TJIE CANADIAN ENTOMOLOGIST. 213 



am not aware of any test by which it shall be decided that a genus is 

 sufficiently characterized. \Vhen the species is already known, less words 

 are, I should think, needed. It is better to supplement missing characters 

 in a diagnosis, than to needlessly criticize its author, especially in the case 

 where a good number of genera have been fully and clearly made out by 

 him and his work is largely of a pioneer kind, and often has to be accom- 

 plished with borrowed specimens or single examples. The difficulty of 

 being always right is shown by Mr. Smith in putting Polenta among genera 

 with unarmed tibiae, while, per contra, I wrongly stated as it appears 

 (thougli hesitatingly) that Feralia had no ocelli. There is room for care- 

 ful work in the Noctiiidce, but the species must be fully examined as I have 

 tried to do in the genera allied to Erotyla. A good lens, a good or per- 

 fect male specimen and a duplicate for dissection, a quick eye and 

 experience are needed. If, with all these, patience and courtesy are 

 possessed by the author, who must also know the literature well, satis- 

 factory work cannot fail to be accomplished. Even with all these the 

 student will be disappointed if he expects to produce a " Synopsis " that 

 shall be correct and complete, in a short time. We probably shall have 

 to classify nearly 2,000 kinds of Noctiiidce ; I have examined or described 

 about 1,200. 



Genus Platysamia Grote. 

 Hubner's genus Samia, erected in the Verzeichniss for species incor- 

 rectly associated, and with a diagnosis devoid of characters of value, is 

 used by anti-Hubnerists instead of Platysamia, a term fully explained and 

 correctly limited by me to the three or four species, Cecropia, Gloveri, Col- 

 umbia and Ccanothi. Upon what ground this is excused does not appear. 

 It is not consistent ; and can only be done by those who give to Hubner's 

 genera the same value as those of scientific writers. Even in this case 

 the procedure is doubtfully defensible. In using Hubner's genera I have 

 been often guided by the prior use of the rejected term, /. e. in preferring 

 Lithophane to Xylina, Etistrotia for Erastria, etc., both Xylina and 

 Erastria being previously proposed by Hubner for different genera from 

 those to which Treitschke and Ochsenheimer gave the terms. The entire 

 (juestion of Hubner's genera has been treated in a personal way, and 

 every attempt I have made to compromise the matter has been met by 

 unnecessary insistence on unimportant points. As it stands now, and 

 taking the "Brooklyn List" as an example, Hubner seems only to be 



