60 
A. F. GRIFFITH-LEPIDOPTERA 
time to indicate briefly what localities may be expected best to 
repay investigation. The chalk-slopes which bound the county 
with few breaks from Royston to Berkhamsted will no doubt 
yield a rich harvest of insects to any one who will hunt them 
systematically. I myself spent a couple of hours collecting in a 
very high wind on Royston Down one day last August, and even 
under these unfavourable conditions succeeded in finding three 
species of Tortrices which I had not previously met with in the 
county. Here we may expect to find at least three or four additional 
species of blue butterflies and the silver-spotted skipper, all of which 
I have taken a few miles off on similar chalk-slopes in Cambridge¬ 
shire. In the beech-woods near the borders of Buckinghamshire 
we ought to find Lithosia Jielvola and aureola , Demas coryli, and 
many other species. Perhaps some fortunate collector may there 
meet with the very rare Ennomos alniaria, for it was only just over 
our border that the late Mr. Harpur Crewe found a larva of this 
species, which unfortunately emerged in a crippled condition. Here, 
too, Ptilophora plumigera and Notodonta cucullina may be expected 
among maples, Eupithecia tog at a among spruce-firs, and E. 
arceuthata among junipers, while the seed-pods of Campanula 
Trachelium should be searched at the end of August for Eupithecia 
campanulata, and the flowers of the foxglove for E. pulchellata. 
In fact, our list probably does not include more than half the species 
of the genus Eupithecia which occur in the county. We may safely 
expect, also, that an immense number of peculiar Pyrales , Crambites^ 
and other Micros, will reward a careful search along these chalk- 
hills, the peculiar vegetation of which always supports a large and 
varied fauna. 
With the exception of this comparatively narrow strip, the 
whole of Hertfordshire consists of undulating country, for the most 
part well wooded, and with a great variety of subsoils, nearly all 
however, overlying the chalk and varying from the very heavy 
clay to the hardest gravel, and, in a few spots, the lightest 
sand. With the exception of the river valleys, of which more 
anon, the fauna of the whole of this division of the county may be 
expected to be on the whole fairly uniform, and it is in a small district 
of this character that the species mentioned in the accompanying 
list have been observed. I will therefore not delay over this part 
further, except to reiterate what I said at the beginning of the 
paper, that the subjoined list is not to be thought at all complete. 
My brother and I have yearly added a considerable number of 
species to it. Last year we added over 15 species; and the great 
variety of subsoils, which makes it very necessary to hunt each 
locality thoroughly, at the same time makes it highly improbable 
that more than a part only of the species inhabiting this division 
have as yet been observed. In fact, scarcely any of the numerous 
inhabitants of fir woods, and none of the alder-feeders, figure in our 
list at all. 
Lastly, with regard to the river-valleys, neither my brother nor 
myself have ever had an opportunity of working these mines of 
