442 
PALEONTOLOGY OF NEW YORK. 
In form, this shell is very like the preceding, but uniformly smaller in size 
and marked by more or less distinct, angular concentric ridges. The variation 
of form, and surface characters, is illustrated in the figures cited on plate lxxii. 
It also resembles Lucina lineata, Goldfuss (Pet. Germ., p. 226, pi. 146, fig. 8), 
from the Devonian of the Eifel, and may not be specifically distinct. 
Formations and localities. Very abundant in the shales of the Hamilton group, 
in the eastern and central parts of New York, and in the cherty layers above 
the Hydraulic beds at the falls of the Ohio, and in Clarke county, Ind. 
Paracyclas Ohioensis. 
PLATE LXXII, FIG. 1; AND PLATE XCV, FIG. 24. 
Lucina ( Paracyclas) Ohioensis, Meek. Proc. Acad. Nat. Sci., Phila., p. 6. 1871. 
“ “ “ “ Pal. Ohio, vol. ii, p. 199, pi. 18, figs. 7 a, b. 1873. 
In part Paracyclas lirata (Conrad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 72, 
figs. 1-19. 
This species is a smaller and more delicate form than P. lirata , and with 
much finer concentric strise; the anterior end is more produced and flattened 
than in either of the preceding species, and the posterior depression, caused by 
the ligamental groove, is more oblique and more decidedly marked on the exte¬ 
rior of the shell. 
The posterior extension, as shown by Mr. Meek, is exaggerated in the origi¬ 
nal figures, giving the aspect of an appendage or extension on the posterior 
side, while it is only that part of the post-cardinal slope above the ligamental 
groove. Fig. 7 b ( loc. cit.) well represents the form of the species. A compar¬ 
ison of several specimens of this species, with a large collection of P. lirata , 
shows it to be a very distinct form. 
Formation and localities. The original specimens were derived from Dublin, 
Ohio. The specimens which have come under our observation are from cherty 
beds above the Corniferous limestone at the falls of the Ohio and in Clarke 
county, Ind. 
