INDEX. 



Family LittorinidsB . 

 Genus Littorina 

 Sub-Genus Tectus 



Echinella . 

 Genus Limnotrochus . 



Plesiotrochus . 

 Sub-Family Fossarinaa 

 Genus Kisella . 

 Sub-Genus Feasiella . 

 Genus Phaneta . 



k Fossar 



Sub-Genus Couthouyia 

 Genus Conradia 

 Sub-Genus Gottoina . 

 Genus Raulinia . 



Cithna . 



Isapis 



Fossarina . 

 Sub-Family Lacuninse 

 Genus Cremnoconchus 



Stenotis . 



Lacuna . 



Modulus . 

 Family PlanaxidaB 

 Sub-Family Litiopinse 

 Genus Litiopa . 



Styliferina 



Diala . 



Alaba 



Planaxis . 



Quoyia . 



Holcostoma 

 Family Melaniidse 

 Sub-Family Ceriphasinaa 

 Genus lo . . 



Pleurocera 

 Sub-Genus Strephobasis 

 Genus Goniobasis 

 Sub-Genus Schizostoma 



