i6o 
The Irish Naturalist. 
July, 1914. 
NOTES, 
ZOOLOGY. 
The Opisthobranchs of Co. Dublin. 
We propose to issue about August 15th a special double number of the 
Irish Naturalist (for August and September, 1914) consisting of a full 
account of this section of the marine molluscan fauna of Co. Dublin, by 
Nathaniel Colgan, m.r.i.a., who has devoted several years' study to the 
group from both the systematic and bionomic standpoints. 
Early Butterflies at Killarney. 
The remarkable spell of perfectly calm hot weather which made its 
appearance in April was much enjoyed at Killarney where the hottest 
days were the 20th, 21st and 25th, and the maximum shade temperature 
of 72°, F. was recorded. Butterflies were numerous all over the district, 
especially Tortoiseshells and Peacocks, and on the sunny side of Cow 
Island, Lower Lake, I watched from a boat for some time a pair of freshly - 
born Brimstones flitting through the leafy glades and frequently returning 
to sun themselves on the hot rocks near the water's edge. A few of the 
specimens seen were faded and ragged hybernated individuals, but the 
majority were in beautifully fresh condition evidently hatched out by the 
unusual heat. 
Alexander Williams. 
Dublin. 
BOTANY. 
The Southern Element in the Britannic Flora. 
A paper of more than usual interest to students of geographical 
distribution in this country, from the pen of Dr. Otto Stapf appears in 
the Festhand fiir A. Engler recently issued as a supplementary volume 
of the Botanische Jahrbucher. Its title is " The Southern Element in 
the British Flora." Dr. Stapf has analyzed the flora of the British Isles 
from the point of view of its distribution in Europe, the natural and 
proper standpoint, suggesting, as it does, the origin of the elements of 
our flora, where intra -British analysis, such as that of Watson, only leads 
us to a dead end. Putting on one side all British species which occur 
in Northern or Central Europe (in a wide sense), he concentrates attention 
on the remainder, i.e., plants which are confined to the British Isles, 
France, Spain, or the Mediterranean. These he divides into a Western 
(Atlantic) and an Eastern (Mediterranean) type, and he traces the range 
of these along the south, east, and west coasts of Great Britain and 
Ireland. We cannot here go into Dr. Strapf's figures ; but we may say 
that as regards the origin of our southern flora in space and in time he 
believes that it migrated as a whole into the British Isles from the south- 
west in post-glacial times, and he strongly opposes Clement Reid's theory 
of recent accidental dispersal of the forms of discontinuous distribution. 
