Note 30 — Chapter VI · THE DISTRIBUTION AND THE ÆTIOLOGY OF THE CRAYFISHES.
Reading edition
Dr. Hagen in his “Monograph of the North American Astacidæ,” enumerates six species; A. Gambelii, A. klamathensis, A. leenisculus, A. nigrescens, A. oreganus, and A. Trowbridgii.