ERRATA. 



Page 509, line 21, for varicosa read cicatricosa. 



Page 516, before Heterogenje insert Exobranchi?e. 



Page 548, line 36, Unio striatus Sowerby should be preceded by a mark of 



interrogation. 

 Page 559, line 6 from the bottom, /or L. prevostianus read U. prevostianus. 

 Page 591, line ^,for Lampsilis read Medionidus. 

 Page 648, omit 8th and 9th. lines from the bottom. 

 Page 719, Unio striatulus Lea and U. amabilis Lea should be placed in the Argenteus 



group of Pleurobema. 

 Page 760, last line, for bigbyana read bigbyensis. 

 Page 766, line 6 from bottom, for multiplicata read heros. 

 Page 802, omit line 8. 



Page 806, line 19, /or gequitoria read gequatoria. 

 Page 823, lines 10 and 11, /or sequitoria read sequatoria. 

 Page 825, omit lines 8 and 9. 

 Page 851, line 27, for incertus read murinus. 

 Page 862, omit line 31. 

 Page 894, omit line 28. 



Page 906, 13th and following lines, /or Chelidoneura r(;ad Chelidonura. 

 Page 933, omit lines 16 and 17. 



