THE DENTITION OF THE CYNOMOEPHA. 473 



There is a complete double set of extensors in the four 

 ulnar digits of the manus, the extensor minimi digiti giving 

 a tendon to the fourth digit, and the extensor indicis one to 

 the third digit. The extensor ossis metacarpi pollicis gives a 

 distinct slip to the trapezium, and thus precisely corre- 

 sponds with the tibialis anticus, which has two tendons, one 

 for the ento-cuneiform, and one for the metatarsal of the 

 hallux. The flexor digitorum profundus and flexor longus 

 pollicis are represented by one muscle, a slip from the ulnar 

 side of the tendon of which usually goes to the poUex. 



The tendons of the flexor perfo7-ans digitorum and flexor 

 liallucis unite to form the deep flexor tendons of the pedal 

 digits in very variable proportions. The flexor accessorius 

 is very generally present. 



The anterior upper pi'emolar has its outer cusp peculiarly 

 modified and sharpened. The anterior lower premolar has 

 the anterior margin of its crown prolonged and cutting, so 

 that it works, like a scissor-blade, against the posterior edge 

 of the upper canine. In the upper jaw, the premolars have 

 three roots ; in the lower, two. The molars in both jaws 

 have four cusps connected by two transverse ridges. Some- 

 times there is " heel " behind the posterior ridge of the last 

 lower molar. 



The formula of the milk dentition is d.i. ^ d.c. j^ d.m. 

 -77 = 20 ; and the anterior milk molar resembles the per- 

 manent premolars, while the posterior is like a permanent 

 molar. 



The permanent canines make their appearance before or, 

 at latest, contemporaneously with, the hindermost molar in 

 both jaws. They are large and long, and are separated, by 

 a well-marked diastema, from the outer incisor above, and 

 from the first premolar below. 



The Cynomorpha very generally possess cheek-pouches, 

 which serve as pockets for the temporary stowage of food. 

 The stomach is usually simple, with a globular cardiac 

 extremity and an elongated pyloric portion ; but, in Semno- 

 pithecus and Colobus, the stomach is divided into three com- 



