POLYGYRA. 



283 



Fig. 181. 



l " The digestive system is also very much elongated. The oesophagus especially 

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



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

 The large form I found almost restricted to the moat of the old fort, especially 

 at the foot of the main western wall. 



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 

 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, 3J mill. 

 A large specimen, 20 greater diameter. 



Helix cereolus, MUHLFELDT, Berlin Mus., VIII. (1816), 41, PI. II. 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. a. BINNEY, Terr. Moll., IV. 80, part, PI. LXXVII. Fig. 



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

 Helix septemvolva, ? FERUSSAC, Hist., PI. LI. Fig. 6. ?"\Vooo, Index Test. 



Suppl., VII. Fig. 14; ed. HANLEY, 226, Fig. 14. ?SOWERBY, Conch. Man., 



ed. 2, Fig. 275. BIXNEY, Bost. Journ. Nat. Hist., III. 391, PI. XIX. Fig. 4 



(1840); Terr. Moll., II. 196, PL XXXVIII. central line. DESHAYES in FER. 



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. laminifcra, W. G. BINNEY, Proc. Acad. Nat. Sci. Phila. 1858, 



200, no descr. 

 folygyra cereolus, TRYON, Am. Journ. Conch., III. 158, PL XL Figs. 19-21 



(1867). 



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

 of the Florida Subregion. 



P. ctreolus, 

 enlarged. 



