OF HARTING. 323 



and water courses ; and the White Coil Shell (Planorbis 

 albus), generally distributed. We have seen specimens 

 of the Keeled Coil Shell (Planorbis carinatus) ; and 

 the Streaked Coil Shell (Planorbis lineatus), said to 

 have been found here, but we have never been so 

 fortunate as to collect any of either species ourselves. 



Returning to the Land Shells, we find that our list 

 of mollusca appropriately closes with an operculated 

 species, the Cyclostoma elegans. This is provided with 

 a purple-tipped, prettily-banded, brownish-grey shell, 

 about half-an-inch long, and having a circular mouth, 

 fr.om which latter character its generic name is derived. 

 It is generally, but not plentifully distributed in our 

 covers and hedge rows, and appears to be particularly 

 unwilling to encourage the familiarities of the Con- 

 chologist, at the least alarm it suddenly drops from 

 the plant on which it may be engaged, hurriedly 

 withdraws itself into its mansion, and securely closes 

 the door. 



We do not flatter ourselves that the fact incidentally 

 revealed to us by this species is destined to lead to 

 any very startling or even useful results, we never- 

 theless venture to make a note of it here, although it 

 might with more propriety be included in the geo- 

 logical section. In a little spring, at the foot of one 

 of our downs, we have, season after season, for many 

 years past, met with specimens of the dead shells of 

 the Cyclostoma, of the Helix rufescens, and of the 

 Helix hispida, thickly and uniformly coated with a 

 hard calcareous deposit, similar in appearance to that 

 on the so-called Derbyshire petrifactions. In all pro- 

 bability this deposit is very slowly formed, otherwise 

 more perishable substances than the shells of snails 

 would be found encased by it, but shells are the only 

 objects we have noticed in this condition, and we have 

 hitherto seen them in no other locality in the parish. 



X 2 



