EASTERN PROVINCE^- INTERIOR REGION SPECIES. 229 



number of whorls, mucli wider umbilicus, and in the character of its 

 internal denticles, which are long and winding on the wall of the whorl, 

 while in significans the denticles are simply erect and conical, with 

 broad base. The same difierences distinguish it from muUidentatus^ 

 which is still smaller than significans and has a much narrower um- 

 bilicus. 



Zonites Andrewsi, W. G. Binney, Aun. N. Y.Ac. Nat. Sc, i, 359, pi. xv, fig. D. 



A species of the Cumberland Subregion ; Koan Mountain, Mitchell 

 County, North Carolina. Named in honor of the discoverer, Mrs. G. 

 Andrews, to whom we are indebted for our knowledge of the richness 

 in molluscan life of this and other mountains of the region. 



Zonites intei'iius, Say. 



Shell very narrowly perforated, depressed, slightly convex; epider- 

 mis reddish-brown, shining ; whorls 8, with regular, equi- ^^^'- -^^■ 

 distant, elevated, oblique, rounded ribs, separated by dis- 

 tinct grooves ; suture deeply impressed; aperture flattened, 

 transverse, narrow; peristome thin, acute, thickened in- 

 ternally; within the base of the aperture, somewhat distant 

 from the margin, are 2 prominent, sublamelliform, white z. hiiernus. 

 teeth, not reaching the edge of the peristome; base smooth, polished, 

 umbilical region indented. Greater diameter, 5^"™; height, 3^'"™. 



Helix interna, Say, Joiirn. Acad., ii, 155 (1822); Binnp::v's ed., 18. — Binxey, Bost. 

 Journ. Nat. Hist., iii, 405, pi. xxi, fig. 1 (1840); Terr. Moll., ii, 24V, pi. xxx, 

 fig. 4.— De Kay, N. Y. Moll., 46 (1843).— Chemnitz, ed.2, i, 200, tab. ci, figs. 

 1-4.— Pfeiffer, Mou. Hell.Viv., i, 183.— Reeve, Con. Icon., 718.— W. G. Bin- 

 ney, Terr. Moll., iv, 121. 



Helix pomum-adami, Green, Doughety's Cab., iii, 35 (1834). 



Gastrodonta inierna, Tryon, Ain. Jouru. Couch., ii, 258 (1866). 



Hyalina inierna, W. G. Binney, L. &. Fr.-W. Sh., i, 49, fig. 79 (1869). 



Zonites internns,W. G. Binney, Terr. Moll., v, 133. 



A species of the Interior Region, traced thus far from the Alleghany 

 Mountains to Missouri, Ohio to Georgia. 



The teeth within the aperture are in general formed of a single promi- 

 nent lamina or tooth-like fold ; but sometimes one or both of them are 

 bifid, or even trifid. A second set often, and sometimes a third set of 

 teeth are seen through the transparent base of the shell, irregularly 

 situated, but generally having equal spaces between each two sets. 

 They are apparent in the youngest as well as in the oldest specimens, 

 and continue to be formed from time to time, so long as the shell in- 

 creases in size. They probably mark regular periods of growth, and 



