TURBO. 



Lamarck does not once mention this thick testaceous 

 operculum, although it is characteristic of his first thirteen 

 species of Turbo as well as of some others : it is also 

 peculiar to some of Lamarck's Trochi, which we conse- 

 quently withdraw from Trochus and unite to Turbo, 

 Another circumstance relating to the operculum is also 

 worthy of notice, it is that the spiral line of the thick 

 shelly operculum of Turbo is on the side by which it is 

 fixed to the foot of the animal, whereas that of the thin 

 horny operculum of Trochus is external. The outer surface 

 of these shelly opercula is very differently constructed in 

 in the various species, and would be quite sufficient as a 

 character by which the species might be distinguished. 



The Turbines are marine, and for the most part 

 belong to tropical climates, one species alone abounding 

 on the shores of the Mediterranean. We have not any 

 one on our own coasts. They are mostly handsome shells, 

 and when deprived of the outer coat and polished the 

 pearly substance of which they are formed is particularly 

 brilliant. The Turbo marmoratusis remarkably splendid. 



Few indeed are the known fossil species of this Genus, 

 and such as we are acquainted with belong to the forma- 

 tions of the latest period ; we have one from Sicily very 

 similar to the Turbo rugosus; another from New South 

 Wales nearly approaching in its characters to T. torquatus 

 and we have some fossil opercula from the vale of Ronca. 



Fig. 1. Turbo brevispinosus, with its operculum. 

 2. 3. 4. and 5. Various opercula. 



6. Turbo setosus. 



7. ■ n. sp. from Valparaiso. 



8. coronatus var. 



9. n. sp. whose locality is unknown to us. 



