A new cave crayfish of the genus Orconectes, subgenus Orconectes, from southcentral Missouri, USA, with a key to the stygobitic species of the genus (Decapoda, Cambaridae)

The cave-adapted crayfish, Orconectes (Orconectes) stygocaneyi sp. nov., is described from Mud Cave, Ozark County in south central Missouri, U.S.A. Or conectes stygocaneyi is the first stygobitic crayfish of the genus to be fo und west of the Mississippi River and is compared with other, related speci es of cave crayfishes. It is unique in that the mesial process of first ple opods of Form I males recurves cephalically toward the central projection. Figures are presented and a key to the stygobitic members of the genus Orco nectes is provided.