36 
about it, but as he cites Hiibner (though only with a query), it should 
he a Sdadion ( Gnophos ), and, therefore, another light form of 
£>. obscurata ,* * * § as it was certainly the serotinaria of Stephens and 
Wood. Stephens! added yet another supposed species through 
mistaken identification of a Hiibnerian figure—namely, dilucidaria. 
Wood figures the same four in his Index Entomologicus (figs. 626- 
629), but the mistake with regard to serotinaria and dilucidaria was 
soon discoveredJ, and Westwood sinks them as varieties of pullata, 
i.e., of the paler forms of obscurata. Pullata ( Auctt. Brit, nec, Schiff.) 
died harder, and although Guenee in 1857 accepted the correct German 
synonymy, Stainton, in vol. ii. of the Manual, maintained the old 
British usage of pullata. But Doubleday’s widely-circulated second 
edition§, dated the same year as Stainton, soon obtained currency in 
this country for Guenee’s corrected nomenclature. 
I have already, in my quotation from Tutt, reminded you of the 
general range of colour variation to which S. obscurata is subject. 
Roughly, perhaps four is the most convenient number of colour groups 
to mention, although every division attempted must necessarily be 
arbitrary, inasmuch as every intergrade is liable to occur. But by 
choosing the number four, I am able to use the familiar and (as applied 
to insects) comprehensive terms black, white and grey, with the 
addition of the interesting forms in which the sandy or reddish hue— 
which is often traceable in a few scales—becomes dominant. Staudin- 
ger’s Catalogue recognises three of these ( Dritte Auflage, p. 844), the 
whitish (var. calceata), the sandy or clay-coloured (var. argillacearia ), 
and the residue, or the dark and darkish specimens comprehensively 
(obscurata type). Unfortunately his diagnosis of var. calceata —“ alis 
cinereis ” has been misinterpreted by Robson and Gardner||, who give 
“var. calceata, Std. Cat.," as “from peat districts, nearly black,” 
and call the very pale form from the chalk “ var. serotinaria, 
W.V. ! ” The “ brown ” form from clay or sand districts they give as 
“ var. dilucidaria, Stph.,” adding argillacearia, Std. Cat., and pullata, 
Hb., as synonyms thereto; the latter citation should evidently be 
deleted. Mr. Tuttll has given us a rather better idea of what 
Staudinger’s classification meant, for he says that “ the white form is 
known as var. calceata," but he has unfortunately missed a point in 
dealing with var. argillacearia, by rendering Staudinger’s argillaceo- 
griseis simply as “the grey form,” and so applying it to the form which 
is “ common on limestone formations.” 
As I have compared the various type figures and descriptions with 
a good deal of care, I hope to be able to lay before you a scheme which 
is sufficiently accurate to furnish a working basis for the future, and 
so avoid—for the best-known forms at least—the need for the circum¬ 
locutory references with which we have generally hitherto had to be 
* “ Albidis, atomis numerosis fuscis,” apparently described from a single 
specimen, locality unknown. 
t Cat. Brit. Ins., ii, p. 140 (1829) ; III. Haust., iii., p. 267 (1831). 
} Dale seems to have been the first to suspect that all four might be vars. of 
one species ( Ent. Mag., i., p. 515, October, 1833). 
§ The Zoologist Synonymic List of British Butterflies and Moths, 2nd 
edition (1859). 
|| A List of British Lepidoptera and their named Varieties, p. 35. 
II British Moths, p. 297 (1896). 
