Vol. XXviii] ENTOMOLOGICAL NEWS 203 



film and by main strength wrench themselves free from its 

 fatal clutches. Some, indeed, perish by drowning, although 

 their vitality is surprising. In time, some six days or so, they 

 cast their skins with accompanying changes in structure. This 

 takes place four times more before they reach the perfect in- 

 sect at the end of about six weeks. It is thus possible for G. 

 rcm'ig'is to have at least three generations in a summer, if not 

 more, depending, of course, on the length and temperature of 

 the season. 



For food Gcrris remigis depends on other insects and it is 

 very voracious. I have found it sucking Capnia nccydalo'ides, 

 the small stone-fly, abundant in this latitude, so very early in 

 the spring that it is frequently frozen into the snow when the 

 sun that melted its surface no longer shines upon it. 



In the aquaria it is fed flies, the most common, abundant and 

 obnoxious insect of the summer, although any other insect 

 would do as well. A specimen I had in an aquarium played 

 havoc with the other living things, devouring such tough cus- 

 tomers as Notonecta and Dinciites, after a long struggle, in 

 which each was endeavoring to get the other. It finally perish- 

 ed to a Notonecta irrorata. If sufficiently hungry they will 

 feed on their own nymphs and even on each other. 



Polymorphism is not displayed by this species, which is only 

 dimorphic, being found, but very rarely, fully winged, its com- 

 mon form being apterous. The possession of wings always 

 causes a change in the structure of the thorax to accommodate 

 the much enlarged muscles which the use of organs of flight 

 requires. These winged adults are generally found solitary 

 in the most unlikely places — isolated little pools, springs, rock- 

 holes, beach driftS far from the favorite haunts of this stream- 

 loving bug. 



The manner in which it uses its legs for propulsion is quite 

 interesting. The first pair is prehensile and is used to hold its 

 prey. In locomotion its tarsi only touch the surface of the 

 water. The bug rows itself with the middle legs only, the 

 tarsi being in contact with the water along their entire length, 



* 1915. Heteroptera in Beach Drift. Bueno, Ent. News xxvi : 277. 



