71 



but one. This curious fossil I extricated from a calcedonic mass from 



France. 



Among the Veronese fossils which I possess, is one which, though 

 somewhat mutilated about the aperture, bears not only sufficient proofs 

 of its belonging to this genus, but strong marks of its species, C. inter- 

 ruptum. It is of a remarkable size, being nearly four inches long. 



In the stratum of fossil shells running through Plumsted and Wool- 

 wich, and appearing at Bromley, in Kent, shells of this genus are fre- 

 quently found ; but in so brittle and so injured a state, as not often to 

 allow of their species being made out. I have however, I think, discovered 

 C. tuiritellatum, C. denticulatwn, C. serratum, C. davatulatum, C. mutahile, 

 and C. cinctum. 



In the whetstone of Blackdown Hills, Devonshire, a turreted shell 

 exists in considerable numbers ; but it is very difficult to extricate them 

 from the matrix, with their mouth perfect. I think, however, that I 

 am right in considering these as belonging to C. turritellatum. They are 

 completely silicious; and many of them, with their included matrix, 

 are transparent. 



The most extraordinary shell of this genus is, C. giganteum. It is tur- 

 reted, extremely long, and transversely striated: the turns, in their 

 upper part, are tubercular, and the columella has one fold. These 

 enormous shells are generally a foot in length. One of the specimens 

 which I possess, and which has lost at least an inch or two of its length, 

 still measures fourteen inches. They are found at Grignon, and are 

 not very rare : they are however, in general, very much injured, very 

 seldom indeed having the lip and sides of the opening perfect. Their 

 form is that of a winding turriculated pyramid, with in general twenty 

 turns, beset on their upper part with a row of nodular tubercles, and 

 having the general surface lightly and transversely striated. The open- 

 ing is oblong and oblique, and terminates in the lower part in a canal, 

 the extremity of which is moderately recurved ; and the superior part, 



