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IS THECLA JESCULI, Hb., A SWISS INSECT? 



By F. E. Lowe, M.A., F.E.S. 



Mr. Rowland-Brown's interesting and enlightening article, 

 *' Some Remarks on Thecla asculi, Hb.," in the 'Entomologist' 

 of September last, awoke again in me the question at the head 

 of this note. And I set out to work through my Theclids in the 

 hopes of solving the problem. I am now convinced that, whether 

 T. (ssciili is a separate species or a variety of T. ilicis, at least it 

 is certain that the butterfly which has passed as ab. cesculi from 

 Swiss localities differs much more from the cesculi of Southern 

 France than it does from typical ilicis, and that the butterfly we 

 take in Switzerland is an undoubted form of ilicis, whose only 

 claim to be called var. cesculi is that it lacks the white line on 

 the under side of the upper wings.* To this I would give the 

 name of '' pseudcesculi,'" though, except for this agreement in the 

 absence of the white line, there is practically no other likeness to 

 cesculi, but it is in every other respect a typical ilicis. Whereas, 

 cesculi from the South of France and La Granja differs con- 

 sistently in almost all points from ilicis, and while showing some 

 variation, inter se, always exhibits certain distinctive qualities 

 of its own. It differs in size, shape, colour, markings, and 

 wing-tails. I have never attempted the difficult study of the 

 construction and comparison of the male appendages, and judge 

 only by examination of the outward appearance. From externals, 

 cesculi, Hb,, appears to me much nearer akin to acacicethsm to 

 ilicis. For many years I was content to believe that any speci- 

 men destitute of that white line was var. cesculi, following the 

 lead of other collectors and authors, who probably, like myself, 

 had never come into the happy relations of a field-naturalist 

 with the southern insect. But, when I took T. cesculi in Spain, 

 and later in various localities in the South of France, I began 

 seriously to question the validity of the Swiss and Tirolese 

 examples' claim to the title. 



I venture to propose a comparison of certain differences, as I 

 see them, between Swiss pseudcesculi and cesculi. My specimens 

 of the former come from Eccl^peus, Aigle, Martigny, and other 

 parts of the Rhone Valley, Innsbruck, and Bozen. 



> The chief points for comparison are : (1) the colour; (2) white 

 lines ; (3) red spots ; (4) tails, 



(1) The colour to my eye differs but little on the upper side, 

 but on the under side pseudcesculi is deep coffee-brown, while 

 cesculi is hardly brown at all, but a dark grey with something of 



* Mr. Harold Powell is of the same opinion as Mr. Lowe. He 

 says {in litt.) that he regards all Swiss *^ cesculi" as a form only of ilicis, — 

 H. R.-B. 



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