PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 929 
STROPHOMENA AUBURNENSIS NASUTA Cooper, new subspecies 
Plate 257, B, figures 3-12 
Strophomena incurvata Forrste (not Shepard), Bull. Sci. Lab., Denison Univ., vol. 17, p. 24, 
pl. 11, fig. 7, 1I912—Butrts (not Shepard), Alabama Geol. Surv., Special Rep. 14, pl. 31, 
figs. 25-27; pl. 33, figs. 3, 4, 1926. 
Shell large for the genus, subrectangular in outline; hinge usually forming 
the greatest width; sides nearly straight; anterior margin strongly rounded and 
generally somewhat nasute. Costellae unequal in size, 1 or 2 fine ones alternat- 
ing with stronger ones, and 13 to 16 costellae occupying 5 mm. at the front 
margin. 
Pedicle valve deeply concave in lateral profile and with the maximum con- 
cavity in the median region; umbonal region marked by a low and narrow fold 
that disappears at about one-third the length from the beak; posterior third 
gently concave, median third deeply concave and anterior third less concave than 
the preceding. Sides and anterior strongly reflected toward the pedicle valve. 
Cardinal extremities more or less auriculate, deflected sharply toward the brachial 
valve ; interarea moderately long, strongly apsacline. 
Brachial valve unevenly convex in lateral profile, the posterior third flattened 
but the anterior two-thirds strongly convex ; anterior profile strongly and broadly 
convex; umbo marked by a fairly wide but shallow sulcus that extends nearly 
to the valve middle; posterior third flattened ; anterior two-thirds strongly swol- 
len and with steep lateral and anterior slopes. Posterolateral slopes long but only 
moderately steep; cardinal extremities strongly deflected toward the brachial 
valve. 
Interior of pedicle valve with large subcircular to quadrate muscle scar, the 
anterior end of which reaches to about the valve middle; teeth and dental ridges 
strong; sides of muscle field with a thick and strongly elevated rim reaching 
nearly to the front of the scar. Subperipheral rim thick and beaded by numerous 
pallial distributaries. Brachial interior with short, stout cardinal process and 
delicate socket cups. Median ridge short. 
Measurements in mm.— 
Brachial Hinge 
Length length Midwidth width Thickness 
FIGIGty Pee ens a eaties cep eioees 20.4 28.6 37.0 35.2 5.8 
Paratype'*(45507b)'...'2 2 S22) 2! 26.5 ? 28.3 31.6 ? 
“ (87008) Hsia. 28% 32.0 ? 36.4 40.7 ? 
Types.—Holotype: 45507a; figured paratypes: 45507b, 87091, figured hypo- 
type: 117703a; unfigured paratypes: 45507c,d. 
Horizon and locality—Tyrone formation in Kentucky: At High Bridge, 
Harrodsburg (30’) Quadrangle. 
Carters formation in Tennessee: On the north side of U. S. Highway 70S, 
0.8 mile east of Readyville, Rutherford County; McKnights Branch, 2 miles 
west of Willow Swamp School, Woodbury (15’) Quadrangle; 1 mile east of 
Mount Carmel Church, same quadrangle; road crossing Watson Branch, 4 mile 
southwest of Conico Church, Franklin (15’) Quadrangle; on U. S. High- 
