48 THE CANADIAN ENTOMOLOGIST. 



shading into ground colour on outer edge, or coalescing near inner margin; 

 all markings, especially subapical dentate spots, equally distinct in both 

 sexes. It is slightly smaller than erechtea, more variable, and marked 

 alike in both sexes. After reading the above I have been able to make 

 what I believe to be a fairly satisfactory separation of my eastern material 

 upon this basis, and certainly find the form of $ abdomen a rather striking 

 character, combined with the practical absence of subapical black spots in 

 $ erechtea. The males are certainly darker, but those of crassiuscula 

 seem to be less gray than in the other species, and in specimens where the 

 two bands are well joined on inner margin so as to form a rude U, the 

 reference to crassiuscula is probably safe. Mr. Slingerland states, how- 

 ever, that " specimens occur which it is almost impossible to separate by 

 markings alone, and the structural characters must then be resorted to." 

 In Ent. News, XV, 221, Mr. E. J. Smith states that Dr. Holland's pi. 

 XXX, fig. 15, is not crassiuscula ^ , but erechtea. From Mr. Slingerland's 

 papers I should judge that it might be either, with the probabilities rather 

 in favour of the latter. Fig. 14 is certainly an excellent representation of 

 Calgary $ erechtea. 



I have so far received nothing from the east under the name of 

 distincta, but have males so closely resembling the Calgary form as to 

 make their specific difference very doubtful, and have sent out numbers of 

 local specimens at different times without having the name questioned. 

 But, despite this fact, and that Mr. Slingerland says that crassiuscula is 

 " marked alike in both sexes," I find more tendency to a sexual colour 

 difference in my eastern series under that name than exists in Calgary 

 distificta, of which the primaries may be best described as ashen-gray. 

 Though the form of 9 abdomen resembles that of crassiuscula, the males 

 much more nearly approximate those o{ erechtea. The bands on primaries 

 scarcely seem to show more tendency to join, and with males alone to 

 deal with, and knowing nothing about the different habits of the two in life, 

 I should be almost inclined to look upon them as one seasonally 

 dimorphic species. Distincia averages decidedly smaller, and is usually 

 much grayer, but single specimens are sometimes rather hard to place 

 without the aid of the date label. But the strong colour difference be- 

 tween the sexes of erechtea prevents any real confision with distiiicta. 

 The capture of the above listed typical 9 crassiuscula on the Red Deer 

 River, in company with the smaller and quite di-similar Calgary form of 

 distincta, makes it hard for me to accept them as one species. 



