Rediscription and Circumscription of the Acuminate Crayfish, Cambarus acuminatus Faxon, 1884

Cambarus acuminatus was described by Walter Faxon in 1884 from three specimens collected in the Saluda River in northwestern South Carolina, USA; a form II male and two females. The types have since disappeared or deteriorated so as to be taxonomically useless. Cambarus acuminatus sensu lato has been acknowledged to comprise a species complex known as Cambarus sp. C. This complex ranges across much of the Piedmont Plateau and Coastal Plain from central South Carolina to Maryland and southeastern Pennsylvania. Because C. acuminatus lacks taxonomically useful type material and a detailed description, taxonomic reassessment and revision of this species complex has been problematic. For these reasons, we redescribed C. acuminatus based on modern standards for astacoidean crayfishes and provide a revised circumscription of the species. This lays the groundwork necessary for future taxonomic and phylogenetic work involving the C. sp. C complex.