Entomology of tlie liUnois Rlcer. 249 



Last segment with four long bristles; head slender, 

 eyes prominent, at middle of side NemotdvA. 



Stratiomyia. 

 8. obeaa Loew. 



S. quatema/ria Loew. 



The types of these species were collected in Illinois by 

 LeBaron. 



S. apicula Loew. 



The most abundant imago in our general collections, 

 but not yet taken at Havana. We have it from Cham, 

 paign and McLean counties in central Illinois, and 

 from Cook, Lake, Kendall, and LaSalle counties in 

 northern Illinois. It occurred abundantly not far from 

 the University June 21, near a shallow pond, and less 

 abundantly May 22 and 25; and it has been taken on 

 various dates from May 17 to August 2. 



S. discalis Loew. 



Described by Loew from Illinois examples received from 

 LeBaron. In our collection from Provo, Utah. 



S. marginalis Loew. 



Imagos taken June 23 to Aug. 18, in Bureau, Rock Is- 

 land, McLean, and Champaign counties. 



S. norma Wied. [Fig. 57.] 



April 16, at Havana, the hibernated pupae were found 

 under drift some distance from water. In May larvae 

 were taken in vegetation alongshore. In June, close ex- 

 amination of bare mud on the wet shore at station B 

 revealed numerous larvae trailing over the surface, scarce- 

 ly distinguishable from it. July 9, a pupa from this 

 place contained a fully developed and perfectly colored 

 imngo. August 6 the imago appeared in the breeding- 

 cage. Meanwhile the larva occasionally occurred in dip- 

 net collections along shore. At Matanzas Lake, August 

 23, about fifty examples were found in a mass of cow- 

 dung lying half submerged near the margin. November 

 10 undersized larv^ne were frequent on the shore at 



