June, 1902.] OtTOLENGUI : PlUSIA AND ALLIED GeNEKA. 59 



Smith subsequently renamed the true nwnodou, calHng it insolita. My 

 own accession of material was largely due to my work in the White 

 I^Iountain region, where it may be interesting to note, that in one 

 season, I captured eighteen species around the piazza lights of the 

 Waumbek Hotel, at Jefferson. 



Since announcing my interest in Pliisia I have received the most 

 liberal assistance from collectors everywhere. Indeed, so many have 

 aided me in one way or another, that I shall not attempt to mention 

 them all by name, for fear of omissions. For the presentation of 

 material from which I have made new types I must particularly thank 

 all of those whose names are mentioned in connection with the de- 

 scriptions. Great obligation is due to Sir Geo. Hampson, Mr. 

 Schaus and Professor Smith for comparing material for me at different 

 times, with the types and material in the British Museum. For com- 

 paring my insects with types I must likewise thank Professor French 

 and Mrs. Fernald, the latter very kindly forwarding her type of siirena 

 to me at a time when it was presumably unique. I was able, however, 

 to match it with a specimen in my own possession, but never really 

 knew the species till Mr. Roland Thaxter kindly presented me with a 

 magnificent fresh example which proved conclusively that only a poor 

 description can be based upon a poor type. I should also specially 

 mention Dr. Barnes, Dr. Bethune and Professor Smith, all three of 

 whom not only presented me with specimens which proved to be new, 

 but likewise forwarded me all of their material. 



I must now indicate briefly the method which I have adopted in 

 working out the synonomy, in order that subsequent students may 

 fairly determine upon the value of my deductions. Having obtained, 

 as far as possible, copies of all the descriptions of species listed as 

 North American, I first endeavored to satisfy myself of the correctness 

 of my labels by comparing material with descriptions. I very soon 

 gave this over as unsatisfactory because it could not be certain beyond 

 possibility of doubt. The earlier description may have been adequate 

 when made, but in many instances, the subsequent discovery of other 

 species closely allied has rendered the descriptions unsatisfactory, fit- 

 ting as they do several forms almost equally well. An author, know- 

 ing but a few species, necessarily was ignorant of the very character- 

 istics which prove most reliable as distinguishing marks, and therefore 

 failed to record them at all. On the other hand many considered the 

 metallic sign of great specific value and often minute description of 



