134 



Bulletin of the Brooklyn Entomological Society Vol. XVI 



{Arctocorisa sp.) became less numerous, and finally, on January 

 9, none were seen; on this last date five specimens of Cymatia 

 were taken from under the ice, which was now about twenty 

 inches thick, and which showed no trace of the air-pockets in 

 which the bugs had been found the previous winter. 



These last five individuals were all torpid. They were taken 

 back to the laboratory in ice-water, and gradually warmed to 

 room-temperature, but none of them survived. The only move- 

 ments made by any of them were spasmodic twitches of the legs 

 and were induced by flashing a strong light over them. 



At present we can give no answer to the many interesting prob- 

 lems which' are suggested by these observations, such as the 

 manner of formation of the air-pockets, the entrance of the bugs 

 into them, the occurrence of but the one species of Corixids in 

 the pockets, the fact that no individuals of Cymatia were found 

 singly and frozen tightly in the ice, whether this mode of hiberna- 

 tion is merely accidental in Cymatia, or is characteristic of the 

 species. All of these are problems which merit investigation, and 

 I regret that I have been unable to continue my studies of them. 



II. Notes on the Food Habits of Cymatia americana. 



Until recently it has been very generally stated by writers on 

 the aquatic Hemiptera that the Corixidae are carnivorous insects. 

 But Hungerford (Science, N. S., xlv: 336-337, 1917; Jl. N. Y. 

 Ent. Soc, XXV : 1-5, 1917; Kans. Univ. Sci. Bull., xi: 234-249, 

 1920) has shown that various species of Arctocorisa, Palmacorixa 

 and Rhamphocorixa commonly feed upon organic ooze which de- 

 velops on the debris in the pools which they frequent, and that 

 they are primarily herbivorous insects. And the structural adap- 

 tations of the head and of the fore-legs are indeed admirable for 

 their mode of feeding. 



The structure of the head and of the mouth-parts of Cymatia 

 is essentially the same in Cymatia as in the other genera of the 

 family; but the adaptations of the long cylindrical tarsi (palae), 

 with their rows of long bristles (for figures of the palae of 

 Cymatia, see Bull. Brookl. Ent. Soc, vol. 15, pi. i, 1920), for 

 this type of feeding is much less obvious than in the case of Arc- 



