North American Helices. 

 7. Gastrodonta Albers. 

 Type 



23 



bicostata Pfr. 



is gularis Say. 

 interna Say. 

 gularis Say. 

 suppressa Say. 

 macilenta Shuttl. 



is lasmodon Phil!. 



II. interna Say. 



labyrinthica Say. 

 lineata Say. 

 multidentata Gould 



is multidentata Binn. 

 lasmodon Phill. 



Gen. XII. ftlacrocyclis Beck. 



vcllicata Forbes 



is Vancouver ensis Lea 

 Vancouverensis Lea. 



C. Helicacea. 



Type. M. laxata Fer. 



concava Say. 



(planorboides Raf.) 



minnscula Binn. 

 vortex Pfr. 



Gen. XV. Helix Linn. 



2. Microphysa Albers. 



Type. II. Boothiaua Pfr. 



incrustata Poey. 



5. Patula Held. 



Type. II. rotundata Mull. 



perspectiva Say. mordax Shuttl. 



striatella Anthon. is var. of Cumberland iana Lea. 



exigua Stimp. solitaria Say. 



Cumberlandiana Lea. strigosa Gould. 



alternata Say. sportella Gould 



is var. of Vancouverensis Lea.. 



15. Polygyra Say. 



Type. H. auriculata Say. 



cereolus Mublf. Troostiana Lea. 



volvoxis Parr fatigiata Say (non Binn.) 



var. of septemvolva Say? is fastigans L. IV. Say. 

 delitescens Shuttl. 



