454 ARIONID^. 



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

 conical, bluish 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 unfortunate 

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

 in the fourth volume of the " Terrestrial Mollusks " 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-deiiressed, thin; whorls six ; a[)erture transverse; peristome sim- 

 ple, one or two lamelliibrm teeth within ; umbilicus small. 



Helix siippresfa, S.vy, New Harm. Diss. ii. 229 (1820) ; Dcscr. 14 ; Bi^'net's cd. 36. — 

 BiNNEV, Best. Joiirn. iii, 410, pi. 11, fi<,'. 3; Terr. Moll. ii. 253, pi. 37, fi.ir. 1. — De 

 Kay, N. Y. Moll. 38, pi. 3, fig. 24 (1843). — Heeve, Con. Iton. 723. — W. G. Bm- 

 NEv, Terr. Mull. iv. 122. — Pfeiffeh, Hon. Ikl. Viv. iv. 153. — Morse, Am. Nat. 

 i. 411, fig-. 25 (18C7). 



Helix (pilnrix, var. ft, Pfeiffeu, Ciiemxttz, 2d cd. &c. 



Gastiodunla suppressa, Tkvox, Am. Juuni. Coiicli. ii. 258, pi. 4, fig. 41 (186G). 



Shell convex-depressed, thin, pellucid ; ei)idermis polished, yel- 

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

 oblique striae ; suture impressed, distinct ; aperture 

 Fi?. 713. transverse, not expanded ; peristome simple, thin 



at its edge, thickened within ; base rather convex, 

 near the aperture oi)a(iue, yellowish-white ; umbili- 

 z si,prfssa. Q^^^ 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 half; aperture very oblique, lunate- 

 ovate ; peristome simple ; umbilicus deep. 



Helix fill ifjimm, Griffith in letters. — Binney, Terr. Moll. ii. 222, pi. 31 ; Bost. Journ. 

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

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

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



