VITRINA. 137 



Vitrina Americana, Pfeiffeh, Dec. 1852, Proc. Zool. Soc, 156. — Chemnitz, 

 ed. 2, 9, PI. I. Figs. 22-25 (1854). 



Vitrina limpida, Gould, in Agassiz' Lake Superior, p. 243, 1850 ; Terr. Moll., 

 1. c. — Pfeiffer, Malak. Blatt., II. 10 (1856) ; Mon. Hel. Viv., IV. 798.— 

 W. G. Binney, T. M., 33. — Reeve, Con. Icon., 62. — Morse, Journ. Portl. 

 Soc, I. 11, PI. V. Fig. 17 (1864) ; in Amer. Nat., I. 314, Fig 20 (1867).— 

 Tiiyon, Am. Journ. Conch., II. 243 (1866). — W. G. Binney, L. & Fr.-W. 

 Sli., I. 27 (1869). — Gould and Binney, Invert, of Mass., ed. 2, 394 (1870). 



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

 Superior, and at Troy, Utiea, Mohawk, and Palmyra, N. Y. The species may 

 be said to belong to the Northern Region. 



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

 eye-peduncles, and eyes black ; tentacles very short. The prolongation of the 

 mantle extends from under the shell, over the back and neck to the base of 

 the eye-peduncles, but is unattached and free ; from the right side of the man- 

 tle posteriorly there arises a tongue-shaped process, which is reflected back 

 upon the shell, and reaches to the spire. Respiratory foramen in the nosterior 

 part of the mantle, taken with its prolongation. 



In V. limpida I have counted 71 rows of 30 — 1 — 30 teeth, with 9 perfect 

 laterals. The seventh marginal is the largest. Another gave 39 — 1—39, 

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

 25 — 1 — 25 teeth, with 9 laterals. I have figured of this species, on PI. 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 prove identical with the European pellucida, as formerly 

 believed, it must be considered a circumpolar species. . The complete anatomy 

 of pellucida is given by Lehmann (Lebenden Schnecken, 47, PI. IX. Fig. 

 12). His count of the teeth, 103 rows of 37 — 1 — 37 teeth, does not agree with 

 our species as to number of transverse rows, but that may be far from indicat- 

 ing specific difference. 



Vitrina Angelicas, Beck. 



Shell convexly depressed, smooth, polished, pellucid, greenish-yellow ; spire 

 short, subprominent ; suture delicately crenulated ; whorls 3^, rapidly increas- 

 ing, the last broad below ; aperture oblique, lunate-oval ; peri- 

 stome simple, subinflected, its columellar margin not receding and 

 slightly arched. Greatest diameter 6, lesser 4§ mill.; height, 

 3| mill. 



Vitrina Angelica, Beck, Ind. 1. — Mollek, Ind. Moll. Gr., 4 

 (1842). —Pfeiffer, Mon. Hel. Viv., II. 510. — Morch, Nat. 

 Bidr. af Gr., 76. — W. G. Binney, T. M. U. S., IV. 32, PI. LXXIX. Fig. 9. 

 — Reeve, Con. Icon., 45. — Tryon, Am. Journ. Conch., II. 243 (1866).— 



