CYLINDER SHELLS, POND SNAILS, 



1 Cylindrella Gheisbrechti. 4 



2 Clausilia tridens. 5 



3 Clausilia Ardoniniana, 6 



Megaspira elatior. 

 Cylindrella Agnesiana. 

 Strophia (Crriaii) decuviana. 



MIDAS' EAR AND TOOTH SHELLS 



7 Auricula auris-Mida. 1 1 Limnma stagnalis. 



Planorhis trivohis. 

 Circinaria concava. 

 Phvsn gyrina. 



12 

 13 



Dentalium elephantinum. 

 Dentalium preliosum. 



