THE CANADIAN ENTOMOLOGIST 293 



GEOMETRID NOTES— HYDRIOMENA. 



BY L. W. SWETT, LEXINGTON, MASS. 



The recent issue of Barnes and McDunnough's "Contributions 

 to the Natural History of the Lepidoptera of North America,-" 

 vol. IV, No. 1, contains an excellent "Revision of the Genus 

 Hydriomena". It is a vast improvement on any former revision, 

 as it is illustrated by excellent plates including figures of the 

 genitalia. The work gives evidence of .great pains and careful 

 study and is based on large series of specimens, which unfortunately 

 were lacking to the present writer in his original work on this 

 genus. I would suggest that in order to supplement the revision 

 the future student might work out the egg and pupal structure 

 including the cremaster thorn and the life-histories, which would 

 render it practically complete. In my early paper (Can. Ent., 

 vol. 43, March, 1911) I attempted to straighten out the group 

 on the basis of the palpal structure. I had little material and most 

 of this was loaned, so that I could not study the genitalia, as stated 

 in my article. From the date of my publication until two years 

 ago I had received few additions in this group, and so had no chance 

 to work out the life-histories. Barnes and McDunnough's paper 

 with the figures of the specimens and the genitalia, is quite an 

 advance over my early attempts. During the past year or two I 

 had been in correspondence with Dr. McDunnough on the species 

 of Hydriomena and their genitalia, with the result that except 

 in one or two points we were practically of the same opinions. I 

 have, therefore, very little to add to this valuable work except a few 

 notes on thfr species. I believe that this classification, based on the 

 genitalia and palpi, is on a sound basis and will be little changed. 

 Dr. McDunnough's separation of H. furcata Thunberg and 

 qiiinquefasciata Packard is a painstaking piece of work. I could 

 not separate these in my early paper as the material was all loaned, 

 and it was only recently after I had made slides of the genitalia 

 that I realized the differences between them. 



In regard to H. albifasciata Pack. Dr. McDunnough is quite 

 correct. I had only the female to judge by, and it was impossible 

 to place the species correctly without the male. Reseda seems 

 also to be a suffused, ruddy form of albifasciata, but it may later 



September, 1918 



