62 Unite r si ly of Michigan 



PLATE I 



EUiptio and Actinonaias. Young and depauperate specimens. 



Figures i and 2. A. walkeri. Young specimens. 



Figure 3. E. plexus distinctus; juvenile. 



Figures 4 and 5. E. plexus; depauperate race. 



Figures 6 and 7. E. liebmanni cnatotolapamensis; young. 



