264 THE KNTOMOLOfilST'.S RECORD. 



necessary, in order to form an idea of the relative time occupied by 

 ditterent stay;es in active metamorphosis, to note the temperature. In 

 coohni^' experiments, where the temperature is low down among the 

 forties, four weel^s are equivalent in physiological progress, to not 

 more than two or three days of a forcing temperature of 80° (see Tram. 

 Ent. Soc. Loud., 1891, p. IGl). 



Thepupfe of the eight larvte of /'. luac/iaou that attached themselves 

 for pupation to green stems of growing plants have no dark pigmenta- 

 tion whatever, and are scarcely changed from the green which appeared 

 at the moment when the larval skin was cast off. The colour only 

 seems to become of a brighter hue, both on the green parts and on the 

 yellowish dorsal region. 



Some notes on Acidalia emarginata and its sexual dimorphism. 



By W. S. KIDING, B.A., M.D., F.E.S. 



I have recently reared a small brood of Acidalia finan/inata, and 

 find the imagines are conspicuously sexually dimorphic in both colour 

 and shape. 



The colour of the ^ is pale ochreous-yellow, and the lines and 

 spots are reddish-brown, the latter very dark. Some reddish-brown 

 scales (only distinctly seen under the microscope) are sparingly 

 scattered near to and outside the 1st line, and also between the 2nd 

 and hind-marginal lines. These scales occasionally produce a faint 

 blush. The colour of the ? is pale ochreous-yellow on the costa, and 

 as far as the upper median nervure, but the rest of the wing is reddish- 

 brown. This is owing to a great increase of the scattered scales above 

 described, and some of these more closely massed form a dark median 

 shade, almost blackish, outside and adjacent to the 1st line, and 

 extending from the dorsal to the discal spot where it ceases. The 

 lines and spots are similar to those of the S • 



The scallops on the margins of the wings are much more concave 

 in the $ , and give a different contour to both wings, which become 

 truncatedly angular, as though they belonged to a different species. The 

 apex of the fore-wings is consequently more produced, and the marginal 

 extensions between nervures three and four appear much more 

 developed on both wings (especially the hind). The colour of the ? , 

 though best described as reddish-brown, has a very distinct pinkish 

 hue when viewed by oblique light. 



The head, thorax, and abdomen are pale ochreous-yellow in both 

 sexes ; the antennie ciliated in the c? but not in the ? (Newman calls them 

 erroneously " nearly simple in both sexes "). There is little difference 

 in size, as some specimens of both sexes are equally large (20-22mm.), 

 but one of my ? s ran as small as 18mm., and so the average of the 

 latter is reduced. Newman's description and correct drawing are 

 evidently taken from a ^ , and no reference is made by him to the $ ; 

 Stainton's description, on the other hand, is that of a ? , but his 

 figuring is valueless, though presumably of that sex. Meyrick seems 

 to describe from both sexes, but scarcely to recognise the sexual 

 differences as he writes of the median shade of both, as "a line (sic) 

 broad, fuscous, sometimes faint." In my specimens of the ^ this is 

 never more than a faint blush on the forewing, in a few a little more 

 marked on the hindwing, and in some indiscernible on both. The 



