(_Plate XXVII._)
_Simia æthiops_, Linn., Syst. Nat., i., p. 39 (1766).
_Cercocebus æthiops_, Geoffr. Cat. Méth. Primates, p. 25 (1851); Gray,
List Mamm. Brit. Mus., p. 7; id., Cat. Monkeys Brit. Mus., p. 27 (1870);
Schl., Mus. Pays-Bas, vii., p. 95 (1876).
_Cercopithecus lunulatus_, Temm., Esquiss. Guin., p. 37 (1853).
CHARACTERS.--This species is very similar to _C. collaris_, but differs in
being slightly darker above, and in having a spot on {40}the back of the
head, as well as a narrow streak down the back greyish-white.
DISTRIBUTION.--West Africa.