TEETH OF DIPIIYODONTS. 



315 



Otolicnus and Lemur have the same number and kinds of 

 teeth. In the upper jaw the incisors are small and vertical ; the 

 two on the right side are separated by a wide space from the 

 two on the left. The lower canines are compressed and procum- 

 bent like the incisors, but are a little larger. The upper canine 

 is long, curved, compressed, sharp-edged, and pointed. The 

 three upper premolars have the outer part of the crown pro- 

 longed into a compressed pointed lobe, whilst the inner part 

 forms a tubercle, which is largest in the third. In the true 

 molars the inner division of the crown is so increased as to give 

 it a quadrate form, the outer division being divided into two 

 pointed lobes. The premolars below are long, and the molars 

 4-cuspid in Otolicnus. 



All the American Quadrumana are distinguished from the Apes 

 and Monkeys of the Old World by the superior number of the 

 premolars, and, by this resemblance to the Lemurs, they show 

 their inferior position in the zoological scale. The small ' Mar- 

 mosets,' however, forming the genera Hapale and Midas, have but 

 two true molar teeth on each side of both jaws, their dental 



formula being- 



2.2 



1.1 



3.3 



l 2.2 ; C l.i ;/> 3.3 ; 



2^2 



272 



32. 



The lemurine character of the long, narrow, inferior incisors con- 

 tinues to be manifested by the Sakis (Pithecia 111.), which, like 

 the larger species of Platyrhines called Howlers, Capuchins, and 

 Spider-Monkeys, have the normal number of true molar teeth in 

 the Quadrumanous order, their dental formula being — 



2.2 1.1 3.3 3.3 

 t ^^i c t-t; p — „ ; m 



2.2' 



\.V r 3.3' 



3.3 



36. 



251 



The Capuchin Monkeys ( Cebus, vol. ii. fig. 349) have the four 

 lower incisors broad, thick, and wedge-shaped — a form which 

 these teeth retain, with slight modi- 

 fications, throughout the Quadru- 

 manous order. The canines are 

 sufficiently developed to inflict se- 

 vere wounds. The first three of the 

 molar series, p, 2, 3, 4, are bicuspid 

 premolars; the rest, m, l, 2, 3, are 

 quadricuspid true molars. The de- 

 ciduous formula is — 



.2.2 1 



l 2^ ;c I 



3^3 

 3.3 



24. 



Fig. 251 shows the deciduous series, 



Deciduous Mid perniaueut teetli of ;i young 

 Ccbus Apclla, clxxii". 



