LINNEA>f SOCIETY OF LONDON. II 



interesting group with peculiar larvae and pupae. Their conspicuous 

 patterns are displayed in a floating flight and the under surface of 

 the wings is not procryptically coloured like that of the Vanessas — 

 cliaracteristics which are found in the specially protected models 

 for mimicry, and the Miillerian mimics of other still more distaste- 

 ful species. And so it is with Lintenitis. The English L. sibj/lla 

 is resembled by the female of the " Purple Emperor " {Apatura 

 iris) which flies in the same woods, while the tropical American 

 re])resentatiA'es of Lintenitis — the powerful genus Adelpha — are 

 beautifully mimicked by the females of the representatives of 

 Apatura — the genus Chlorippe. The African representatives of 

 Limenitis — the genus Pseudacrcea — are almost all of them wonder- 

 ful mimics of the Acrseas and in one instance of a Danaine. 



Tlie North American species form a singularly interesting group 

 divided until recently into six species. Of these, two, weidermeyeri 

 and arthemis, are black-and-white butterflies somewhat resembling 

 sibijlla ; one, lorquini, appears to be a similar butterfly, modified 

 by mimicry of an Adelplia or allied form which meets it on the 

 west of the continent ; two, archippus and obsoleta (hulsti), are 

 beautiful mimics respectively of Danaida (Anosia) plexippns and 

 D. strigosa, both ancient Danaine invaders from the Old World 

 into the New ; finally one, astyanax, is a mimic of Papilio pJiihnor 

 or more probably of Papilio co-mimics of the same model. 

 Astyanax is also, according to Scudder, tlie model for the female 

 of Argynnis diana. 



The black-and-white arthemis of the north and the southern 

 dark astyanax meet and overlap in a narrow zone where an inter- 

 mediate form proserjyina is also found, considered by Scudder as a 

 hybrid between the two. The recent successful breeding experi- 

 ments of W. L. W. Field leave no doubt that proserpina is certainly 

 a heterozygote which splits up into the two parent strains in the 

 Fj generation. In the light of this important result astyanax 

 becomes the southern race and arthemis the northern of a single 

 species, but the rarity of proserpina seems to prove the reality of 

 sexual preference within each race in the zone of overlap. 



Lord Eothschild, Mr. W. Bateson, Dr. G. B. Longstaff, Mr. 

 Hamilton H. C, J. Druce, and Sir Henry Ho worth, F.E.S. (visitor), 

 engaged in a discussion, the Author replying. 



Mr. Hamilton Deuce exhibited several species of Mimacrcea 

 from his collection, amongst them M. Landhecki, M. Eltringhami, 

 M. Krausei, and M. shopioles. 



March 21st, 1918. 



Sir Davio Pkain, C.M.G., CLE , F.ll.S., President, 

 in the Chair. 



The Minutes of the General Meeting of the 7th March, 1918, 

 were read and confirmed. 



