1897.] 201 



under-side. One only produced an imago ; it was hopelessly deformed, 

 and unable even to use its legs. One pupa in an ordinary cocoon was 

 exceedingly small, and it produced the smallest imago (a male) that I 

 have yet seen ; it is not more than quarter the size of a fully developed 

 moth, and bore evidence of starvation in having the wings almost 

 devoid of scales. The pale lines too, which form the edge of the band, 

 are in close contact for their entire length, so that in lieu of a band 

 there is merely a double oehreous line. Other two males, both 

 undersized, had these lines in contact on the inner margin and partly 

 across, three or four had them closely approximating, with a portion 

 of the area (usually darker than the rest of the wing) filled up with 

 the same pale oehreous scales. The curves of these marginal lines 

 vary very much, and are not always alike on both wings. There is, as 

 might be expected, considerable diversity in shade, but all are cold 

 brown, never approaching the richer red-brown of southern examples. 



There is rather less variety in the markings of the females, but 

 they are of the same character. The curves of the margin of the 

 band differing, and sometimes approaching each other on the inner 

 margin. In one specimen, with a band of average width, the space 

 between the margins is all pale whitish-grey. No corresponding spe- 

 cimen appears among the males, where the band is only pale when 

 narrow. Some of the females have a tendency towards the brown 

 hue of the males, and these are all large and evidently well nurtured 

 specimens. 



The most interesting point is that the earlier found larvge, though 

 pupating almost as quickly as those found later, were so much longer 

 in producing the perfect insect. All were exposed to the same con- 

 ditions after capture, and I would have expected them to remain about 

 the same time in pupa ; yet the earlier found larvae required from 53 

 to 64- days to produce the imago, and the later ones only 21 to 35 days, 

 some of them being, therefore, three times as long in pupa as others. 

 May we deduce from this a reason why they cannot be forced through 

 in autumn. Though pei-fectly full-fed, they are evidently not mature, 

 and require eight or nine months for the slow internal changes neces- 

 sary. The autumn larvae will die rather than spin their cocoons. 

 Four or five months later they will spin and pupate, but the needed 

 time is taken in the pupal state. A somewhat parallel case may be 

 cited in Lyccena Ahus, which remains nine or ten months as a full-fed 

 larva. 



Hartlepool : August \st, 1897. 



