461 



but have fince found it not uncommon in drifted fand, 

 in the river Avon with the lad, and fometimes on aquatic 

 phints; but more plentiful in a ditch near Wcdfiampton 

 in WiltJJiire : it may, however, be confidered as rather 

 a fcarce, or at lead, a very local fpecies. 



When alive, it is covered with a very thin epidermis, 

 which removed, the flaell is a little glofly : dead ones 

 become white and fomewhat opaque. It is at once dif- 

 tinguifhcd from all others by the cylindric volutions, 

 and perfeftly round mouth ; and in a living flate, by 

 pofTefling a corneous operculum, ftriated fpirally to the 

 centre, but fo clofe as to appear, at hrfl fight, like 

 concentric circles. 



The animal too, is different from any we are acquainted 

 with, except that of Turbo fontinalis, to which it bears 

 great refemblance. It is dufky above, light beneath, 

 with four tentacuia, or feelers, two of which are placed 

 as ufual in other aquatic linmces ; thefe are light-colour- 

 ed, fetaceous ; on the right fide of the head behind, is 

 a third flender feeler, not quite fo long as the others, 

 and clofe to it, more in the middle of the hind head, is 

 a crert, or plumofe appendage, very pellucid, and ex- 

 quifitely fenfible, retracing inflantaneouflv at the leaft 

 motion : eyes two, placed at the bafe of the two ante- 

 rior t.pntacula : fore part of the body bilobated, makinp- 

 the head to appear as if ifTuing from a Oieath, when 

 viewed underneath. 



MULLEE. 



