EASTERN PROVINCE — SOUTHERN REGION SPECIES. 373 



PoIyg"yra Jacksoni, Bland. 



Shell narrowly umbilicate, depressed, shining, dark or pale hoin- 

 colored, little elevated above, striated, convex beneath, with fig. 408. 

 finer, almost obsolete stria^ ; whorls 6, slightly convex, fff 

 gradually increasing, the last suddenly detlected, contracted _^^ 

 and above gibbously inflated behind the aperture ; suture f ^) T 

 impressed; aperture oblique, lunate -circular, with 3 teeth ; V J i 



peristome thickened, brownish-red, shortly reflected, with p.jacksoni. 

 the scarcely approaching margins joined by a white, linguiform, bicru- 

 ral, deeply entering tooth, the basal margin with a strong, oblique, 

 sinuous fold, the right with a deeply seated tooth. Greater diameter 

 7, lesser 6"™ ; height, 4'"™. 



i7e?ij: JacA-soni, Bland, Am. Jonru. Conch., ii, 371, pi. xxi, fig. 8 (1866).— W. G. BiN- 



NEY, L. & Fr.-W. Sh., i, 98, fig. 174 (1869). 

 Da'dalochila Jacksoui, Tryon, Am. Jouru. Conch., iii, 67 ^^1867). 

 Pohjgyra Jackso>ii,W.G. Binney, Terr. Moll., v, 275. 



Fort Gibson, Ind. T. (Cherokee); Springfield, Mo. ; Arkansas. I am 

 inclined to rank it among the species of the Texan Subregion. 



This species belongs to the same group as and is most nearly allied 

 to P. Hazardi, Bland {Helix plica to, Say), from which, however, it may 

 be readily distinguished by the very different character of the parietal 

 and basal teeth. This species has no internal tubercle. 



Jaw as usual in the genus, with stout anterior ribs. 



Lingual membrane with 17-1-17 teeth; centrals bicuspid; laterals 7 

 on each side, bicuspid; the eighth tooth has the inner cutting point 

 bifid, beyond which all the teeth are marginals, 10 in number. All the 

 teeth are such as I have figured in Terr. Moll., V, Plate VI, Figs. A 

 to M, for other species of this genus. 



Polygyra. oppilata, Moricand. 



Shell umbilicated, depressed, delicately striate, subpellucid, light 

 horn-color or white; si)ire scarcely elevated; whorls 5, rather convex, 

 gradually increasing, the last deflected at the aperture, in- fig. 409. 

 flated below, constricted behind the peristome; umbilicus at 

 first widened, then narrow, pervious ; aperture diagonal, lu- 

 nateiy circular, riugeut ; peristome briefly reflected, its termi- p- oppUata. 

 nations joined by a tongue-shaped, entering, two-forked callus, the 

 right margin subequally bidentate. Greater diameter 7, lesser 6™™ ; 

 height, 3""". 



