TO GEOLOGY. 171 



slightly canaliculate above ; mouth subovate, rather nar- 

 row ; columella with four folds, curved ; outer lip sharp. 



Length Breadth .5, of an inch. 



Observations. At first view this species might be mis- 

 taken for the above. Its curved columella and more re- 

 flected lip, however, serve readily to distinguish it. The 

 striae on the superior part of the whorls are stronger than 

 on the body. Having but a single specimen, the apex of 

 which is removed, the description is somewhat defective. 



Three species* only of Mitra have been observed in 

 England and those are all from Barton Cliff, London Clay 

 Formation, having been described by Mr Sowerby in his 

 Mineral Conchology. M. Deshayes gives sixty-six species, 

 in his Tables, from the Tertiary. Twenty-four are from the 

 Paris basin alone, and thirteen from the Subappennines. 

 No fossil species have, I believe, been before observed in 

 our Formations. 



GENUS VOLUTA. Linnceus. 



V. DefranciiJ Plate 6. Fig. 179. 

 Description. Shell turbinate, transversely striate, coro- 



* Fleming (British Animals, p. 333,) makes a fourth, by adding the 

 Valuta Lamberti to his list of Mitra. The genus must be considered to 

 be very badly denned, for Mr Conrad places this species among the 

 FasciolaruB, (Journal of the Acad. Nat. Sci. vol. 6, p. 216.) I should 

 certainly agree with Mr Sowerby, and keep it with the Volutes. 



\ Named after the distinguished fossil conchologist M. Defrance. 



