226 ALLEN'S NATURALIST'S LIBRARY. 



THE BROWN WOOLLY SPIDER-MONKEY. BRACHYTELES 



ARACHNOIDES. 

 Atehs arachnoides, Geoffr., Ann. Mus., vii., p. 271 (1806); 



xiii., p. 90, pi. 9 (1809); xix., p. 106 (1812); Schl., Mus. 



Pays Bas, vii., p. 184 (1876, part.). 

 Ateks hypoxanthus, Desm., Mamm., p. 75 (1820); Neuwied, 



apud Kuhl, Beitr. Zool., p. 25 (1820); Schl., t. c. 



p. 185 (1876, part.). 

 Brachyteles macrotarsus, Spix, Sim. et Vespert., Bras., p. 36, 



pi. 17 (1823). 

 Eriodes hemidactylus and E. tuberifer, Geoffr., Mem. Mus., 



xvii., pp. 161, 163 (1828). 



Eriodes arachnoides, Geoffr., Mem. Mus., t. c. p. 160 (1828) 

 Brachyteles arachnoides, Gray, Cat. Monkeys Brit. Mus., p. 45 



(1870). 



Characters. Male. Size small; face nude, flesh-coloured; general 

 colour of body yellowish-brown, darker on the back of the head, 

 with a few long black hairs on the forehead ; hairs of head short 

 and directed backward ; buttocks, vent, base of tail and perineal 

 region dark ferruginous -brown ; the thumb wanting or rudi- 

 mentary. Length of body, 22 inches; tail, 26 inches. 



Female. Ashy-brown, instead of yellowish-brown, in appear- 

 ance. 



Young. In some young specimens the general colour is dark 

 brown, with the sides of the face white. 



Dr. Slack observes, in the " Proceedings of the Academy of 

 Natural Sciences of Philadelphia" for 1862, in reference to 

 this species : " I had long suspected that the three species 

 of this genus described by Isidore Geoffroy St. Hilaire, were 

 in reality one and the same ; no specific characters are mani- 

 fest in their coloration, or skulls, the supposed differences being 



