species, dates of occurrence, and the like, and have been exten- 

 sively used in the preparation of this paper. Such are those of 

 the late Dr. Kellicott ('95, '96, '97a) ; of Miss Wadsworth ('90) 

 and Mr. Harvey ('91a) for Maine ; of Calvert, Banks, and Van 

 Duzee for New York ; of Calvert for Virginia and the vicinity of 

 Philadelphia ; of Williamson ('00) for Indiana ; and of Elrod for 

 Iowa, and Banks for Kansas. The above localities are not far 

 from our own latitude, and the data given are presumably quite 

 close to the normal for Illinois. 



Among Illinois contributions to this subject we may men- 

 tion the elaborate papers ('62, '68) of our pioneer entomologist, 

 Mr. B.D.Walsh, who listed sixty species occurring about Rock 

 Island, describing a number as new ; a list of dragon-flies 

 taken at Kensington, 111., by Mr. Jas. E. McDade ('92) ; and the 

 treatment of the Odonata in Mr. H. Carman's "Animals of the 

 Waters of the Mississippi Bottoms near Quincy, 111." ('90). Eight 

 nymphs are listed in the latter paper. The original specimens 

 have been examined and determined as follows: His "4" is 

 Gomphus externus] "8. Epiieschna heros" is Naskf^schna penta- 

 cantha of this paper; "9" is Tramea lacerata ; "10", Epicordulia 

 princeps ; and " 11", Perifhemis domitia. "12" is immature and 

 not positively determined as yet. The others are correctly 

 identified by him. 



LIFE HISTORY. 



Dragon-flies hibernate commonly as nymphs, less com- 

 monly in the egg stage, and in one species as imago. Nymphs 

 of the AiNsopfera mostly transform to the imago in the early 

 part of the season, especially from the latter part of May to the 

 first of July in our latitude, the imagos scattering and becom- 

 ing reduced in numbers by midsummer. Some species, particu- 

 larly those of the Gomphkhe, have a very short period of emer- 

 gence, large numbers transforming within a few days. Ah(u\ 

 and perhaps some species of y^schna, has apparently two broods 

 in a year. The adults appear very early in the season, and 

 the young nymphs, feeding voraciously and actively, grow rap- 



