GASTEROPODA OF THE LOWER GREEN MARLS. 131 
This species is the most elevated form found in the New Jersey marls 
and is at the same time the most erect. It closely resembles Gyrodes altispira 
of the same author, and in internal casts can be distinguished only by the 
very slight flattening of the volution adjacent to the suture, and perhaps in 
a very slightly greater rotundity of the body volution of that species. So 
far as can be ascertained from the specimens in hand, there has been no 
thickening of the columeliar lip to form a callus or any marking on it what- 
ever, and the substance of the lip has been rather thin. Mr. Gabb compares 
it with N. paludineformis H. & M., from the Upper Missouri region, which 
it very closely resembles, and speaks of its open umbilicus. This is not to be 
considered as meaning a wide open umbilicus, but one not solid as in that 
species. 
Formation and locality: In the Lower Green Marls at Mullica Hill, near 
Burlington, near New Egypt, and other places in New Jersey. 
Genus AMAUROPSIS March. 
AMAUROPSIS MEEKANA, 0. Sp. 
Plate xvi, Figs. 22-25. 
Amauropsis paludineformis (in part) Gabb: Synopsis, p. 38; Proc. Acad. Nat. 
Sci., Phila., 1876, p. 296. ; 
Not Amauropsis paludineformis (Hall and Meck) Meek: U.S. Geol. Surv. Terr., 
Invert. Pal., vol. 9, p. 318, Pl. x1x, Fig. 15. 
Not Natica paludineformis Hall and Meek: Mem. Am. Acad. Arts and Sciences, 
Boston, new series, vol. 5, p. 389, Pl. 11, Fig. 3; D’ Orb., Prod. Pal., 1850, 
vol. 2, p. 312. 
Shell of medium size, elongate-subovate; spire moderately elevated, 
only about two-thirds as high above the aperture as the length of the aper- 
ture; volutions five or five and a half in the largest specimen; ventricose, 
with distinct, well marked sutures, which are very slightly channeled; 
body volution more distinctly ventricose than the others; axis solid; aper- 
ture ovate, acute at the upper end, rounded and slightly effuse below; 
outer lip thin and sharp; columella somewhat thickened by the deposit of 
the lip, and grooved below the margin of the deposit, but not umbilicate; 
surface of the shell marked by proportionately strong, transverse lies of 
