of Nortli American Ilelicidoe. 445 



H. monodon Rack., lip reflected, var. with denticle on outer lip. 

 " barbigera Redf. " 



H. Edvardsi Bland, small notch, lower lip more or less appressed. 

 " spinosa Lea, " " " 



H. Edgariana Lea, « " " 



" stenotrema Per., " " " 



H. hirsnta Say, deep notch, " " 



" labrosa Bland, " lower lip produced. 



H. maxillata Gould, no notch, lower lip produced and duplicated 

 within the aperture. 



D. Lip reflected— with fulcrum. 



IG. Parietal 2yroc€ss modification o/§ 11, and tu'o lip teeth. 

 H. leporina Gould — lip teeth modified form of notch. 

 " pustuloides Bland. 

 " pustula Fer. 



H. Mooreana W G. By. 



" tholus.* " 



H. vultuosa Gould, continuation of parietal lamella to lip inci- 

 pient only. 



H. Dorfeuilliana Lea. 

 " Troostiana " 

 " fastigans L._W. Say. 

 " Hazard! Bland. 



17. One parietal and two lip teeth. 



H, introferens Bland, — allied to H.fallax. and H. vultuosa. 



18. Parietal process modification o/" § 11, with lamella on lower lip 



and tivo extending downivards, forming, far within the aperture, 

 a modified duplication of the lower lij), vjith notch having 

 refiexed hook. 

 H. hippocrepis Pfr. 



* H. tholus is, I believe, a large var. of H, Mooreana. 



