EASTERN PRUVINCK — NORTHERN R1:GI0N SPECIES. 177 



Vitriiiii linipida, Gould. 



Shell globose-discoid, thiu, fragile, transparent, shining ; whorls 2J 

 to 3, scarcely convex, with very minute lines of increase, the last whorl 

 large and much expanded ; suture not much impressed, some- fir. 170. 

 times with an impressed line revolving near it; aperture large, 

 subovate, somewhat diminished by the intrusion of the penul- 

 timate wliorl ; peristome thin and acute, the columellar margin umpida. 

 a little reflected ; axis imperforate. Greatest transverse diameter nearly 



VHrina pellucida, De Kay, N. Y. Moll., 25, pi. iii, fig. 42 (1843), not of MxJller. — 

 AoAMS, Sli. ofVt., 162.— BiNNKY, T. M., ii, 58, pi. Ixvii, a, fig. 1. 



Fitrina Americana, Pfkiffer, Proc. Zool. Soc, Der;., 1852, 1.56. — Chemnitz, erl. 2, 9, 

 pi. i, tigs. 22-25 (1854). 



Fitrina lim2nda,Govi.v, in Agassiz, Lake Superior, 243 (1850) ; Terr. Moll., 1. c. — 

 Pfeiffer, Malak. Blatt., ii, 10 (1856) ; Mou. H(3l. Yiv., iv, 798.— W. G. Bin- 

 NEY, T. M., iv, 33; v. 136. — Reeve, Cou. Icon., 62. — Morse, Joiirn. Portl. Soc, 

 i, 11, pi. V, fig. 17 (1864) ; in Amer. Nat., i, 314, fig. 20 (1867).— Try on, Am. 

 Journ. Conch., ii, 243 (1866).— W. G. Binney, L. &Fr.-W. Sli., i. 27 (1869).— 

 Gould .ind Binney, Invert, of Mass., ed. 2, 394 (1870). 



Found in Maine, Vermont, New Brunswick, and to the northwest of 

 Lake Superior, and at Troy, Utica, Mohawk, and I'almyra, N. Y. The 

 species may be said to belong to the Northern l\egion. 



Animal whitish, grayish, or blackish, large compared with the shell. 

 Head, eye-peduncles, and eyes black ; tentacles very short. The pro- 

 longation of the mantle extends from under the shell, over the back 

 and neck, to the base of the eye-])eduiicles, but is unattached and free; 

 from the right side of (lie nuintle posteriorly theie arises a tongue- 

 shaped process, wliich is retiected back upon the shell and reaches to 

 the spire. Ees])irato]y foramen in the posterior ])art of the mantle, 

 taken with its prolongation. 



In V. Umpida 1 have counted 71 rows of 3()-l-3(Heeth, with perfect 

 laterals. The seventh marginal is the largest. Another gave .JU-l-.^!*, 

 with 10 perfect laterals. The membrane figured by Morse had 30 rows 

 of 2o-l--!5 teeth, with laterals. I h;ne figured of this species, in Terr. 

 Moll., V", Plate II, Fig. C, one central and its adjacent lateral, and the 

 twenty-third tooth. The marginals increase in size up to the .seventh, 

 then gradually decrease. , 



In color the shell varies from almost white to dark horn. 



Should the species i^rove identical with the European ^e/Zi/ctofa, as 



. formerly believed, it must be considered a circumjjolar species. The 

 1749_r,ull. 28 V2 



