staircasesheir'of the English collectors, and Scalata of the 

 French, belonging to the subdivision of this genus, which 

 is distinguished by having the volutions separated, or only 

 touching each other by the projecting ribs. This shell 

 was very highly valued, and Leach mentions a specimen 

 "which was purchased at a sale for twenty pounds ; but it 

 is now (1815) estimated as worth more than double that 

 sum." Cubieres says that in his time, a fine specimen of 

 four French inches long by three inches at base, was worth 

 six thousand livres. To the same division of the genus, it 

 is said, about twelve species are now referred. 



Blainville, after Plancus and MuUer, describes the ani- 

 mal to be spiral, with a short oval foot inserted under the 

 neck ; two tentacula, with a filiform termination, support- 

 ing the eyes at the extremity of the inflated part ; a pro- 

 boscis ? ; a long canal at the anterior right margin of the 

 respiratory cavity ; sexes separate. 



They are all inhabitants of the sea. Lamarck has cha- 

 racterized seven recent and five fossil species ; but De- 

 france enumerates twelve fossil species. 



PLATE XXVII. 



SCALARIA CLATHRUS. 



SYNONYMS. 



Turbo clathrus. Linn. Gmel S^e. 

 ScALARiA COMMUNIS. Lam. 



ScALARIA CLATHRUS. Suct. 



