59 



ViTRiNA PELLUciDA (The Transparent Glass Bubble 



Shell). Muller. 



Figures 29 and 30. 



29. 



30. 



The above solitary representative of this family in 

 Great Britain v\ as described by Pennant, in 1777, in his 

 " British Zoology." 



The animal appears to be more hardy then any other 

 of the helicidae, as it is found in greater abundance 

 from October to December than in summer. Nilson 

 observed it crawling about amongst leaves in the south 

 of Sweden in the depth of winter. 



It is greyish in colour, with much darker head and 

 tentacles. The tentacles are short. The mantle of tbe 

 animal is reflected on its shell. The tail is narrow, and 

 much produced behind the shell. 



The colour of tbe shell is watery-green, but varies in 

 the depth of colour, some specimens being even pea- 

 green. It is exceedingly thin and transparent, very 

 glossy, smooth, and extremely fragile. The body whorl 

 is large. There are three and a half v\horls, which are 

 much depressed, and the spire, which is blunt, is but 

 little ele? ated above the last whorl. The form of tbe 

 shell is elliptic, the aperture 1 being large and nearly 

 oval ; the breadth somewhat greater than the length. 



The eggs are oval, white, almost transparent, having 

 an opaque spot in the centre. They are deposited in 



