78 THS KNTOMOLOGIST’S RHCORD. 
wings is widespread and very black; the apical marking, too, is deep 
black and extends far back along the outer margin; on the under-side 
the neuration of the fore-wing is distinctly bordered with grey scaling, 
that of the hind-wings with very broad and very dark olive-green veins. 
The female sex is sti]l more characteristic, exhibiting two well-marked 
forms: one with black bands along all the nervules and one with a 
deep yellow ground-colour and with very wide diffused bands of brown 
scaling, so broad as to blend together in extreme specimens and pro- 
duce a uniformly brown wing (concolor, Rober). Very similar to this 
arctic napt is bryoniae, O., from the higher Alpine altitudes, differing 
from it only by minor characters. 
In marked contrast with this group stands the well-known 
butterfly of Central and Southern Europe, including Southern 
Scandinavia, whose summer brood Esper has named napaeae and 
which in the first generation, though more similar than the latter 
to bryoniae and the Linnean specimens of napi, can be distinguished 
from it by its larger size, more elongated wings, very reduced basal 
suffusion, shorter and often much lighter coloured apical crescent, 
shadeless neuration of the under-side of fore-wings, narrower, more 
sharply outlined and more vividly green veins of hind-wings and by 
the fact that the female sex never offers examples of the form with 
yellow ground-colour and ample brown suffusion; in most localities 
the yellow ground-colour never occurs either, but in some regions, 
such as Austria, specimens with a slightly yellow tinge are to be met 
with also in vulgaris (flava, Kane), and are more frequent in the 
second brood (favescens, Stgr.). 
Having thus clearly defined the two distinct groups of napi-forms 
which occur in Europe, it will be seen by a most superficial observer 
that in the British Islands corresponding forms are to be met with. 
It would be very interesting to make out whether they overlap in their 
distribution and, if so, whether they blend in transitional forms or 
fly together without mixing. Mr. Bethune-Baker, with whom I have 
lately been corresponding on this subject, has already set to work 
collecting series of this species from different parts of Britain, and I 
think he will very soon be able to clear up this point. All I can say 
for the present is that in the series in my possession two races are 
distinctly noticeable. ; 
The form I named britannica belongs to the napi-bryoniae group, 
although it differs constantly from the continental races by the under- 
sides, which are of a much brighter sulphur yellow; besides it must be 
noticed that the female form with yellow ground-colour and brown 
markings is not produced by britannica, as far as I have been able to 
ascertain, this race not varying in this direction further than jlava, 
Kane. This is probably due to the fact that britannica is in reality 
but a modified vulgaris and not a true arctic nap?. An examination of 
the genitalia of the races of napi will probably give some clue as to 
the exact position each of them should occupy in this group. My 
“ types” of britannica were collected in the south of Ireland (they are 
preserved in the Oberthiir collection at Rennes), but a series from the 
northern coast of Scotland, in my own collection and for which I am 
indebted to J. W. H. Harrison, of Birtley, exhibit the same characters 
even to a higher degree, as might have been expected. 
Turning our attention to napi from England and especially from 
