PLATE CXLVII. 



Europe : in England it is very common in some places. The animal, 

 as Gmelin describes it, has two truncated and concealed tentacula, 

 each of which is furnished with an eye at the inner angle. 



Dr. Lister informs us, that they couple in September, and fix their 

 spawn plentifully on stones and other bodies in the water : this spawn 

 consists of little gelatinous globules, in each of which it is said many 

 small shells may be distinguished. — The shell is shewn of the natural 

 size in the annexed plate. 



