364 A MANUAL OF AMERICAN LAND SHELLS. 



contracted; peristome acute, continuous, the margins joinerl by a short 

 liuguiform fold, entering within the aperture, the right margin with 

 an obtuse submarginal lamella, and the base with an oblique, sinuous, 

 tooth-like fold. Greater diameter 11^, lesser 10™"^ ; height, G""". 



Helix am-iformis, Bland, Ann. N. Y. Lye, vii, 37, fig. (1858). — W. G. Binxp:y, L. & 



Fr.-W. Sh., i, 88 (1869). 

 Helix anriculala, BiNXEY, Bost. Journ. Nat. Hist, (ex parte), pi. six, fig. 2 (1840) : Terr. 



Moll, ii,l (ex parte), pi. xl, fig. 1 (right hand), 2. — Reevb, Cod. Icon., 700. — 



Deshayes, in Fer., Hist., var. mivor, pi. 1, fig. 3. 

 Helix avara, Chemxitz, ed. 2, 37 (ex parte), t. Ixv, tigs. 1, 2.— Pfeiffer, Men. Hel. 



Viv., i, 418.— Reeve, Con, Icon., 720. 

 f Helix Sayii, Wood, Ind. Suppl., pi. vii, fig. 34 ; ed. Haxley, 228, fig. 34. — De Kay, 



N. Y. Moll.,47. 

 Dadalochila auriformis,TRYO'S, Am. Jonrn. Couch., iii, 15.5 (1867). 

 i'oluyyra auriformis, W. G. BiNNEY, Terr. Moll., v, 265. 



Inhabits the Southern Region. From Texas to Georgia it is an 

 extremely common species. Immense beds of semi-fossil specimens 

 are found in Middle Alabama. 



This species is common in American cabinets, and usually labeled 

 P. avara or var. of P. aririculata, but it appears entirely distinct, it 

 is most nearly allied to the former, but is larger, not hirsute, and has 

 the groove in the last whorl within the umbilical region, like the latter. 

 The parietal fold is somewhat similar to but does not descend so far 

 into the aperture as that of P. Postelliana, but the teeth on the peri- 

 stome are in form and position, though more developed, rather like 

 those of P. avara. They are separated by the same deep sinus, but 

 the upper one generally without the sharp reflexed hook at its termi- 

 nation. 



Jaw as usual in the genus ; ribs numerous. 



The lingual membrane (Terr. Moll., Y, Plate VI, Fig. R) has 2G-1-26 

 teeth, with 8 laterals. Fig. c shows the proportional greater develop- 

 ment of the cutting point in the outer laterals. The change from lat- 

 erals to marginals is not formed by the splitting of the inner cutting 

 point, which remains simple to the extreme outer margin. This i)ecul- 

 iarity is shared by PostelUana, cspiloca^ and Hazardi. 



Genitalia unobserved. 



Polysfyra Postelliaiia, Blaxtd. 



Shell rimately perforate, above slightly convex, with rib-like striic, 



Fig. 397. wider ai)art and more prominent behind the aperture, be- 



/^M^k ^^^^^^ inflated, convex, almost smooth, and with microscopic 



P^^^^^ si)iv<il lines, brown horn-color, thin, sliiuiiig, subpellucid; 



TB"hlmL) whorls 5, gradually increasing^ rather (jonvex, the last de- 



