HELIX. 



99 



slightly entering, tongue-like, heavy callus, the basal margin with a sub- 

 marginal obtuse stout denticle, right margin witli a more deeply seated, 

 broader denticle. Greater diam. 9, lesser 8 ; height 3 mill. 



Polygyra troostiana, Lea, Tr. Am. Phil. Soc. VI, 107, pi. xxiv, f. 119 ; 



Obs. II, 107 (1839).— Troscuel, Arch. f. Nat. 1839, III, 222. 

 Helix troostiana, Pfeiffer, Mon. Hel. Viv. I, 419, excl. syn. et var. ; in 



Chemnitz, ed. 2, I, 376, pi. Ikv, f. 21-24. — Deshayes in Feb. I, 75, 

 ' pi. ixix, D, f. 4 ?— Reeve, Con. Icon. no. 70(5 (1852).— W. G. Binney, 



Terr. Moll. IV, 88, pi. Ixxviii, f. 11.— Bland, Ann. N. Y.^Lyc. VI, 



288, pl. ix, f. 21-23 (1858). 

 Helix fatigiata, Binney, Bost. Journ. Nat. Hist. Ill, 388, pl. xix, f. 3, 



part, excl. syn. ; in Terr. Moll, part, II, 193, pl. xxxix, f. 2. 

 Helix plicala, Binney (not of Say), Terr. Moll. pl. xxxix, f. 2, not text. 

 Dadalochila troostiana, Tkyon, Am. Journ. Conch. Ill, 67, pl. x, f. 19, 25 



(1867). 



Murfreesboro', Tennessee. 



H. troostiana is most nearly allied to H. fastigans. 



Fig. 176. 



Helix bazardi, Bland. — Shell rimately umbilicated, discoidal, 

 depressed above, convex below, light horn-color, sparingly hirsute, with 

 separated rib-like strife ; spire planulate ; whirls five, gradually increasing, 

 the upper ones rounded, smoother, the last convex, plane below, scrobicu- 

 lated and with an insulated, smooth, prominent bulge behind 

 the peristome, deflected at the aperture ; rimatiou level, at 

 first grooved, showing one and a half whirls, and ending in 

 a narrow umbilicus ; aperture subreniform, very oblique, 

 contracted ; peristome white, thickened, not reflected, con- 

 tinuous, its terminations approached, joined by a promi- 

 nent, excavated, heavy, somewhat flexuose, emarginate, 

 tongue-like callus, projecting almost across the aperture; 

 within the columellar margin of the peristome is an erect, 

 blunt, stout denticle (its inner end continued back within the aperture 

 into an erect lamella joining the inner wall) somewhat overlapping and 

 thus partially concealing from view a smaller, more deeply seated, erect, 

 obtuse, stout denticle on the right margin of the peristome ; an internal 

 transverse tubercle on the base of the shell. Greater diam. 7, lesser 6 ; 

 height 3 mill. 



Polygyra plicata. Say, Journ. Acad. Phila. II, 161 (1821) ; ed. Binney, 21. 



Helix fatigiata, Binney in Bost. Journ. Nat. Hist. Ill, 388 (1840), part 



(excl. syn. and fig.) ; in Terr. Moll, part (excl. syn. and fig.). 



Helix hazardi, 

 enlarged. 



