132 Bulletin of the Brooklyn Entomological Society Vol. XVI 



•abundant of these was Cymatia americana Hussey. In connec- 

 tion with the description (Bull. Brookl. Ent. Soc, xv, p. 82, 

 1920) of this species, I noted that it had been found hibernating 

 in a very pecuHar situation, and stated that further investigation 

 of this habit was planned. However, owing to the great scarcity 

 of material during the following winter, I was unable to carry 

 my studies further; and as I am no longer located in a region 

 where this species occurs, it seems advisable to publish the data 

 which I have. 



On January 15, 1919, I went to these ponds for the purpose of 

 obtaining specimens of Biienoa margaritacea Bueno for experi- 

 mental work in the laboratory. At this time about ten days of 

 very mild winter weather had followed four or five days of zero 

 temperatures, and the ice on the ponds was only about eight 

 inches thick. I had chopped down to a depth of about six inches 



■ over an area about a foot square before the axe broke through 

 and the hole filled with water. At the next stroke of the axe 

 some twenty or thirty Corixids, of the species referred to above, 

 appeared and floated up ' to the surface, where they remained 

 motionless. I collected these, and soon had obtained seventy or 

 eighty more in the same manner, all apparently coming from 

 below the ice. Then a block of ice about six inches square and 

 two or three inches thick was broken ofif, and I discovered the 

 source from which I was obtaining at least a part of the specimens. 

 In the ice itself, from half an inch to an inch above the water, 

 there were several small pockets, the largest of which was less 

 than an inch and a half in diameter, and in these the Corixids 

 were tightly crowded in groups of from ten to fifty individuals. 

 Some of the pockets had small open passages leading into them, 

 which may possibly have communicated with the water or with 

 other pockets ; but others were entirely sealed in by the ice. In 

 some cases which I found later there was a space of two or three 

 millimeters between the mass of bugs and the wall of the cham- 

 ber. No bugs were found singly and only the one species was 

 found hibernating in this manner. In all, I collected nearly three 

 hundred specimens from an area of little more than a square foot. 

 The water here was about fifteen inches deep below the ice. 



