THE WING-FINGER OF PTERODACTYLS 



699 



nosaurus, are zygocrotaphic reptiles that may be included in the 

 order Theromorpha or Pelycosauria. 



Fig. 2. — Right front leg of Limnoscelis Williston, a cotylosaur reptile from the 

 Permian of New Mexico. A little less than one-half natural size. 



