37 
the two anal points acute, the slender, dark green dorsal line bordered 
by the (/round colour, while that of the latter has the anal points blunt, 
the dorsal line bordered by a space paler than the pround colour, and it 
is altogether a duller-looking creature than truncata, its shape seems 
more cylindrical, etc. 
I really do not know that we have advanced much, if any, further 
than this as regards the early stages. Buckler’s “ Larva? ” (viii., p. 87) 
simply quotes Hellins’ article, and gives (pi. cxliii., figs. 2-2e, 3-3 b) 
figures of various forms of the fullfed larvae, some of those of C. trun¬ 
cata showing red lateral markings. On the imago, we have Fenn’s 
note already referred to {Eat. Bee., i., p. 276), in which he emphasises 
the course of the line on the hindwing (only distinct on the under¬ 
surface) as a differential character, illustrating it with woodcuts. I 
am told hy Mr. Sydney Webb, who also places great faith in it, that 
he had pointed it out to Mr. Fenn some years previously, hut I do not 
find any definite published reference to it prior to Mr. Fenn’s*. The 
main point is that the line in question has, in C. immanata, a sharp 
angle (virtually rectangular, sometimes even more acute), while in C. 
truncata it is more or less gently curved. The test is a very useful 
one, and very seldom fails; but, like so many of our artificial 
characters, it is not infallible when taken singly. Sparre Schneider 
(Troms. A [us. Aar.sh.. xv., p. 71) thinks that the more material one has 
before one, the deeper becomes one’s perplexity in the attempt to find 
constant differential characters ; yet he finds general differences in the 
dates of appearance, and in the habitat, and says that in general 
one can arrange them satisfactorily in the two series, though there 
will be occasional examples difficult to locate. I fully agree with this, 
and will only mention some points of distinction which are borne in 
upon one in examining a large mass of material, though quite worth¬ 
less for locating an individual specimen with certainty. In C. trun¬ 
cata (excepting the doubtful concinnata ) the markings of the basal area 
show a very general tendency to be blurred and ill-defined ; in imman- 
ata an equally strong general tendency to be sharply defined. In 
truncata the white subterminal line is generally almost uninterrupted 
behind the lobes of the central area; in immanata it is generally well- 
interrupted there. In black-banded truncata, as Barrett mentions, 
the sienna shades are generally darkened or w T eakened; in the same 
form of immanata they are often brighter or intensified. In immanata 
there is often a bold whitish patch on costa behind the white line which 
bounds the central area exteriorly ; in truncata such patch is rarely 
present, never striking. In truncata the black central spot of the fore¬ 
wing is nearly always large, or moderately large ; in immanata it is 
much more variable in size, often quite small. In truncata the hind- 
wings are generally darker than in immanata, not infrequently showing 
the row of pale, roundish ante-marginal spots which becomes so con¬ 
spicuous in concinnata. It is curious that Hormuzaki ( Verb . z-b. Ges. 
Wien, xlv., p. 254), while noting some of these distinctions very care¬ 
fully, has inverted his species ; fortunately he gives dates, which render 
* Gregson (Weekl. Ent., i., p. 45) vaguely indicates a “ striga faintly delineated 
on the underwing ” as a distinctive character of C. immanata, but gives no details 
and seems himself to have confused the two species, see supra. 
xviii. 
