1900.] 



189 



tlie pronotuni a scarlet hood was visible, the inflation of whicli bladder-liko organ 

 always indicates fear or anger. The other specimens showed the natural position of 

 the head and pronotum. Mr. H. J. Elwes communicated a paper on " Bulgarian 

 Lepidoptera," and made some remarks on the more notable species which he had 

 taken in the Balkan Peninsula during the months of June and July, 1899. Tlie 

 number of species of Rhopalocera captured was 120, which, with a further 20 

 recorded by Haberhauer and Lederer, brings up the total to 140. The mountains 

 visited were an extension of the Rhodope range, where the climate was particularly 

 rainy, a great number of ferns flourishing everywhere, in contrast to tlie drier 

 Balkans, where the number of species of Rhopalocera is not l.^ss than 200. Some 

 interesting forms, but no new species, were encountered. A variety of CQlias 

 Myrmidone occurred, much larger and brighter than the Austrian, and more nearly 

 agreeing with the Ural, form ; and whereas in Austria the white aberration is ex- 

 ceedingly rare, in this locality it predominated. Meanwhile, the orange forms 

 clearly resembled Colias Heldreichi. The form of Coenonympha Davus met with 

 showed an affinity with the Asiatic, and not the European, form, and was almost 

 precisely similar to specimens taken in the mountains of Armenia by Haberhauer. 

 Tlie form of Argynnis Pales was intermediate between that found in Greece and 

 the central European Alps, while a form of Erebia, var. Gorgone, was taken similar 

 to that in the Pyrenees— a curious instance of interrupted distribution.— C. J. 

 Gahan and H. Rowland-Beown, Hon. Sees. 



MEMORANDUM FROM THE EVOLUTION COMMITTEE OF THE 

 ROYAL SOCIETY. 



1.— The Committee appointed by the Council of the Royal Society to promote 

 investigation of facts relating to Variation, Heredity, Selection, and other phenomena 

 connected with Evolution, are desirous of instituting a collective investigation into 

 the progressive melanism of certain moths, particularly Geometridce. 



2.— It is well known that in certain districts, especially within the British area, 

 dark forms of several species of moths have recently appeared and become increas- 

 ingly abundant. There is reason to believe that these dark forms are in some cases 

 extending into other districts, and even to the European Continent. 



3.— It is to be regretted that no systematic or statistical records of these phe- 

 nomena have been kept, and it appears to the Committee that if such a record be 

 now instituted and continued for a period of years, it cannot fail to have considerable 

 scientific importance. 



4.— The matter is one that may conveniently be made the subject of collective 

 investigation, and the Committee will be glad to hear from any entomologist who 

 may be willing to contribute now, or hereafter, particulars as to the condition of 

 these species in the district or districts with which he is personally familiar. The 

 returns should relate as far as possible to specimens found in a lolld state, whether 

 as imagines, or pupae, larvae or eggs. Information respecting specimens bred from 

 wild parents nmst be kept distinct. 



5. — It is thought desirable that the enquiry should for the present be confined 

 to the following species :—^ci(fMZ/a aversata, Anifhidasys betularia, Boarmia rs- 



M -2 



