ZONITES. 129 



Zonites gularis, SAY. 

 Vol. III. PI. XXXVII. Figs. 3, 4. 



Shell subperf orated, subconical ; epidermis shining, pale yellowish horn-color; 

 spire sometimes tending to a point, at other times obtuse ; whorls 7 or 8, very 

 minute at the apex, increasing in diameter regularly and gradually, until they 

 reach the aperture, with strongly marked, curved wrinkles ; suture impressed 

 and distinct; aperture transverse, not much expanded ; peristome simple, thin 

 at its edge, within thickened with a white, testaceous deposit ; base flat, in- 

 dented in the centre, near the aperture yellowish-white and opaque ; umbilicus 

 small and rounded in young shells, obsolete or diminished to a mere point in 

 older ones ; within the base of the aperture are one or two lamelliform, elon- 

 gated, nearly parallel teeth, one near the base, the other more central. Greater 

 diameter, 8 mill.; height, 5 mill. 



Helix gularis, SAY, Jouvn. Acad. Nat. Sci. Philad., II. 156 (1822); BINNEY'S 

 ed. 18. BINNEY, Bost. Journ. Nat. Hist., III. 408, PI. XI. Fig. 1 (1840); 

 Terr. Moll., II. 251, PI. XXXVII. Figs. 3, 4. DEKAY, N. Y. Moll., 46 

 (1843). FERUSSAC, Hist., PI. LI. a, Fig. 4 (?). PFEIFFER, Mon. Hel. Viv., 

 I. 183, excl. /3 ; Symbol, II. 29. excl. /3 ; in CHEMNITZ, ed. 2, II. 201, Tab. 

 CI. Figs. 5-8. W. G. BINNEY, Terr. Moll., IV. 122. MRS. GRAY, Fig. 

 Moll. An., PI. CXCI. Fig. 4. ex Bost. Journ. H. & A. ADAMS (Gastrodonta), 

 Gen. Rec. Moll., PI. LXXI. Fig. 4 (no descr.). REEVE, Con. Icon., No. 719 

 (1852). 



Helix bicostala, PFEIFFER, Mon. Hel. Viv., I. 182; Symbolic, III. 697 (1852) ; 

 in CHEMNITZ, ed. 2, II. 196, PI. C. Figs. 21-23 (1846). REEVE, 1. c. 



Gastrodonta gularis, TRYON, Am. Journ. Conch., II. 257 (1866). 



Zonites gularis, W. G. BINNEY, L. k Fr.-W. Sh., I. 292 (1869). 



A Post-pleiocene species. At present it seems to be restricted to the Cumber- 

 land Subregion. It ranges along the Appalachian chain into Pennsylvania, 

 and southerly into Georgia and Alabama. In East Tennessee it appears to 

 reach its greatest development. 



Animal bluish-black on head and back, other parts dingy white; eye-pedun- 

 cles long, slender, enlarged, but not much bulbous at tip; foot above, dirty 

 greenish. A distinct locomotive disk ; longitudinal furrows above the margin 

 of the foot, meeting over a longitudinal mucus pore. 



There is an umbilicated variety of the species. 



The present species resembles some varieties of Z. ligerus, Say, in form and 

 general appearance, although its size is much less. This remark, which was 

 made by Say, in his original description, is entirely inapplicable to the speci- 

 mens which arc usually known as Z. gularis. It also resembles Z. suppi-essus, 

 Say, the next described species, with which it has long been confounded. But 

 it has at least one more whorl ; the spire is much higher ; the nucleus of the 



VOL. iv. 9 



