278 



ZOOLOGY 



FIG. 2(il. Crotalus, the rattlesnake. Photographed as the snake was about 

 to strike. Taken in Ari/ona and kindly lent by H. ~\V. Menke, Chicago, 111 



FKI. 2(!2. The rattlesnake. The recoil after striking. Photographed in 

 Arizona and kindly lent by H. AV. Menke. 



Note in both figures the elevated rattle, toward the right. 



