EASTERN PKOVINC: INTERIOR REGION SPECIES. 289 



Tri4>«loi><>»js BBiAccta, Say. 



Shell with the umbilicus closed, depressed; epidermis brownish horu- 

 color, with very fiue, hair like projections; whorls fig. 310/ 



5, with very minute transverse striie ; suture not 

 much impressed; aperture three-lobed, very much 

 contracted; peristome white, narrow, reflected, 

 with a deep groove or indentation behind the re- HeUx injiccta. 



flection, contracting the opening- so that the outer edge of the peristome 

 does not project beyond the surface of the whorl ; on the inner margiu 

 of the peristome are two acute teeth with the points directed inwards, 

 one near the base, the other midway between that and the junction of 

 the peristome with the body-whorl, with a circular sinus between them, 

 forming one of the lobes of the aperture; parietal wall with a long, 

 aicnated, white tooth; umbilicus covered, its place considerably im- 

 ])rossed. Greater diameter 12, lesser 11"""; height, 6§™". 



Jlelix wfltcta, Say, Joiirn. Phila. Acad., ii, 153 (1821); ed. Binney, 16. — Bixney, 

 Bost. Joni'ii. Nat. Hist., iii, 358, pi. ix, fig. 1 (1840) ; Terr. Moll., ii, 143, pi. 

 xlv, figs. 2, 3.— Die Kay, N. Y. Moll., 45 (1843).— Mrs. Gray', Fig. Moll. An., 

 pi. cxciii, fig. 7 (ex Bost. Joiirn., uo descr.) — W. G. Binxey', Terr. Moll., iv, 

 5'J ; L. & Fr.-W. Sb., i, 128, fig. 216 (1869).— Bland, Ann. N. Y. Lye, vii, 425. 

 — Pfeiffer, Mou. He). Viv., iv, 319. 



Hdix clausa, Feruss vC, Tab. S.vst., 38, No. 104; Hist., pi. Ii, fig. 2. — Deshayes, Eucycl. 

 Metb., ii, 252 (1830) ; in Lamarck, viii, 114; ed. 3, iii, 309; io Fer., i, 143. 

 — Pfkiffer, Mon. Hel. Viv., i, 420; in Chemnitz, ed. 2, i, 368, t. Ixiv, figs. 

 25, 26.— Rkeve, Cou. Icon., No. 704 (1852). 



Xoh)tre)na claiiiia, Rafinksque, Eunuieratiou, &c., 3 (1831); ed. Binney and Tryun, 



Isofj 110)11 ostoiiia injlcrlii, Tkyox, Am. Journ. Concb., iii, 54 (1867). 

 'J'riodopgiis bijlccUi, W. G. Binney, Terr. Moll., v, 305. 



X Post Pliocene species, now found in the Interior Eegion, from 

 Texas to the Api)alachian Chain in Peuu.«3 Ivania and New York, 

 from sea islands of Georgia through the Northwestern States. 



The l.irger specimen here figured is from University Place, Tenn. 

 where the species seems most developed. 



Animal daik-bluish slate-color; head, eye-peduncles, and tentacles 

 almost black; eye-peduncles long and slender; foot narrow, in length 

 more than twice in diameter of the shell, terminating in an acute angle 

 (see Dost. Journ. X. H., I, Plate, IX). 



Jaw thick, short, broad, arched, of almost uniform width quite to the 

 blunt ends, with 14 stout, crowded ribs, visible on both anterior and 

 posterior surface and denticulating either margiu. 



' Tbe birsute cbaracter of the epidermis is not shown in the figure. 

 1749— BuU. 28 19 



