136 



OHIO STATE ACADEMY OF SCIENCE. 



Plate II. 



nostrl I 



Fig. 1. External View of Rattler's Head. 

 The pit is seen between and below the eye and nostril. {From Stejneger. )> 



d g 



e b c 



Fig. 2. Head of Rattler. 



a, venom gland ; a' ', duct ; b b\ temporal muscle ; f sheath of fang. 



(After Stejneger from Duvernoy.) 



Fig. 3. Skull of Rattler— {from side.) 



The long fangs in the upper jaw are fixed in the maxillary bone ; this bone 



is hinged on the lachrj-mal (above) and the pterygoids (posteriorly). 



The excavation for the pit in the maxillary bone is seen at the 



end of the pterygoid bones. {From Stejneger after Jan.) 



