1002 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
Benbolt formation in Tennessee: In Raccoon Valley just east of Edgemoor, 
3.1 miles southwest of Claxton, Clinton (T.V.A. 137-SW) Quadrangle. 
Pierce formation in Tennessee: At old Pierce Mill on Stone River just south 
of Walterhill, 74 miles north-northeast of Murfreesboro, Rutherford County. 
Ridley formation on Kensington (T.V.A. 106-SE) Quadrangle in Georgia: 
1 mile south-southeast of Cove Church, 5 miles south of Chickamauga; on U. S. 
Highway 27, 4.3 miles north of Rock Spring. 
Chickamauga limestone (=Ridley part) in Alabama: 2 miles southwest of 
Argo, Birmingham (30’) Quadrangle. 
Wardell formation (upper part) in Virginia: At Hagan, Rose Hill (T.V.A. 
161-NE) Quadrangle= Woodway formation of Miller and Brosge. 
Discussion.—This species is characterized by its large size, strong and sub- 
equal convexity of the valves, the subequal depth of the valves, the strong cos- 
tellae with numerous swollen ribs of the first and second generations, and well- 
defined fasciculation. The individuals of this species attain the largest size of 
any known species of this genus. The stronger ribbing, the numerous, swollen 
ribs, more convex valves, and lesser carination of the pedicle valve distinguish 
this species from F. subcarinata. 
FASCIFERA SUBCARINATA Ulrich and Cooper 
Plate 152, A, figures 1-13; plate 153, A, figures 1-6; plate 153, C, figures 10-32; 
plate 155, F, figure 31 
Fascifera subcarinata ULricH and Cooper, Journ. Paleont., vol. 16, No. 5, p. 620, pl. go, 
figs. I-5, 1942. 
Shell of about medium size, nearly circular in outline, with rounded lateral 
and anterior margins. Hinge narrower than the greatest shell width which is at 
about the middle. Cardinal extremities obtusely rounded. Surface costellate, 
costellae appearing in 4 generations and somewhat fasciculate near the margins ; 
4 costellae occupy I mm. at the front margin. 
Pedicle valve gently and evenly convex in lateral profile, with elevated and 
slightly incurved beak. Anterior profile subcarinate with moderately steep, flat- 
tish slopes. Umbonal and median regions subcarinate, the angularity decreasing 
anteriorly from the middle. Interarea slightly curved, moderately long, apsacline. 
Delthyrium open except for a short plate at the apex. Interior with well- 
developed, divergent dental plates defining shallow umbonal cavities. Diductor 
scars elongate, adductor field moderately wide. Vascula media short, usually 
indistinct, divergent. 
Brachial valve more convex than the pedicle valve in lateral profile; anterior 
profile broadly but gently convex; umbo gently convex; sulcus originating just 
anterior to the umbo, narrowly U-shaped in outline, widening very slightly an- 
teriorly and extending nearly to the anterior margin. Interarea short, anacline. 
Brachiophores moderately long, acute, supported by thin plates that converge to 
the floor of the valve on each side of the median ridge. Notothyrial cavity deep, 
cardinal process small. 
