120 Remarks on Certain Species 



2. Tivo teeth vnthin at base of aperiu7-e. 

 II. suppressa Sa}'. 



" gularis " 



3. Two internal lamellce. 

 H. lasmodon Phill. 



4. Tivo or more internal teeth repeated in two or more series, 

 H. lineata Say. 



" interna " 



" multidentata By. 



B. Lip reflected — no fulcrum, 



5. One jMrietal tooth.* 

 11. exoleta By. 



" thyroides Say, 



'" bucculenta Gould. 



" Wheatleyi Bland. 



" dentifera By. 



" Roemeri Pfr. 



" Christyi Bland — allied in form to II. inflecta Say. 



6. One tooth on lower Up.\ 

 IT. profunda Say. 



" Pennsylvanica Green, tooth not prominently developed. 



7. One parietal toothy and one on loiver Up). 

 H. Sayii By. 



8. One parietal tooth., and one {la^nelliform) on loioer lip. 

 H. elevata Say — var. without lip tootli. 



" Clarkii Lea. 



" appressa Say — var. with outer lip tooth, like H. pmUiaia. 



9. One parietal tooth, one {lamelliforni) on lower lip and one on 



outer lip. 

 H. palliata Say. 

 " ohstricta " 



* JI. albolabris not unfrequently, and JI. multilineata rarely have this tooth, 

 f H. albolabris, exoleta, and thyroides have often a tooth-like callus on the lower 

 lip near its columellar termination. 



