Key to PA Crayfishes

3a    Base of immovable finger of chela with conspicuous tuft of setae and base of dactyl with deep notch (fig A); suborbital angle obsolete (not angular) and cervical groove usually interrupted (fig B) - Fallicambarus fodiens (This species is not yet reported in PA.  It might appear in the extreme northwestern and extreme southeastern corners of PA since it is found in Ohio, West Virginia, and Maryland.  Prefers seasonally flooded plains and swampy areas.  Mud chimneys present near opening to tunnel.)

3b    Base of immovable finger of chela without conspicuous tuft of setae and base of dactyl without deep notch (A in fig); suborbital angle acute (angular) and cervical groove usually continuous (B in fig) --> go to couplet 4.