XEROPHILA ITALA. 123 
FOREIGN DISTRIBUTION. 
In France, M. Dollfuss cites it from deposits of Roman age at Lyons-la-Forét, Eure; 
and Caziot and Maury from the tufaceous beds exposed in the railway eutting near 
the Imperial Hotel, Nice, Alpes Maritimes. 
Variation.—.Verophilu itala is a member of a very difficult and complex 
group whose component members are so intimately linked together, struc- 
turally and conchologiecally, that until a thorough examination of the 
various doubtful forms has been made, it will be quite impossible to 
accurately determine their precise status. 
Dumont and Mortillet have observed that the character of the shell 
varies in harmony with the features of the environment, the shell tending 
to become uniformly whitish, more calcareous and thicker in substance in 
arid places, fully exposed to the sun, but when living in shady places the 
shell tends to become less calcareous and more horny in character with 
the banding less distinctly marked. Dr. Paul Fischer found that in the 
voleanic region of Auvergne this species, lke /7elia nemoralis and H. 
hortensis, is characterized by pellucid and excessively thin shells. 
The size of shell is very variable, ranging in diameter from about 8 milli- 
metres to 25 millimetres or even more ; the dwarfing is doubtless largely 
due to the hardships of their life conditions and the meagreness of the 
available food supply, while the larger forms are the result of more favour- 
able conditions of life, though M. Beaudouin has especially remarked that 
in the Cote d’Or the larger specimens are more particularly found in very 
arid places, while the smaller forms dwelt among very varied surroundings. 
The effects of altitude and the modifications of other features of the 
énvironment upon the shell of -V. itala have also been studied by M. 
Debeaux, who affirms that in the valley of Baréges, Hautes Pyrénées, where 
the soil is naturally richer in soluble lime than the higher slopes formed 
solely of primitive rocks, the shells attain a good size (diam. 18 mill.), but 
are always thin and fragile, and the bands though present are quite pellucid. 
On the Pic de Midau, at about 1,400 feet above the valley, the shells 
diminish in size, attaining only a diameter of 10—12 millimetres, while 
on the still higher altitudes of 4,800 feet and upwards to 6,000 feet, all 
traces of banding are lost, the shells are still further dwarfed, only attain- 
ing a diameter of S—10 millimetres, and are thin and delicate and of an 
uniform ‘‘ pale white.” 
The pigmentation of the shell differs in its shade and intensity of the 
ground colour, from white, through yellowish-fawn to very deep brown ; 
and Mr. C. E. Wright mentions a very beautiful rosy-pink form, which he 
found at Roundstone, Galway. The bands also vary from being perfectly 
transparent through greyish or yellowish to brown, or rose-pink, etc., to 
almost black. ‘I'he spiral banding generally shows a broad dark band 
above the periphery and several slender lines beneath, but these vary so 
much in number and character that scarce two specimens are exactly 
alike; the bands may also by transverse coalition and disruption present 
a radiate aspect on the upper side, this, according to Mr. Ashford, being 
the normal form in King’s Co., Ireland; and Mr. A. W. Stelfox in June 
1918 found a similarly marked and almost purely albine variety to be 
the prevailing form on Great Blasket Island, off the coast of Kerry. 
The modifications of shape are chiefly those from a flat or greatly 
depressed spire to an elongate form, with the whorls almost dislocated as 
in var. disjuncta of Turton. 
