Ill 



werk); Lilycash Creek, Will Co. (Handwerk) ; Cook Co. ( Hig- 

 ley, Nason); Winnebago Co. (Hinkley) ; Mercer Co. (Marsh); 

 Algonquin, McHenry Co.; Athens, Menard Co. (Nason); Auro- 

 ra, Kane Co. ( Oakes) ; Fulton Co. (Wolf). 



Genus Bifidaria Sterki. 

 Section Bifidaria s.s. 

 Bifidaria corticaria Say. 



Northern Illinois (Calkins) ; La Salle Co. ( Calkins, Huett) ; 

 Sheridan, La Salle Co. (Ferriss); Mt. Carmel, Wabash Co. 

 (Gratacap); Washington Co. (Hinkley); Will Co. (Marsh); 

 Fulton Co. (Wolf). 



Bifidaria procera Gould (= rupicola of authors not of Say). 



Joliet, Will Co.; Du Page Co. (Ferriss): Will Co. (Marsh); 

 Fulton Co. (Wolf). 



Section AlMnula Sterki. 



Bifidaria armifera Say. 



Oregon, Ogle Co. (Baker) ; Cook Co. (Baker, Higley, Jensen) ; 

 Northern Illinois (Calkins); La Salle Co. (Calkins, Huett) ; 

 Peoria Co. (Chamberlain) ; Stark Co. (Chase) ; Joliet, Will Co. ; 

 Utica, La Salle Co. (Ferriss, Handwerk); Winnebago and 

 Washington counties (Hinkley) ; Mercer Co. (Marsh); Elgin, 

 Kane Co.; Algonquin, McHenry Co.; Athens, Menard Co. 

 (Nason) ; Fulton Co. (Wolf) ; Illinois River, Havana, Mason Co. 

 (State Laboratory). 



Bifidaria contraeta Say. 



Oregon, Ogle Co. (Baker); Cook Co. (Baker, Jensen); La 

 Salle Co. (Calkins); Stark Co. (Chase) ; Joliet, Will Co. (Fer- 

 riss, Handwerk); Mt. Carmel, Wabash Co. (Gratacap); Wash- 

 ington Co. (Hinkley); Mercer Co. (Marsh); Elgin, Kane Co. ; 

 Algonquin, McHenry Co. ; Athens, Menard Co. (Nason); South- 

 ern Illinois (Ulff'ers) ; Fulton Co. (Wolf) : Havana, Mason Co. 

 (State Laboratory). 



Bifidaria holzingeri Sterki. 



Joliet, Will Co. (Ferriss, Handwerk); Northern Illinois; Will 

 and La Salle counties (Ferriss, Sterki) ; Will Co. (Marsh). 



