531 



Illinois locality, Thompson's Lake, near Havana, April 27, 1914 

 (C. A. Hart and j. R. Malloch). 



Only pupal exuviae of the foregoing two species were obtained. 



Tanytarsus sp. C 



Larva. — Length, 4-5 mm. Very like cxiguits, but differing in 

 form of labium (PI. XXIX, Fig. 14). 



Illinois locality, Illinois River at Havana. 

 May be a variety of exigims. 



Orthocladius sp. A 



Larva. — Length, 4-5 mm. Yellowish. Head slightly more than 

 a fourth longer than broad ; eye spots distinctly separated, the upper 

 one largest ; antenna short, about equal in length to the mandible, base 

 slightly raised, basal joint five times as long as its diameter, second 

 joint slightly less than one third as long as basal and as long as next 

 two joints together; labium (PI. XXIX, Fig. 13) with the central 

 portion pale, without teeth, lateral portions much darker, with four 

 teeth. 



Illinois locality, Illinois River at Dresden Heights, by dredging. 



No attempt was made to rear the species. 



Orthocladius sp. B 



Larva. — Length, 6 mm. Yellowish brown. Head a third longer 

 than wide; labium as in Figure 21, Plate XXIX. In other respects 

 similar to dissiuiilis. 



Illinois locality, Salt Fork at Homer Park, March 16, 1914 (C. A. 

 Hart and J. R. Malloch). 



Orthocladius sp. C 



Larva. — Length, 5-6 mm. Yellowish. Labium as in Figure 20, 

 Plate XXIX ; mandibles with three distinct teeth. Except in the form 

 of the labium this species closely resembles species E. 



Illinois locality, Illinois River at Havana (C. A. Hart). 



Orthocladius sp. D 



Pupa. — Length. 4-5 mm. Yellowish brown. Thoracic respira- 

 tory organs long and slender, of nearly equal diameter throughout 

 their entire length, surfaces without noticeable setulae. Second ab- 



