ECOLOGY OF ISLE ROYALE. 309 



Family Culicidae. 



1. Culex pipiens Linn. The rain barrel Mosquito was taken July 

 11, (Station I, Sub. 1) and August 3, (V, 3). This is the common mos- 

 quito that breeds in receptacles of standing Avater and small pools 

 generally, and widely distributed in this country and in Europe, hav- 

 ing been described under various names. I hesitated somewhat in giv- 

 ing the specimens a specific name for the reason that they were dropped 

 into alcohol when they were collected and lost many of their scales be- 

 fore they reached me. 



Family SwiuUid,ae. 



2. Simulhim venustwn Say. Black Fly. Taken July 14 (I, 5) and 

 July 28, (III, 5). In Ohio I have found the larvae of this species cling- 

 ing to rocks in swift flowing brooks and at the outlet of a small artifi- 

 cial lake where the water passed through an iron pipe and dropped a 

 foot or two on to rubbish and stones. This minature waterfall seemed 

 to furnish ideal breeding grounds for the species, for the larvae were 

 there in abundance and the adults were flying about in swarms. The 

 type locality for the species is along the Ohio Eiver near Cincinnati, 

 but it has been identified from a number of states and from Canada. 

 It is a matter of interest to know that the species is a member of the 

 genus with the well known and destructive Buffalo Gnat. 



Family Stratiomyidae. 



3. Stratiomyia 'badia Walker. Judging from the large number of 

 specimens taken the species must have been common from July 17-31. 

 All specimens were taken at the Light-house clearing (I, 7). At San- 

 dusky (he species appears in numbers on flowers of White Sweet-clover 

 and milkweeds, and specimens are often seen with the pollen-masses of 

 the latter plant clinging to their feet. The Isle Royale specimens are 

 typical in coloration but are slightly larger on an average than other 

 specimens I have seen. The type locality is New Hampshire but its 

 range is known to extend over a large part of northeastern North 

 America. 



Family Taianidae. 



4. Glvrysops carbonarius Walker. Specimens were taken along the 

 McCargoe Cove trail and at the head of Eock Harbor (III, 3), July 11- 

 14. This is usually a northern species but has been taken on the east- 

 ern coast of the United States as far south as North Carolina. It be- 

 longs to the group without an apical spot and is closely related to mitis, 

 the species next considered, and from which it is separated by the pres- 

 ence of a hyaline spot at the base of the fifth posterior cell. In these 

 specimens this spot is very small, sometimes making it difficult to say to 

 which species they really belong. As a usual thing specimens of car- 

 ionarius are noticeably smaller than specimens of mitis. 



5. Ghrysops mitis Osten Sacken. A number of specimens taken 

 along the McCargoe Cove Trail, July 11, are of this species. As stated 

 above the difference between this species and the former is not always ap- 



