Fic. 315.—Skeleton of frog. The half of the pectoral girdle, and 
fore- and hind- limb of the right side are not shown. 
gmx., premaxilla; mx., maxilla; ., nasal; s4%., sphenethmoid ; 
PS, Pparieto-frontal; P.O., pecs 24., pterygoid; g.7., 
a 
quadrato-jugal ; sg., squamosal; Q., quadrate; ¢., columella 
auris ; 4., atlas ; ¢.g., transverse process ; S.7., sacral vertebra 3 
U., urostyle ; S.sc., supra scapula; H., humerus; 2.U., radio 
ulna; C%., carpals ; Mc., metacarpals ; /2,, ilium ; Zs., ischium ; 
f., femur; 7./., tibio-fibula; Ca., calcaneum; As., astra- 
galus; C., calcar; .4¢., metatarsals. 
