38 
Aug. F. Foerste 
None of these specimens was found in place. The two speci- 
mens collected at Stony Point, east of Higginsport, were obtained 
just above the level of the railroad, among debris regarded at the 
time of collecting as of lower Eden, or Economy age. The speci- 
men from Ivor, in Pendleton county, was found in the quarry a 
quarter of a mile east of the railroad station, and evidently had 
fallen from some ledge exposed in the upper part of the quarry 
wall. Since both the Winchester or Cynthiana formation, and the 
lower part of the Eden are exposed here, the exact horizon must 
remain in doubt. 
The danger of founding a new species on the interiors of three 
ventral valves of a species of Strophomena are too obvious to 
require comment. The possibility of these specimens belonging 
to the widely spread species of the Eden, Strophomena hallie, 
must be taken into account. Contrasted with the latter species, 
the following differences are noted. The outline of the shell 
in Strophomena hallie is distinctly more triangular. The brachial 
valves are strongly convex, and hence the pedicel valve always is 
distinctly, although not necessarily strongly concave. Compared 
with the width, the shell is relatively longer. The muscular area 
is more circular in outline, and is relatively broader. The sides 
of the delthyrium are more divergent, forming an angle of about 
100 degrees. The surface striae are coarser. Usually the speci- 
mens of Strophomena hallie also are distinctly smaller, equalling 
about 22 to 25 mm. in width, but one large valve from the lower 
Eden 1 mile west of Foster, in Bracken county, Kentucky, trian- 
gular in form, and referred to this species, measures 37 mm. in 
width, 27 mm. in length, and has a round muscular area 9 mm. 
wide. 
Strophomena hallie, Miller^ 
{Plate II, Figs. 1 A, B, C, D, E; 2) 
Strophomena hallie was described by S. A. Miller from Cincin- 
nati, Ohio. The types were found about 150 feet above low water 
mark on the Ohio Biver, in an excavation made for Columbia 
Avenue. This places their horizon in the Southgate or middle 
Eden bed. The types are preserved in the Faber collection, in 
the W alker Museum at Chicago University. They are numbered 
^Cincinnati Quarterly Journal of Science, vol. 1, p. 148^ 1874. 
