MAMMALIA 



79 



premolars and twelve molars, a Marmoset has twelve premolars 

 and eight molars, agreeing in the former particular with the New 

 World monkeys proper. 



Order 2. — Lemurs (Lemuroidea) 



This order includes a somewhat 

 heterogeneous collection of tropical 

 climbing mammals, of which the large 

 majority are limited to Madagascar, 

 while a smaller number are found in 

 South-east Asia and in tropical West 

 Africa. They have usually been in- 

 cluded in the Primates, but on insufficient grounds, the chief 

 common peculiarity being the possession of opposable thumb 



Fig. 48. — Skull of Black Indris Lemur 

 ft Temporal fossa; o^ orbit. In this case 

 the orbit is open behind and thus communi- 

 cates with the temporal fossa. 



Fig. 49. — Ring-tailed Lemur {Lemur catta) 



