OLD WOELD MONKEYS. 399 



whose distributional area extends from Ceylon and the snow-bound 

 heights of Thibet (S. Roxellanas) to the islands of the Malay Archi- 

 pelago, which properly constitute its headquarters, the better- 

 known species are the sacred entellus, or hoonuman (S. entellus), 

 from the Gangetic provinces, and the proboscis monkey (S. nasi- 

 cus) of Borneo. A form related to the last, characterised by an 

 excessively up-turned nose, is the proboscis monkey of Thibet 

 above mentioned (S. Roxellanse). 



The African Colobi are slender, long-tailed monkeys like the 

 Semnopitheci, from which they are barely separable, but differ in 

 the complete absence of the thumb. Of probably not more than a 

 dozen species, whose combined habitat embraces the greater part 

 of the African continent, from the west coast to Abyssinia and 

 Zanzibar, the best known, and, at the same time, probably the 

 most graceful and beautiful of all monkeys, is the guereza (C. gue- 

 reza), whose home appears to be the highlands of Abyssinia, at 

 elevations of from 7,000 to 10,000 feet. A closely related form is 

 Colobus Angolensis. 



The total number of apes inhabiting the islands of the Malay 

 Archipelago is, according to Rosenberg, ''' twenty-five, distributed 

 among the different islands as follows : Sumatra, twelve ; Banca, 

 four; Borneo, eleven; Java, five; Celebes, two; and Bali, Lombok, 

 Flores, Sumbawa, and Timor, each one.' The rapid diminution in 

 the direction of the Australian continent, which is entirely deficient 

 in the animals of this class, is very marked. Only one form, the 

 common macaque, is common to all the islands; Sumatra holds 

 only one species in common with Java, whereas, surprisingly enough, 

 four of its species are represented in Borneo. The greater number 

 of the species are restricted to individual islands. 



No unequivocal remains of true monkeys are known to antedate 

 the Miocene period, and in America they do not appear before the 

 late Pliocene or Fost-Pliocene. Several forms, referred to the 

 South American genera Cebus, Callithrix, and Hapale, and one 

 representing an extinct type, Protopitheeus, probably allied to the 

 howlers, have been described by Lund from the cavern deposits of 

 Brazil. Protopitheeus Bonseriensis is founded upon a number of 

 incisor teeth obtained by Ameghino in the neighbourhood of the 

 city of Buenos Ayres. No quadrumaaous remains other than those 



