( Ixiii ) 



fore- wing being very broad. In few were the tails as well- 

 developed as in (2). In the darkest the copper still preserved 

 some brightness along the discal cell and the two cells beyond 

 it, whilst two or three might have been ordinary English 

 specimens. 



Mr. G. J. Arrow showed specimens and diagrams in 

 illustration of a point mentioned in his paper on " The 

 Laparostict Lamellicorn Coleoptera of St. Vincent and 

 Grenada." This had reference to a remarkable kind of 

 variability noticed in beetles of the Trogid genus Acantho- 

 cerus. These beetles have the faculty of rolling themselves 

 into a ball in the interior of which all the vulnerable parts are 

 enclosed. The head forms a large triangular plate in which 

 the eyes appear half on the upper and half on the lower 

 surface. In some examples of the species exhibited (^Acantho- 

 cerus rehtcens, Bates) the upper division of the eyes forms a 

 large, nearly circular mass, while in others it is reduced to 

 a mere thin vestige, and in extreme examples of another 

 species of the genus Mr. Arrow had even found it to vanish 

 altogether. 



The President showed an exhibit sent by Mr. A. H. Thayer, 

 of Monadnock, N.H., U.S.A. The greyish silhouettes of two 

 butterflies were represented in a tint nearly the same as the 

 background, but sufficiently distinct to be easily recognizable. 

 On one side of one silhouette a row of white spots had been 

 placed in a submarginal position. It was evident that the 

 adjacent border was thereby rendered far less distinct than 

 that of the opposite side of the silhouette, or of both sides of 

 the other silliouette. The spots in position and shape were 

 approximately as in Fajyilio polydamas, and Mr. Thayer con- 

 sidered they possessed a similar significance in this butterfly. 

 The dark ground-colour of many Rhopalocerous species he 

 thought represented shadow under vegetation, the white sub- 

 marginal lines and dots a generalization of flowers and flower- 

 masses. But these markings also had a second meaning in 

 that they tended to obliterate the tell-tale margin of the wings. 



Professor Poulton also exhibited specimens of Drurya 

 antimachus, together with the butterflies which he suggested 

 as forming a group synaposeraatic with it. The centi-al species 



