190 



THE CANADIAN ENTOMOLOGIST. 



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Notes on Illustrations. 

 No. 5. — The wing on the other side has the cell present. 

 No. 6. — The wing on the other side has a small cell present. 



The specimens represented in the other figures are approximately! the same on 

 both sides. 



From these figures it will be seen how many genera could be founded 

 upon a few of my specimens of this common and well-known species. 



When a common species is found to vary greatly in this way, it is 

 fair to infer that an examination of an equal number of each of the other 

 species in the same genus would probably disclose as surprising 

 variations, and it therefore becomes of the highest importance that 

 in founding new genera every available specimen should be carefully 

 examined to see whether the characters proposed to be used for 

 differentiation are sufficiently constant to warrant the erection of a new 

 genus upon them, and authors should invariably state the number of 

 specimens which they have examined for this purpose. If this were done 

 we should have fewer genera, but they would be more satisfactory. 



