II. THE BLACK-HEADED SQUIRREL-MONKEY. CHRYSOTHRIX ENTOMOPHAGA.
Callithrix entomophagus, d'Orb., Voy. Amér. Mér., iv., Mamm. pl. 4 (1836).
Callithrix boliviensis, d'Orb., Nouv. Ann. Mus., iii., p. 89 (1834).
Saimiris entomophagus, d'Orb., Voy. Amér. Mér., iv., Mamm., text, p. 10 (1847); Is. Geoffr., Cat. Méth. Primates, p. 38 (1851).
Saimiri entomophagus, Schl., Mus. Pays Bas, vii., p. 246 (1876).
Chrysothrix sciurea (nec L.), Frantz. in Wiegm. Arch. f. Nat., xxxix., p. 260 (1869).
Chrysothrix entomophagus, Wagn., Ann. Nat. Hist., xii., p. 42 (1843); Gray, Cat. Monkeys Brit. Mus., p. 53 (1870).
Characters.—Face grey, washed with yellow; ears haired; head black; hairs of back black, with long yellow tips, or yellow with black tips, producing a shade of brown washed with golden; outer side of upper part of arms and legs yellow, peppered with black; throat, under surface of body and inside of limbs yellowish-grey; tail long, black.
In some species the upper part of the head has a shade of yellow, caused by the colour of the lower half of the hairs showing through the black tips.
Distribution.—Bolivia; Veragua, Central America; and the warmer regions of Costa Rica, where it inhabits the humid forests.