HELIX. 



149 



Helix bucculenta, Gould, Proc. Bost. Soc. Nat. Hist. 111,40 (1848) ; Terr. 



Moll. Ill, 9, pi. xi, a.— Pfeiffer, Mon. Hel. Viv. Ill, 211 ; IV, 323.— 



,W. G. BiNNEY, Terr. Moll. IV, 54. 

 Eelix thyroides, B, Pfeiffer, Mon. Hel. Vlv. 1,345.— Var., Fig.J254. 



Fekdssac, Hist. pi. 1, a, f. 7. 

 Mesodon bucculenta, Tkyon, Am. Journ. Conch. Ill, 41, pi. 



viii, f. 2 (1867). 



From North Carolina to Texas. 



Very nearly allied to, if not identical with H. 

 thyroides. 



Fig. 254 represents a smaller form of this variable 

 species. 



Helix clausa, Say. — Shell subimperforate, conoidly-semiglobose, 

 rather solid, with crowded, rib-like striae, j^ellowish horn-color ; spire sub- 

 regularly conoid ; whirls five aud a half, rather convex, gradually increas- 

 ing, the penultimate subangular, the last rounded, an- 

 teriorly subcoustricted and briefly deflected ; umbilicus 

 narrow, almost covered by the reflected peristome ; aper- 

 ture diagonal, subregularly lunate ; peristome with a 

 heavy, white thickening, uniformly subangularly re- 

 flected, its columellar portion subdilated. Greater diam. 

 18|, lesser 16 ; height lU mill. 



Helix clausa, Say, Journ. Phila. Acad. II, 154 (1821) ; American Conch. 



(1832), No. 4, pi. xxxvii, f. 1 ; Bixney's ed. 17, pi. xxxvii, f. 1 ; ed. 



Chenu, Bibl. Conch. Ill, 50, pi. xiii, f. 2. — Bixney, Bost. Journ. Nat. 



Hist. I, 482, pi. XV (1837) ; Terr. Moll. II, 107 (excl. syn.), pi. iv 



(excepting the outline figures). — DeKay, N. Y. Moll. 31, pi. iii, f. 



13 (1843).— Reeve, Con. Icon. f. 694.— Bland, Ann. N. Y. Lye. VI, 



336.— Pfeiffer, Mon. Hel. Viv. IV, 321.— W. G. Binney, Terr. Moll. 



IV, 46. 

 Helix pennsijlvanica, Pfeiffer, ex parte, Symb. ad. Hist. Hel. II, 36 ; 



Mon. Hel. Viv. I, 291 ; in Chemnitz, ed. 2, II, 51, ex parte.— Reeve, 



ex parte, Con. Icon. no. 676. 

 Helix mitcheUiana, Pfeiffer in Chemnitz, I. c. I, 332, pi. Ivi, f. 6-S. 

 Mesodon clausa, Tryon, Am. Journ. Conch. Ill, 47, pi. viii, f. 16 (1867). 



In the States bordering on the Ohio River, and in Wisconsin, 



