Mr. Osbert Salvin met with several of these Monkeys near the town of San Juan del Sur, in Nicaragua. He was walking up the course of a half-dry stream when he came upon a troop of Monkeys which had come to a pool to drink, and were climbing about the low trees on the bank of the watercourse. Most of the troop consisted of _Cebus hypoleucus_, but with them were several _Ateles_ of the present species, of one of which Mr. Salvin wrote a description as it sat jabbering at him and throwing down sticks from a branch above his head. Mr. Salvin also told Mr. Alston that it was not unusual to see Monkeys kept in confinement in the court-yards of the Spanish houses in Guatemala. Amongst them were occasionally to be seen specimens of Geoffroy's Spider-Monkey; but he always found that they had been brought from Nicaragua or Costa Rica, the species not extending into Guatemala. III. THE RED-BELLIED SPIDER-MONKEY. ATELES RUFIVENTRIS. _Ateles vellerosus_ (_?_) (nec Gray), Scl., P. Z. S., 1871, p. 478. _Ateles rufiventris_, Scl., P. Z. S., 1872, p. 688, pl. lvii.; Schlegel, Mus. Pays Bas, vii., p. 182 (1876). CHARACTERS.--Fur rough, upstanding less on the tail than on {237}the body, that on the forehead erect and directed backwards, that on the top of the head long, projecting forward. Face and muzzle, except a black line from the side of the nose and inner corners of the eyes to the cheeks, flesh-coloured. General colour uniform black, but the whole under surface deep bright rufous, this colour extending but slightly on to the inner surface of the limbs. Thumbs entirely wanting. Differs from _A. geoffroyi_ by its flesh-coloured face and by the two colours of the upper and under sides being clearly defined. Length of body, 12 inches; of tail, 15½ inches. DISTRIBUTION.--This species was first discovered on the Atrato river, in Northern Colombia, and has since been found in Panama. HABITS.--The Red-bellied Spider-Monkey is very rare, only one or two specimens having yet been obtained. Nothing is, therefore, known of its habits. IV. THE RED-FACED SPIDER-MONKEY. ATELES PANISCUS. _Simia paniscus_, Linn., Syst. Nat., i., p. 27 (1766). _Ateles pentadactylus_, Geoff., Ann. Mus., vii., p. 269 (1806); Schl., Mus. Pays Bas, vii., p. 172 (1876, in part). _Ateles paniscus_, Geoff., Ann. Mus., vii., p. 270 (1806); Gray, Cat. Monkeys Brit. Mus., p. 42 (1870); Schl., Mus. Pays Bas, vii., p. 169 (1876, part.). _Le coaita_, F. Cuv. et Geoffr., Nat. Hist. Mamm., liv., v. (Avril, 1819). _Sapajou paniscus_, Slack, Proc. Acad. Nat. Sci. Philad., p. 509 (1862).