IN THE BRITISH ISLANDS. 67 



are pale and nearer together at the inner margin than on the costa. 

 Between these are the two ordinary stigmata surrounded with black, 

 the orbicular whitish, the reniform obscure grey and scarcely notice- 

 able. The claviform is grey bordered with black, whilst at the base 

 of the wing and touching the costa is another grey patch. There are 

 some black cuneiform spots near the hind margin" ('Histoire 

 Naturelle ' &c., xiii., p. 592). Guene'e treats this as a distinct species 

 and writes : " It is distinguished from occulta by its size, its more 

 unicolorous appearance, being paler, more purplish, less clouded " &c. 

 In fact, Guenee gives in some particulars, an exactly opposite 

 description to Lefebvre's typical figure. Newman says of this variety : 

 " The northern specimens are remarkable for their dark colour, some 

 of them being almost black " (< British Moths,' p. 407). Newman also 

 figures this variety on p. 406, fig. 2. Mr. Kobson writes of a specimen 

 in Mr. Gregson's collection : " One dark specimen taken by Mr. 

 Carrington in Perthshire, is without the white lines on the wing 

 on the right side. NocTiLas with odd wings must be very rare, this is 

 the only instance I remember " (< Young Naturalist,' vol. viii., pp. 122- 

 123). Of a specimen in his collection, Mr. Sydney Webb writes: " One 

 of my Scotch specimens has odd wings, arising from a black cloud 

 slanting obliquely across the wing from the pale patch at the base to 

 the renal stigma ; from the farther end of this cloud, at the inner 

 margin, the dark subterminal proceeds as usual to near the apex, so 

 that the only pale portions visible on the wing, are the basal patch, 

 an obscure orbicular and ordinary reniform stigmata ; posterior to the 

 last of which are three pale dashes which fade away where the second 

 line should be ; hind margin, as usual, slightly paler " (in litt. 7.4/92). 

 I do not know whether the var. passeta, Mieg. <Le Nat.,' 1886, 

 which was named from a Scotch specimen, is this form, as I cannot 

 refer to the original description, but it is very probable. Herr A. 

 Hoffman, in writing of the Shetland examples says : " They resemble 

 the light southerly forms. The black form of the Scotch mountains, 

 which occurs also in our own mountains (Upper Hartz &c.), has not been 

 taken " ( Ent. Zeit. Stett.,' 1884, p. 363). 



/3. var. extricata, Zett. This appears to be an intermediate form 

 between the paler mottled grey type and the black var. implicata. It 

 is only distinguished from the latter by certain minor characters by 

 Zetterstedt, such as " the transverse lines being whitish and double, the 

 costal markings white " &c. Zetterstedt writes : " H. extricata : alis 

 anticis nigricantibus cinereo fuscoque variis, strigis duabus geminis 

 dentatis, macula ordinaria interiori ovata, striolisque, basalibus ad 

 costam, albis ; posticis fuliginosis, fimbria alba. . (Long. al. exp. 

 2| poll.)." " Hab. in Lapponia. D. Schonherr, e cujus museo mecum 

 ad describendum communicata (Lappon. borealis ?) ". " Magna, 

 pulchra et distincta. Similis quodammodo et aifinis H. implicates, 

 Lefeb. $ , sed vix ejus mas. Differt ab ilia : alis anticis nonnihil 

 longioribus et angustioribus, strigis albis geminis, seu singula per 

 striolam mediam tenuissima longitudinaliter divisa (nee ut in 

 implicata simplici), exteriori angulato-dentata, nee siinpliciter arcuato- 

 dentata, ut et tandem strigulis costalibus ad basin albis. Maculae 

 ordinarise, exterior reniformis cinerea, interior vero obliqua ovata ad 

 costam adscendens. Ipsa costa punctis strigiformibus tribus albis 



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