STROBILA. 259 



Lateral teeth like the centrals, but asymmetrical by the suppression of the 

 inner lower angle of the base of attachment, and the inner side cusp and side 

 cutting point. Outer laterals gradually changing into the marginals, which are 

 low, wide, with a reflection equalling the base of attachment, and furnished 

 with numerous (about five) subequal, short cutting points, the inner one longest 

 and bifid (PI. V. Fig. O). 



Morse mentions no ribs on the anterior surface of the jaw, but they are well 

 developed on the specimen examined by me. 



S. Hubbardi, a specimen from Bonaventure Cemetery near Savannah, kindly 

 opened by Mr. Bland, furnished a jaw and lingual membrane. Jaw long, low, 

 slightly arcuate, ends acuminated; no median projection to cutting edge; ante- 

 rior surface with numerous crowded ribs, denticulating either margin. Lingual 

 membrane with 14 1 14 teeth, 5 laterals. All the teeth like those of 5. laby- 

 rinthica (PI. V. Fig. N). 



There are no known species foreign to North America, with which to com- 

 pare the dentition and jaw of labyrinthica and Hubbardi. 



Strobila labyrinthica, SAY. 

 Vol. III. PI. XVII. Fig. 3. 



Shell umbilicated, globose-conic, brownish horn-color, with stout ribs above, 

 and below lighter with arborescent wrinkles ; spire obtuse ; umbilicus narrow, 

 pervious ; aperture scarcely oblique, Innately rounded ; peristome briefly re- 

 flected, thickened ; parietal wall with three revolving, deeply entering, parallel 

 laminae, the central further within the aperture and less developed, and around 

 the axis one stout lamella-like rib not reaching the columella ; on the base of 

 the outer whorl are two short, deeply seated internal revolving rib-like laminae. 

 Greater diameter, 2^ mill.; height, If mill. 



Helix labyrinthica, SAY, Journ. Phila. Acad., I. 124 (1817) ; Nich. Encycl., ed. 

 3, IV. (1819); ed. BINNEY, 10. BINNEY, Bost. Journ. Nat. Hist., III. 393, 

 PI. XXVI. Fig. 1 (1837); Ten-. Moll., II. 202, PI. XVII. Fig. 3. GOULD, 

 Invertebrata, 184, Fig. 106 (1841). ADAMS, Vermont Mollusca, 160 (1842). - 

 FERUSSAC, Tab. Syst., 38; Hist., PI. LI. B, Fig. 1. PFEIFFER, Symbols, 



11. 31; Mon. Hel. Viv., I. 416. CHEMNITZ, 2d ed. I. 382, t. LXVI. Figs. 

 17-20. REEVE, Con. Icon., No. 728:(1S52). DEKAY, N. Y. Moll., 39, PI. 

 III. Fig. 31 (1842). DESH AYES in FEU., I. 210. W. G. BINNEY, Terr. 

 Moll., IV. 95; L. & Fr.-W. Sh., I. 84 (1869). MORSE, Amer. Nat., I. 545, 

 Figs. 41, 42 (1867). GOULD and BINNEY, Inv. of Mass., ed. 2, 415 (1870). 



Strobila labyrinthica, MORSE, Journ. Portl. Soc., I. 26, Figs. 64-67, PI. II. Fig. 



12, a, b ; PL VIII. Fig. 68 (1864). TUYON, Am. Journ. Conch., II. 259 (I860). 



A post-Pleiocene 1 species, now found over all of the Eastern Province. It 



l Woodward (Man. 384) refers an extinct English Eocene Helix to this species. I have 

 seen no specimens of it. Mr. Bland writes me that he has received from France a fossil 

 shell under the name of If. labyrinlhicula, apparently identical with our specii-s. 



Whiteaves (Can. Nat., VIII. 56) says //. labyrinthica has been found in Upper Eoceno 

 at Headon Hill, Isle of Wight, and in the Paris basin. 



