426 THE CANADIAN ENTOMOLOGIST 



2. Johannsen, O. A. 



1903. Aquatic Nematocerous Diptera. N. Y. State Museum, 

 Bull. 68. 



3. Malloch, J. R. 



1915. The Chironomidae of Illinois. Bull, of 111. State Lab. 

 of Nat. Hist., Vol. X, pp. 472-474. 



4. Miall, L. C, and Hammond, A. R. 



1900. The Structure and Life-history of the Harlequin Fly 

 (Chironomus dorsalis). 



5. Moore, E. 



1915. The Potamogetons in Relation to Pond Culture, Bull. 

 Bur. of Fisheries. Vol. XXXIII, pp. 284-285. 



6. Needham, J. G.;Morton, K. J., and Johannsen, O. A. 



1905. Mayflies and Midges in New York State. N. Y. 

 State Museum Bull. 86, pp. 239^41, pi. 23, fig. 7-13; 

 pi. 29, fig. 12. 



7. Needham, J. G. 



1908. Aquatic Insects of Walnut Lake. A Biological Sur- 

 very of Walnut Lake, Mich. Rept. of Biol. Sur. of 

 State of Mich., pp. 252-262. 



8. Needham, J. G., and Lloyd, J. T. 



1916. Life of Inland Waters, pp. 227-230. 



9. Tilbury, M. R. 



1913. Notes on Feeding and Rearing of the Midge, Chi- 

 ronomous cayugse Johannsen. Jour. New York Ent. 

 Soc, Vol. XXI, pp., 305-309. 



Explanation of Plate XXI. 



Fig. 1. — Fertilized egg beginning to develop. 



Fig. 2. — Young larva just hatched with only two anal gills. 



Fig. 3. — Mature larva. 



Fig, 4. — Pupa. 



Fig, 5. — Adult male. 



