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XXII. Notes on Seasonal Dimorphism in certain 

 African Butterflies. By ARTHUR G. BUTLER, 

 Ph.D., F.L.S., etc. 



[Read Oct. 16th, 1895.] 



MB. CECIL W. BARKER'S most interesting and instructive 

 paper upon this subject is before me, and I only regret 

 that the impossibility of risking the effect of night air 

 prevented my being present at the meeting in April, 

 when it was read, because I note, in the Proceedings of 

 the Society, that the question was asked by Prof. Meldoht 

 whether Mr. Barker's observations had been supported 

 by breeding experiments. Although this had not been 

 done, our cabinets afford such a mass of evidence in 

 support of his suggestions, that the case may be almost 

 considered as good as proved. 



As an example of what is here affirmed I may take 

 one example ; that of Teracolus vesta : 



The form T. argillaceus differs from the typical form 

 chiefly in the rosy-ochreous instead of lemon-yellow 

 colouring of the undersurface of the hindvvings and apical 

 area of forewings. If such a difference occurred in one 

 type only of the same group, it might fairly be con- 

 sidered to have a specific value ; but when we lind that it 

 recurs throughout the group, whether in Asia or Africa, 

 the evidence in favour of its being illustrative of seasonal 

 dimorphism becomes almost conclusive ; so much so, that 

 most Lepidopterists will certainly accept it, as having the 

 authority of proof. 



The following forms of this group of Teracolus in the 

 Museum series will, in this event, have to be united : 



ASIATIC SPECIES. 



Summer form Winter form 



1. Unnamed. Teracolus protractus, Butl. 

 '-'. Teracolus vestalis, Butl. Teracolus intermissus, Butl. 



; ; . Teracolus puellaris, Butl. Teracolus ochreipennis } Butl. 



TRANS. ENT. SOC. LOND. 1895. PART IV. (DEC.) 





