CRAYFISH FROM ALABAMA CAVES — HOBBS 



11 



Figures 13-20— First pleopods of first form males: 13, generalized Procambarus (see 

 Hobbs, 1962, p. 275); 14, hypothetical ancestor of stocks and species indicated; 15, 

 hypothetical ancestor of the barbatus and gracilis sections of Procambarus; 16, hypo- 

 thetical ancestor of the Mexicanus Section of Procambarus; 17, Procambarus alleni (Faxon); 

 18, Procambarus pecki; 19, hypothetical ancestor of Orconcctes and Faxonella; 20, hypo- 

 thetical ancestor of Cambarus. 



