CONTENTS. 
Page 
Introduction . . . . . . . . . . . . 41 
List of species . . . . . . . . . . . . 42 
Systematic Account of the Fauna 
Family Succineidae . . . . . . . . . . . . 42 
Family Limnaeidae . . . . . . . . . . . . 43 
Family Melaniidae . . . . . . . . . . . . 44 
Family Hydrobiidae . . . . . . . . ■ . . . . 45 
Family Viviparidae . . . . . . . . . . . . 46 
Family Valvatidae . . . . . . . . . . . . 47 
Family Unionidae . . . . . . . . . . . . 47 
Family Cyrenidae . . . . ' . . . . . . . . 51 
Geographical Distribution 
Species endemic in the lake . . . . . . . • • 55 
Species endemic in Japan . . . . . . . . • ■ 55 
Species found also on the mainland of Asia . . . . . . -55 
Biological Distribution 
Physical characters of Lake Biwa . . . . . . . . 57 
Zones of life . . . . . . • . . . . . . 59 
Rupicolous forms . . . . . . . . . . . . 60 
Shallow-water forms . . . . . . . . . . . . 61 
Deep-water forms . . . . . . . . . . . . 63 
Deep-water mollusca of European lakes . . . . . . 68 
Deep-water fauna of Lake Baikal . . . . . . . . 69 
Mollusca of the Lake of Tiberias . . . . . . . . 69 
Non-lacustrine species of the Biwa basin . . . . . . 70 
vSummary and conclusions . . . . . . . . . . 71 
Bibliography . . . . . . . . . . . . . . 72 
