EASTERN PROVINCE INTERIOR REGION SPECIES. 299 



marked and distinct; aperture contracted by the peristome; peristome 

 white, flattened in the plane of the mouth, abruptly and vt-ry widely 

 reflected; umbilicus of the mature shell covered by the reflected per- 

 istome, which is continued to the base of the shell. Greater diameter 

 30, lesser 20"""; height, 17""". 



Helix all>olal))is, Say, Nicb. EncycL, pi. i, fig. 1 (1817-'19); Journ. Acad. N.it. Sci. 

 Phila., ii, 101 (1821); Americau Conch., No. 2, pi. xiii (1831) ; Binney's ed., 

 21, pi. Ixix, fig. 1. — Chenu, Bibl. Concb., iii, 21, pi. iii, fig. 3, a. — Adams, in 

 Tboinpsou's Vermont, i, loB, witb wood-cnt. — Eaton, Zool. Text-Book, 193 

 (1826).— Fkrussac, Tab. Syst., 36; Hist., pi. xliii, figs. 1,2, 3.— Binxey, 

 Bost. Jonni. Nat. Hist., i, 47.5, pi. xiii (1837) ; Terr. Moll., ii, 99, pi. ii.— De 

 Kay, N. V. Moll., 26, pi. ii, fig. 12 (1S43).— Gould, Invert., 170, fig. 101 (1H41) ; 

 ed. 2, 423(1870).— Leidy, T. M., i, 252, pi. vi (1851), anat.— Pfeiffer, Synib., 

 ii, 22, excl. y and d ; Men. Hel. Viv., i, 290, excl. |3 and y; in ChEiAInitz, ed 

 2, i, 81, pi. XV, figs. 7, 8 (1847), excl. var. C and D, pi. x, figs. 4, 5.— Potiez 

 et Michaud, Gal., i, 69. — Reeve, Con. Icon., No. 624.— Deshayes, in Feu., i, 

 137, pi. xliii, figs. 1, 2, 3, 5.— Billings, Canadian Nat. and Geol., 1857, ii, 98, 

 figs. 2. 3.— Bland, Ann. N. Y. Lye, vi, 358 (1858).— W. G. Binney, Terr. 

 Moll., iv, 43; L. & Fr.-W. Sb., i, 136, figs. 229,230 (1869).— Morse, Amer. 

 Nat., i, 6, pi. i, figs. 1-11; 96, fig. 2 (1867). 



Helix rvfa, De Kay? N. Y. Moll., 44, pi. iii, fig. 30 (1843). 



Mesodon alholabris, MORSE, Journ. Portl. Soc, i,8, fig. 7, pi. iii, fig. 8 (1864).— Tryon, 

 Am. Journ. Concb., iii, 39,44 (1867).— W. G. Binney, Terr. Moll., v, 317. 



A species of the Eastern Province ; Canada to Arkansas, Georgia 

 to Minnesota. Also in the Post-Pliocene of the F1G.320. 



Mississippi Valley, 



Specimens of M. alholabris are sometimes found 

 bearing a well-developed parietal tooth. Such are 

 very plenty in tlie Alleghany Mountains in Penn- 

 sylvania. One is here figured (Fig. 320). The 

 genitalia and lingual dentition of this form are M.aiboiabris,viiT. 

 the same as in the typical form. 



Pfeifler's var. y and d of the Symbolse are respectively major and 

 exoJetns. In the Monograph his /? is perhaps the former, and his y 

 certainly is. In Chemnitz ed. uov. he figures exoletus as var. D and 

 places major as C. In Vol. VII of the Monographia the- synonymy of 

 the group is correctly given. 



Deshayes, in Ferussac's History, erroneously gives Guadeloupe as the 

 habitat. From his reference to Ferussac's plates he seems to confound 

 major with albolahris. 



Petiver mentions this species in Phil. Trans., 1G98, 395. 



I have this species from fourteen States. The series presents very 

 remarkable variation in the height of the spire and in the form of the 

 aperture. From Illinois I have a few of a large variety (greater diam- 



