242 Annals Entomological Society of America [Vol. XV, 



and was teneral. It was taken on wild black cherry. I had 

 observed several specimens on plum blossom in a neighbor's 

 garden about a week earlier It is therefore safe to say that 

 specimens may be looked for from the time plum begins to 

 bloom, until towards the latter part of June. Choke cherry 

 bloom followed the black cherry, and while not as productive, 

 a stray specimen was taken. The vast majority, however, were 

 taken in open, sub-swampy woods on bloom of Asmorrhiza 

 clatoni, and in a single hour I captured over forty specimens, 

 including four species. Where they appeared from so suddenly 

 I cannot imagine, as I had collected in the same spot for several 

 days previously without a sign of one. This was in June, 

 and by the 14th they had disappeared entirely, having been 

 present for less than a week. 



The adults are rather peculiar in habit, and invariably 

 appear to arrive on a blossom from nowhere. Only one speci- 

 men was observed arriving on bloom and it appeared to fly 

 quickly, and settle solidly at once and commence feeding. 

 They are diligent feeder'^, and hence are usually easy to capture. 

 Unlike //. ferruginea, they frequently are found high up on a 

 tree. 



DISTRIBUTION. 



In Ontario I have taken six of the ten known species, and 

 in view of the fact that some of these are recorded from the 

 Pacific coast, while others are supposedly more or less southern, 

 I conclude that all the species may be expected to occur at 

 least in the northern States and Canada, with the exception 

 that B. gigas Lovett probably occurs only in the Rockies and 

 west. B. media was described from California, but occurs 

 in Ontario, while B. notata, originally described from New 

 Hampshire, occurs in British Columbia, Oregon and Wash- 

 ington Territory. 



CHARACTERS USED IN CLASSIFICATION. 



Several of the characters which might be used in classification 

 are not employed here because they are often open to dispute 

 and may cause confusion. One such character is the pilosity 

 of the arista, which may vary somewhat in the same species, 

 as is the case in the British Columbia specimen of B. notata, 

 which has the pile distinctly longer than in any of the eastern 

 specimens which are before me. While the structure of the 



