226 THE CANADIAN ENTOMOLOGIST. 



form I have given the varietal name f(rfrac1a (Can. Ent., XLII, p.279, 

 19 10). The differences that Giienee points out seem pretty constant, but 

 the enlarged central band does not hold, as he has every variation of it 

 among European specimens. The pointed wings and green or gray 

 ground colour with slate-coloured bands seem to be rather distinctive of 

 the American form ; also the basal band is apt to be thicker and the first 

 mesial more pronounced, but I think a careful study of the genitalia with 

 extensive breeding will be necessary before we can be sure. However, I 

 feel that the American form will at least prove to be a good variety of the 

 European, and it might be well later to adopt the name pliiviata. The 

 uncus in Hydriomena autumnalis is very peculiar, being forked while it is 

 spatulate with a tendency to fork xwfurcata Thmb. 



Hydriomena aiiiti?n?ialis, trifasciata or pliiviata Gn., if our form 

 proves distinct from the European, is more common in the Atlantic States 

 than the Pacific. In Europe it seems to vary less in colour than here, 

 though the bands are variable in width and the specimens in size. There 

 is more tendency to melanism in the European specimens, but I have 

 some from Saskatchewan, from Mr. A. J. Croker, that are as dark as those 

 from Norway. 



H. atdumnalis Strom appears to be more common in Maine than 

 Massachusetts, as my friend Mr. Frost took a very large number one day 

 in a cedar swamp at Monmouth, and Mr. Emerton even took a specimen 

 on the summit of Mt. Kataadn. In Europe it is said to feed on alder 

 and willow, but the American food plant has not been recorded to my 

 knowledge. The palpi of the European and American forms are all 

 moderately long and do not vary. My kind friend, Mr. Chagnon, of 

 Montreal, is working on the genitalia, and I hope to publish some notes 

 on his results later. There is an excellent figure of pluviata or aiitum- 

 nalis in Packard's Monograph, PI. VI 11, fig. 29, which is typical of eastern 

 specimens and of certain of the European specimens in markings, but not 

 wholly in colour. The venation is shown in the Monograph, PI. I, fig. 6. 



Taking autionnalis as a whole, it is far less variable in markings than 

 furcata or quijiquefasciata, but is about the same in regard to colour 

 variation. It is very easy to separate the species with moderate palpi, as 

 there are fewer closely-allied forms, the only difficult one being calif oriiiata 

 Pack., which is liable to be confounded with var. perfracta of aniu7nnalis. 

 Nearly all the collections I have seen contain autu?n7ialis, so I do not 

 think it can be rare in any particular locality in the North Atlantic States. 



