PREFACE. 
HE following list is based upon that of MR. ALFRED O. 
WALKER, F.L.S., published in 1885 in the Proceedings of 
the Chester Society of Natural Science. The district covered, 
however, has been extended so as to include the whole of Cheshire 
and the Counties of Flint, Denbigh, Carnarvon, and Anglesea. 
The total area is 2,878 square miles, the length (from east to west) 
being about 120 miles, and the average breadth about 24 miles. 
The physical geography is very diversified. In the extreme east, 
on the borders of Derbyshire and Yorkshire, we have hills of 
considerable altitude, reaching 1,834 feet at ‘‘Shining Tor’’ in the 
high-lying country between Buxton and Macclesfield. Proceeding 
westward the country slopes downward to the plain of Cheshire, 
which forms the greater part of the county, with a few out- 
cropping hills as at Alderley Edge, Helsby, Peckforton, Beeston, 
and Broxton. Nearing Wales the land again rises, and attains 
the height of 1,820 feet at Moel Fammau in Flintshire. From 
this point, westward, the country is more or less mountainous, 
with the intervening valleys of the Clwyd and Conway, until 
Anglesea is reached, when the surface again becomes compara- 
tively flat. In Cheshire the New Red Sandstone formation 
predominates, overlaid with soils of clayey and sandy loams. 
In Flintshire and Denbighshire there is an isolated ridge of 
carboniferous limestone, with its attendant peculiar flora and 
fauna. This formation again appears, to a small extent, near 
Penmaenmawr. The mountains of Carnarvonshire consist of, 
chiefly, the Upper and Lower Silurian Rocks, and are of majestic 
proportions; they are disposed in the wildest manner, and often 
rise to a height of over 3,000 feet. Such peaks are mostly bare 
of vegetation, excepting occasional heather and short grass; but 
the jlora of the lower slopes and valleys is of varied character, 
and often accompanied by rare Lepidoptera. 
With the exception of Cheshire, some parts of Flintshire, 
the coast-line, and the valleys of Llangollen, Clwyd, and Conway, 
the district appears to have been very inadequately. worked by 
lepidopterists. Reports are greatly needed for the country round 
Snowdon, and for the Isle of Anglesea; and in the following 
pages the absence of records from Anglesea must not be taken as 
evidence that the insects do not occur in that County. 
