OF WASHINGTON, VOLUME XII, 1910. 65 



satisfactorily, and, in the case of our American species, also 

 the difficulty of identification, have caused these insects to be 

 much neglected. 



I am under obligation to Mr. E. S. Steele, of the U. S. Na- 

 tional Museum, for kindly determining for me the plants in my 

 observations. 



Since the above was written Mr. S. A. Rohwer has placed 

 at my disposal his notes on two flower-visiting species of Ti- 

 pulidae, observed by him at Florissant, Colorado,' The spe- 

 cies were determined by Mr. Coquillett as Erioptera caloptera 

 Say and Helobia hybrida Meigen (the latter is placed as a 

 synonym of H. pnnctipennis Meigen in the Aldrich Cata- 

 logue). Both species were found on the flower-heads of the 

 common cow parsnip, Heracleum lauatnm Michx., July 2-4, in 

 the heat of the day. Only a few of the Helobia were found, 

 but the Erioptera was very abundant and he swept many of 

 them off the flowers with his net in capturing Hymenoptera. 

 They were present on the flowers only during the heat of the 

 day and in the evening they were found on leaves or resting 

 upon the sides of buildings. In view of what has been said 

 above regarding the preponderance of Umbelliferse in the Eu- 

 ropean records, the occurrence of two of our species, one of 

 them in abundance, on a plant of this family, is significant. 



Dr. Howard stated that specimens of Geranomyia were 

 frequently sent in by correspondents under the supposition 

 that they were mosquitoes, and asked if there was anything in 

 their habits that caused the error. 



Mr. Knab stated that during the day they remained in dark 

 situations, such as cellars or outhouses, resting on the walls, 

 just as Anopheles and others mosquitoes do. 



Mr. Knab pointed out that the habits of Geranom\ia throw 

 an interesting side-light on the origin of the blood-sucking 

 habit in mosquitoes. While the probosces of mosquitoes and 

 of Geranomyia were developed independently and differ in 

 structure, they could nevertheless both be considered adapta- 

 tions to similar habits. In other words, mosquitoes were 

 originally feeders upon the juices of plants, such as the nectar of 

 flowers, and in fact many species are exclusively so at present. 

 The males, which as a whole have continued plant-feeders, 

 represent, then, a more primitive state in this respect, and 



