Strophomena and Other Fossils 
133 
lies above the Dinorthis ulrichi-Strophomena vicina horizon, re- 
garded as corresponding to the Cornish ville limestone. 
Excellent specimens of Orthorhynchula linneyi are found in 
a very fine-grained, white limestone, belonging to the Perry- 
ville horizon, about 4 miles north of Versailles, Kentucky. The 
locality is reached by going from Wallace nearly IJ miles west 
and then about the same distance southward, to a turn in the 
road. The exposures are poor, but loose blocks dragged out 
from the fields west of the road present beautiful specimens of 
Orthorhynchula, together with Tetradium and other fossils usually 
found in the lower part of the Perry ville bed, such as Isochilina 
jonesi. In the specimens of Orthorhynchula, the beaks of both 
valves are less incurved than in the Catheys or Fairmount spec- 
imens, so that the delthyrium is better exposed. 
Trematospira granulifera, Meek^^ 
{Plate VIII, Fig. 5, enlarged) 
Pedicel valve with shallow sinus. Median plication narrow, 
bifurcating, 2 mm. from the beak, into two narrow branches, 
which at the anterior margin are 0.7 mm. distant from each other. 
On each side of the resulting median pair of plications there is a 
distinctly larger plication, forming the sides of the sinus poste- 
riorly, but lying within the depression of the sinus anteriorly. 
The axes of this second pair of plications are about 3 mm. 
distant from each other at the anterior margin of the valve. The 
third pair of plications, counting from the median pair outward, 
forms the sides of the sinus anteriorly. Their axes are 6 mm. dis- 
tant from each other anteriorly. Near the beak, all the plica- 
tions, except the median bifurcating one, are approximately of 
the same size, but anteriorly they differ considerably. The 
width of each of the two branches of the median plication is 0.8 
mm. The first plication on each side of this median pair is 
from 1 to 1.2 mm. wide. The second plication on each side, 
counting from the median pair, varies from 2.2 to 2.4 mm. in 
width. The third, fourth, and fifth plications on each side also 
are of considerable width, and, together with the second pair, 
Proc. Acad. Nat. Sci. Philadelphia, 1872, p. 318. Ohio Paleontology, vol. i, p. 
128, 1873. 
