85 



Musculium spJmricum Anthony. 



Mississippi River (Marsh) ; Canton, Fulton Co. (Nason) ; Ful- 

 ton Co. (Wolf). 



Musculium secure Prime. 



Rock Run, Joliet, Will Co.(Ferriss) ; Cook Co. (Jensen) ; Sand 

 and Cedar lakes, Lake Co. (State Laboratory). 

 Musculium rosaceum Prime. 



Fulton Co. (Wolf). A somewhat doubtful record, as this 

 species is an eastern one. 



Musculium jayanum Prime (=jayensis Prime). 



Winnebago Co. (Hinkley) ; Mercer Co. (Marsh); Havana, 

 Mason Co. (State Laboratory). 



Genus Corneocyclas Ferussac, 1818. 

 ( = Pisidium Pfeiffer, 1824. ) 

 Corneocyclas abdita Haldeman. 



Cook Co. (Baker, Calkins, Higley, Nason); Northern Illinois 

 (Calkins); Kankakee River (Ferriss); Joliet, Will Co. (Fer- 

 riss, Handwerk) ; Lilycash Creek, Will Co. (Handwerk) ; Win- 

 nebago Co. (Hinkley, Marsh); La Salle Co. (Huett); Canton, 

 Fulton Co. (Nason) ; Quiver and Matanzas lakes, and Illinois 

 River, Havana, Mason Co. ; Pistakee, Sand, and Cedar lakes, 

 Lake Co. ; Thompson's Lake, Fulton Co. ; Grand Pierre Creek, 

 Herod, Pope Co. ; Lake Michigan, Cook Co. (State Laboratory). 

 Corneocyclas abyssorum (Stimpson) Sterki. 



Off Racine, Wisconsin, in deep water, dredged by George L. 

 Marston (Hoy, Sterki). 



As this species probably inhabits that part of Lake Michigan 

 bordering on Illinois, it is included in this list. 



Corneocyclas wquilateralis Prime. 



Mercer Co. (Marsh); Havana, Mason Co.; Thompson's Lake, 

 Fulton Co. (State Laboratory). 



Corneocyclas aMnis Sterki. 



Winnebago Co. (Hinkley); Illinois (Sterki). 



Corneocyclas compressa. Prime. 



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

 (Calkins) ; Joliet, Will Co. (Ferriss, Handwerk) ; Lilycash Creek, 

 Will Co. (Handwerk) ; Winnebago Co. and Big Muddy River, 

 (Hinkley) ; La Salle Co. (Huett) ; Mercer Co. (Marsh) ; Canton, 



