Variation in Lepidoptera. 459 
considering these latter more in the light of monstrosities ; also 
those cases which must come under the head of accidental varia- 
tion; likewise variation in the broods of species that have two 
generations in the year. In this country the species of the genus 
Selenta are familiar examples of the latter, and a more remark- 
able one is found on the continent in the case of Vanessa Prorsa. 
Local variability is therefore the chief head under which to class 
Variation in the imago. 
Many species become more or less ‘“ melanised” when oc- 
curring in the North of England and Scotland, the darkening 
becoming more marked the further we proceed northwards. 
Among these may be cited, Spilosoma fuliginosa, S. mendica ( $ ), 
Liparis monacha, Crocallis elinguaria, Hypsipetes elutata, Melanthia 
rubiginata, Cidaria testata, C. populata, C. suffumata, Notodonta 
dromedarius, Ceropacha flavicornis, C. or, C. duplaris, Acronycta 
rumicis, Xylophasia rurea, X. polyodon, Luperina testacea, Celena 
Haworthii, Rusina tenebrosa, many species of A grotis, Noctua festiva, 
N. neglecta, Trachea piniperda, Teniocampa gothica, T. leucographa, 
T. miniosa, Orthosia lota, all the genus Dianthecia, Polia chi, 
Aplecta nebulosa, A. tincta, A. occulta, Hadena adusta, H. dentina, 
Calocampa vetusta, together with many species of Tortrices and 
Tineina. On the contrary there are a few species which become 
paler the further we proceed north. As instances of this 1 may 
cite Fidonia piniaria, in the male of which those portions of the 
wing which are rich yellow in southern examples, become white in 
northern ones ; and Cidaria corylata, in which, in northern examples, 
the ochreous bands entirely disappear, and the black markings are 
_much less extensive, being frequently broken up into grey spots. 
Another instance may be cited in which locality actually changes 
and confuses the normal sexual variation in the colour; I allude 
to Hepialus humuli, in which the sexual characters in the colora- 
tion are generally so well marked, but in the Shetland Islands 
a form of this species is found with the male frequently coloured 
as in the female. Variation tending towards melanism, but of a 
peculiarly smoky character, is found in many species from the 
northern districts of England, especially the country about War- 
rington (but disappears again still further north), and this district 
would appear to be peculiarly adapted to the production of 
varieties. I may mention Lpunda viminalis, Amphidasys betularia, 
Hypsipetes impluviata, Tephrosia biundularia, and Cidaria russata, 
as instances in which this smoky form predominates in that 
locality; and Mr. Doubleday remarks that aberrations of Arctia 
caja, Spilosoma menthastri, and Abraxas grossulariata, are much more 
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