454 ARIONID^. 



its posterior termination. Behind the junction is a prominent, sub- 

 conical, bluish white gland, on the extremity of the loot. 



The shell which is described above is well known in collections, 

 and not easily confounded with any other. It has been unfortunate 

 in its synonymy, whose history is treated at length and explained 

 in the fourth volume of the " Terrestrial MoUusks " and " Annals of 

 the New York Lyceum," quoted above. 



I have in my collection a curious specimen from the Pennsyl- 

 vania mountains, in which are three well-developed, sharp, tooth- 

 like processes on the internal thickened margin of the peristome. 



Zonites suppressa. 



Shell convex-depressed, thin; whorls six ; aperture transverse; peristome sim- 

 ple, one or two lamelliform teeth within ; uniliilicus small. 



Helix siippres<;a, Say, New Harm. Diss. ii. 229 (1829) ; Dcscr. 14 ; Binnet's cd. 36. — 

 BiXNKV, Best. Journ. ill. 410, pi. 11, fi,!,'. 3 ; Terr. Moll. ii. 253, pi. 37, fi-,^ I. -De 

 Kay, N. Y. iNIoll. 38, \)\. 3, i\<x. 24 (1843). — Ri:evi:, Con. Icon. 723. — W. G. Bin- 

 key, Terr. Moll. iv. 122. — Pfeiffek, Mon. Ikl. Viv. iv. 153. — Morse, Am. Nat. 

 i. 411, tig. 25 (1867). 



Helix gitlarls, var. fi, Pfeiffer, Chemnitz, 2d ed. &c. 



Gustiodonta suppressa, Tryon, Am. Jourii. Conch, ii. 258, pi. 4, fig. 41 (18C6). 



Shell convex-depressed, thin, pellucid ; epidermis polished, yel- 

 lowish horn color ; spire flat ; whorls six, with crowded, minute, 

 oblique stria? ; suture impressed, distinct ; aperture 

 transverse, not expanded ; peristome simple, thin 

 at its edge, thickened within ; base rather convex, 

 near the aperture opaque, yellowish-white ; umbili- 

 z supr^ssa. ^.^^ Small, but rounded and distinct in young shells, 



Enlarged. ' ... 



obsolete or hardly apparent in older ones ; within 

 the peristome are one or two lamelliform, elongated, oblique teeth. 

 Greater diameter, five mill. ; lesser, four mill. ; height, two milli- 

 metres. 



From Florida to Pennsylvania. New England {3Iorse}. 



Zonites fuliginosa. 



Shell thin, depressed ; whorls four and a lialf ; aperture very oblique, lunate- 

 ovate ; peristome simph; ; umbilieus deep. 



Helix fill tfjinosn, Griffith in letter.-;. — Binney, Terr. Moll. ii. 222, pi. 31 ; Bost. Journ. 

 iii. 417, pi. 24, excl. syn. (1840). — Leioy, in Terr. Moll. U. S. i. pi. 9, fig. 4, anat. 

 — Adams, Vermont Moll. ICI, cxel. syn. (1842). -De Kay, N. Y. Moll. 37, pi. 3, 

 fig. 22 (1843). — Pfeiffer, Mon. liel. Viv. i. 88; in Chemn. 2d cd. ii. 104, pi. 84, 



