150 Beautiful Shells. 
The widely-spread Balea fragilis has been con- 
founded with the pupe, but it is far too tapering. 
It is a small, thin, delicate, shining, and rather 
transparent shell, of a yellowish horn-colour, and in 
length about the third of an inch. It is found in 
trunks of trees, and amidst mosses and lichens. 
The dark close shell, Clausilia igricans, with 

55. 
55. Balea fragilis (the Fragile Moss Shell), Draparnaud. 
56. Clausilia nigricans (the Dark Close Shell), various. 
which we have grouped it, is better known as the 
common Clausilia; but it is quite a conchologist’s 
shell, having long escaped vulgar popularity, though 
very generally distributed throughout Great Britain. 
This exclusiveness is due to its habits and colour, 
which render it far from easy of detection. Its 
length is half an inch, breadth from a twelfth to an 
eighth, and it inhabits old walls. The animal, as 
may be inferred from the shell, is very thin and 
slender, so much so that in motion it is incapable 
of raising its shell, but drags it along in the same 
line as its foot and neck, although when going to 
