856 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
Pedicle valve gently convex in lateral profile but with the anterior third some- 
what flattened; anterior profile gently convex; median region slightly swollen. 
Interarea short, strongly apsacline; foramen large. 
Brachial valve unevenly convex in lateral profile, the posterior half somewhat 
flattened but the anterior half gently convex; median region marked by a shal- 
low, irregular sulcus extending from the beak to the anterior margin; flanks 
bounding sulcus swollen; lateral slopes short and moderately steep. 
Measurements in mm.—Holotype, length 8.5, brachial length 8.4, midwidth 
10.8, hinge width 9.0, thickness 2.8. 
Type.—Holotype: 117653. 
Horizon and locality.—Bromide formation (Mountain Lake member) in Okla- 
homa: From the top of the green shale on the east side of the cut on Oklahoma 
Highway 18, 1.8 miles south of Sulphur, Murray County. 
Discussion—This species is characterized by its small size and the com- 
pressed, biconvex form. It is suggestive of B. subquadrata but is a smaller and 
differently shaped species. Furthermore, the wrinkling of the two species is 
quite different. Bellimurina compressa is marked by finer wrinkles, particularly 
in the marginal regions, than B. subquadrata. 
BELLIMURINA CONCENTRICA Cooper, new species 
Plate 222, A, figures 1, 2 
Shell of about usual size for the genus, wider than long and with the hinge 
forming the greatest width. Sides gently oblique; anterior margin rounded. 
Pedicle valve gently convex in both profiles; umbo somewhat swollen; antero- 
median region marked by a shallow depression. Umbonal and posterior region 
marked by fine interrupted wrinkles; anterior and lateral areas marked by 
strong, discontinuous wavy wrinkles. Brachial valve gently convex. 
Measurements in mm.—Holotype, length 9.8, midwidth 14.4, hinge width 15.4, 
thickness 1.9?. 
Type.—Holotype: 117650. 
Horizon and locality.—Pierce formation in Tennessee: At Pierce Mill, on 
Stone River at crossing with Tennessee Highway 10 just south of Walterhill 
about 74 miles north of Murfreesboro, Rutherford County. 
Discussion.—This is a fairly large species definitely suggestive of Leptaena 
but not strongly geniculated. The umbonal and median regions are marked by 
the short, interrupted wrinkles characteristic of Bellimurina. The strength of 
the wrinkles of this species suggest B. subquadrata, but concentric wrinkles of 
the lateral and anterior region are much stronger and more regular. No other 
described species is really very close to this one. 
BELLIMURINA PARVIPLICIFERA Cooper, new species 
Plate 222, B, figure 3; plate 223, C, figures 5, 6 
Shell moderately large for the genus, wider than long and with the hinge 
forming the widest part; sides rounded, somewhat oblique; surface marked by 
