NASSA. 



sharp, sometimes terminated by a strong point, and often 

 a little rugose. Canal extremely short, not projecting 

 beyond the shell, but turned backwards. Operculum 

 horny. 



The shells of this Genus are commonly tuberculated, 

 grooved, striated, or granulated, outside; but they are 

 sometimes nearly smooth and polished. Several of them, 

 on account of the thickened and expanded lip, have a very^ 

 singular appearance, such are the N. Ther sites and gih- 

 hosuta. There are a great number of species of this 

 Genus, several of which are common on our shores; par- 

 ticularly the N. reticulata (Buccinum reticulatum. Linn.) 

 N, Macula, (Buccinum macula. Linn.) &c.: these are 

 found alive in the sand feeding upon the common Mactrae, 

 which they pierce by means of a peculiar proboscis, mak- 

 ing an extremely regular round hole. 



Few fossil species are known, they occur however, 

 in the London clay and contemporaneous beds in France, 

 Italy, &c.; also in the crag, and in some of the beds of 

 green sand. 



We think this Genus more nearly related to Cassis 

 than to the true Lamarckian Buccina; in its thickened 

 and spread lip, and its sharp edged Columella, it differs 

 materially from Buccinum, and accords with Cassis. 



A very singular little shell, called Buccinum neri- 

 teum belongs to this Genus, although it has been elevated 

 to the rank of a distinct Genus, under the name of Cy- 

 clops, by De Montfort. 



We have figured 



1. Nassa Arcularia. 



2. Thersltes. 



3. 'Neritea. 



