229 



Columella within fomewiiat indented. Length five-eighths 

 of an inch; breadth two-eighths. 



This fpecies has fometiines been confounded with the 

 lafl defcribed, but is readily diftinguifiied by its taper, 

 produced fpires ; and by the aperture, which is much 

 fhorter, and more contrafted : is alfo much more gloffy, 

 and of a darker colour. It is a more local fhell ; we have 

 found it tolerably plentiful in a watery ditch near Exetef ; 

 and in Wiltjliire of an extraordinary fize, meafaring nearly 

 three-quarters of an inch. In a pond, fubjeft to be over- 

 flowed by the Avon\\\ that county, we have feen great abun- 

 dance ; and in the fame field were plenty of the B.fontina- 

 lis, and yet they had never communicated with each other, 

 for in neither place were they to be found together. This 

 is Petiver's Buccinulum Jluviatile heterojirophon, who 

 fays, it is found in fome ponds and ditches about London. 

 We have received it from Kent. 



Da Costa was unacquainted with this fliell, but erro- 

 neoufly quoted it for his Turbo adverfus ; the Bulla fon- 

 tinalis of Linn^us; as is evident by his defcription and 

 figure. 



This and the preceding are two of the few known fpe- 

 cies which are hetcrojtmphe fliells, or turn from right to 

 left, from the apex to the aperture; that is, the fpires re- 

 prefent a left-handed fcrew, turning contrary to the fun's 

 apparent motion. 



Both 



