THE NATURAL HISTORY SURVEY. 191 
Distribution: Europe and America. 
KEY TO SPECIES OF GASTRODONTA. 
A eonell depressed, spire almost Mat neycmtis «oes (hae) cs he eas demissa 
Bsanell elohular, spire Much Clevated tis oivem enact ex re viele ce ana ligera 
73. Gastrodonta ligera Say, pl. xxviii, fig 14. 
Felix ligera Say, Journ. Phil. Acad., Vol. II,'p. 157, 1821. 
Helix rafinesguea FERUSSAC, Tab. Syst., p. 50, Hist. pl. li, a, fig. 5; pl. 
l, a, figs. 4, 5, 1822. . 
Helix wardiana LEA, Trans. Amer. Phil. Soc., Vo). VI, p. 67, pl. xxiil, 
fig. 82, 1839. 
Gastrodonta ligera stonet PILSBRY, The Nautilus, Vol. III, p. 46, 1889. 
(Variety.) 
Shell: Umbilicated, orbicular, convex; epidermis shining, 
straw-colored or yellowish-horn color, deep yellow onthe base 
of the last whorl, the color frequently running high up toward 
the suture; whorls seven, covered,with closely crowded, trans- 
verse striz, which disappear on the base of the shell; umbil- 
icus small, rounded and deep, appearing to extend clear to 
the apex of the shell; umbilical region impressed; sutures 
impressed; aperture rounded, semilunate, the base and side of 
the last whorl being covered by a thick, white deposit of tes- 
taceous matter, greatly thickening that portion of the shell; 
Animal of GASTRODONTA LIGERA Say. (Binney, fig. 68.) 
peristome thin, acute; spire elevated, exhibiting nearly all the 
whorls in a lateral view. 
Gr. diam., 12.00; lesser, 11.00; height, 9.50; umbil. diam., 1.00 mill. (8460.) 
Ss ie Bikes wrt se PLO smart 6.50; es SS Oo MES. Yeah) 
Animal (Fig. 41): With-a long and narrow foot, acutely 
pointed behind; color slaty-black on the upper surface, lighter 
on the base and posterior extremity, grayish on the collar; 
eye-peduncles tapering, slender, frather long, eyes placed as 
usual; other characters as described for the genus. 
Yaw: Not examined. Said by Binney to be “strongly 
arcuate, ends rounded; anterior surface striated; concave mar-’ 
gin with a well-developed median projection.” 
Radula formula: %$+'4+4+43¢+77 (38—1—38); centrals 
tricuspid, the central cusp long, the side cusps short; lateral 
teeth similar, but bicuspid, the inner cusp the longest; mar- 
