34 Journal New York EntoiMOLogical Society. [Voi. x. 



have authorized new specific names : varieties from other faunal regions 

 within our own borders have shown constant characters that have made 

 their real status a matter of serious question, and the collector who, 

 now-a days, fails to secure a good series of all the " common " species 

 within his reach fails to grasp the opportunity to contribute towards 

 an answer to the question, " What is a species ?" 



My greatest difficulty has been, of late, to get such "common 

 species," for nobody has them in duplicate : and yet, in such types as 

 Agrotis {N'oc/i/a) nibifera, perconflua and allies we find the influence 

 of locality most strongly marked and the range o!" variation in macula- 

 tion, as compared with sexual divergence most markedly illustrated. 



In other words, one male and one female from any given locality 

 may, but do not necessarily, illustrate a species. One hundred speci- 

 mens of each sex may illustrate the species as it occurs in one locality, 

 but they do not necessarily illustrate the range of the species. We 

 have always admitted that genera were matters of individual opinion. 

 I am not ready to say as much for species ; but I do claim that we 

 cannot say positively what is a species and what is a local variety until 

 we have an abundance of material from each of the localities concerned. 

 Furthermore, my studies seem to lead to the conclusion that there are 

 very few species, comparatively, that occur unmodified in two or more 

 real faunal regions. We may have closely allied, or representative 

 species and we do undoubtedly have some widely distributed forms 

 that hold their characteristics under the most divergent conditions ; 

 but as a rule si)ecimens from well-defined faunal regions must be very 

 closely compared before they can be said to be certainly the same. 



Euthyatira pennsylvanica, var. nov. 



In the course of a paper on the geographical distribution of North 

 American Lepidoptera, Mr. Grote referred (Can. Ent., XVIII, p. 215) 

 to a form of Thvatira pudens found in Anticosti. In a footnote he 

 adds: "This variety is worthy of a distinct name, and in my second 

 Check List of N. Am. Noct. (MSS.) I have called it anticostiensis. 

 The moth is grayer, more hoary, the pink color has faded. Mr. Wm. 

 Couper has taken this form on the island." In the text he refers to 

 the matter in this wise : " From what I have seen I think that Thyaiira 

 pudens, found on Anticosti, has become grayer, the pink spots less 

 vivid than on the mainland ; the darkening by mixture of color, 

 noticeable in polar species, has here taken place." 



