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Water Beetles. 



Looking over several collections of Water Beetles recently, I was 

 surprised to see how poorly they are usually represented. Mr. Roberts 

 and myself last season took numerous species, most of them in large 

 numbers, out of a single pond, and in fact a very limited tract of that 

 pond; and that in mid-summer. April and May are the best months to 

 collect those insects, and any moderate sized pool in which there is some 

 vegetation is sure to yield an abundant harvest. A stout net ring is re- 

 quired, the bag to be of coarse cheese cloth, and the vegetation should 

 be swept nearly to the bottom: not once only, but half a dozen times. 

 In a single haul over a hundred specimens, representing ten or a dozen 

 species have been taken. Rather sluggish ditches in meadows form ex- 

 cellent collecting grounds. J. B S. 



Oviposition in Agrion. 



Mr. McLachlan has noticed Agrion mercitria/e, ("a very local British 

 species') with a part or the whole of the abdomen incrusted with mud, 

 caused by its sinking its eggs in the mud left from the dried up pools. 

 He is not aware that this species descends beneath the surface of the 

 water. (Ent. Mo. Mag. Vol. XXI, p. 211.) Remembering the same 

 thing, on referring to my collection, I find a few females of our common 

 Agrion civile with mud on a part of the abdomen. The egg laying habit 

 of this species is to sink about the last four segments beneath the water, 

 generally on grass. I know only one species of North American Agrion 

 to descend beneath the surface of the water, viz: our common A.exulans. 

 I have noticed it a foot or more beneath the surface, fastening its eggs to 

 the stems of water grass, and remaining submerged a long time during 

 the operation. When a stick is thrust near it, or a slight commotion 

 caused that will shake the grass stalk, it will let go, rise quickly to the 

 surface and as quickly take wing. 



ACAD. NAT. SCI. PHILA. S. FRANK AaRON. 



In June 1870 I took about sixty cocoons of Samia Cynthia to New- 

 burgh, N. Y., and there freed them. In August 1884 I found on Eagle 

 Cliff, Lake Mohawk, some distance west of Newburgh, several cocoons 

 of -5". cynthia on Sassafras. These were evidently the descendants of those 

 I had freed in 1870. Ailanthus is not found on Eagle Cliff, and the 

 species has evidently adopted the food plant of its near ally, promethea. 



Chas. A. A. During. 



