ArticLeE 1—The Dragon-flies (Odonata) of Illinois, with 
Descriptions of the Immature Stages. — Part 1. Petaluride, Aesch- 
nide, and Gomphide. By James G. NeEDHAM AND CHARLES A. 
Harr. 
INTRODUCTION. 
The present paper is the combined product of studies made 
by the authors upon the collections of the [linois State Labo- 
ratory of Natural History, including those of the Biological 
Station at Havana, and by Professor Needham on his private 
collection. The state collections comprise the results of many 
years’ work in all parts of Illinois, including five successive 
years of field observation and collection at the Illinois Biolog- 
ical Station on the Illinois River at Havana; specimens ob- 
tained by Professor H. Garman from the Mississippi and related 
waters at Quincy, Ill. (Garman, ’90); a large series from the 
small lakes of northeastern Illinois; and collections made by 
Professor Forbes in Yellowstone Park and its vicinity (Forbes, 
93) and from lakes Geneva and Delavan, Wis., under the au- 
spices of the U.S. Fish Commission. Professor Needham’s pri- 
vate collection used in the preparation of this paper contains 
many Illinois and New York species, reared by him to the 
imago, and others contributed by correspondents, particularly 
by Mr. F. G. Schaupp in Texas, Mr. Adolph Hempel in Florida, 
and Mr. F. C. Willard in Arizona. The preparation of the in- 
troductory matter, biological discussions, and keys to the 
nymphs has devolved upon Mr. Hart, while the descriptive 
matter, with a few exceptions, was prepared by Professor 
Needham. 
We are indebted to Mr. C. C. Adams for abundant data on 
the occurrence of the imagos in Illinois derived from his large 
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