GEOGRAPHICAL DISTRIBUTION. 101 



33. C. cornutus. 



Kentucky : Green River, near Mammoth Cave. 



34. C. hamulatus. 



Tennessee : Nickajack Cave. 



Group IV. 



35. C. medius. 



Missouri : Irondale, Washington Co. 



36. C. immunis. 



New York. 



Indiana: White River; Fall Creek, Indianapolis; Long Lake, Kendall ville. 

 Illinois : Aux Plains ; Belleville ; Lawn Ridge ; Normal ; Oquawka. 

 Michigan : Detroit River, Detroit. 

 Wisconsin : Milwaukee. 

 Minnesota: Richfield, Hennepin Co. 

 Iowa : West Liberty. 

 Missouri : St. Louis. 

 Kansas : Leavenworth ; Ellis. 

 Wyoming : near Laramie. 

 Alabama : Huntsville. 

 Mexico : Orizaba. 

 VaR. spiuirostris. 



Tennessee : Obion Co. 



37. C. Mississippiensis. 



Mississippi : Macon. 



38. C. Palmeri. 



Tennessee : Obion Co. 



39. C. Alabamensis. 



Alabama: Waterloo, Lauderdale Co. 



40. C. compressus. 



Alabama : Lauderdale Co. 



41. C. lancifer. 



Mississippi: Root Pond. 



42. C. affinis. 



New York : Niagara. 



New Jersey: Schooley's Mountain and Dover, Morris Co.; Red Bank, Monmouth 

 Co.; Trenton, Mercer Co.; Camden Co. 



Pennsylvania: Brandywine Creek ; Schuylkill; Reading; Philadelphia; Bristol; 

 Susquehanna River ; Bainhridge; Carlisle. 



Maryland: Cecil Co. ; Harford Co. ; Havre de Grace ; Baltimore Co.; Anne Arun- 

 del Co. ; Montgomery Co. ; Potomac River, Charles Co.; Williamsport, Wash- 

 ington Co.; Cumberland, Alleghany Co. 



District nf ( 'iihimbia : Potomac River, Washington. 



Virginia : Potomac River, Gunston, Fairfax Co. 



? Lake Erie. 



? Lake Superior. 



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