HELICIGONA LAPIOCIDA. 405 
Horocsng.—Found in the tufaceous deposits at Blashenwell, Dorset, by 
Mr. J. C. Mansel-Pleydell. 
In West Kent, it has according to Kennard and Woodward been found 
at the base of an interment of early Romano-British age in Stanley’s 
Quarry, Ightham; and Mr. B. B. Woodward tabulates it as from the 
deposits at Crossness. 
In Surrey, it is recorded from a depth of eighteen inches in the Horse- 
shoe Pit, at Reigate, Colley Hill, by the Rev. R. Ashington Bullen. 
In North Essex, it has been found in the black earth and peat alluvial 
deposits of the River Cann, at Chignal, near Chelmsford, also in an alluvial 
bed disclosed by draining a field on Duke’s Farm, Roxwell, by Mr. Miller 
Christy ; and in the shell marl at Felstead by Mr. J. French. In South 
Essex, it is recorded by Kennard and Woodward as not common in a 
patch of alluvial shell-marl of the River Lea, near the south side of Lock- 
wood Reservoir, Walthamstow ; from the deposits on the Clapton side of 
the river, and also cited as found by Dr. F. Corner in the alluvial beds 
alternating with deposits of mud and peat disclosed during excavations at 
Canning 'l'own. 
In Cambridge, it has been found by the Rev. R. Ashington Bullen in the 
Romano-British deposit at Harlton. 
In East Gloucester, it is recorded by Hinton and Kennard from the 
“old soil” beneath deposits of Roman age, from the ‘‘quarry tip,” and from 
a depth of 24 feet or more in King’s Beeches Gravel Quarry, Cleeve Hill. 
In Germany, Dr. von Ihering records it from the diluvial tufa at Ober 
Zaunsbach, Franconia. 
In France, it is recorded by Comm. Caziot from the quaternary beds of 
Cap Martin, Alpes Maritimes; by M. Laville from the gravels of Joinville- 
le-Pont, Seine; by M. 'l'ournoiier in the tufa of the Celle, near Moret, 
Seine-et-Marne ; by M. Cardot from the calcareous tufa of Melandry, 
Ardennes ; and by M. Locard from the freshwater Molasse near Lyons. 
In Belgium, M. Grégoire records it as rather common in the “‘lourbe” 
at Uccle lez-Bruxelles, Brabant, and M. van den Broeck from alluvium at 
Ghent in East Flanders. 
In Denmark, it is recorded by Dr. A. C. Johansen from the “ kitchen- 
midden” at Meilgaard, Jutland ; and from the Neolithic deposits at Stova- 
flejring near Oxnebjerg in Funen. 
Variation.—The variation of this species is not so remarkable as that 
presented by many species, but it is said to be loftier, smaller, and darker 
coloured in woods than on rocks and walls, the depressed forms being an 
especial adaptation for effective concealment in their chinks and fissures. 
It is a form of shell which attains its maximum development in the 
North Pacific Islands, in Cochlostyla listeri, C. rota, ete., of the Philippine 
Islands, though the organization of H. lapicidu is much more advanced 
than that of these more feebly endowed and more primitive Eastern Asiatic 
species, so similar in their outward form. 
The most striking variation is that in which the carination is quite lost 
and the periphery rounded, as in //. rufescens, H. cornea, ete., which in 
general aspect it very much resembles, and which is attributed by Clessin 
to a deficiency of calcareous substances, though other observers deny that 
differences in geological strata effect any essential changes in the form of 
the shells living thereon. 
