STRATA OF THE HAMPSHIRE BASIX. 



161 



a Psammobia sestuarina, Edw. MS. 

 a, X rudis, Lam. (P. solida, Sow.). 



X Tellina ambigua, Sow. 



reflexa, Edw. 



a, X Mya angustata, Sow. 



a producta, Edw. MS. 



a Corbida nitida, Sow. 



a cuspidata, Sow. 



a, X pisum, Sow. 



fortisulcata, Edw. MS. 



a, X Panopeea subeffusa, Edw. MS. 



The comparison of the terrestrial and freshwater Mollusca of these 

 two groups with one another, and with the forms contained in strata 

 of equivalent age upon the Continent, is now greatly facilitated by 

 the publication of Prof. Sandberger's " Land- und Siisswasser-Con- 

 chylien der Yorwelt."' The conclusions to which we are led are in 

 perfect agreement with those which result from the study of the 

 marine faunas. About 120 forms of freshwater and terrestrial 

 Mollusca have been described as occurring in these strata. Of these 

 more than one half are peculiar to the Headon beds, about one 

 quarter are peculiar to the Bembridge, while the remainder are 

 common to the two groups of strata. The distribution of these 

 forms is illustrated in the following Table : — 



Freskwater and Terrestrial Mollusca of the OUgocene of the Isle of 



Wight. 





Bem- 

 bridge 

 group. 



Headon 

 group. 



Hehx globosa, Sow 





45- 



- Morrisii, Edw 



^ 



tropifera, Edw 





Fruticola (Hehx) vectensis, Edw 



Hyahna (Hehx) d'Urbani, Edw 



Nanina (Hehx) occhisa Edw . .... 



^ 



Patula (Hehx) omphalus, Edw 



^ 



Strobilus (Hehx) sublabyrinthicus, Edw 



(Hehx) pseudolabyrinthicus, Sandb. (= H. labyrin- 

 th ica, >S V. Wood, non Say) 



Gastrodonta (Helix) headonensis, £'(^w 



BuHmus conTexup Edw. . . 



^ 







* 1 



Amphidroraus (Bulimus) elhpticus, Sow 



Nystia (Bulimus) polita, Edw 



* i 



... i * 



(Bulimus?) vectiensis, Edw 



* ! 



1 * 



Pupa oryza, Edw 





Torquilla (Pupa) perdentata, Edw 



Clausiha striatula, Edw 







Callia ? (Pupina ?) Levis, Edw 



* 





Oyclotus cinctus Edw. . 





1 







1 



