104 



Cincinnati Society of Natural History. 



80. Anodonta pavonia, Lea. 



Like No. 77, but shell thinner. 



81. Anodonta salmonia, Lea. 



Like No. 80, but nacre salmon color. 



82. Anodonta wardiana, Lea. 



Like No. 78, but not so cylindrical. 



Family Corbiculid.*;. 



83. Pisidium abditum, Hald. 



L. y&, H. }&. Small and very oblique. 



84. Sphaerium occidentale, Prime. 



L. 5-16, H.^. Globose, redish brown, edge white, surface 

 glassy. 



85. Sphaerium partumeium, Say. 



Like No. 84, thin, frail and more compressed. 



86. Sphaerium rhomboideum, Say. 



Like No. 85, but more rhombic. 



87. Sphaerium simile, Say. 



Not quite as rhomboidal as No. 86. 



88. Sphaerium solidulum, Prime. 



More ventricose and shell thicker than No. 89. 



89. Sphaerium stamineum, Conr. 



Sub-triangular, lines of growth well developed. 



90. Sphaerium striatinum, Lea. 



Quite common, dark brown, parallel ridges on beaks. 



91. Sphaerium transversum, Lam. 



Like No. 85, but longer. 



Abbreviations, Stgns, Etc. 



H.— Height. 

 W.— Width. 

 L. — Length. 



Figures following any of the above represent inches or fractions 

 thereof. 



Figure following the names are the numbers of species which are 

 very similar. 



