377 
THE GEOGRAPHICAL DISTRIBUTION OF THE 
MOTHS OF THE SUBFAMILY BISTONINAE. 
J. W. HESLOP HARRISON, M.Sc. 
(Continued from page 362). 
VII—THE GENUS NYSSIA (DUPONCHEL). 
Nyssia zonarva (Schiff.). Distribution :—N. and W. Ireland, 
N. Wales, N.W. England, Inner and Outer Hebrides,—in all 
cases on the coast. Central Europe as far west as Paris, (but 
excluding Holland and Belgium), Southern Scandinavia, Asia 
Minor and Armenia. . 
Nyssia zonaria var. vossica (Harrison) South Russia and 
Kirghiz Steppes. 
Nyssia incisania (Ld.). Armenia. 
Nyssia alpina (Sulzer). The Alps—both of Switzerland 
and the Tyrol. 
Nyssia italica (Harrison). Mountains of Italy from the 
Piedmont to Tuscany. 
Nyssia grecaria (Boisduval-Staudinger). Greece, Mace- 
donia, Albania, Bulgaria and the Island of Corfu. 
Nyssia grecaria var. istriana (Stgr.). Carniola, Dalmatia, 
Istria. 
Once more our attention is directed toward a genus, 
one of the exponents of which is found in the British Islands. 
As has been indicated previously, both from a consideration 
of the distribution of Poecilopsis and of that of Nyssiodes, 
this genus was evolved at some point to the north of what 
now constitutes the continent of Europe. Against this, it 
might be urged that possibly we are here dealing with part 
of the great Westward migratory horde of Tertiary times 
which brought Palg@onyssia into Africa, and this is apparently 
emphasised by the close superficial, and to a certain extent, 
structural resemblance between Nyssia zonaria and Nyssiodes 
lefuarius. This, however, is negatived by many very cogent 
reasons. In the first place, the genus is not primitive, and, 
judging from the evenness of its physiological divergence from 
Lycva, it is quite homogeneous, and consequently its members 
revolve like planets around one centre, and that central species 
is Nyssia zonaria. And the very close relationship between 
Poecilopsis lapponaria, a purely north western form of older 
origin, and N. zonaria is so pronounced as in itself to forbid 
~ any direct» Eastern origin of the group. 
Again, had these species advanced from the East, it is 
clear that they must have done so via the Caucasus or via 
Asia Minor. Necessarily, therefore, the more Alpine forms 


1916 Dec. 1. 
