328 WILLIAM MORTON BARROWS. 



EXPLANATION OF PLATE I. 



FIG. i. Showing a female Epeira sclopetaria in the normal resting position in 

 the web. The arrow indicates the place where the vibrator straw touches a radial 

 strand of the web. 



FIG. 2. The same individual, shown in Fig. i, orienting to the vibrator which 

 had been in motion for a fraction of a second just before the photograph was taken. 



