f>UIiEi;S OF ^rAMMAI.lA. 3.^7 



which the nostrils are simple, and are placed far apart ; the thuuiljs 

 of the fore-feet are wanting, or, if present, are hardly opposable ; 

 and the tail is generally 2)rehensile. The Platyrhine Monkej's are 

 exclusively confined to South Ameiica, occurring es]-iecially in 

 Brazil, and they are all adajited for a more or less purely arboreal 

 life. The best-known members of this section ai-e the Marmosets 

 {Hapalidi£), and the great family of the Cehiila', comprising tlie 

 Spider-monkeys, tlie Howlers, and otliers. The Howlers (Mi/ceten) 

 are remai'kable for having a bony drum at the suiriniit of the wind- 

 pipe, by which the voice is rendered extraordinarily lesonant, and 

 ]jeculiarly weird and teri-ifying to those who hear it. 



As regards their dentition, the Platyrhine Monkeys differ from 

 the Old World Monkeys, as also from Man, in having an atlditional 

 premolar on each side of each jaw. They have, therefore, three 

 ])r;emolars on each side of each jaw, instead of (jnly two. (Jn the 

 other liand, they have either three molars on each side, as have the 

 Old World Monkeys and Man, or they have only two. The dental 

 formula of the Marmoset is — 



. 2—2 1—1 .■3— 3 2—2 „ , 



^ - \ c - — ; run ; in — — .)2. 



2—2 1 — 1 ^ 3-3 i—i 



The dental formula of the Howlers [}fijivtix) is — 



.2—2 1—1 3—3 .3—3 .,,. 



t :<■--; pm — ; in — =3(i. 



2—2 1—1^ 3—3 3—3 



iHection C. C'atarldiia. — In this, the highest section of the Quadru- 

 mana, the nostrils are oblique and placed close tugetber, and the 

 thumbs of all the feet are opposable, so that the}' are truly " (piadru- 

 manous." The dental ffjnnula agrees with that of Man : — 



.2-2 1—1 2—2 3—3 ., , 



( ; c ■ pin - : in = ■vl. 



2—2 1 — 1 ^ 2—2 3—3 



The incisor teeth, however, are jirominent ;ind i>rojecting, and the 

 canines, especially in the males, are large and pointed, whilst the 

 teeth form an uneven series. The tail is never preliensile, and is 

 sometimes absent. Cheek-pouches are often present. In one single 

 instance (fjulohus) the thumbs of the fore-limljs are wanting. 



With the single exception of a Monkey which occurs on the Rock 

 of Gibraltar, all the Catarhine Monkeys are eonhned to Africa and 

 Asia. The most typical forms of the section are the Semnopitheid 

 and Macarpies of Asia. Less typical are the Baboons, which inhabit 

 Africa, and are amongst the most repulsive of all the Quadrumana. 

 In these the tail is alwa^'s short, and often quite rudimentary. The 

 head is large, and the muzzle greatly ]jrolonged, having the nostrils 

 at its extremity. The skull (fig. 202) is furidshed wltli great bony 

 24* 



