HELIX NEMORALIS. 289 
Prof. Beddard, on the authority of Leydig, remarks on the rich citron- 
yellow of the shells inhabiting the sunny hillside vineyards of the Mid- 
Rhine Valley, and emphasizes the change to red of the shell in the vicinity 
of Bonn, and the deepening into chocolate-brown lower down the river as 
the moister districts nearer the coast are approached. 
The var. albinw, though occasionally locally common, sometimes, as at 
Meylan, Grenoble, occupies a district to the exclusion of other forms. 
The var. rubella is the most abundant form in East Prussia and other 
parts. It is elso quite predominant within a restricted area at Bettws-y- 
Coed, Carnarvonshire, and the most plentiful form at Porthleven, Cornwall, 
and other western localities ; while the var. a/bolabiata is quite as plentiful 
as the dark-lipped shells in the Pyrenean Mountains, and nearly as numerous 
in the west of Ireland. 
The different types of banding show similar local concentration, the 
typical banded form—which in its many modifications is so common—being 
quite unknown in South Bavaria, where the formula 00345 is the prevalent 
form, it is also one of the most plentiful in Wurtemburg, Normandy, many 
parts of Belgium, ete. In this country itis most frequently found on open 
elevated slopes, and Mr. L. E. Adams has recorded it as especially plentiful 
on the sunny railway embankment at Great Houghton, Northamptonshire. 
The vars. punctate and interrupta, whose peculiarities are due to the 
intermittent action of the pigment glands, are with a yellow ground colour 
often dominant on the arid and minutely parti-coloured sand dunes by 
the sea, with scanty vegetation, as at Portsalon, Donegal, Spurn Point, 
Yorkshire, ete.; in the last locality nearly every specimen belonged to the 
var. punctuta. 
The var. undulata is a modification of the preceding forms, constituted 
by the transverse fusion at various intervals of the broken banding ; it is 
the common form about Keswick and Bassenthwaite in Cumberland, but 
is far from being a generally prevalent form. 
Mr. E. Collier has observed at Carrickfin, Donegal, where the var. 
citrinozonata is locally plentiful, that the inhabited ground is closely 
overspread by a rank growth of a yellow mushroom-like fungus, approxi- 
mating closely in colour and size to the shell, which thus probably reaps 
the benefit of protection from the resemblance. 
The var. rubella has been noticed by Lieut.-Col. Parry to display a 
similar harmony with a favourite habitat, as at Eaux Chaudes, Basses 
Pyrénées, where at an altitude of about 2,200 feet, it lives amongst the 
box trees, the colour of the shell exactly matching the colour of the red 
fallen leaves upon which the animals live and feed. At Ayelés, where there 
are no box trees, the red variety is not found. 
This effect of environment is also strikingly shown in North America, 
in the modifications now being undergone by the Virginian colony of this 
species, which shows in addition to a greatly increased and extraordinary 
tendency of the normal banding to split up into numerous supplementary 
bandlets (a feature which is comparatively or quite rare in this country 
and Europe, but at Lexington is affecting almost five per cent. of the total 
specimens found), there is also a remarkable lack of the brilliant coloration 
the species usually presents in Europe, and an approximation to the sombre 
hues characteristic of the North American Helicide. 
1/7/10 S 
