69 



on 6 to 9, sharp, the last pair as long as 10 ; lateral margins of 

 7 to 9 serrate ; dorsal hooks well marked on 2 to 9, sharply 

 pointed ; appendages as long as last segment. 



2. Gomphus graslhicUHS Walsh. 



Imagos of this species have been reported from the states 

 of Washington (Hagen '85, p. 264), Indiana, and Ohio. The 

 State Laboratory has a number of the nymphs from the shal- 

 lows of Cedar and Sand lakes, in northeastern Illinois, taken in 

 June, August, and October, many young occurring in the latter 

 month. It is common in ponded waters near Urbana, but appar- 

 ently does not occur in the bottom-land lakes and streams about 

 Havana. Mr. Needham studied the species at Purington Lake, 

 near Galesburg, 111., in 1895, collecting and rearing a large num- 

 ber of nymphs. His notes are as follows : " Very early in the 

 spring I obtained from steep clayey banks in the lake nymphs 

 lacking one and two molts of maturity. Placed in my aquaria 

 these nymphs quickly descended into the mud of the bottom un- 

 til only the upturned tip of the abdomen remained exposed, then 

 burrowed along parallel to the surface, leaving a shallow groove 

 to mark their course. When out of the mud they crawl stiffly 

 and very slowly, but swim fairly well under compulsion, by ex- 

 pulsions of water in the usual manner. Transformation takes 

 place commonly between daybreak and sunrise. The nymph 

 usually crawls but a few inches from the water, and appears to 

 transform oftenest while lying flat upon the bare earth or upon 

 tangled mats of dwarf club-rush and other semiaquatics. Ex- 

 uviae picked up in such places are usually incrusted with mud. 

 The species appears on the wing in Illinois about the 20th of 

 May, and flies for about a month. Imagos were oftenest seen 

 when flushed from the grass or from the bare paths which ter- 

 raced a steep hillside beside the lake. Females were little in 

 evidence. I took one ovipositing and obtained in a tumbler of 

 water an immense number of eggs." 



Other Illinois localities for the imago are Coal Valley Creek 

 (Rock Island county), Des Plaines and Chicago Rivers; Chicago, 

 Bloomington, and Urbana, — the dates ranging from late in May 



