6 



PSTCHE. 



[January 1S91. 



this absence of the cricket serenade dur- 

 ing the months of June and July and 

 early August is accounted for by the 

 fact that this locality is north of the 

 range of G. pennsylvanicus. This 

 species has not been, I think, reported 

 from Canada and G. luctuosus as rare, 

 so thar if I have not erred there should 

 not be heard anything more than an 

 occasional cricket chirp there before the 

 middle of August. The only invariable 

 and easily recognized difference between 

 G. pennsylvanicus and G. abbreviatus 

 is that in the females of the former the 

 ovipositor is decidedly shorter than the 

 body, in the latter this organ is nearly or 

 quite as long as the body. 



8. Gryllus abbreviatus Serv. Mo- 

 line, August 14. Very abundant. 



9. Gryllus domesticus Linn. Mo- 

 line and Urbana. Very rare, a single 

 specimen having been taken at each 

 place at the electric light. 



10. Nemobius fasciatus De Geei\ 

 Abundant everywhere, especially in 

 blue grass meadows. It is very com- 

 mon at the electric light about July 

 27. The wingless form vittatus Harr. is 

 at least in the northern part of the State 

 more abundant than fasciatus. 



11. Anaxipha pulicaria Burm. 

 Taken in a single locality on Rock 

 River near Colona, Rock Island Co., 

 about August 20. 



12. Phylloscirtus p?dchellus Uhler, 

 A few specimens have been captured at 

 Pine Hills, September 14, 1883. 



13. Oecanthus niveus De Gcer. 

 Abundant throughout the State from 

 the latter part of July to the late fall. 



There are five species of Oecanthus 

 in Illinois which are very widely disti'i- 

 buted in North America. Two of these, 

 Oecanthus fasciatus Fitch and Oecan- 

 thus angustipennis Fitch, have gener- 

 ally been considered varieties of Oecan- 

 thus niveus De Geer, but several years 

 observation of this genus has led me to 

 conclude that they are quite distinct in 

 structure, habits, and song and they must 

 therefore rank as species. 



The last named species can be distin- 

 guished from the two former by its 

 broader wing covers, the width of the 

 dorsal field compared with the length 

 being about one to two in latipennis 

 and niveus, one to three in angusti- 

 pennis and two to five in fasciatus. 

 The average of these dimensions is in 

 the first mentioned species .30 by .62 

 inches ; in the second .26 by .54 inches ; 

 in the third .16 by .44 inches; and in 

 the last .iSby .46 inches. Niveus can 

 usually be distinguished from all the 

 other species by its color, which is ivory 

 white with almost no perceptible infusion 

 of green in the male but the elytra of the 

 female may be quite decidedly green. 

 In angustipennis the male as well as 

 the female, probably, is deeply suffused 

 with green. In fasciatus the greenish 

 tint is also predominant in the wings 

 and elytra but the other pails of the bodv 

 vary in color from deep black to ivory 

 white varied with fuscous. In typically 

 colored specimens however the head and 

 pronotum are whitish with three dis- 

 tinct fuscous or black stripes, extending 

 one over the top of the head and pro- 

 notum and the other two on the lateral 



