5*1 



B 



FIG. 200. Skull of Grass Snake. (From W. K. PARKER). 



A. Dorsal surface px. , premaxilla ; mx., maxilla ; an., external 

 nostril; n., nasal; ol., nasal cartilages;^/!, prefronto-lachrymal ; p., 

 parietal ; /., frontal \pa., palatine ; t.fia., trans-palatine ; pg. , pterygoid ; 

 Pro., pro-otic; ep., epiotic : op., opisthotic ; so., supra-occipital; eo., 

 ex-occipital; ar., articular; s.ag., sur-angular ; ag., angular; d., 

 dentary ; q., quadrate ; sg., squamosal ; B. Ventral surface px., pre- 

 maxilla ; ol., nasal cartilage; m.r., maxilla; v., vomer ; pa., palatine; 

 p., parasphenoid ; f., frontal ; pg. , pterygoid ; frs., basisphenoid ; 

 als., alisphenoid ; b.o., has -occipital ; oc.c., occipital condyle ; eo., ex- 

 occipital ; q. , quadrate ; ar. articular ; ag., angular ; s.ag'., sur-angular ; 

 cr., coronary ; sp., splenial d., dentary ; op., opisthotic region. 



