THE SPIDER-MONKEYS. 233 



Humboldt, which is the most beautifully coloured of its 

 group, is said to go about in small parties, passing through 

 the forest at a rapid rate, feeding on different kinds of berries. 



II. geoffroy's spider-monkey, ateles geoffroyi. 



Aides geoffroyi, Kuhl, Beitr. Zool., p. 26 (1820) ; Schl., Mus. 

 Pays Bas, vii., p. i8i (1876); Alston, in Godman and 

 Salvin, Biol. Centr. Amer. Mamm., p. 8 (1879). 



Ateks 7nelanochir, Desmar., Mamm., p. 76(1820); Gray, Cat. 

 Monkeys Brit. Mus., p. 43 (1870); Sclater, P. Z. S., 1871, 

 p. 226, pi. XV.; 1875, p. 419, pis. xlviii. and xlix. 



Eriodes frontatus, Gray, Ann. Nat. Hist., x., p. 256(1842); 

 id. Voy. H.M.S. "Sulphur," Zool., p. 9, pi. i. ; Scl., 

 P. Z. S., 1882, p. 186; Von Frantzius, Arch. f. Naturg., 

 XXXV., 1869, pp. 257, 258. 



Sapajou geoffroyi, Slack, Pr. Ac. So. Philad., 1862, p. 51T 

 (= female). 



Aieles variegatus (nee Wagn.), Von Frantzius, Arch. f. Naturg., 

 XXXV., 1869, p. 257. 



/Lteles hybridus, A. ornatus et A, albifrons, Gray, Cat. Mon- 

 keys Brit. Mus., pp. 43 and 44 (1870). 



Characters. — Body light greyish-drab all over ; hands, elbows, 

 feet, knees, and the upper side of the extremity of the tail, 

 black ; face black, with the exception of the lips and a ring 

 round the eyes, broad above and narrow below, flesh-coloured. 

 Hair of forehead reflexed, meeting that of the crown above 

 the eyes, forming a triangular patch of erect black hairs. Top 

 of the head and upper part of the tail buff. Length of body, 

 17 inches; of tail, 21 inches. Thumb entirely wanting. 



This species is remarkably variable. The description given 

 above belongs to the form described as A, inelanochir by Des- 



