454 ARIOXID^. 



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

 conical, bkiish white gland, on the extremity of the foot. 



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

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

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

 in the fourlh 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; ai)erture trnnsverse; peristome sim- 

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



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

 BiNNEV, Bust. Journ. iii. 410, pL 11, fiix. 3; Terr. Mull. ii. 253, pi. 37, tijr. 1 . — De 

 Kay, N. Y. Moll. 38, pi. 3, ti<,^ 24 (1843). — Reeve, Con. Icon. 723. — W. G. Bin- 

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

 i. 411, fig. 25 (1867). 



Helix (ji(l(tr is, var. /*, Pfeiffer, Chemnitz, 2d cd. &c. 



Gustiodonta suppressa, Tryon, Am. Journ. Conch, ii. 258, pi. 4, fig. 41 (1866). 



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

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

 oblique striae ; 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- 

 cus small, l)ut rounded and distinct in young shells, 

 obsolete or hardly apparent in older ones; within 

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

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

 metres. 



From Florida to Pennsylvania. New England (3Iorse). 



Zonites fuliginosa. 



Shell thin, depressed ; Avhorls four and a half; aperture very oblique, hmate- 

 ovate ; peristome simple ; umbilieus deep. 



Helix fiilifjinom, Griffith in letter.^. — Binney, Terr. Mnll. ii. 222, pi 31 ; Bost. Journ. 

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

 — Ada.ms, Vermont Moll. 161, excl. syn. (1842). -De Kay, N. Y. Moll. 37, pi. 3, 

 fig. 22 (1843).— Pfeufer, Mon. Hel. Viv. i. 88; in Cuejin. 2d ed ii. 104, pi. 84, 



