8 ARKIV FÖR ZOOLOGI. BAND 14. NIO 4. 



the arms are coloured almost like the back, but more mixed 

 with black on the forearm shading in the black hands. The 

 fur is also on the outside of the arm similar to that of the 

 back, while on the inner side of the arm it is longer, black 

 with fawn-coloured basals parts. The condition of the hind- 

 legs is similar both with regard to colour and fur. The 

 upper side of the tail has short fur like the back and ba- 

 sally also the same colour, but distally it becomes more 

 brown somewhat resembling a dark shade of »raw umber» 

 (1. c. 301, 4), though a little more vivid. The lower side of 

 the tail is covered with longer hair (proximally 3 V2, distally 

 2 V2 cm), which is fawn coloured with blackish tips. Åt 

 the beginning of the naked portion the long hairs cease and 

 the fur of the lower side continued only as a blackish brown 

 stripe bordering the naked area. 



Condylobasal length of skull 87, zygomatic breadth 75, 

 width of braincase 57,5, upper molar series 24 mm. 



As Rio Curaray is a tributary to Rio Napo, joining it 

 on its Southern side, but the type locality of the species is 

 forests near Rio Ica, this specimen has been collected some 

 way south of the type locality. Thomas recorded it 1880 

 from Rio Copotas (or Copotaza) not far south of Curaray, 

 but it has also been reported from the Peruvian Amazon. 



Pithecia monacha E. Geoff. 



1 skin from Napo. 



Thomas has 1880 recorded it from Rio Copotas a little 

 further south, and Allén from Baeza on the eastern slopes 

 of the Andes. Its distribution in Brazil is verv wide. 



Saimiri ef. cassiquiarensis Humboldt. 



1 native skin from Napo. 



The colour is similar to that of S. sciurea L., but a 

 blackish line bord ers the grey of the head and curves down 

 in front of the ears, which may indicate that it belongs to 

 Humboldt's race. Thomas mentions specimens with similar 

 black stripes from Rio Copotas, and Elliot regards them as 

 belonging to this form. 



