IN THE BRITISH ISLANDS. 



87 



2. The dark shade (having in 

 its upper part the orbicular 

 stigma), is clearly outlined with 

 black, and on the side next the 

 base with white ; the orbicular 

 stigma (the same colour as the 

 rest of the shade) is indicated 

 by its marginal black line. 



3. The reniform stigma and the 

 wavy line beyond it, are both 

 distinct markings. 



4. The subterminal line is a 

 clearly dotted black one, with 

 two dark dashes on the inside, 

 one not quite half way from the 

 costa, and the other quite near 

 the inner margin. 



2. This shade is so dark as to 

 form a distinct black blotch so 

 much so, that the margin of, 

 as well as the orbicular stigma 

 itself, is obscured. 



5. There are 9 or 10 black spots 

 along the costa. 



3. These markings are very in- 

 distinct. 



4. Is generally quite obsolete, 

 and only indicated by a light 

 shade. Some distinctly marked 

 specimens, have a portion of it, 

 from the inner margin, just 

 showing the first dash. I know 

 of two specimens having the 

 line almost entire. 



5. These spots form almost a 

 complete line which is densest 

 near the base, and again about 

 the centre of the costa. 



6. Posterior wings marked with 6. These lines entirely wanting, 

 two wavy lines. 



To summarise from the above, and looking at a long series each 

 of muralis and impar, the specimens of impar will look much darker 

 and not so decidedly varied in colour, blue-grey, rather than green, as 

 in muralis, the latter looking smooth and neat by the side of impar, the 

 thick, loose look of which is caused by the scattering of black scales 

 (not ferruginous as is the case with muralis var. par, Hb.). 



It is not at all necessary to describe either of the sub- varieties of 

 impar as the type, nor is it found quite practicable to give the right of 

 precedence to the most frequent form. In the following table I have 

 adopted the method of commencing with the form which most nearly 

 resembles a form of muralis, though by no means the type form of muralis. 

 At the same time, it happens to be the rarest form of impar I have 

 taken. 



a. A sub- var. nearly resembling muralis var. par. Hb., as 

 described in ' British Noctuas and their Varieties,' vol. i., pp. 9-10 ; but 

 the grey ground colour is not so strongly tinged with green, and the 

 markings are not so red. This sub- var. is that in which impar approaches 

 most nearly to muralis. 



/3. A sub-var. in which the ground colour is greyish-white, 

 covered with black scales, and with the usual black markings ; the 

 subterminal line however, obsolete, or indicated only by a light shade. 

 This var. corresponds with muralis var. pallida, Tutt (' British Noctuse 

 and their Varieties/ vol. i., p. 10), but thejscattered black scales render 

 it distinct. 



y. This sub-var., in which the ground colour is dark blue-grey, 

 very thickly covered with black scales, and having the shade surrounding 



