CONTENTS. 



Preface 



Systematic index 

 Suborder Limnophila 

 Auriculidse 



Auriculinse . 

 Auricula 

 Alexia . 

 Carychium 

 Melampiuse 

 Melampus 

 Tralia . 

 Leuconia 

 Pedipes 

 Blauneria 

 Otinidse 

 Limnseidse . 



Limnseinse . 

 Limnsea 

 Physella 

 Pompholyx 

 Carinifex 

 Physa . 

 Bulinus 

 Planorbinse . 

 Planorbis 

 Segmentina 

 Ancylinffi 

 Ancylus 

 Acroloxus 

 Gundlachia 

 Suborder Thalassophila 

 Siplionariidse 



Sipbonaria 

 Addenda . 

 Index 



HI 



vii 



1 



1 



3 



3 



4 



6 



9 



9 

 16 

 18 

 19 

 20 

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 22 

 24 

 24 

 73 

 73 



74 



75 



97 

 103 

 103 

 136 

 138 

 138 

 147 

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 155 

 157 



( V) 



