234 



ELEMENTAR Y ANA TOM \ r . 



[LESS. 



This variation may, however, be carried out to a much greater 

 decree, and in two different ways, as regards the tarsus. 



FIG. 174 RUDIMENTARY PELVIC EXTREMITY OF Ophiodes. 

 /.fibula; t, tibia. (After Fiirbrin%er.) 



For, first, the os calcis and naviculare may be so extra- 

 ordinarily produced as to become completely long bones 

 adding a segment to the limb as in Tarsius, and, in a less 

 degree, in Galago and Cheirogaleus. 



FIG. 175. ELONGATED TARSUS OF CERTAIN LEMUROIDS. 



Left-hand figure, Tarsus of Cheirogaleus; right-hand figure, Tarsus of Tarsius. 

 A, calcaneum ; , cuboides ; C, naviculare. 



Secondly, the os calcis and astragalus may be similarly 

 elongated, as in the Frogs. 



