U. S. NATIONAL MUSEUM 



PROCEEDINGS, VOL. XX PL. LXVI 



Crayfishes. 



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



Fig. 3. Cambarus montezumce areolatus. 



For explanation of plate see page 693. 



