CONTENTS. 



PI..I: 



Corrigenda et Addenda viii 



SYNOPSIS OF THE FAMILY UNIONIDJE ix 



Division of the Family Uuionidae xxvi 



Genus Margaron 25 



Subgenus Triquetra 25 



Subgenus Prisodon 27 



Submenus Unio xiii., 28 



Subgenus Margaritana 67 



Subgenus Plagiodon 71 



Subgenus Monocondyloea ~2 



Subgenus Dipsas ............... 74 



Subgenus Anodonta . 75 



Subgenus Columba 86 



Subgenus Byssanodonta ............. 87 



Genus Platiris 88 



Subgenus Iridina .............. 



Subgenus Spatha - 89 



Subgenus Mycetopus 90 



GEOGRAPHICAL DISTRIBUTION OP THE SPECIES OP THE FAMILY UNIONISE 93 



Genus Margaron 93 



Subgenus Triquetra 



Subgenus Prisodon 



Subgeuus Unio 



Subgenus Margaritana ....... . ... 



Subgenus Plagiodon 104 



Subgenus Monocondyloea 



Subgenus Dipsas 



Subgenus Anodonta 



Subgenus Columba ...... 



Subgenus Byssanodonta . . . 



Genus Platiris 



Subgenus Iridina ........ 



Subgenus Spatha 



Subgenus Mycetopus 



Index of Species 



Alphabetical List of Works referring to the TJnionidie in this volume . 



Chronological Bibliography of the Unionidae 



Appendix 



