75 



(Marsh) ; Fox River, Algonquin, McHenry Co; Athens, Menard 

 Co. (Nason); Southern Illinois (Ulffers) ; Fulton Co. (Wolf); 

 Havana, Mason Co. (State Laboratory). 



Subgenus Pterosygna Rafinesque, 

 Symphynota complanata Barnes. 



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

 sen); Northern Illinois (Calkins); Peoria, Peoria Go. (Cham- 

 berlain) ; Mazon Creek, Grundy Co. (Dilg) ; Hickory Creek, 

 Will Co. (Ferriss, Handwerk) ; Starved Rock, La Salle Co. 

 Illinois River (Handwerk); Kappa, Woodford Co. (Hart) ; Mis- 

 sissippi River, Quincy, Adams Co. (Hart, Nason) ; Winnebago 

 Co. ; Kaskaskia, Big Muddy, and LittleWabash rivers (Hinkley) ; 

 Spoon River; Illinois River (Kelly, Strode) ; Mercer Co., Missis- 

 sippi River (Marsh); Athens, Menard Co. (Nason); Southern 

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

 (State Laboratory). 



Genus Alasmidonta Say. 



Subgenus Pressodonta Simpson.* 



Alasmidonta calceola Lea (= deltoidea Lea). 



Cook Co. (Baker, Jensen, Lyon) ; Northern Illinois (Calkins) ; 

 Hickory Creek, Joliet, Will Co. (Ferriss, Handwerk) ; Mack- 

 inaw River, Kappa, Woodford Co. (Hart) ; Kishwaukee River 

 and Kent's Creek (Hinkley) ; La Salle Co. (Huett) ; Mercer Co., 

 Edwards Creek, Wabash River (Marsh) ; Algonquin, McHenry 

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

 ton Co. (Wolf). 



Subgenus Rugifera Simpson. 



Alasmidonta marginata Say. 



Cook Co. (Baker, Higley ) ; Northern Illinois; Fox River 

 (Calkins); Hickory Creek, Will Co. (Ferriss, Handwerk) ; Illi- 

 nois River (Handwerk); Mackinaw River, Kappa, Woodford 

 Co. (Hart); Winnebago Co. (Hinkley) ; Mercer Co., Mississippi 

 River (Marsh) ; Athens, Menard Co. (Nason) ; Fox River, Dun- 

 dee, Kane Co. (Nason, Swick) ; Spoon River (Strode); Ful- 

 ton Co. (Wolf) ; Havana, Mason Co. (State Laboratory). 



*Alasmidanta heterodan Lea is reported from Southern Illinois by Ulffers. As this 

 species is confined to the Atlantic states from Maine to Virginia, this reference 

 must rest upon a misidentification. 



