718 PRIMATES 
At least twenty species have been described (C. fatuellus, C. lunatus, 
C. capucinus, C. albifrons, C. hypoleucus, ete.), but it is probable that 
some of these are not entitled to stand, since there is a large 
Fic. 343,--The White-cheeked Sapajou (Cebus lwnatus). From Proc. Zool. Soc. 1865, pl. 45. 
amount of individual variation. Fossil remains of species of Cebus 
have been described from the Pleistocene cavern-deposits of Brazil. 
Family CERCOPITHECIDA, 
Dentition: ¢ 2, ¢ 4, p 2, m 8; total 32. Crowns of molars elon- 
gated antero-posteriorly, with the tubercles forming a pair of 
imperfect transverse ridges, and the last lower molar usually with 
a hind talon. A bony external auditory meatus. A narrow inter- 
narial septum. Tail non-prehensile. Ischiatic callosities present. 
Cheek-pouches present or absent. Pollex, when present, opposable. 
Pelvic limbs never much longer than pectoral. 
Czcum without vermiform appendage. 
This family includes all the Old World Apes, with the excep- 
tion of the Stmiide, and may be divided into the subfamilies Cerco- 
pithecinee and Semnopithecina. 
Subfamily Cereopithecinze.—Pelvic and pectoral limbs approxi- 
mately equal; tail variable; cheek-pouches present; stomach 
simple. 
Sternum narrow. 
