﻿U. 
  S. 
  NATIONAL 
  MUSEUM 
  

  

  PROCEEDINGS, 
  VOL. 
  XX 
  PL. 
  LXVI 
  

  

  Crayfishes. 
  

  

  Fig. 
  1. 
  Cambarus 
  montezumce 
  dugesii. 
  Figs. 
  3. 
  4. 
  Carnbarus 
  montezumce 
  occidentalis. 
  

  

  Fig. 
  2. 
  Cambarus 
  montezumce 
  areolatus. 
  

  

  For 
  explanation 
  of 
  plate 
  see 
  page 
  693. 
  

  

  