426 HELICIDiE. 



tracted hj the lip ; lip white, widely reflected, and sometimes 

 grooved, its exterior yellowish ; at the inner side, 

 Fig. 683. ^j^ ^YiQ la^gt whorl, is a white, tooth-like tubercle, 



placed obliquely ; umbilicus exhibiting only one 

 volution, and partially covered by the reflected 

 lip. Diameter about three fourths of an inch. 

 Animal of a dirty yellowish color, with a crrav- 



H. thyroides. . . •' '' ' » / 



isli hue in some individuals ; tentacula darker ; 

 eyes black ; base of the foot dirty white ; length equal to twice the 

 diameter of the shell. 



Found in nearly all parts of this State, but by no means common. 

 It is numerous from Canada through all Eastern North America, 

 and in the post-pleiocene of the Mississippi Valley, 



This is a plain but ])retty shell, bearing a great resemblance to 

 H. albolabris, yet readily distinguished from it. It is a smaller 

 shell, more globose ; its aperture is more oblique, and the partially 

 closed umbilicus and tooth on the inner lip are specially character- 

 istic. It varies considerably in its size, and in the degree of its 

 convexity. The umbilicus is sometimes entirely closed ; and in 

 immature shells the tooth is generally wanting. It is occasionally 

 found reversed. 



Helix Sayii.* 



Shell depressed, light russet ; Avhorls between five and six ; aperture lunately 

 sub-circular; peristome white, reflected, with tooth on inner edge; white tooth on 

 parietal wall ; umbilicus open. 



Helix dioclonta, Say, Long's Exped. (1824) ii 257, pi. 15, fig. 4 ; cd. Binnet, .39, pi. 74, 

 fig. 4. — De Kay, N. Y. Moll. 34, pi. 2, fig. 18. — Deshayes, in Ferussac, pi. 69, 

 i. fill. 2. 



Helir Sm/i, Binney, Best. Journ. Nat. Hist. ill. .379, pi. 16 (1840) ; Terr. Moll. ii. 180, 

 pi. 23. — Adam.s, Vermont Moll. 160 (1842). — W. G. Binney, Terr. Moll. iv. 70. 

 — Leidy, Terr. Moll. U. S. i. 236, pi. 11, fio..s. 1-4 (1851), anat. — Pfeiffer, 

 Mon. Hcl. Viv. i. 382; in Chemnitz, 2(1 ed. iii. 419, t. 14S, rigs 13, 14 —Mrs. 

 Gray, Fi,l,^ Moll. An. pi. 193, fip:. 10, from Bost. Jonrn., no dcscr. — Deshayes, 

 in Feu. i. 79. — Reeve, Con. Icon. No. 679 (1852). -Morse, Am. Nat. i. 98, figs. 

 4, 5 (1867). 



Mrmdon Sai/ii, Morse, Journ. Portl. Soc. i. 9, fig 9 ; pi. 4, fig. 10 (1864). 



Ulostoma Sayii, Tryon, Am. Journ. Conch, iii. 38, pi. 7, fig. 4 (1867). 



Shell umliilicated, orbicularly-depressed, thin ; epidermis light 

 russet, shining ; whorls between five and six, with numerous fine, 



* The name II. Sayii is preoccupied, but Wood fjives no description, and even if he did 

 I should not reject the well-established use of the name for this species. — W. G. B. 



