EASTERN PROVINCE INTERIOR REGION SPECIES. 291 



those of tndenfafa, but distiuguished by the genital bladder, which is 

 small, globular, on a duct of equal width throughout its course, not 

 swelling as it approaches the vagina. 



Triodopsis trldciatata, Say. 



Shell umbilicated, orbicularly dei)ressed, with crowded, rib-like stri£e, 

 light horn or chestnut colored; spire very short; Tig. 312. 



whorls 5.^, rather convex, the last scarcely deflected 

 in front; aperture lunar, subtriangular; peristome 

 white, reflected, its outer contour rounded, thickened 

 within, its terminations converging, joined by a light 

 deposition of callus, bearing a tongue-like, erect, en- 

 tering tooth, both the right and basal portions bear- 

 ing on the inner margin a stout, acute denticle. i. truientata. 

 Greater diameter 16, lesser 14""'; height, 8"™. 



Helix tridentata,^.\x,W\c\\.'E.nQ.\c\.,Y>\. ii.fig. 1(1817-'19); Einney's ed., 6, pi. Ixx, 

 fig. 1.— Eaton, Zool. Text-Book, 193 (1826).— F^bussac, Tab. Syst., 38; 

 Hist., pi. li, fig. 3.— WooT>, Ind. Supplem., 21, pi. vii, fig, 2 (18-^8); ed. Han- 

 ley, 226, fig. 11.— Deshayes, Eiicycl. Mf^tli., 11,213(1830) ; iu Lam., viii,llo; 

 ed. 3, 309; iu F^R., 1. c, i, 72.— BiNXEY,Bost. Jouru. Nat. Hist., iii, 382, pi. 

 xvii (1840), part; iu Terr. Moll., ii, iK?, pi. xxvii.— De Kay, N. Y.Moll., 28, 

 pi. ii, fig. 7 (1843). — Adams, Venuont Mollusca, 160 (1-42). — Gould, Iiiverte- 

 brata, 173, fig. 115 (1841).- Pp'eiffer, Mon. llel. Viv., i, 412 ; in Chemxitz, 

 - ed. 2, i,84, pi. x, figs. 7, 8. — Potikz et Michaud, Gal., i,ll4.— Mus. Gray, 

 Fig. Moll. Ad., pi. ccxci, fig. 3 (ex Bost. Jonrn., no deser.). — Reeve, Con. 

 Icon., No. 690 (18.^)2). -W. G. Binney, Terr. Moll., iv, 70 ; L. »fc Fr.-W. Sh., 

 i, 129 (1869).— Bland, Ann. N. Y. Lye, vii, 423.— Morse, Amer. Nat.,i, 150, 

 figs. 8, 9 (1867).— Gould and Binney, Idv. of Mass., ed. 2, 422 (1870). 



Triodopsis htuula, Rafinesque, En. and Ace., 3; ed. Binney and Tryon, 68. 



Triodoims nideniata, Tryon, Am. Jouru. Conch., iii, 50 (1867).— W. G. Binney, Terr. 

 Moll., V, 308. 



, Lister, pi. xcii, fig. 92. 



From Canada through all Eastern North America. A species of 

 the Eastern Province. 



A curious pathological specimen, with a double peristome, is figured 

 here. 



Animal dark-bluish slate-color, deeper on the head, eye-peduncles, 

 and tentacles ; length of eye peduncles about a quarter of fig. 313. 

 an inch ; foot narrow, equal iu length to near'y twice the ^^^!f^^^-^,_ 

 diameter of the shell, terminating in an acute angle (see B. ^ . j 



J. :N". H., I, Plate XVII). r. irUMla. 



Jaw as usual ; over 10 ribs. 



The lingual membrane (Terr. IMoU., V, Plate VII, Fig. M) has 2o-l- 



