263 



Lamarck has therefore farther reduced the enormous 

 number of shells called Buccina, and established the 

 genera, Harpa, Dolium, Monoceros, Concholepas, and 

 Eburna, each presenting distinctive and peculiar char- 

 acters, very different from those possessed by the 

 G. Buecinum as it now stands; in which there is still 

 a great variety and diversity of species, though they 

 are nevertheless allied to each other by characteristic 

 assimulation. Shell oval or conical oval, generally 

 small, aperture longitudinal, a notch at the base, no ca- 

 nal, columella not flattened, swelled at the upper part. 

 The exterior variously sculptured ; the marginal lip 

 most frequently thin and sharp, and a cartilaginous 

 operculum. Of one very numerous section of this ge- 

 nus Lamarck had formed his G. Nassa> but he has since 

 reunited them to the Buccina. In it the thickened lip 

 and great callosity of the columella, with the irregu- 

 lar lump or tuberculations on the back of some species, 

 are remarkably characteristic. 



Buecinum undatum Buecinum testudineum 



glaciale achatinum 



Anglicauum glans 



papyraceum papillosum 



annulatum olivaceum 



lyevissimum canaliculatum 



