OCT., 1916. MAMMALS, COLLINS-DAY EXPEDITION OSGOOD. 215 



brownish. At the tip of the tail the terminal tuft of hairs is wholly 

 light-colored, practically white, but with innumerable, fine peppery 

 annulations. The under parts are mixed with blackish and chestnut, 

 the blackish predominating. 



Saimiri sciurea collinsi subsp. nov. COLLINS SQUIRREL MONKEY. 



Type from Fazenda Teso, near Soure, Marajo Id., Brazil. No. 

 19534 Field Museum of Natural History. Adult male. Collected 

 November 15, 1911 by E. Snethlage. 



Characters. Similar to typical Saimiri sciurea, but hands and feet 

 darker, more richly colored; white area around ears very narrowly or 

 not continuous with white surrounding eyes; back much paler, less 

 fulvous. 



Upper parts in general similar to those of 5. sciurea, but head, shoul- 

 ders, and foreback almost wholly grayish, the median suffusion of ful- 

 vous reduced to the merest trace; middle and hind back with a strong 

 tinge of fulvous but much paler than in sciurea; hands and feet and 

 lower limbs tawny rather than orange ochraceous; white face marking 

 not broadly continuous with white around ears, but separated from it 

 by a grizzled area connecting the color of the top of the head with the 

 gray patch on the lower cheek; under parts and tail practically as in 

 sciurea. 



Skull and teeth small. 



Measurements. Type: Total length 660; head and body 249; 

 tail 411; hind foot 86. 



Skull of type: Greatest length 63.6; zygomatic breadth 37.3; 

 breadth of braincase 34.6; palatal length 17.5; upper toothrow (molars 

 and premolars) 12.8; width of first upper molar 3.9. 



Remarks. A single specimen of a squirrel monkey purchased in the 

 market at Para is included in the collection brought back by the expedi- 

 tion and has led to comparisons showing rather marked differences 

 between the animal of the lower Amazon region and that of Guiana 

 to which the name sciurea restrictively applies. Comparison has 

 not been possible with 5. madeirae and S. macrodon which are 

 doubtless related, although apparently not quite so closely as is typical 

 sciurea. 



Specimens from the Rio Branco region in northern Brazil agree 

 closely with typical examples of sciurea from Georgetown, British 

 Guiana. 



Saimiri boliviensis D'Orbigny. BOLIVIAN SQUIRREL MONKEY. 

 Two specimens, Todos Santos. 



