POLYGYRA. 



283 



*' The (li<j;estivc system is also very much elongated. The oesophagus especially 

 is excessively long, as are also the ducts to the salivary glands. 



Tliis species is extremely common all over St. Augustine and its vicinity. 

 Tho lar<ie Conn I found almost restricted to the moat of the old fort, especially 

 at the foot of the main western wall. 



P. ctreolus, 

 enlarged. 



Polygyra cereolus, Muhlfeldt. 



Shell broadly umbilicated, subcarinated, discoidal, white, scarcely convex, 

 and with rib-like stria? above, smooth and plane below ; whorls 7 or 8, gradu- 

 ally increasing, the last subcarinated, briefly deflected at 

 the aperture, constricted behind the peristome ; below Fig. 181. 



three full whorls revolving on the same plane, the bal- 

 ance visible in the broad, pervious umbilicus, the penul- 

 timate somewhat lapped over by the last, the antepenul- 

 timate the most swollen ; aperture remote from the axis, 

 subreniform ; peristome white, thickened, acutely re- 

 flected, somewhat angular at the carination of the last 

 whorl, continuous, its terminations joined by triangular, 

 elevated, acutely pointed callus ; on the parietal side of 

 the inner fourth of the last, and running round rather 

 obliquely within from two thirds to three fourths of the 

 penultimate whorl, thus revolving nearly once round the 

 shell, is a thread-like, elevated, white internal lamina. 

 Greater diameter 14, lesser, 12^ mill.; height, 3| mill. 

 A large specimen, 20 greater diameter. 



Melix cereolus, Muhlfeldt, Berlin Mus., VIII. (1816), 41, PI. 11. Fig. 18.— 



Pfeiffer, Mon. Hel. Viv., I. 408 ; in Chemnitz, ed. 2, I. 378, PI. LXVI. 



Figs. 1-3. — ? Reeve, Con. Icon., 698. —Bland, Ann. N. Y. Lye, VII. 



136, Fig. 2. — W. G. BiNNEY, Terr. Moll., IV. 80, part, PL LXXVII. Fig. 



23 ; L. & Fr.-W. Sh., I. 106, Fig. 182 (1869). 

 ffelix septemvolva, ? F^.russac, Hist., PI. LI. Fig. 6. — ?Wood, Index Test. 



Suppl., VII. Fig. 14; ed. Hanley, 226, Fig. 14. — ?Sowerby, Conch. Man., 



ed. 2, Fig. 275. — Binney, Best. Journ. Nat. Hist., III. 391, PI. XIX. Fig. 4 



(1840); Terr. Moll., II. 196, PL XXXVIIL central line. — Deshayes in F^r. 



Hist., 5. 

 Helix planorbula, Lamarck ? An. s. Vert., VI. 89. — ?Deshayes in Lam,, VIII. 



67; Encycl. Meth., II. 208 (1830). — ?Delessert, Rec, PI. XXVI. Fig. 3 



(1841). — ?Chenu, Illust. Conch., PI. XII. Fig. 3. 

 Helix cereolus, var. laminifera, W. G. Binney, Proc. Acad. Nat. Sci. Phila. 1858, 



200, no descr. 

 Pohjgyra cereolus, Tryon, Am. Journ. Conch., III. 158, PI. XI. Figs. 19-21 



(1867). 

 Indian River, Indian Key, Key West, Egraont Key, Florida. It is a species 

 of the Florida Subre^ion. 



