PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 903 
Same formation in Virginia: On Hiatt Run, 3 miles north of Winchester, 
Winchester (15’) Quadrangle. 
Elway formation in Giles County, Virginia: On Sinking Creek, 12 miles 
northwest of Blacksburg. 
Same formation in Tennessee: On U. S. Highway 25W, 4.7 miles south of 
Clinton, Powell Station (T.V.A. 137-SE) Quadrangle. 
Lincolnshire formation in Virginia: On the Norfolk and Western RR. 4 mile 
upstream from Benton Station, Giles County. 
Discussion.—This species is more strongly costellate than P. ? dubia. The 
pedicle valve is marked medianly by a narrowly folded umbo and the brachial 
valve has a corresponding sulcus, both features being better developed than on 
corresponding parts of the Effna species. It is larger and more finely fasciculate 
than P. pulchra from the Grazier limestone of Pennsylvania. 
PIONOMENA PULCHRA Cooper, new species 
Plate 248, C, figures 4-7 
Shell small, unequally biconvex, the pedicle valve having the greater con- 
vexity. Hinge narrower than the greatest width which is at about the middle. 
Sides and anterior margin well rounded. Surface fascicostellate. 
Pedicle valve somewhat carinate umbonally but with flattened to somewhat 
concave lateral areas. Umbo continued anteriorly as a low fold which does not 
meet the anterior margin. Brachial valve gently convex and marked medially 
by a shallow sulcus best defined in the posterior third but variable. 
Measurements in mm.— 
Brachial Hinge 
Length length Midwidth width Thickness 
Holotype (brachial valve) ........ i 10.2 13.3 10.5 Fy 
Paratype (pedicle valve 123275c).. 10.8 ? 11.6 10.0 ? 
Types.—Holotype: 123275b; figured paratype: 123275c; unfigured paratype: 
1232758. 
Horizon and locality—Carlim formation (base) =Grazier member of the Hat- 
ter formation, in Pennsylvania: On Elk Run, 3 miles southwest of Nealmont, 
Tyrone (15’) Quadrangle. 
Discussion—This species is suggestive of P. neumani but is smaller, has a 
flatter brachial valve and more distantly fasciculate ornamentation. 
Genus 6PIKINA Salmon, 1942 
Opikina SALmon, Journ. Paleont., vol. 16, No. 5, p. 589, 1942. 
OPIKINA ALATA Cooper, new species 
Plate 246, C, figures 5-11 
Shell small for the genus, wider than long; hinge forming the widest part; 
cardinal extremities alate; sides oblique; anterior margin narrowly rounded; 
costellae numbering 5 or 6 at the front margin. 
