PLATE XXI. 



Conchologlsts ; Rapum rostratum of the Colonnian Museum ; and 

 inhabits the seas of Tranquebar. 



As the preceding shell is distinguished by the name of the Long 

 beaked Turnip Shell, in allusion to the elongated structure of the 

 beak, there is another known by the appellation of the High Spired 

 Turnip Shell, in reference to the greater elevation of its spire ; this 

 is a second species of Solander, and is called by him Voluta 

 PoNDEROSA ; in the Calonnian Museum it stood under the name 

 of Rapum productum. This shell inhabits the seas of Madagascar, 

 and is the kind which becomes the more immediate object of our 

 consideration as the subject of our present plate. 



The third kind of Turnip Shell is from the straits of Malacca, 

 a shell more ponderous than the preceding ; of a broader form and 

 having the spire more depressed. This is the common Heavy Turnip 

 Shell of our English Cabinet, Voluta gravis of Solander. 



These distinctions proposed by the late Dr. Solander are found 

 conformable, in a particular degree, with the classification observable 

 iu the cabinet of M. de Colonne. The shells of M. de Colonne, it 

 appears, were thus arranged by the celebrated Conchologist 

 M. Favanne. They have, nevertheless, we believe, passed unnoticed 

 by any of the modern writers upon this subject. The distinctions 

 are certainly obvious, and might probably fully authorize their sepa- 

 ration into species : it must be at least admitted that as varieties of 

 the same species they are strikingly distinct. 



Having so far treated upon the generical distinctions of Voluta 

 Pyrum, and pointed out the differences that exist among its principal 



