CONCHOLOGIA CESTRICA. 



T. f allay. 



[B..& B.J 

 Fig, 29, 



Fig, 30, 



T. fallax, SAY. 



Helix fallax, Say, Jour. Phil. Acad. F. 

 S, V., 1825. 



Similar in outline; but differs from T. 

 tridentata, in being much smaller; the spire 

 is more elevated ; the teeth are larger ; and 

 the upper one, of the lip teeth, is strongly 

 inflected. H. 7^, W. 13, mill. 



Station, in woods, under leaves and de- 

 cayed wood. Chester County ; common. 



T. introferens, BLAND. 



Helix introferens, Bland, Ann. N. Y. Lye. Vij., 1860. 



Shell narrowly umbilicate, depressed-globose, thin, 

 T. introfe- costate-striate, pale ; whorls 6, the last scarcely 

 [E. e & 8 E.] deflected, but deeply constricted at the aper- 

 ture, with two exterior pits ; periphery sub- 

 angular; convex beneath, with a spiral groove 

 within the umbilicus ; aperture oblique, lunate, 

 with a strong, arcuate, parietal tooth ; peris- 

 tome reflected, thickened within ; an obtuse, inflected, 

 tooth, within the right margin ; at base, a submarginal, 

 lamelliform, tooth, with a transverse tubercle in the 

 centre ; the basal lamella is continued within the aper- 

 ture, where it forms a strong, white, tubercle. H. 7> 

 W. 15, mill. 



Station, in woods, under loose bark, and moist decayed 

 leaves. Chester County. 



T. introferens, var. Minor, BLAND. 

 Helix introferens, var. Minor, Bland, Ann. N. Y. Lye. 

 Vij., 1860. 



Shell smaller; whorls 5. H. 6, W. II, mill. 

 Station, in woods, gardens, and among rubbish. Ches- 

 ter County ; abundant. 



