536 



In none of the three states can the list be considered as exhaustive, 

 and much work remains to be done before analytical comparison can 

 be made between the genera and species of these or other states. 



Of the 54 species of Ceratopogonincc listed as occurring in Illinois, 

 21 are described as new either in the present paper or in recent arti- 

 cles by the writer. Six of these species have been taken in other 

 states; 3 in Michigan — one of these occurring also in Arizona — i 

 in New York, i in Indiana, and i in Virginia. Of the 21 species 

 of TanypincB listed as occurring in the state, 5 are described as new. 

 None of the new species have been seen from other states up to the 

 present time. Of the 103 species of CliirunoDiincc listed for Illinois 

 50 are described as new, 6 of these being also represented in the 

 Laboratory collection by specimens from other states. 



One of the most striking instances of the unexpected occurrence 

 of a species is that of Cliirouoiinis octopiinctatus Loew. This species 

 was originally described from Cuba, in the West Indies, and has not 

 hitherto been recorded again as far as I am aware. Two specimens 

 were taken on store windows in Urbana in October. 



The fragmentary condition of our knowledge of the species of 

 Chironomidcc occurring in North America furnishes insufficient data 

 for an indication of even their probable distribution. I have included 

 under the species descriptions in this paper, lists of states for which 

 I have found records of the occurrence of the species, but no doubt 

 the lists are incomplete in some cases. It is also probable that in 

 some instances erroneous indentifications are listed, but without hav- 

 ing access to the material upon which these records are based the 

 writer can not indicate misidentifications. 



Urbana, Illinois, May 1, 1915. 



