Ixx 



purporting to be of British origin : the one exhibited, labelled 

 " Chattenden," one reported to have been taken in the New 

 Forest by the late E. Morris, which is presumably now in 

 the collection of Lord Rothschild, and one originally in the 

 Howard Vaughan Collection, later in that of S. Webb, disposed 

 of at the sale of his collection, and the present location of which 

 is not known. 



Mr. Sheldon also exhibited five examples of Acrohasis 

 tumidana Schifi., from Darenth Wood, 1873-5, with the nearest 

 related British species, A. zelleri Rag. = A. tumidella Zk., for 

 comparison. 



The procryptic resting attitude of Polygonia c-album 

 L. and certain allied species. — Prof. Poulton exhibited 

 a living specimen of P. c-album captured by Commander Walker 

 at Oxford a few weeks earlier. He called attention to the 

 out-turned edges of the wings in the resting position, as 

 described in Proc. Ent. Soc, 1922, p. xix. The exhibited 

 individual had been watched daily by Mr. A. H. Hamm, who 

 observed that in darkness the fore- and hind-wings were only 

 separated by a narrow chink passing inwards from the strongly 

 marked bay formed by the hollowing of both approximated 

 angles. When exposed to diffused daylight the fore- wings 

 were very slowly moved forward until the narrow chink became 

 a wide gap. In direct sunlight, or as the result of a shake or 

 jar, the change of attitude was made comparatively rapidly. 



Dr. R. C. L. Perkins, F.R.S., wrote on September 29 that 

 he too had " noticed that raising or separation of the front 

 from the hind-wing in c-album, and not only in this but in the 

 ' Tortoiseshells ' and I think in other Vanessas. They also 

 do this when disturbed during hibernation." 



In the latter Vanessids it was probable that the change of 

 attitude was a preparation for flight — impossible when the 

 costal margins of hind- and fore-wings lay one over the other, 

 as in the resting position for which the under surface pattern 

 was adapted. In such species the change of attitude necessary 

 for flight detracted from the procryptic significance by exjDosing 

 the part of the fore-wing covered by the hind when the resting 

 butterfly was undisturbed. 



C-album offered an interesting contrast in this respect, 



