658 PRIMATES. 



Fam. 3. Cercopithecidae. These Old-World monkeys are essentially 

 quadrupedal, and the hind limbs are not much l.mger than the fore-limbs. 

 Both poUex (when present) and hallux are opposable, and they usually 

 have a tail which is never prehensile. Ischial callosities are present ; 

 cheel-: -pouches present or absent. All the digits of both limbs have nails. 

 Dentition ifcip|m-|-; molars elongated an tero -posteriorly, usually 

 tretracuspidate, last lower molar often with a talon ; the outer and inner 

 pairs of cusps are sometimes separated by a longitudinal furrow and 

 sometimes connected by transverse ridges ; premolars bicuspidate. The 

 skull varies in shape, the frontal region being roixnded and the facial 

 angle small, or the face is prolonged and dog-like and the facial angle is 

 large. The nasal septum is narrow. There is no distinct mastoid pro- 

 cess, and the styloid process is not ossified ; the parietals do not unite with 

 the alisphenoid, being cut ofi by the imion of tlie squamosal and frontal. 

 There is a bony external auditory meatus. The frontal bones usually 

 unite across the base of the skull in front of the imion of the presplienoid 

 and ethmoid ; the basicranial axis is shorter than the length of the cerebral 

 cavity, and the foramen magnum looks obUquely backwards and down- 

 wards. The suture between the premaxillary and maxillary bones does 

 not disappear imtil the permanent dentition is complete. The carpus 

 has a centrale, and the pollex is complete except in Colobus. The pos 

 terior ends of the ischia are everted and rough. The stomach is usuallj' 

 simple, the caecum small and without a vermiform appendix. A median 

 air-sac is sometimes present opening into the larynx below the epiglottis : 

 it may be large, extending down the neck and sending processes into the 

 axilla. The brain is large, the cerebrum projects behind the cerebellum, 

 and its surface is always complexly convoluted. The penis usually has 

 a bone. The phenomena of oestrus appear to approximate to those 

 found in the human female.* They are confined to the Old-World, being 

 found in the Ethiopian (absent from Madagascar), Oriental, and Palae- 

 arctic regions. The fossil remains are few, but representatives of living 

 genera are found as far back as the Pliocene ; and a few genera classed 

 with existing families are known from the Phocene and Miocene of Europe. 



Sub-fam. 1. Cercopithecinae. Omnivorous, with cheek -pouches, 

 simple stomach ; fore- and hind-limbs sub-equal, nostrils terminal, 

 tail long, short or absent. Papio Erxl. (Cynocephalus Lacep.), 

 African baboons ; muzzle elongated, dog-like, and tail moderate, 

 ischial callosities large ; they usually inhabit rocky ground and are 

 frequently gregarious ; about 9 living species, Africa and Arabia, 

 and a few extinct from the Pliocene and Pleistocene of India and the 

 Pleistocene of Algeria ; P. maimon, mandrill, tropical W. Africa ; 

 P. porcarius, chaima, S. Afr. Theropiihecus I. Geoffr., like the 

 last, but nostrils sub-terminal, 2 sp., Abyssinia. Cynopithecus 

 I. Geoffr., 1 sp., the black ape of Celebes. Macacus Lacep., muzzle 

 produced, nostrils not terminal, tail long, short or absent ; last lower 

 m. with talon ; generally gregarious ; about 20 sp., all Asiatic except 

 M. innuus, the Barbary ape of N. Afr. and Gibraltar, without tail ; 

 M. rhesus, the Bengal monkey ; M. speciosus, Japan, the most nor- 

 therly monkey and the only one found in Japan. Cercocebus E. 

 Geoffr., mangabeys, like Cercopithecus, but last lower molar with 

 talon ; long tail, upper eyelids white, 6 sp., W. Afr. Cercopithecus 



* Heape, op. cit., p. 517. 



