CONTENTS. 



PAGE 



Corrigenda et Adrlenda viii 



Synopsis of the Family TJnionid^ ix 



Division of the Family Union idte xxvi 



Genus Margaron' ............... 25 



Subgenus Triquetra 25 



Subgenus Prisodon . 27 



Subgenus Unio .............. xiii., 28 



Subgenus Margaritana 67 



Subgenus Plagiodon 71 



Subgenus Monocondylcea ............. 72 



Subgenus Dipsas 74 



Subgenus Anodonta 75 



Subgenus Columba 80 



Subgenus Byssanodonta 87 



Genus Platiris 88 



Subgenus Iridina .............. 88 



Subgenus Spatha . 89 



Subgenus Mycetopus 90 



Geographical Distribution of the Species of the Family IJnionid^ 93 



Genus Margaron 93 



Subgenus Triquetra 93 



Subgenus Prisodon 93 



Subgenus Unio . 93 



Subgenus Margaritana 103 



Subgenus Plagiodon 101 



Subgenus Monocondylcea 104 



Subgenus Dipsas 104 



Subgenus Anodonta 104 



Subgenus Columba .............. 107 



Subgenus Bj^ssauodonta 107 



Genus Platiris 108 



Subgenus Iridina . 108 



Subgenus Spatha 108 



Subgenus Mycetopus 108 



Index of Species 109 



Alphabetical List of Works referring to the Unionidae in this volume . . . . . . 149 



Chronological Bibliography of the Unionidse ........... 157 



Appendix 183 



