318 Mr. H. J. Elwes' notes on 



by some systematic lepidopterists, yet I cannot say that 

 I have found them satisfactory as a means of discrimi- 

 nating species of butterflies. It seems to me that, 

 though they answer very well when applied to typical 

 specimens, yet there are so many specimens in a large 

 and well- selected collection which vary in some character 

 or other, that even the short diagnoses which have been 

 used for named varieties in Staudinger's Catalogue will 

 not always apply ; and, as far as my experience goes, 

 we are reduced at last to rely upon a more or less 

 indefinite opinion, based on examination of a large 

 number of specimens, and upon our knowledge of the 

 extent of variation found in other species of the genus. 

 It is supposed by some that we may eventually arrive at 

 a more accurate systematic arrangement, by a knowledge 

 of the preparatory stages and the life-history of a 

 species ; or again, by an anatomical examination of 

 the sexual organs, scales of the wings, or other parts. 

 But though it is not so easy to observe variation in 

 characters which require such minute examination as 

 these, yet I do not doubt that variation exists ; and 

 though in the genus Parnassius I have found anatomical 

 characters of the greatest assistance ; in Erehia I have 

 at present not been able to do so. 



There is no doubt that the systematic arrangement of 

 Staudinger's Catalogue, which I look upon as one of the 

 most accurate and careful works ever produced, based as 

 it is on his unrivalled knowledge of species, is incom- 

 parably better than the one adopted in the British 

 Museum, where the idea seems to have been, — in the 

 genus Erehia at least, — to find a specimen to match, or 

 which is assumed to match, almost every name or 

 description ever published, quite overlooking the fact 

 that the authors of many of these names and descriptions 

 were at the time very imperfectly acquainted with either 

 the forms they were attempting to discriminate, or with 

 their allies. And I think it is most detrimental to the 

 value of such a Museum, which should be of use to all 

 students who wish to have their own collections in good 

 order, that the peculiar views which Mr. Butler holds in 

 opposition to those of almost all other lepidopterists, 

 should be developed to such a pernicious extent in the 

 arrangement of this and many other genera. 



It is true that when he published his Catalogue of 



