426 ^ HELICID^. 



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

 grooved, its exterior yellowish ; at the inner side, 

 FiK. 6S3. ^^^ ^YiQ last 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 gray- 

 ish hue in some individuals ; tentacula darker ; 

 eyes l)lack ; 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-plciocene of the Mississippi Valley. 



This is a plain but pretty shell, bearing a great resemidance 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 umljilicus is sometimes entirely closed ; and in 

 immature shells the tooth is generally wanting. It is occasionally 

 found reversed. 



Helix Sayii.* 



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

 siili-cu-cular : peristome white, reflected, with tooth on inner edge ; white tooth on 

 parietal wall ; umbilirus open. 



Helix diodonta. Say, Long's Exped. (1824) ii. 257, pi. In, fig. 4 ; ed. Binney, .39, pi. 74, 

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

 i. fiix. 2. 



Helix Smii, BixNEY, Bost. Journ. Nat. Hist. iii. 379, pi. 16 (1810) ; Terr. Moll. ii. 180, 

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

 — Leidy, Terr. Moll. U. S. i. 256, pi. 11, fios. 1 -4 (1851), anat. — Pfeiffer, 

 Mon. Hel. Viv. i. 382; in Chemnitz, 2d ed. iii. 419, t. 148, figs 13, 14. — Mrs. 

 Gray, Fig. Moll. An. pi. 193, fig. 10, from Bost. Jonrn., no descr. — Deshayes, 

 in Fer. 1.^79. — Reeve, Con. Icon. No. 679 (1852). — Morse, Am. Nat. i. 98, figs. 

 4, 5 (1867). 



Mesodon Sai/ii, Morse, Jonrn. 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 umbilicated, orbicularly-depressed, thin; epidermis light 

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



* The name H. Saijii is preoccupied, but Wood gives no description, and even if he did 

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



