PLATE CXXXIII. 



pears to be slightly incurvated, whilst Pennant's shell is perfectly 

 straight ; a difference, perhaps, sufficient to constitute two distinct 

 species. Martini figures a kind of Sabella, which he considers as 

 the S. granulata of Linnaeus, and in that figure the curvature at the 

 narrowest end is very apparent : with Martini we consider that as 

 the true Sabella granulata of Linnaeus, and not having observed the 

 same character in any of those shells that have occurred to notice on 

 our own coasts, have thought it most adviseable to retain the name 

 Mr. Pennant had previously given it. 



Gmelin seems to be under some doubts respecting this shell, for 

 he entirely omits the Linnaean granulata among the species of this 

 genus. — Sabella Belgica of Gmelin, which some have conjectured 

 to be the S. tubiformis of Pennant, is undoubtedly different, ac- 

 cording to Kit in and Martini. 



Our shell is of an elegant form and remarkably delicate : it con- 

 sists of two coatings, the inner one of which is composed entirely 

 of grains of sand, and the outer one of sand intermixed with little 

 fragments of shells. This kind is local : it is supposed to inhabit 

 deep waters only, and is sometimes found upon the shore after a 

 high sea. 



