama; Islet of Hicaron, at the southern extremity of Quibo Island, off the Coast of Veragua. South of the Isthmus of Panama, the Red Howler (_A. senicula_) replaces the Mantled Howler.

HABITS.--The habits of the Mantled Howler do not differ widely from those of the species already described. It prefers the highest branches of the trees of the dense forests; and is harmless to the plantations of the natives. In disposition it is dull and melancholy, and is rarely kept in confinement. It is said, however, to reconcile itself to captivity more than some of the others referred to in previous pages. According to Dr. v. Frantzius, a tame male individual of this species was observed to howl whenever rain-clouds gathered, and also regularly at five o'clock every morning.

{204}THE CAPUCHINS AND SPIDER-MONKEYS. SUB-FAMILY CEBINÆ.

We now come to describe the remaining Monkeys of the New World. The _Cebinæ_ are characterised by having the incisors vertical, not procumbent; they have no inflated hyoid bone as in the foregoing Sub-family. The tail in all is long and prehensile, although in some species it is a less perfect grasping organ, being clothed with hair to the tip, instead of being there naked and highly sensitive. The thumb may be present or absent.

This Sub-family contains four genera: the Capuchins (_Cebus_); The Woolly Monkeys (_Lagothrix_); the Woolly Spider-Monkeys (_Eriodes_); and the Spider-Monkeys (_Ateles_). The species belonging to these genera are very numerous, and are found over the whole region from Mexico in the north, to Paraguay and Bolivia in the south, or from about 25° N. lat., to 30° S. lat.

THE CAPUCHINS. GENUS CEBUS.

_Cebus_, Erxleb., Syst. Regne Anim., p. 44 (1777).

This is the typical genus of the American Monkeys. They are distinguished by having a robust body, covered with woolly fur, with a rounded head and a face which, instead of having a protruding muzzle, is more erect and Man-like. They are the commonest Monkeys seen in captivity in our streets. Their tail is long and covered with hair to the tip, and, though prehensile, it is not the perfect substitute for an additional hand noticed in several other genera. Their limbs are only moderately long, and are less slender than in the Spider-Monkeys. The fore-limbs have a well-developed thumb, which, as compared with the length of the hand, is the most {205}Man-like of all the Apes; in some species the nails of the digits are compressed laterally.

In the skull the cranial portion exceeds the facial. Professor Mivart observes that in this group the facial part is relatively smaller than in many of the higher Old-World Apes. The skull has no external bony canal (or _meatus_) to the ear; and its frontal bones possess large air-cavities. In the Capuchins the incisor teeth are erect, and are always shorter than the canines. The molars are four-cusped, and have, on their crowns, two transverse ridges and the oblique ridge, already described in the _Lemuroidea_, from the front inner cusp to the hind outer cusp. These animals have also one milk-molar tooth more than in Man.

The outer surface of the main brain (_cerebrum_) is almost as much convoluted as in the Old World Apes.

The Capuchins range from Costa Rica to Paraguay, and are represented by about eighteen species. They are very gentle and docile animals.

F. Cuvier observes in his "Histoire Naturelle des Mammiferes," that of all the Quadrumana--indeed, of all the Mammals--there are none so difficult to characterise as the Capuchins of America, whose colours vary almost with every individual. No two authors agree in the number of species the genus contains. Brisson recognised three, Linnæus four, Gmelin six, Buffon two, and George Cuvier supposed it possible that they all belonged to but one species. Two causes help to produce this diversity of opinion; one is, as remarked above, the natural disposition which these animals have to vary, and to become lighter or darker in colour according to circumstances, and the other is the extremely close relationship that exists between the different species of the genus. Observations, {206}however, are not yet numerous enough, nor exact enough, to enable those who have only studied the species alive in Europe, or had skins, to decide with such imperfect data as to their sex, age, and habitat. Not until some naturalist has made a prolonged study of these animals in their native country, and watched their conduct and relations in the living state, can we hope to attain to any certain knowledge of how many species the genus contains; and of the differences between the old and young of both sexes at different periods from youth to age.