CHARACTERS.--MALE.--Body massive and strong; trunk declining backwards; head disproportionately large; muzzle much elongated and protruding, with large longitudinal rugose swellings along each side when full grown; mouth large, and with very animal-like lips; brows strongly projecting over the base of the nose and the small, approximated, deep-set eyes; {259}ears black, naked, and pointed; under-jaw heavy; tail carried erect, very short, two inches long, and naked beneath; limbs short and powerful; the Dog-like nose shorter than the upper lip; nostrils large. Hair rising from the ridge on the lower edge of the brow to a crest on the top of the head, descending into a mane on the back of the head and neck; hair of the body bristly; chin bearded; whiskers proceeding from over the cheek-bones and from under the outer corner of the eyes, long, and directed from the face; the very large callosities, parts of the rump in their neighbourhood, and the inside of the thighs naked. Hands and feet naked. Skull very massive, having numerous strong muscular crests; the jaws and teeth very powerful, especially the canines, which are huge; the forehead flat and the brain-case small, and further reduced by the great projection backward of the orbits. The cheek-bones enormously swollen along the side of the nose; in the neck a large air-sac. The back-bone has to some extent the peculiar double curve characteristic of the human vertebral column but in the conformation of certain of their vertebræ a similarity to the lower quadrupeds, especially to the Carnivora, is seen in the Mandrill, in accordance with their quadrupedal mode of progression. The metacarpal bones, except that of the thumb, are all of the same length, while in the Man-like Apes they are unequal. The thumb is much restricted in its motions on account of the disposition of certain of the muscles of the hand. The pectoral and pelvic muscles are strongly developed. Face-ridges bright blue, with purple in the intervening furrows. The bridge of the nose (after the development of the permanent teeth) red, the tip scarlet; lips greyish-black. {260}General colour of fur black, fringed with yellow; centre of the crown of head, crest, nape (extending down the back), and sides of the body black; beard citron-yellow; callosities and surrounding naked skin violet; genital and anal regions scarlet. FEMALE AND YOUNG MALE.--Facial rugosities less marked outwardly, as well as on the skull, than in the adult male, and the purple colour of the grooves wanting. The nose is black, not scarlet. A hybrid between a female of this species and a male Macaque (_M. cynomologus_) was born in the Zoological Gardens of London in October, 1878. DISTRIBUTION.--West Africa, from Senegambia to the Congo.