80 BRITISH LEPIDOPTERA. 



legs are roughly tuberculated, perhaps, rather than wrinkled. The 

 thorax is finely wrinkled in a " cerebral convolution " sort of 

 pattern, without special features, except to be coarser at the wing- 

 bases. The wings have coarse transverse wrinkling along the costa, 

 finer and longitudinal at the hindmargin, varying in some specimens 

 to nearly smooth ; the nervures are visible, more so at a little distance 

 as paler lines than on closer inspection. The abdominal wrinklings 

 down to the 6th segment are of the cerebral convolution pattern, 

 except that they are arranged to be practically transverse. On the 

 5th and 6th abdominals they are much coarser in front than behind the 

 spinous ridge, with a somewhat intermediate condition on the 7th, 

 on the 8th and 9th the sculpture is largely pitting. The colour is 

 terracotta, with a very varying amount of black. The thorax and 

 wings, a dorsal line, and the subdorsal region are always dark, 

 sometimes quite black. Individuals vary so that one would expect 

 as rare varieties to see one pure terracotta or pure black. On 

 the thorax the sulci of the wrinklings are black, even when the 

 ridges are pale ; the same is the case with the wings and 

 these often have black spots in rows down the nervures. 

 On the abdomen the black especially affects the hair-spots, but 

 is also more widely distributed. Viewed as a transparent object, 

 the shell structure is very elaborate. The sulci in thorax and 

 wings are marked as dark dendrites. At the wing-bases are a 

 considerable group, on each side on meso- and metathorax, of fine 

 hairs in minute circles or in chitinous points ; these are less common 

 dorsally. The hindwing, by the way, just falls short of the spiracle 

 of the 3rd abdominal before being lost under forewing. The minute 

 hair-points become more numerous on the abdominal segments 

 and only fail on the absolute dorsal line. No definite arrange- 

 ment of them is detected. Passing backwards, the hairs and hair- 

 points become more numerous ; when hairs are absent the hair- 

 points are present as dark spots at the intersections of the dendritic lines 

 of the sulci. On the final segments the pits are these same points 

 enlarged into coin-like hollows, with either a minute hair or a hair- 

 point in the centre. The spines on the abdominal ridges are seen 

 to be a special development of these hair-points. Seen under the 

 microscope, some of these are solid projections rising from the 

 surface, not unlike, in colour and shape, the anal spine of the 

 pupa. Some are then found with a deep pit under them, or rather 

 behind them ; then, in the neighbourhood of these, hair-points 

 with hairs, but with the forward margin of the surrounding circle 

 of chitin raised into a ridge with central point, clearly the same 

 structure as the spine. In the course of examining the pupae, bits 

 of fine scale became detached, and it is found that the pupa is 

 covered by a fine scale, as in Mimas tiliae (anted, vol. hi., p. 412), 

 most often observable on the thorax, where it is consolidated with 

 the ridges, but passes across the valley of the wrinkling, but, when 

 looked for, it is seen to cover the whole pupa, at least in some 

 specimens. The anal scar is a longitudinal depression with a 

 raised, rather broad, lip surrounding it, with parallel impressed lines. 

 The lips pass round the posterior end of the depression and over- 

 hang the cavity at the base of the anal spike. Anteriorly they 

 rather fade out into the general surface. There is considerable 



