VITRINA. 155 



near Bideford in North Devon. Mr. Kenyon is said to 

 have found it near Glasgow^ Mr. M'^ Andrew at Balti- 

 more^ Mr. Wright and Mr. Carroll near Cork, and 

 Mr. Waller discovered it among turf-bogs at Finnoe, 

 Co. Tipperary. The last appears to be the only inland 

 locality. It is not uncommon in our upper tertiaries. 

 This species is widely diffused on the Continent from 

 Sweden to Lugano ; and the S. ahbreviata of Morelet, 

 from Braganza in Portugal, appears to be only a variety 

 of it. 



S. oblonga is unmistakeably different from either of 

 the foregoing species, being invariably so very much 

 smaller and having such a large spire in proportion to 

 the size of the shell, with a deeper suture and a rounder 

 mouth. I can scarcely regard the S. arenaria of Bou- 

 chard-Chantereaux as even a well-marked variety of this 

 species. Most, if not all, of the British specimens belong 

 to this form. The greater solidity of its shell and the 

 comparatively shorter spire are probably owing to the 

 nature of its habitat. According to Bouchard-Chan- 

 tereaux this variety buries itself in the sand and makes 

 a rather solid epiphragm. The shell is usually covered 

 with a viscous slime or exudation from the animal, by 

 which a slight coating of dirt is sometimes formed. 



Genus II. VITRlNA*, Draparnaud. PL VI. f. 4-6. 



Body short, usually incapable of being quite contained within 

 the shell : mantle furnished with a supplementary lobe, which 

 is extended over the front of the shell when the animal crawls ? 

 tentacles 4, cylindrical, the lower pair very short : foot rather 

 narrow. 



Shell somewhat globular, extremely thin and transparent : 

 spire short : mouth obUquely semilunar : outer lip thin : no 

 umbilicus. 



* From vitrum, glass. 



