AQUATIC NEMATOCEROUS DIPTERA II 

 Chironomidae 



BY OSKAR AUGUSTUS JOHANNSEN 



The present work forms £i continuation of the paper entitled 

 "Aquatic Neniatocerous Diptera," published in bulletin 68 

 of the New York State Museum (190ii). In that paper the 

 Blepharoceridae, Siniuliidae, Culicidae, and 

 the D i X i d a e were treated. In this paper the Chironomi- 

 dae will be considered, the classification reviewed, the chirono- 

 mid genera of the world described and discussed, and finally de- 

 scriptions given of the imagoes of all known North American 

 species except those belonging to the group Ceratopogon 

 (sens. lat.). Descriptions will also be given of all larvae and 

 pupae as far as known. The bulk of the material studied was 

 collected in New York, but many specimens were obtained from 

 the Mississippi valley. Rocky mountain and Pacific coast states. 

 In drawing up the descriptions of the species upward of 5000 

 pinned specimens and much alcoholic material was studied. In 

 order to save space the references to works of authors are abbre- 

 viated, only the author's name followed by a date is given, the 

 complete reference being given in the bibliography in the back 

 of the book. The study upon this family of flies was begun 

 in the spring of 1901 and was continued throughout four sea- 

 sons. The work -w&s done in the entomological laboratory of 

 Cornell university under the direction of Professor J. H. Com- 

 stock, to whom I wish to express my thanks for advice in the 

 preparation of this work. I am also under obligations to Pro- 

 fessor Kellogg of Leland Stanford jr. university. Professor C. O. 

 Houghton of Delaware agricultural college. Professor Aldrich of 

 Idaho, Mr, A. L. Melander of Washington State, and Doctors Mac- 

 Gillivray and Riley of the instructing staff of Cornell university; 

 and especially to Professor J. G, Needham of Lake Forest uni- 

 versity for specimens and many favors. 



The family of the Chironomidae or midges comprises 

 a large number of very delicate, and often minute flies, of which 

 over 800 species are known throughout the world. They resemble 

 mosquitoes in some respects, but are usually more delicate, and 



