of St Ives^ Whitesand^ and Mounfs Bays. 183 



edenlula ; And bithinitt ventricomi Those which I found in 

 other parts of the Towans, at vadous depths, are helix aspef' 

 sa, nerttoralis, hortensis virgata, and ericetorum ; bulimies acu- 

 tus ; zua lubrica ; and pupa marginata ; in all^ fouHeen spe- 

 cies, of which the most abundant^ as well beneath as on the 

 present surfacdi w^fe the bulimm acutus, helix virgattti and 

 helix ^ricetofUM. 



Mr R. y. Couch, authoi* of the Cornish Faiitia, who kindly 

 furnished me with the names of these shells, makes the fol- 

 lowing interesting remarks in his letter to me on the occa- 

 sion. " Of the Helices all are common in the locality except 

 the helix pulchella, Thi^ last I have found near Falmouth, 

 at Pendennis ; near Penzance, at Trereife ; and near the 

 Land's-end. It is, ho\V6ver, rare in this coimty. The quan- 

 tity found on the ToWans ^Vithin so small a spac6 is very re^ 

 markable, and should further research shew that they are of 

 frequent occurrence in other parts of the Towans, we must 

 come to the conclusion that they were once abundant in Corn- 

 wall, but are now gradually becoming extinct in this locality. 

 The pupa marginata and bithinia ventricosa are very rare : I 

 have found a few dead specimens near Hayle, and at White- 

 sand Bay, which might have come from the sand-hills, but I 

 have not yet found them alive in Cornwall. It would be very 

 desirable to examine the Towans at different depths, to ascer- 

 tain the changes which the Fauna of our county has been un- 

 dergoing during the last one or two thousand years." 



The observations now made on the origin of the sand-hills 

 of St Ives, are equally applicable to those of Whitesand Bay,* 

 near the Land's-end, and to the sand-banks of Mount's Bay, 

 except that the last are principally granitic. I have examined 

 the sand-bank between Penzance and Marazion, especially 

 the highest part of it, near Marazion Bridge, and have found, 

 throughout a depth of about 10 feet from the surface, a great 

 number of land-shells (Jielix virgata and bulimus acutus) in 

 perfect preservation, and in similar circumstances to those 



* Besides the helix virgata and bulimus acutus, with which the sections of the 

 sands of Whitesand Bay are thickly studded, I found there likewise a specimen 

 of the clausiUa biUcntata. 



