SPECIFIC DIFFBKENCES IN LITHOSID^. 85 



to narrow again to a sharp tip, beak-like. The uncus is short, 

 wider near the apex and pointed, and the juxta is deeply indented 

 in the centre, the tips being long-pointed. 



Lithosia griseola (Fig. 11). — The harpes are pointed ; the 

 clasper rapidly broadens out, when it takes a round turn ; toothed 

 at the edge of the rounded portion, falling almost straight down 

 to the chitinous point ; the uncus is elegantly shaped upwards, 

 when it broadens out and is abruptly angulated to a point. The 

 juxta is produced into a long chitinous spine about half as long 

 as the harpes. 



Lithosia rubicollis (Fig 12). — The harpe is rounded; the 

 clasper runs up fairly parallel to about three-quarters, when it 

 takes a backward curve, leaving a deeply emarginate curve, and 

 then makes the chitinous point. The uncus is very long and 

 tapered, and the juxta is bifurcated into two round lobes. 



Lithosia 7niniata (Fig. 13). — The harpe broadens out and 

 becomes deeply emarginate at the apex ; the claspers about a 

 third up become thickly clothed with fine spines up to about 

 three-quarters, when it makes its chitinous point ; the uncus is 

 long and parallel, and the juxta is not distinguishable in my pre- 

 paration, but this is immaterial on account of the distinctness of 

 the harpes and claspers. 



With regard to the tuft of scales on the under side of the 

 costa, which I believe is referred to by Speyer, whose article 

 I have not seen, although I have searched through the ' Ento- 

 mologists' Intelligencer ' for the criticism mentioned by Tutt. 

 This tuft of scales lies under the yellow stripe, and is, as far 

 as I can see, about the same length in good specimens of com- 

 plajia and sericea, but is very different in colour, being yellow, 

 same as the costa in complana, and silky grey in sericea. 



This brings me to the shape of the wing, which in sericea is 

 said to be narrower than in complana. I cannot agree that this 

 is so, for in all the specimens of sericea that I have seen the fore 

 wings have not been fully flattened out in setting, and as they 

 are apparently inclined to fold over on the costa, the collector 

 does not appear to have taken sufficient care in setting, and 

 thus the costa is in each case bent over, giving an appearance of 

 narrowness to the wing ; but may there not be some real reason 

 for this undevelopment ? The species is known to run smaller as 

 a rule, and of course raises the question of unsuitability of food, 

 environment, &c., which, if carried to an extreme extent, may 

 produce pygnusola. 



I think it is now generally accepted that dampness is one 

 cause of melanism. One of the differences given is that the 

 hind wings are darker. It has been pointed out by Mr. Joseph 

 Collins, of Warrington, who rediscovered the species, that since 

 his acquaintance with it some of the localities have been drained, 

 with the natural result that the darkness of the hind wings has to 



