294 THE MANUS. [CHAP. 



is reduced to a short metacarpal ; the fifth digit has but 

 t\vo phalanges, and the centrale is united with the trapezoid. 

 The ungual phalanges of the three middle digits are small 

 and somewhat conical in form. 



In the Elephant (Fig. 98) the manus is short and broad, 

 the carpal bones are massive and square, and articulate by 

 very flat surfaces ; they consist of scaphoid, lunar and cunei- 

 form, a pisiform and the usual four bones of the distal row; 

 ail distinct, without the centrale. There are five digits, with 

 short stout phalanges, the terminal ones being very small 



and of irregular form. 



\ 



All the existing true Ungulate Mammals agree in the 

 complete suppression of the pollex, in the absence of 

 an os centrale, and in the complete separation of- the 

 scaphoid and lunar. The carpus is very compact, the bones 

 being generally more or less square, and articulating by flat 

 surfaces with each other, and with the radius and ulna 

 above. The second or distal row of the carpal bones has, 

 in comparison with the Subungulata, been shifted altogether 

 towards the radial side of the limb, so that the os magnum 

 is brought considerably in relation with the scaphoid, and is 

 entirely removed from the cuneiform as in the great majority 

 of existing Mammals. The axis of the third toe passes 

 therefore through the os magnum but between the lunar 

 and scaphoid. The Ungulata are eminently digitigrade, the 

 limb being (except in the Tylopodd] entirely supported on 

 the ungual phalanges, which are large, and encased in a hoof. 



The digits are arranged according to one or the other of 

 two distinct types, each characteristic of, and giving name 

 to, one of the sub-orders. 



i. The Perissodactyla, or " odd toed " Ungulates, have the 

 middle or third digit the longest, and symmetrical in itself, 

 the free border of the ungual phalanx being evenly rounded. 



