PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 967 
long, steep slopes. Median region folded medianly. Beak narrow, strongly in- 
curved, Interarea curved, steeply apsacline. 
Brachial valve evenly and moderately convex in lateral profile, broadly and 
gently convex in anterior profile. Sulcus broad and shallow; flanks gently in- 
flated, with short and moderately steep slopes. 
Measurements in mm.— 
Brachial Hinge 
Length length Width width Thickness 
PIOIGEV DG 6 aidseis «x alc ates E- 6.7 8.1 6.0 4.5 
Paratype (117281b)..... 7.6 7.2 9.0 UE 4.2 
o (UIZZ5TOa ac. 6.8 6.5 7.9 6.4 3.9 
Types.—Holotype: 117281a; unfigured paratypes: 117281b-d. 
Horizon and locality—Ward Cove formation in Fountain City (T.V.A. 
146-SW) Quadrangle, Tenn.: Inskip, military coordinates E-2, 604, 600- 
700/N596, 350; Hickey place, 2 miles southwest of Hall Crossroad. 
Discussion.—This is a rare species and is known only from a few silicified 
specimens. It is strongly fasciculate, but the fascicles are narrower than those of 
P. fasciculata. The species is more strongly sulcate and more strongly fasciculate 
than P. catawbensis. 
PAURORTHIS GIGANTEA Cooper, new species 
Plate 260, F, figures 25-31 
Large for the genus, subcircular in outline with the length and width nearly 
equal; sides rounded; anterior margin rounded; hinge narrow, in width about 
two-thirds the length. Anterior commissure gently sulcate. Surface fascicostel- 
late, fascicles low, generally best defined near the valve middle. Costellae fine, 
rounded, closely crowded, numbering 4 or 5 in 1 mm. at the front margin of an 
adult. 
Pedicle valve unevenly convex in lateral profile, the maximum curvature being 
located in the umbonal region and the anterior two-thirds gently convex; an- 
terior profile strongly domed. Median region from umbo to anterior margin 
somewhat swollen to form an ill-defined fold; flanks gently swollen and steep. 
Interarea long, curved; beak strongly incurved. Interior with deep delthyrial 
cavity and prominent median ridge anterior to it. 
Brachial valve less convex than the pedicle valve, gently convex in lateral pro- 
file with the maximum convexity in the posterior third; anterior profile broadly 
and gently convex. Anterior half flattened and bearing a poorly defined shallow 
sulcus. Flanks gently swollen. Interarea long and curved. Interior unknown. 
Measurements in mm.— 
Brachial Hinge 
Length length Midwidth width Thickness 
FIGIOEVDE ic \s 2c cataract aek 19.0 17.8 18.2 13.1 II.1 
Paratype .(124235b)......... 16.9 15.8 17.0 rit 9.0 
Types.—Holotype: 124235a; figured paratype: 124235c; unfigured paratypes: 
124235b, d-f. 
