THE CANADIAN ENTOMOLOGIST • 15 



P. pulverulenta Smith. If my identification of this is correct, it- 

 is unquestionably distinct from assimilis, though it still, stands 

 as a variety, as described by Smith, and subsequently listed 

 by him and all other authors. Both occur in Alberta, and 

 not only are they separable superficially, but the male geni- 

 talia differ obviously. This happens to be at variance with 

 Prof. Smith's own statement, and it is not unreasonable to 

 suspect some inaccuracy on his part. I must admit I have 

 not seen the type, but my identification fits the description 

 exactly, except as to genitalia. 



P. larissa (1739). I cannot consider this to be distinct from 

 afiguina (1732). The type of the latter is in the British 

 Museum, and a comparison with seven Calgary larissa there 

 shows them, to my mind, to be identical. Imbiina, vicina, 

 acutipennis and pensilis stands as four species. They com- 

 prise a rather puzzling aggregate which requires thorough 

 investigating with the aid of breeding and genitalic study. 

 There seems little to separate imbnna from vicina except size, 

 and that difference is well within the reach of variation. 

 Acutipennis seemed satisfactorily referred to vicina also, where 

 Hampson left it. I still try to keep pensilis separate in my 

 collection, though I have much difficulty in placing material 

 from some localities. 



P. negussa (1682), whilst correctly in close association with plicatus 

 (1681), stands widely separated from gussata (1742) in the 

 new list. In so far as it is possible to be sure without having 

 bred them, I am convinced that the first and last named are 

 forms of one species. Mr. Tams worked specially for them 

 in the spring of 1915, and procured a fine series, whilst Mr. 

 Sanson took a number at Banff in the same year. The varia- 

 tion is continuous between the two extremes. I refer both 

 names to segregata (1741). 



P. beani (1743). The nearest ally of this is surely legitima (1741) . 



P. tenisca Sm. stands as a variety of stricta, and, contrary to my 

 original belief, I consider this correct. 



