Nos 



Figure 1. 



The crown or top of the head of a typical snake to show 

 head shields. 



Nos. — nostril, 

 E = eye. 

 K = rostral. 

 I = internasal. 



Pf. = prse-frontal. 

 F = frontal. 

 S = supra-ocular. 

 P = parietal. 



T = temporal. 



