CHARACTERS.--Larger than _Hapale jacchus_; ears naked, external, exposed, with a band of long hairs across the inner surface of the conch, forming a short grey tuft; tail ringed, blackish, the hair minutely punctulated with yellow or red; sides of the head, limbs, and hinder part of body blackish-brown; face more or less white; back blackish, without indication of cross-bands. DISTRIBUTION.--Brazil. IV. THE WHITE-FOOTED MARMOSET. HAPALE LEUCOPUS. _Hapale leucopus_, Günth., P. Z. S., 1876, p. 743, pl. lxxii. CHARACTERS.--Hair of back and sides moderately long, silky, brownish-grey; nape and occiput darker; face and head covered with short sparse white hair; ears large, naked, and without tufts; throat greyish-brown; under side of body and {135}inside of legs rusty-red; fore-arm, hands, and feet white--the hairs short, blackish or black, with white tips. Head and body, 11½ inches long; tail, 14½ inches. Dorsal and lumbar vertebræ together, 19. FEMALE.--Similar to the male, but with the hairs of the upper parts silver-tipped. DISTRIBUTION.--Medellin, in the province of Antioquia, United States of Colombia. HABITS.--Unknown. V. THE GOLDEN MARMOSET. HAPALE CHRYSOLEUCA. _Hapale chrysoleucos_, Wagner in Wiegm. Arch., 1842, i., p. 357; id. in Schreb. Säugeth., Suppl., v., p. 125 (1855); Sclater, P. Z. S., 1869, p. 594. _Mico sericeus_, Gray, P. Z. S., 1868, p. 256, pl. xxiv. _Miocella chrysoleucos_, Gray, Cat. Monkeys Brit. Mus., p. 131 (1870). _Miocella sericeus_, Gray, Cat. Monkeys Brit. Mus. App., p. 131 (1870). _Hapale chrysoleuca_, Schl., Mus. Pays Bas, vii., p. 227 (1876). CHARACTERS.--Ears large, naked, exposed, margined with long white hairs. General colour white; limbs, under surface, and tail, uniform greyish-yellow, or reddish-brown in some varieties. DISTRIBUTION.--Forests of Brazil; vicinity of Borba, on the Rio Madeira. VI. THE PIGMY MARMOSET. HAPALE PYGMÆA. _Jacchus pygmæus_, Spix, Sim. et Vespert. Bras., pl. xxiv., fig. 2 (1823). _Hapale pygmæa_, Wagner in Schreber, Säugeth., v., p. 126 (1855). Castelnau, Voy. Amér. Sud, pl. 5, figs. 1, 2; Schl., Mus. Pays Bas, vii., p. 277 (1876). {136}_Cibuella pygmæa_, Gray, Cat. Monkeys Brit. Mus., p. 64 (1870). CHARACTERS.--Face with long brown whiskers, naturally brushed back over the ears; ears small, with a few scattered hairs over them, but no ear-tufts, sunk in the long fur of the head. General colour brownish-tawny; tail ringed with black. The young resemble the adults from their earliest days. This is the most diminutive Monkey known, and measures only six inches in length.