Lritish species of Scoparia, 509 
also less discussion as the consensus of opinion is now 
that they are one species, a consensus that in the case of 
dubitalis only refers to English ingratella, the result pro- 
bably of English acumen applied to this point, and not to 
whether English and Continental ingratel/a were identical. 
The appendages of ambigualis and atomalis are identical 
except again that those of ambigualis are altogether larger, 
quite distinctly so in typical instances, viz. as 12 to 11. 
In ambigualis we have a southern larger and paler, in 
atomalis a northern smaller and darker form. I should 
say that the extreme forms were much more nearly 
distinct species, than were any forms of duditalis and 
ingratella. 
Two other forms, manifestella and ulmella, have append- 
ages that I cannot distinguish except in size. Though I 
have no hesitation in saying that in a certain broad sense 
these two forms are one species, they are nevertheless 
vastly more distinct from each other than is ingratella 
from dubitalis or atomalis from ambigualis. Their habitats 
are widely separated. I know of no intermediate forms. 
The difference in size is very great, 26 mm. and 17 mm., 
and there is one really important difference in marking, 
viz. the orbicular stigma is usually separate from the first 
line in manifestilla, never I think in wlmedla. 
They are, again, a northern and southern form whose 
differences have been exaggerated by long segregation, 
so that for all practical purposes they must be treated as 
distinct species. 
The male appendages of these two forms appear to be 
quite identical except in one point: those of manifestella 
are about 10 per cent. larger than those of u/mella. There 
is a very similar difference in size in the moths so far as 
my examples show, though I believe some of my manifes- 
tella are rather large specimens. Are we to regard these 
two forms as one species or as two? I think the usual 
custom in such cases is to regard them as one species. 
They are, no doubt, very marked geographical races, that 
have not been syngamics for a long period, but, on the 
other hand, they can have separated really only yesterday, 
so to speak, in comparison with the period, whatever it 
may be, necessary to differentiate unquestionable species. 
Though the question may thus be raised as to whether 
ulmella should not be regarded as a race of manifestella, 
its differences from ambigualis are very great, though 
