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THE ENTOMOLOGIST. 



Vol. LII.] OCTOBEE, 1919. [No. 677 



ANTHROCKRA ACHILLE.E, ESPER, IN SCOTLAND. 

 NOTES ON ITS DISTEIBUTION AND VALIATION. 



By H. Eowland-Brown, M.A., F.E.S. 



With the re-establishment of A iithrocera achillece as indigenous 

 in the Western Highlands, it may not be out of place to review 

 the distribution and variation of the species, and to consider its 

 apparent isolation in this one particular region of the British Isles. 



As long ago as 1881 there was published in the ' Entomolo- 

 gist ' (vol. xiv, pp. 265-277) a highly suggestive and interesting 

 paper by the late Dr. F, Buchanan Wbite, entitled " Some 

 Thoughts on tbe Distribution of the British Butterflies." The 

 theories and facts put forward by the author led him to the 

 conclusion that our butterflies in the main — and mutatis mutandis 

 we may postulate the ancestral Anthrocerids — arrived with the 

 rest of tbe Scottish indigenous fauna across the then dry bed of 

 the " German Ocean " and located themselves in places where 

 climate and food plant were favourable to their continuity. 



Let us see how far the possibility of A . acliillece being intro- 

 duced at this geologically remote period is borne out by existing 

 circumstances. It belongs to Hiibner's group Lycastes* which 

 includes A. exulans, also peculiar to and isolated in the United 

 Kingdom in one north-eastern region of Scotland, the (?) Argyll- 

 shire locality cited by Tuttt being, as now determined, that where 

 Mr. Sheldon came across the first suspected British example of 

 achille(e. 



So far A. achillea has been recorded neither from Norway nor 

 Sweden, though A . exulans is widely distributed in Norway from 

 60° 15' to 70° 42' (Sh0yen), and according to Lampa in the form 

 vanadis, Dalm., from Jemtland to Lapland. It is absent from 

 Denmark, the Netherlands, West Belgium (?) and North- West 

 Germany. I That it arrived in Scotland from Scandinavia is 

 practically certain all the same, and I agree with Mr. Sheldon 



* ' Verz.,' pp. 116-118. 



i ' British Lepidoptera,' vol. i, p. 453. 



\ ' Die geograph. Verbreitung der Schmettge.,' Adolf, and August Speyer. 



ENTOM. — OCTOBER, 1919. U 



