( .=xxvil >) 
unusually light. A curious appearance of contrast resulted. 
These specimens proved that a form differing little from the 
Breton type might arise as a sudden variation from the English 
type. 
The series of A. betularia was of considerable interest. 
The result of crossing betularia with the var. doubledayaria 
had previously been the production of specimens of type and 
variety sharply distinct from each other. In the present case 
a single female had produced a number of type specimens, a 
few nearly as dark as doubledayaria, and several intermediates. 
The father was unknown, but not improbably it may have 
been doubledayaria. Cases of this kind showed that the 
degree of discontinuity occurring in crosses between varieties 
cannot be determined without many experiments with different 
strains, Between these two varieties there was reason to 
believe sharp discontinuity was the rule. In this family the 
discontinuity was only partial. Most of the specimens be- 
longed either to betularia or to doubledayaria, but a few of 
each sex were truly intermediate. He hoped a full account 
of these insects would be published. 
Mr. H. J. ELwes gave an account of a journey undertaken 
by himself in the summer of the present year to the Altai 
mountains of Siberia, partly for sport and partly to investi- 
gate the distribution of Lepidoptera in that region, and to 
discover if possible a line of demarcation between the Eastern 
and Western Palearctic, or, as it is now more properly termed, 
Holarctic region. He exhibited a very fine series of Lepi- 
doptera, taken by himself in the Altai, and including about 
140 species of butterflies and 80 of moths, many of which had 
not previously been recorded from Western Asia, and traced 
his journey on a large scalemap. The only entomologists who 
had previously collected in this region, so far as he knew, were 
Kindermann in 1851 and 1852 on the Buchtarma river, and 
Ruckbeil who more recently spent three seasons in the same 
part of the mountains. ‘Their collections were both of a much 
more typical European character than those made by himself, 
which included a number of species previously known only 
from the Upper Amur region and Eastern Siberia, as well as 
several Lapland and Arctic species, amongst which Lrebia 
PROC. ENT. SOC. LOND. V., 1898. D 
