134 
Aug. F. Foerste 
form the prominent, sharp, angular plications of the valve. The 
sixth plication, near the hinge-line on each side, is inconspicuous. 
It is impossible to determine from the specimen whether the 
opening at the beak is due to breakage or not. The beak of the 
pedicel valve laps over that of the brachial valve, and hides the 
latter. 
Brachial valve with median plication narrow, beginning 2 mm. 
from the overlapping beak of the pedicel valve, and remaining 
narrow as far as the anterior margin, where its width is 0.7 mm. 
The first and second plication, on each side of this median one, 
are 1 mm. wide, and belong to the median fold, so that this fold 
bears 5 plications, while the corresponding median sinus of the 
pedicel valve contains only 4 plications. The ridges of the exte- 
rior plications on the fold of the brachial valve are 4 mm. distant 
from each other, and their exterior sides slope downward into 
the deep groove separating the second from the third plication. 
The third, fourth, and fifth pairs of plications are prominent, and 
are separated by deep wide grooves. The sixth plication on 
each side, counting from the median one, is considerably less 
prominent, though considerably more prominent than the sixth 
plication of the pedicel valve. 
Not the slightest trace of a hinge-area is seen on the brachial 
valve, and practically none in the case of the pedicel valve. 
Surface with low, and rather distant, concentric lines of growth. 
Minute granules, probably connected with a minutely porous 
structure of the shell. Much larger granules, rather irregularly 
arranged, but more frequently approximately in line with the 
concentric lines of growth. 
Length, 10 mm.; width, 13 mm.; depth or thickness, 7.2 mm. 
The type, numbered 1622, is preserved in the Dyer collection 
at Harvard University. 
The features which suggest the propriety of referring this species 
to Trematospira, in the absence of all knowledge of the interior, 
are the close enfolding beak of the pedicel valve, obscuring the 
view of the deltidial plates, and the numerous minute granules, 
suggesting an abundantl}^ punctate structure for the shell; also 
the presence of a fairly distinct median fold and sinus. It seems 
so imiprobable that any species of Trematospira could occur in 
Cincinnatian strata, that I have suspected for some time that 
eventually Trematospira granulifera would turn out to be an 
