Oct., 1916. Mammats, Coriins-Day Expepition—Oscoop. 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, 
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 S. sciwrea, 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 S. 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. Bo trviaAn SqurRREL MONKEY. 
Two specimens, Todos Santos. 
