GENERAL NOTES ON SNAKES. 



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1IIJC 



ol 



ar 



FIG. 300. Skull of grass snake. From W. K. Parker. 



A, Dorsal surface /.r. , premaxilla ; >nx., maxilla ; an., external nostril ; n., nasal ; ol. , 

 nasal cartilages ; />f., prefronto-lachrymal ; /., parietal \ f., frontal ; pa., palatine ; 

 t.pa., transpalatine ; pg., pterygoid ; pro., pro-otic ; ep., epiotic ; op., ophisthotic ; 

 so., supraoccipital ; eo., exoccipital ; ar., articular ; s.ag., surangular ; a^., angular ; 

 a., dentaiy ; q., quadrate ; sq., squamosal. B, Ventral surface /.r. , premaxilla ; ol. , 

 nasal cartilage ;/.r., maxilla; v., vomer ',pa., palatine ;/., parasphenoid ;f., frontal ; 

 ^/C,prefrontal;^o-., pterygoid ;y.,basisphenoid ;(7/j.,alisphenoid ;3.t>.,basioccipital ; 

 oc.c., occipital condyle ; eo., exoccipital ; q., quadrate ; ar., articular ; ag., angular ; 

 s.ag., surangular ; cr,, coronary ; s/>., splenial ; d., dentary ; op., opisthotic region. 



