Entomology of the Illinois Bvoer. 227 



C. niger Macq. 



Taken along shore at Station C on May 16, 17, and 

 18. It appears in our collections from McLean and 

 Champaign counties (central Illinois) and from Union 

 county, in southern Illinois, on seven dates between May 

 16 and June 15, being apparently earlier in its appear- 

 ance than callidiLS. 



C. CBstuaThs V. d. Wulp. 



This northern species is common about the small lakes 

 of northern Illinois. They were noted Aug. 3-10 

 flying among the marginal rushes of Fourth Lake, 

 Sand Lake, and Slough Lake, in Lake county, and 

 ovipositing on the stems of the rushes. The flies have 

 also occurred about Urbana June 8, 16, and 17. 



JEgg [Fig. 42].— Length 1.6 mm., diameter 25 mm., 

 Cylindrical with rounded ends, straight or slightly curved, 

 smooth, slightly opaque, cream color when laid, becom- 

 ing dark fuscous brown, placed in a single flat layer, 

 obliquely stacked as in Tabanus, about one fourth of 

 the length of each e^^ being visible at the surface, the 

 remaining three fourths being covered by those stacked 

 against it. The mass is about 10 mm. long and 3 or 

 4 mm. wide, its outline variable, usually diamond-shaped, 

 both ends pointed, or one end short or truncate, making 

 it more or less triangular. 

 C. callidus O.-S. 



One example was found flying along shore at Station 

 C July 16. We have collected this species at Urbana, in 

 the vicinity of a small creek, June 8 and 16 and July 

 20 ; and at Savanna, on the Mississippi, in Carroll county, 

 August 1. 

 C. pudicus O.-S. 



Illinois {Kennicott*) . 

 C. montanus O.-S. 



Ogle Co. {OsterirSacken). 

 G. flavidus Wied. 



*08ten-Sackeii, ••Prodrome," 



