63 



the superior part of this wing forms, at its union with the spire, a lon- 

 gitudinal channel-like fissure. 



o 



A fragment of a fossil shell which I possess, which from its surface 

 appears to be from France, resembles the spire, with part of the fissure, 

 of Rostellaria subulata, Lam.; S 'trombus fusus, Linn. The rriost common 

 fossil shell of this genus is, Rostellaria fissurclla, Lam. ; Strombus fissurella, 

 Linn. It is very abundant at Grignon. The wing is but small ; it 

 however is continued in a channeled ridge, over nearly the whole length 

 of the spire. 



Under this genus may be placed Strombus pes pclicani, Linn. Of these 

 I possess some from Mr. Strange's collection, apparently French fossiis, 

 in a very good state of preservation, and which do not appear to differ 

 materially from the recent shells. 



In the Essex cliff, 1 once met with a shell of this family, but which 

 differs from the preceding in having only one spur-like process passing 

 out of the alated side. My worthy friend Mr. Francis Crow, of Faver- 

 sham, has, since that, presented me with a similar, but more perfect 

 shell, in a silicious state, which he found near that town. This shell has 

 been also found in the Devonshire whetstone-pits, in the same silicious 

 state ; and it is remarkable that, both in Devonshire and at Faversham, 

 these shells are accompanied by a bivalve, Cucullaa decussata, a shell 

 which, I believe, has not yet been found in any other part of this island ; 

 but which is found in both these places, in the same silicious state. A 

 representation of the Devonshire silicious rostellarite, imbedded in its 

 matrix, is given Plate V. Fig. 1 1 . 



Among the very interesting fossils of the whetstone-pits is the minute 

 shell, now entirely flint, represented Plate V. Fig. 2. This shell not 

 only differs from the R. pes pelicani, in its having only one spur-like pro- 

 cess; but seems to differ from the preceding species, both in the length 

 of its spire and of its spur. The number of turns in its spire shows that 

 it is not a young shell of the preceding species, but that it is rather a 

 perfect shell of, a distinct species. 



