512 THE VERTEBRATE SKELETON. 



The Creodonta differ from living Carnivora in the fact that 

 the scaphoid and lunar are usually separate. 



In INSECTIVORA the scaphoid and lunar are sometimes 

 united, sometimes separate, and a separate centrale is usually 

 present. There are generally five digits, but sometimes the 

 pollex is absent. In the Mole the manus is greatly developed 

 and considerably modified. It is very wide, its breadth being 

 increased by the great development of the radial sesamoid 

 which is very large and sickle-shaped. The ungual phalanges 

 are also large and are cleft at their extremities. 



In the CHIROPTERA the manus is greatly modified for the 

 purpose of flight. The pollex is short and is armed with a 

 rather large curved claw, the other digits are enormously 

 elongated, the elongation in the case of the Insectivorous bats 

 being mainly due to the metacarpals, and in the Frugivorous 

 bats to the phalanges. In the Frugivorous bats the second 

 digit is clawed as well as the pollex, in other bats this claw is 

 always absent, and so is often the ungual phalanx, the middle 

 phalanx then tapering gradually to its termination. 



In PRIMATES as a rule the manus is moderately short and 

 wide. The carpus has the scaphoid and lunar distinct, and 

 generally also the centrale : sometimes however, as in Man, 

 the Gorilla, Chimpanzee, and some Lemurs, the centrale has 

 apparently fused with the scaphoid. There are almost always 

 five well-developed digits, but in the genera Colobus and A teles 

 the pollex is vestigial. 



The magnum in man is the largest bone of the carpus. The 

 pisiform also is well developed, but there is no radial sesamoid. 

 In Man, the Gorilla, Chimpanzee, and Orang, the carpus arti- 

 culates only with the radius, in most Primates it articulates 

 also with the ulna. The third digit of the Aye- Aye (Chiromys) 

 is remarkable for its extreme slenderness. 



THE PELVIC GIRDLE. 



The pelvic girdle in all mammals except the Sirenia and 



