Distribution.—Panama, Guatemala, Costa Rica, especially their hotter districts,—being particularly abundant in the Valley of Terraba and on the plain of Piris.
THE TITI MONKEYS. GENUS CALLITHRIX.
Callithrix, Geoffr., Ann. Mus., xix., p. 112 (1812).
This genus is intermediate between the Squirrel-Monkeys and the typical Night-Monkeys. In the Titis, sometimes known by the name also of Whaiapu-Sai Monkeys, the fur is soft, the head small, depressed, and not produced backward as in Chrysothrix; the tail is long and bushy; the eyes are small, and the orbits intermediate in size between those of the last and the next genus; the nasal partition is broad, and the ears large. The canine teeth are small, and the angle of the lower jaw expanded, somewhat as in the Howlers (Mycetes), though to a less extent.
The Titi Monkeys are diurnal animals, arboreal and gregarious, very lively in disposition, noisy and agile, living on fruit, insects, birds' eggs, and even small birds. They range all over South America, from Panama to the southern limits of the forest regions.
I. THE WHITE-COLLARED TITI. CALLITHRIX TORQUATA.
Cebus torquatus, Hoffm., Mag. Ges. Nat. Freund. Berlin, x., p. 86 (1807).
Simia lugens, Humb., Obs. Zool., i., p. 319 (1811).
Callithrix lugens, Geoffr., Ann. Mus., xix., p. 113 (1812).
Saguinus vidua, Lesson, Species Mamm. Bimanes et Quadrum., p. 165 (1840).