Habits.—Like its congeners, the Common Squirrel-Monkey is arboreal, going about in large flocks. Their food consists of insects and fruits. Mr. Bates observes that the "pretty little Chrysothrix sciureus contents itself with devouring what fruit it can on the spot," thus differing from certain species of Cebus, which destroy more than they eat, and when about to return to the forest, carry away all they can in their hands or under their arms.
Mr. Darwin has remarked in his "Expression of the Emotions in Man and Animals," that "with Monkeys the expression of any painful emotion is not easily distinguished from that of anger." "Humboldt," he adds, "also asserts that the eyes of the Callithrix sciureus 'instantly fill with tears when it is seized with fear'; but when this pretty little Monkey in the Zoological Gardens was teased, so as to cry out loudly, this did not occur. I do not, however, wish to throw the least doubt on the accuracy of Humboldt's statement."
This species is a great favourite wherever it has been kept in captivity. It is very bright coloured, has a baby-like face, large and bright eyes, and most gentle manners. These Monkeys are very sensitive to cold, and when a sudden fall in the temperature takes place, they huddle close together, clasping each other with their arms, and embracing their neighbours and themselves with their long tails.
IV. THE RED-BACKED TITI. CHRYSOTHRIX ŒRSTEDI.
Saimaris sciurea ? (nec Linn.), Sclater, P. Z. S., 1856, p. 139.
Chrysothrix sciurea (nec Linn.), Scl., N. H. Rev., 1861, p. 510; Frantz. Arch. f. Naturg., xxxv. (1), p. 260.
Chrysothrix œrstedi, Reinh. Vidensk. Medd. Nat. For. Kjöbenh., p. 157, pl. iii. (1872); Alston, in Godm. et Salv., Biol. Centr. Am. Mamm., p. 16, pl. ii. (1879).
Saimiris entomophaga, Sclater, P. Z. S., 1872, p. 3 (nec d'Orb.).
Saimiri örstedii, Schl., Mus. Pays Bas, vii., p. 245 (1876).
Characters.—Differs from C. sciurea in having the top of the head black, the back and sides shining red, and the limbs olive.