70 



Plagiola elegans Lea. 



Savanna, Carroll Co. (Baker) : Cook Co. (Baker, Calkins, Jen- 

 sen) ; Chicago; Northern Illinois (Calkins); Kankakee River 

 (Ferriss) ; Meredosia, Morgan Co. (Gault) ; Illinois River 

 (Handwerk, Kelly, Strode) ; Mississippi River, Quincy, Adams 

 Co. (Hart); Kaskaskia, Wabash, Little Wabash, Big Muddy, 

 and Ohio rivers (Hinkley) ; La Salle Co. (Huett) ; Mercer Co., 

 Mississippi River (Marsh) ; Athens, Menard Co. ; Quincy, Ad- 

 ams Co. (Nason) ; Spoon River (Strode) ; Southern Illinois 

 (Ulffers); Fulton Co. (Wolf); Havana. Mason Co.; Saline Co. 

 (State Laboratory). 



Plagiola donacifonn'ts Lea {^zigzag Lea). 



Cook Co. (Baker, Calkins) ; Northern Illinois (Calkins) ; Illi- 

 nois River (('alkins, Handwerk, Kelly, Strode) ; Kankakee Riv- 

 er; Spring Creek (Ferriss, Handwerk); Quincy, Adams Co. 

 (Hart) ; Little Wabash, Kaskaskia, and Wabash rivers (Hink- 

 ley) ; La Salle Co. (Huett); Mercer Co., Mississippi River 

 (Marsh); Athens, Menard Co. (Nason); Spoon River (Strode); 

 Southern Illinois (Ulffers); Fulton Co. (Wolf); Havana, Mason 

 Co. (State Laboratory). 



DIGENiE. 



Genus Tritogonia Agassiz. 



Tritogonia tuherculata Barnes. 



Oregon, Ogle Co. (Baker); Northern Illinois (Calkins); Illi- 

 nois River (Calkins, Handwerk) ; Fox River, Dundee, Kane Co. 

 (Engleholm); Kankakee River (Ferriss); Shawneetown, Galla- 

 tin Co. (Fischer) ; Meredosia, Morgan Co. (Gault) ; Illinois River 

 (Handwerk) ; Mississippi River, Quincy, Adams Co. (Hart) ; 

 all rivers visited (Hinkley) ; La Salle Co. (Huett) ; Mercer Co., 

 Mississippi River (Marsh); Athens, Menard Co. ; Quincy, Ad- 

 ams Co. (Nason) ; Spoon River (Strode) ; Southern Illinois 

 (Ulffers); Fulton Co. (Wolf); Havana, Mason Co. ; Saline Co. 

 (State Laboratory).* 



*Calkins (Cin. Quart. Jour. Sci., I., ]i. 244) cites ttiis species from t!hicago, but 

 no specimens have been seen. It is therefore a very doubtful inhabitant of the Chi- 

 cago Area. 



