﻿U. 
  S. 
  NATIONAL 
  MUSEUM 
  

  

  PROCEEDINGS, 
  VOL. 
  XX 
  PL. 
  LXV 
  

  

  Crayfishes. 
  

  

  Figs. 
  1-4. 
  Cambarns 
  dtfflcilis. 
  Figs. 
  5-9. 
  Cambarus 
  ineeki. 
  

  

  For 
  explanation 
  of 
  plate 
  see 
  page 
  693. 
  

  

  