OF WASHINGTON. 23 



past two years, made an attempt to systematically investigate the 

 fauna of the island. Lack of time had prevented a thorough investi 

 gation of the fauna during day time, but a rather thorough collec 

 tion had been made of insects attracted to light, and some 2,000 

 or 3,000 species of insects of all orders would be listed from that 

 particular spot at some future date. The fauna of the island 

 shows a great difference from that found within the limits of the 

 District of Columbia proper. Such species as the beetles Calo- 

 soma and Hydrophilus, the water bug Benacus, the large may 

 flies which swarm around the electric lights, and numerous other 

 insects which are common in Washington, do not seem to occur 

 at Plummer's Island. Mr. Schwarz referred, also, to the re 

 markable difference in fauna between the southern, dry slope of 

 the island and the northern, more shady and more humid side. 

 The fauna of the Virginia shore opposite the island is similar 

 to that of the northern portion of the island. Mr. Morris and 

 Mr. Waite said that Mr. Schwarz's views as to the difference in 

 fauna in that region are borne out by a study of the -flora. Mr. 

 Schwarz remarked, also, on the difference in time of appearance 

 of a number of species at Plummer's Island from that on the 

 lower Potomac in the vicinity of Washington. This was especi 

 ally exemplified in the case of the may-beetles {Lachnosterna), 

 concerning which careful records had been published by Dr. 

 John B. Smith in his well known papers on the Lachnosterna 

 fauna of Washington, D. C. The insects at Plummer's Island 

 seem to come out one or two weeks later in the season than at 

 Washington. 



Mr. Banks reported that he had taken the Chrysopid Mele- 

 oma signoretti Fitch at Plummer's Island the past season. This 

 was the first record for the species so far south. It was origi 

 nally described from the Green Mountains of Vermont and had, 

 since then, been recorded from Mt. Washington and Frariconia, 

 New Hampshire, and Sea Cliff, New York. 



