40 POST-TERTIARY ENTOMOSTRACA. 



In the section on the north, tlie shell-bearing sandy clay was originally twelve or 

 fourteen feet. 



In both beds the deposit of shell-bearing clay appears very circumscribed. It 

 could not be traced for more than twenty yards along the watercourse ; and from the 

 point where the shells are exposed, the overlying gravel deepens on both sides east and 

 west. 



There can be no doubt, however, that many similar patches of fossiliffirous sands 

 and clays exist beneath the surface at different points through the whole district 

 where circumstances have permitted their preservation, and will from time to time be 

 discovered. 



Although the fauna of the two beds described is of precisely the same general 

 character, there are local differences in the species found equivalent to those which 

 occur in neighbouring parts of the same sea bottom at the present day. Tellina 

 calcarea and Trophon clathratum, var. Gunneri, e.g., are more common in the south than 

 in the north, but T. truncatum and Lacuna divaricata, with spines of Echini, are 

 much rarer. 



Height above the sea thirty-eight feet. 



The following Ostracoda were found : 



Potamocypris fulva, Brady. 

 ArgillcBcia cylindrica, G. 0. Sars. 

 Cy there castanea, G. O. Sars, 



— pellucida, Baird. 



— porcellanea, Brady. 



— viridis, Miiller. 



— lutea, Miiller. 



— villosa (G. O. Sars). 



— concinna, Jones. 



— angulata (G. O. Sars). 



— tuber culata (G. 0. Sars). 



— Dunelmensis (Norman). 

 Cytheridea punctillata, Brady. 

 Eucy there Argus (G. O. Sars). 

 Loxoconcha tamarindus (Jones). 

 Cy therm a nigrescens (Baird). 



— similis, G. O. Sars. 



— pumila, n. sp. 



— undata, G. O. Sars. 



