82 
Aug. F. Foerste 
lamellae which are only 1.5 mm, in length, and are separated ante- 
riorly by a space about 1.4 mm. in width. A sharp striation bor- 
ders the sides of the aperture leading to the beak. 
Clinton bed: south of the old abandoned Cement Mill, south of 
Clifton, Tennessee. 
The type of Triplecia is Triplecia extans, a smooth shell. From 
this Triplecia striata differs sufficiently in general appearance to 
warrant the erection at least of a subgeneric term. For the striate 
species, resembling Triplecia striata, the term Cliftonia is here 
suggested. Possibly Triplecia niagarensis. Hall and Clarke is 
congeneric. 
? Triplecia (Cliftonia) tenax, sp. nov. 
{Plate III, Fig. 56 ; Plate IV, Figs. 70 A, B.) 
Shell with the external aspect of a F[ebertella, but apparently 
so similar in form to Triplecia {Cliftonia) striata, that these shells 
are regarded as very closely related, although the interior structure 
of Triplecia tenax is not known. Compared with Triplecia striata, 
Triplecia tenax is a larger, broader, and less strongly convex shell. 
It possesses the low broad median fold on the anterior part of the 
brachial valve, and the broad, shallow depression along the ante- 
rior part of the pedicel valve. The median groove toward the beak 
of the brachial valve is distinct. The hinge area on the pedicel 
valve is well defined, but nothing is known about the delthyrium. 
The radiating striations are distinctly stronger than in Triplecia 
striata, especially in case of che primary striae. Between 6 and 7 
striations are found in a width of 5 mm. Concentric markings 
indistinct on the considerably exfoliated surface of the shell. 
Length, 13.5 mm.; width, 18 mm.; depth, 9 mm. Length of 
hinge line, 10 mm. Height of hinge area, about 1.6 mm. Convex- 
ity of valves approximately equal. Radiating striae increased by 
implantation of additional striae at various distances from the beak, 
resulting in a fasciculate arrangement. 
Osgood bed: Clifton, Tennessee. 
Schuchertella roemeri. 
{Plate II, Figs. 27 A, B, C.) 
Shell evidently related to Orthothetes subplanus with which it 
usually is identified, but the shell is smaller, the number of radiat- 
ing plications is smaller, and the intermediate spaces much broader. 
