78 
The Ohio Naturalist. 
[Vol. VII, No. 4, 
With orange light at the aperture and fifteen to eighteen 
shrimps in the held, white light was placed, at the opposite end, 
removing the orange light at the same time, three shrimps were 
at the other end (white light) in one minute, and eleven or twelve 
in five minutes. Changing back again to orange, five shrimps re¬ 
turned in one and one-half minutes and fourteen in five minutes. 
Experiments were continued in this manner for about an hour and 
a half with practically the same results, however, yellow light 
with which experiments were closed did not cause a ready 
response. This was probably due to the fact that the shrimps 
were suffering from fatigue, because yellow light used on fresher 
individuals had the same effect as any other light. 
weeds to light shed through aperture A in covered end of aquarium. See 
text for explanation. 
Later in the season two apertures were used of equal diameter, 
(about 3-4 by 3-4 inch), side by side, in the same pasteboard 
cap and about two inches apart. Two different colors were then 
used at the same time to test whether there was any preference. 
It was found by careful observation that there was no apparent 
choice, except as stated above, a possible preference for red. 
(Note.— The screen used for colored light was made of the best quality 
tissue paper from one to three fold depending on the density. This paper 
was simply placed over the aperture in front of the acetylene gas lantern. 
The light thus obtained was good for all practical purposes, though great 
stress should not be placed on details, since the writer was not able to 
regulate carefully the intensity of the light so as to secure uniform results.) 
Conclusions. —Palaemonetes^exilipes Stimpson, is the com¬ 
mon shrimp of Sandusky Bay, though not abundant. Shallow 
water with sandy bottom and rich in vegetation affords the most 
