101 



Physa sp. 



Greenhouse, Douglass Park, Chicago, Cook Co. (Hood, Zetek). 



Genus Aplkxa Fleming. 

 Aplexa hypnorum, Linne ( = Physa elongata Say). 



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

 Desplaines River (Ferriss); Rockford, Winnebago Co. (Hink- 

 ley) ; La Salle Co. (Huett) ; Canton, Fulton Co (Lewis) ; Eastern 

 Illinois (Marsh); Elgin, Kane Co.; Algonquin, McHenry Co. ; 

 Canton, Fulton Co. (Nason) ; shores of Illinois (Say) ; Southern 

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



Family ANCYLID^E. 

 Genus Ancylus Geoffroy. 

 Section Lsevapex Walker. 

 Ancylus diaphanus Haldeman. 



Illinois River (Ferriss, Walker). 



Ancylus fuscus Adams. 



Algonquin and Fox Lake, McHenry Co. (Nason). 



Ancylus fuscus euglyptus Pilsbry. 



Havana, Mason Co.; Illinois River (Pilsbry). 



Ancylus kirklandi Walker. 



Havana, Mason Co. ; Crystal Lake, Urbana, Champaign Co. 

 (State Laboratory). 



Section Ferrissia Walker. 



Ancylus rivularis Say. 



Du Page River (Ferriss) ; Winnebago and Washington coun- 

 ties (Hinkley) ; Cook Co. (Jensen) ; Mercer Co. (Marsh) ; creek, 

 Algonquin, McHenry Co. ; Fox River, Elgin, Kane Co. (Nason) ; 

 Salt Fork, Urbana, Champaign Co. (State Laboratory). 



Ancylus parallelus Haldeman* 



Algonquin, McHenry Co. (Nason) ; Pistakee and Cedar lakes, 

 Lake Co. (State Laboratory). 



Ancylus tardus Say. 



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

 River (Ferriss) ; Winnebago Co. (Hinkley) ; Mercer Co. (Marsh) ; 

 creek, Algonquin, McHenry Co. (Nason); Rockford, Winnebago 



*Armflw paraMehJts Haldeman as quoted by Marsh from .Mercer Co., is said by 

 Walker to be A. tardus. (Nautilus XVIII., p. 76. ) 



