428 helicidj:. 



distinct ; foot but two thirds length of shell, whitish ; the body, 

 disk, and mantle are marked with white dots, the edge of the man- 

 tle is of the same color as the head and cye-pedun- 

 Fis. 086. ^|gg^ rpjjg jjgl_, -g i-ounded posteriorly, and broad 



and truncated anteriorly, the lateral borders are 

 deeply crenulated. Tlie head is separate from the 

 disk as in the PtipincB^ bearing two minutely crenu- 

 Animai of H? harpa. latcd lappcts, wliicli liaug dowu ou either side of the 

 mouth like a visor, reminding one of the oblique 

 folds on the head of Glandina truncata, which we believe to be ho- 

 mologous to them. A longitudinal furrow extends from the mouth 

 downward. The body is so translucent that when extended the 

 ganglionic centres can be plainly seen. In motion they are exceed- 

 ingly graceful, at times poising their beautiful shell high above their 

 body, and twirling it around not unlike the Pliysa^ again hugging 

 their pretty harp close to their body, the shell when in this last 

 position continually oscillates as if the animal could not balance 

 it ; it rarely ever moves in a straight line, but is always turning 

 and whisking about, and this is done at times very quickly and 

 abruptly. (^Morse.^ 



Helix pulchella. 



Fig. 102. 



Shell minute, Avhite, depressed ; whorls four, suture deep ; aperture circular, lip 

 reflexed, thickened ; umbiHcus large. 



Helix pnlchclld, Muller, "Verm. 30. — Pfeiffer, Mon. IIcl. Viv. i. 365. — Bixney, 



Bost. Journ. Nat. Hist. iii. 375, pi. 9, %. 2 (1840) ; Terr. .Aloll. ii. 175, pi. 17, fig. 1. 



— Leidv, Terr. Mull. U. S. i. 256, pi. 9, figs. 7_9 (igol) anat. — Gould, Inv. 176, 



fig. 102 (1841). — Adams, Vermont Moll. 159 (1842). 

 Helix minuta, Say, Journ. Acad. i. 123 (1817) ; Nidi. Encyc. .3d cd. (1819); Binney's 



ed. 3. -De Kay, N. Y. Moll, 40, pi. 3, fig. 33 (1843). 

 Helix coftata, Muli.er, i:idi' Pfeiffer, Mon. Hcl. Viv. i. 366. 

 Vallonia minntn, Morse, Journ. Portl. Soc. i. 21, figs. 54, 56; pi. 8, fig. 57 (1864). — 



Tryon, Am. Journ. Conch, iii. 36, pi. 7, fig. 26 (1867). 



Shell minute, semi-transparent, white, or very light horn color, 

 thin, depressed ; whorls four, very minutely marked with lines of 

 growth, the last spreading at the mouth like a trumpet ; suture 

 deeply impressed : aperture circular, the lip very nearly surround- 

 ing it, much thickened, white, and reflected ; umbilicus large, ex- 

 hibiting all the volutions within. Diameter one tenth of an inch. 



Animal pale, semi-transparent. 



