394 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
Pedicle valve very gently to moderately convex in lateral profile, gently con- 
vex in anterior profile. Umbonal region moderately swollen and continued an- 
teriorly to about the middle of the valve as a low, wide, and poorly defined fold. 
Posterolateral slopes gently concave. Anterior median half depressed into a 
shallow, wide sulcus; anterolateral areas very gently convex to flat. Interarea 
short, curved, apsacline. Beak scarcely protruding beyond the brachial beak. 
Brachial valve evenly and moderately convex in lateral profile, the greatest 
convexity located about at the middle; strongly convex in anterior profile. Pos- 
terolateral slopes steep; anterior and anterolateral slopes moderately steep. 
Median and anteromedian regions swollen. Interarea short, apsacline. Beak 
curved over pedicle interarea. Sulcus narrow and indistinct on umbo, narrow 
and shallow anteriorly or absent. 
Pedicle muscle field slightly longer than wide; adductor track narrow; diduc- 
tor impressions wide, not elongated noticeably anterior to the front of the muscle 
field. Brachial cardinalia characterized by delicacy and compactness for such 
large shells. Median ridge short, adductor field small. 
Measurements in mm.— 
Brachial Hinge 
Length length Width width Thickness 
Hypotype (110283k)........ 17.7 17.8 24.6 17.3 8.5 
: (o8216a)).). .2:d. ser 19.5 19.6 26.5 ? 10.2 
ee GOSS) okie ee. 17.0 17.2 23.0 16.2 8.2 
Types.—Holotype: M.C.Z. 8605; figured paratype: M.C.Z. 8606; figured 
hypotypes: 98215 (figured by Butts, 1942), 98216a, 110283e,¢,k; unfigured 
hypotypes: 110283a-d,f,h-j, I-n. 
Horizon and locality—Lincolnshire formation in Tennessee: $ mile northwest 
of Eidson, Kyles Ford (T.V.A. 170-SE) Quadrangle; Oakman; on shore of a 
small point in Norris Reservoir, 4 mile south-southeast of Oakman Tunnel, 
Dutch Valley (T.V.A. 154-SE) Quadrangle; ridge paralleling the railroad, 
Maloneyville, John Sevier (T.V.A. 146-SE) Quadrangle; 90 to 120 feet above 
the ‘““Mosheim” limestone on U. S. Highway 25E, 1 mile north of Indian Creek, 
Howard Quarter (T.V.A. 162-NW) Quadrangle; $ mile southwest of Mount 
Eager Church, 0.2 mile north-northwest of the main road, Hogskin Valley, 
Powder Springs (T.V.A. 154-SW) Quadrangle. 
Lincolnshire formation in Virginia: North of Copper Creek between Speers 
Ferry and Clinchport, Clinchport (T.V.A. 188-NW) Quadrangle; Marcem 
Quarry, 2 miles west of Gate City, Gate City (T.V.A. 188-NE) Quadrangle ; 
Templeton Branch, 5 miles northwest of Gate City; Speers Ferry, Clinchport 
(T.V.A. 188-NW) Quadrangle; 1.8 miles S. 4° W. of Bethel Church, Harrison- 
burg (15’) Quadrangle; 14 miles northwest of Oakwood; on Virginia Highway 
100 just north of junction with Highway 42, Staffordsville, Giles County ; north- 
west slope of Sinking Creek, 24 miles southwest of Huffman; about 200 feet 
east of Whistle Creek bridge on U. S. Highway 60 and 1,200 feet north of the 
highway, 14 miles northwest of Lexington, Lexington (15’) Quadrangle; branch 
of Moccasin Creek, 3 mile south-southwest of Tumbez, Moll Creek (T.V.A. 
