Mycetes bicolor, Gray, Ann. N. H., xvi., p. 214 (1845); id. Cat. Monkeys Brit. Mus., p. 40 (1870).
Mycetes ursinus, Is. Geoffr., Cat. Méth. Primates, p. 55 (part., 1851); Gray, Cat. Monkeys Brit. Mus., p. 39 (1870); Schl., Mus. Pays Bas, vii., p. 155 (1876).
Aluatta ursina, Slack, Proc. Acad. Nat. Sci. Philad., 1862, p. 517.
Mycetes flavicauda, Schl., t. c. p. 147 (part., 1876).
Characters.—General colour shining yellowish-red, or dark brownish-yellow; hairs rather rigid, black with yellowish tips; hairs of the shoulder ringed with black. When half-grown the limbs and tail are very dark brown, nearly black; tail shorter than the body, olive black, with two yellow lateral stripes. Length of the body, 23 inches; of the tail, 22 inches.
Young.—Black, with the tips of the hairs of the body yellowish-brown; base of the tail and the surrounding region reddish-brown.
This species is remarkable for great variation in colour. The young at first sight, as Dr. Slack has pointed out, appear to be of an intense black colour, but upon a closer examination, the hairs, more especially those of the back and sides of the head, are found to be tipped with reddish-brown. As the animal becomes older the black gradually vanishes, a yellowish-brown colour appearing in its place, until in the adult the only remains of the black are to be found in a few annulations in the hairs of the shoulders.
The skins are an article of commerce, for saddle cloths and saddle coverings.
Distribution.—The Rio Negro and Upper Amazonia. Mr. Bates remarks that this is the only species seen in this region.
V. THE GUATEMALAN HOWLER. ALOUATTA VILLOSA.