420 



DISEASES DUE TO VENOMS AND POISONS 



The scales and shield (ihe latter are simply large scales that do not 

 overlap) serve to differentiate the species. The ventral scales, moved 

 by the ends of the ribs, serve the purpose of locomotion. The tongue 



a, head u{ JVa/a bungariis, showing occipital shields; b, maxilla of Detidraspis ; c, Btin- 

 garus candidits, showing enlarged vertebral scales ; d, laterally compressed tail of sea-snake '■> 

 e, head of Cattsus rhombeatus, showing large shields ; f,Cerasles, showing oblique lateral scales > 

 ,<,', head of Ancistrodon, s^howing large shields ; h, head of Bids, showing supra-nasal shield and 

 small scales between nasal and rostral shields. 



is long, very retractile, forked at the tip, is capable of considerable 

 protrusion but is harmless. Some large lizards also possess a similar 

 organ. 



The eyes have no eye-lids; the cloaca! orifice is transverse; the 

 mouth is most extensile. This latter feature is permitted largely owing 



