INTRODUCTION. XV 



NENTS. Among other subjects of interest to which my attention has 

 been directed, is one which merits special attention. This refers to 

 species found in other parts of the globe " representative " of our 

 European species. I had a considerable correspondence with Mr. 

 Grote, the great authority on American NOCTU^E, relative to this 

 question, and it must be owned that he showed a very comprehensive 

 grasp of the subject, and taught me much. In dealing with the fauna 

 of a new district, especially when there is anything strikingly peculiar 

 in the environment etc., there are certain minor differences which lead 

 us to surmise that we have new species. This has been the case with 

 many of our own NOCTU^S, of which the Continental (European) form 

 of Cuspidia euphorbice, and our own peculiar dark form which was 

 named by Guenee as a distinct species under the name of myricce, is a 

 striking example. All over their area of distribution, some species are 

 so fixed in character and so constant, that it is impossible to surmise 

 that they can be other than the species we know under certain names 

 elsewhere. But there are other species which exhibit differences of 

 colour or size, or which present some other unimportant difference 

 which leaves room for honest doubt, and from want of knowledge, the 

 species gets a new name. Nowhere, perhaps, is this so much the case, 

 nor has this naming been carried out to such an extent as in North 

 America. When a really intelligent European collector looks through 

 a collection of American lepidoptera, he thinks he recognises a large 

 number of species as identical, so far as he can determine, with Euro- 

 pean forms, but let that same collector look down an American list and 

 he will be astonished how few names he recognises. The species he 

 thought he recognised have different names, and he knows them no 

 longer, they (the names) represent nothing to his intelligence. He 

 loses touch altogether. Some American species are so positively iden- 

 tical with ours, that there is no longer any question, but these few 

 will not account for the large number of species which have the facies 

 and general appearance of European species. 



IDENTICAL NORTH AMERICAN AND EUROPEAN SPECIES. The species 

 which are allowed to be identical in the American List of NOCTU.*:- 

 GENUIN^B, and which are found in Britain, appear to be as follows : 

 Noctua (Agrotis) conflua, N. baia, N. c-nigrum, N. plecta, Agrotis fen- 

 nica, ypsilon and var. idonea, saucia and var. margaritosa, Aplecta 

 (Agrotis) occidta and prasina, Hadena trifolii, H. exults, Dipterygia 

 scabriuscula, Euplexia lucipara, Hydrcecia nictitans with its vars. ery- 

 throstigma and lucens, Lencania pollens, L. unipuncta, Amphipyra 

 tragopoginis, Tceniocampa incerta, Cosmia paleacea, Xanthia flavago, 

 Scoliopteryx libatrix, Plusia ni, Anarta cordigera, A. melanopa, Heliothis 

 armigera, H. scutosa, H. dipsacea, with a yellow variety, probably 

 identical with the European var. maritima, and Ckariclea (Pyrrhia) 

 umbra. On the identity of European and American forms of these, 

 and a few other species, all lepidopterists are practically agreed, except 

 an individual here and there, who will scarcely allow that anything 

 European can be American also, and vice versa. 



It is not, however, in respect of these acknowledged identical species 

 that our surprise is so much aroused, as at other species, between which 

 and our own we are unable to see any, beyond perhaps the slightest 

 difference in colour and size. Viminia (Arsilonche) hew id in America, 

 appears to be quite identical with V. albovenosa in Europe. Mr. Grote 



