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CONCHOLOGIA CESTRICA. 
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To fallax <SAy. 
1. fallin. - Helix fallax, Say, Jour. Phil. Acad. F. 
[B. & B.] 
Fig, 29. S.; V., To2e: 
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. Lyc. Vij., 1860. 
Shell xarrowly umbilicate, depressed-globose, thin, 
T. introfee Costate-striate, pale; whorls 6, the last scarcely 
deflected, but deeply constricted at the aper- 
ture, with ¢wo exterior pits; periphery sub- 
angular; convex beneath, with a spiral groove 
within the umbilicus ; aperture oblique, lunate, 
is” with a strong, arcuate, parietal tooth; peris- 
tome Dy enicered thickened within; an obtuse, Aieareal 
tooth, within the right margin ; rf 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. Lyc. 
Vij., 1860. 
Shell smaller; whorls 5. H. 6, W. 11, mill. 
Station, in woods, gardens, and among rubbish. Ches- 
ter County ; abundant. 
