882 PHYLUM CHORDATA I CLASS MAMMALIA 



or even earlier they appeared in Europe and N. America, and were 

 then of more generalised type. In the latter continent they became 

 extinct ; but in the Old World they appear to have migrated south- 

 wards at an early period into Ethiopian and Oriental regions. They 

 reached Madagascar at a time when that island was connected to the 

 continent, and before the advent of the larger carnivores. There they 

 have been isolated and have developed in a fashion comparable to 

 that which has occurred in the case of the Australian Marsupials. 

 Of fifty living species thirty-six are confined to Madagascar, and these 

 are very abundantly represented. Outside of Madagascar lemurs 

 maintain a precarious footing in forests or islands, and are usually 

 few in number. They are handicapped by the absence of defensive 

 weapons, the frequent slowness of movement, and the feeble intelli- 

 gence ; they are saved by their arboreal and usually nocturnal habits, 

 by their quiet movements, and by their shyness. 



Order Anthropoidea (= Primates or Simile) 



This order includes five families. 



Family 5. Hominidae. Man. 



4. Anthropomorphidae or Simi- 1 



idae. Anthropoid Apes. | Old World 



3. Cercopithecidae. Baboons, j Catarrhina. 



etc. J 



2. Cebidae. American Monkeys. 'i New World 



I. Hapalidae. Marmosets. J Platyrrhina. 



>> 



>) 





The following characteristics are generally true : — 

 The body is hairy, least so in man ; the incisors do not 

 exceed % ; the molars are ^, except in the marmosets, 



where they are \ ; the back teeth are bunodont, the pre- 

 molars with two cusps, the molars usually with four ; the 

 cranial cavity is relatively large ; the axis of the orbit is 

 directed forward, and the orbit is closed off from the 

 temporal fossa by ingrowths of frontal and jugal meeting 

 the alisphenoid ; the lachrymal foramen is infra-orbital ; 

 the clavicles are well developed ; the radius and ulna 

 move freely on one another in pronation and supination ; 

 the scaphoid, the lunar, and usually the os centrale are 

 distinct ; there are usually five fingers and toes, but the 

 thumb may be absent or rudimentary ; the thumb (or 

 pollex) if present is opposable except in marmosets ; the 



