64 EAMBLES IN SEARCH OF SHELLS. 



The fragile moss-sbell {Balia perversa, or fra- 

 gilis), as its name implies, may be sought for upon 

 moss-grown trees and rocks, and is not uncommon. 

 Cooper mentions it in his list as found at Hammer- 

 smith at the foot of trees, concealed by grass ; but 

 since this list was published, trees at Hammersmith 

 have given way to such an extent to bricks and 

 mortar that this locality must now be accepted 

 with reservation. In "The Zoologist" for 1851, 

 p. 3121, Mr. A. F. Sheppard includes it in a list 

 of shells found in the neighbourhood of Fulham, 

 as having been met with on old walls. Although 

 a small shell, its shape more nearly resembles 

 ClausiUa; that is, instead of being somewhat cylin- 

 drical throughout its length, it has a wider mouth, 

 and tapers gradually throughout the length of 

 the spire. The spire is sinistral or reversed, as 

 in ClausiUa (PI. VIII., fig. 1). 



Bulimus ohscurus and montanus (PI. VIII., figs. 

 5, 6) may both be found adhering to the trunks of 

 trees, especially beech,* ash, and hornbeam, and at 



* The beecli is an especial favourite with snails, more so 

 than any other tree, and after showers the trunks may be 

 seen studded with them. The probable explanation, says 



