THE HISTORY OF BUTTERFLY CLASSIFICATION. 315 



then, if the membrane of the scale be pale, it would account for the 

 gi-eater number of cases in which small areas of the wing become pale. 

 Conversely darker patches might be produced if the ground colour of 

 the scale membrane be darker than the pigment displaced. (2). The 

 scales may be imperfectly developed or fewer scales than usual may be 

 produced. The former condition would greatly affect non-pigmentary 

 colours, i.e., those that are due to striations on the scales, &c. ; the 

 latter would affect the colour by allowing the basement membrane of 

 the wing to appear to a much greater extent than usual, and would lead 

 to an increase of pale or dark coloration, according as the basement 

 membrane of the wing was paler or darker than the scales. Under this 

 head, too, would come those cases where there are two (or more) sets of 

 scales, one set longer than the other and usually more or less covering 

 them. The normal colour would then be affected by the increased 

 conspicuousness of the shorter scales. This phase is shown remarkably 

 in the cases of such insects as Cmpidia psi, Tcmiocampa miniosa, &c., 

 which become quite dark as they get worn, the shorter scales, which 

 become exposed by the rubbing off of the longer, being in each instance 

 darker than the latter. (3). The colour of the wing membrane. In- 

 dependently of the scales, a very large proportion of the colour is due 

 to the membrane of the wing itself. Any failure of coloration in the 

 wing membranes must therefore result in an alteration of colour in the 

 same way as must happen when the pigment in the scales fail. 



That excessive cold sometimes produces dark coloured specimens 

 appears to be simply a fortuitous circumstance, for whilst the specimens 

 of Vanessa poJi/chloros exhibited became darker by the application of a 

 low temperature, the dark brown-black specimens of Araschnia levana 

 var. prorsa (summer brood) reverted to the paler fulvous form (levana 

 type) which occurs as the spring brood. This is exactly what might 

 have l)een expected, for the failure of pigment in the genus Vanessa 

 appears always to throw up conspicuously the darker ground colour of 

 the wings, whilst in A. levana the reduction of the intense black- 

 brown of prorsa to the fulvous colour in levana is exactly in accordance 

 Avith the genetic sequence suggested in Vars. of Brit. Noctuce, vol. II., 

 pp. xii-xiii. 



'TjiE jii^i'oi^y OF BiJi'i'Ei^FLy GL^^^iFie^i'iorl. 



By F. J. BUCKELL, MB. 



The history of butterfly classification and of the origin and varying 

 application of generic names is a subject quite large enough for one 

 evening's consideration and one that presents not a few points of in- 

 terest. It may conduce to lucidity, if at the outset I define the sense 

 in which, throughout this paper, certain terms will be employed. I 

 shall speak of Papilionids as comprehending Swallow-tails, Whites and 

 Yellows ; of Nymphalids as inclusive of Nymphs and Satyrs, Nymphs 

 consisting of Fritillaries and Vanessas with the White Admiral and 

 Purple Emperor, while Satyrs will include the Marbled White, the 

 Meadow Browns and their kindred ; lastly Lycfx?nids will be used as 

 embracing Hair Streaks, Blues and Coppers. 



Linnaius is again our starting-point. At first he included the 

 whole of the Lepidoptera under the generic desigTiation Fapilio, but 



