286 ORTMANN — DISTRIBUTION OF DECAPODS [Aprils, 



Subgenus Potamobius — twelve species : 



European group : 

 i. pallipes (Lereb.). South and West Europe: Central Spain, 

 France, England, Ireland, Southwest Germany, Italy south- 

 ward to Naples, Dalmatia, Greece. 



2. torrentium (Schrk.). Central Europe: Switzerland, South Ger" 



many, Bohemia. 



3. astacus (L.). West Russia (northward to Finland), Austria, 

 Germany, Denmark, South Sweden and Norway (possibly in- 

 troduced), France, southward to Northern Italy. 



4. leptodactylus (Eschz.). Ponto-Caspian basin : Hungary (Danube, 



Theiss), South and Central Russia, northward to the White 

 Sea ; in Siberia in the region of the Caspian Sea. Further, in 

 West Siberia in the basin of the rivers Obi and Irtish, intro- 

 duced, as reported, but possibly indigenous (see Faxon, 1885, 



P- 150- 



5. pachypus (Rthk.). Estuaries of the Black and Caspian Seas. 



6. colchicus (Kessl.). Transcaucasia (upper Rion river). 



7. kessleri (Schimk.). Turkestan (Sir Darja). 



American group : 



8. leniusculus (Dan.). Washington, Oregon (lower Columbia 

 river), California (San Francisco). 



9. trowbridgei (Stps.). Washington, Oregon (lower Columbia 

 river). 



10. nigrescens (Stps.). California (San Francisco), Washington, 

 Alaska (Unalaska). 



11. klamathensis (Stps.). British Columbia (east of Cascade Moun- 

 tains), Idaho, Washington, Oregon, Northern California 

 (mountain rivers). 



12. gambeli (Gir.). In the Rocky Mountains : on the Pacific slope 



in Utah, Idaho, Wyoming and Yellowstone Park ; on the At- 

 lantic slope; mouth of Yellowstone river (eastern State line of 

 Montana). 



Subgenus Cambaroides — four species : 

 i.^schrenki (Kessl.). Lower river Amur. 



2. dauricus (Pall.). ■ Upper river Amur. 



3. japonicus (Haan). North Japan : Yesso. 



4. similis (Koelb.). Korea. 



