chap. it. Extinct Land Shells. 101 



solidated form, during which time, these terrestrial 

 productions were embedded. Mr. G. R. Sowerby has 

 kindly examined three species of land-shells, which I 

 procured from this bed, and his descriptions are given 

 in the Appendix. One of them is a Succinea, identical 

 with a species now living abundantly on the island : 

 the two others, namely, Gochlocjena fossilis and Helix 

 biplicata, are not known in a recent state : the latter 

 species was also found in another and different locality, 

 associated with a species of Cochlogena which is un- 

 doubtedly extinct. 



Beds of extinct land-shells. — Land-shells, all of 

 which appear to be species now extinct, occur embedded 

 in earth, in several parts of the island. The greater 

 number have been found at a considerable height on 

 Flagstaff Hill. On the NW. side of this hill, a rain- 

 channel exposes a section of about twenty feet in thick- 

 ness, of which the upper part consists of black vegetable 

 mould, evidently washed down from the heights above, 

 and the lower part of less black earth, abounding with 

 young and old shells, and with their fragments : part 

 of this earth is slightly consolidated by calcareous 

 matter, apparently due to the partial decomposition of 

 some of the shells. Mr. Seale, an intelligent resident, 

 who first called attention to these shells, gave me a 

 large collection from another locality, where the shells 

 appear to have been embedded in very black earth. 

 Mr. G. R. Sowerby has examined these shells, and has 

 described them in the Appendix. There are seven 

 species, namely, one Cochlogena, two species of the 

 genus Cochlicopa, and four of Helix : none of these are 

 known in a recent state, or have been found in any 

 other country. The smaller species were picked out of 

 the inside of the large shells of the Cochlogena anris- 

 vulpina. This last-mentioned species is in many 



