1910.] 228 



far as we know at present, may be recognised by vein 2 of the fore- 

 wing arising out of the stalk of 3^, whereas, in spilotella, vein 2 is 

 connate with 3-4. 



The comparison of a large number of examples of M. rusticella 

 with many of iveaverella, and an acquaintance with both insects in 

 nature, have firmly convinced me that Scott was right in regarding 

 the latter as specifically distinct from the former, and it is particularly 

 noteworthy that, wliether in the far north of Scotland or the extreme 

 south of England, each species retains its own special characteristics, 

 there being a marked absence of any intermediate forms. The 

 imaginal distinctions, upon Avhich Scott laid stress, are the darker 

 ground-colour of iveaverella , which brings into greater prominence the 

 ochreous markings, its much more distinct central ochreoiis spot [i.e., 

 the hyaline eye-spot. — E.R.B.], and the presence of a large ochreous 

 subtriangular tornal blotch, which is absent in rusticella. Scott 

 (Zool., 1858, p. 5964) adds that " in all other respects they seem to 

 harmonise, — the ochreous head and face, pale palpi, irroratiou on the 

 wings, pale ochreous cilia varied with fuscous, and pale grey postei'ior 

 wings," but it is certain that rusfirella and wea,verelta exhibit, in 

 connection with some of these parts, differences which escaped Scott's 

 notice. 



In iveaverella, the ground-colour of the fore- wing, which is less 

 flecked with ochreous than that of its ally, is silky violet-lilack, while 

 that of the hind- wing, which, as in rusticella, is rather lighter in the 

 male than in the female, is dark grey, sometimes strongly tinged with 

 pvirple. Both fore- and hind- wings are therefore distinctly darker than 

 those of rusticella, while the abdomen is also darker, and the head is 

 more orange. Rusticella only occa.sionally shows a pale ochreous 

 tornal spot, and even then this spot is not nearly so large or con- 

 spicuous, nor is the pale ochreous oblique bar through the tornal cilia 

 nearly so broad, as in -weaver ella. The latter seems remarkably 

 constant in facies, though, in worn or old individuals, the faded 



ground-colour is noticeably brown instead of black. Like rusticella, 

 it is very variable in size, but although, on the whole, tlie males are 

 not so large as the females, size cannot be relied on as any criterion of 

 sex. Weaverella is certainly smaller, on an average, than its congener, 

 good-sized examples expanding 15"5 — 16"5 mm., whereas correspond- 

 ingly large individuals of rusticella show an alar. exp. of 18 — 19 mm. 



Larger examples of both are, however, occasionally met with. 



Scott {!■<'■■) also pointed out certain differences between these 



species in habit, &c., saying that he used to meet with weaverella at 



T 2 



