20 



XII. PEIMATES. — The characters of the order Primates may be 

 gathered from the following table : — 



1. Lemuridse (Lemurs). — In addition to those gathered from above 

 Table, note the following characters: — Lemurs are without a closed orUt. 

 Claw-hke nails on all the digits except hallux and poUex. Mostly nocturnal 

 in habit. Arboreal. Fruit and insect eaters. Once a widely distributed 

 order, now confined to Madagascar and other Indian Ocean islands. e.g. 

 Lemur (Madagascar) dentition i. 2, c. 1, pm. and m. 5 or 6, above and 

 below, lower incisors are almost horizontal. 



2. Simiadse (Monkeys and Apes).- — In addition to characters in above 

 Table, note also closed orbit. Dentition i. 2, c. 1, p. 2, m. 3, above and 

 below (except in Platyrrhini). Canines large. Diastema in front of 

 upper and behind lower canines. Flat nails on all digits (except Marmosets). 

 Face mostly naked, though fringed with hair. Frugivorous. 



1. Aectopithicini (Marmosets). — Soiith America squirrel-like forms. 



Claws on all digits except poUex and hallux. Pollex not opposable. 

 Broad nasal septum between the outwardly-directed nostrils. 



2. Platyrrhini (broad-nosed).— iV^sifi World monkeys. Nostrils wide 



apart, and nose fiat. Pollex non-opposable. Dentition i. 2, c. 1, 

 p. 3, m. 3, above and below. Frontal bone extends backwards to 

 form V-shaped coronal suture. Tympanic bone has a wide oval 

 mouth, e.g. Mycetes (howling monkey), lower jaw is enlarged to 

 support howling apparatus. Ateles. 



