go2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 127 
vexity at the middle; anterior profile broad and gently convex ; umbo marked by 
a narrow and shallow sulcus; median region moderately swollen; lateral and 
anterior slopes short but gentle. Cardinal process bilobed as usual in the genus. 
Measurements in mm.— 
Brachial Hinge Thick- 
Length length Midwidth width ness Height 
Plolotype sb. Psd." 12.6 ? Te 16.0 ? 28 
Paratype (123277a).. 15.0 ? 21.3 19.4 ? Bune 
“a Ciag977 bina FP 13.4 19.5 17.4 ? 1.9 
Types.—Holotype: 98222; unfigured paratypes: 123277a,b. 
Horizon and locality—FEffna formation in Virginia: At Porterfield Quarry, 
5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle. 
Discussion.—This species differs from the others described herein in the char- 
acter of the ornamentation. It is wider and somewhat larger than P. newmam 
and has much finer ornamentation. Indications are that this species is definitely 
a strophomenoid with fairly strongly convex valves and with the cancellated 
ornament characteristic of young strophomenoids. 
PIONOMENA NEUMANI Cooper, new species 
Plate 265, D, figures 7-11 
Shell attaining a length of about 0.6 inch; subcircular to subquadrate in out- 
line, with the greatest width at about the middle; hinge narrower than the great- 
est shell width; sides nearly straight to gently rounded; anterior margin strongly 
rounded ; costellae of unequal size, about 21 in 5 mm. at the front margin, the 
stronger ones separated by 1 to 5 of the finer costellae. 
Pedicle valve very gently convex in lateral and anterior profiles; umbonal 
region marked by a narrow fold that extends anteriorly to beyond the middle 
where it disappears in the general convexity; flanks of fold gently concave and 
extending by long, gentle slopes to the margins. Anterior slope nearly flat. 
Brachial valve gently convex in anterior and lateral profiles ; umbo marked by 
a shallow and narrow sulcus that widens anteriorly and reaches nearly to the 
front margin. Flanks bounding sulcus gently swollen; posterolateral slopes to 
flattened cardinal extremities short and moderately steep. 
Measurements in mm.— 
Brachial Hinge 
Length length Midwidth width Thickness 
Holotype (pedicle valve).......... 14.1 ? 15.7 13.9 ? 
Paratype ( “ MT Te7SOD) oa aed ? 15.6 13.9 ? 
(brachial valve 117756c). ? 12.0 14.6 12.9 ? 
Types.—Holotype: 117756a; figured paratypes: 117755, 117756b-d. 
Horizon and locality—New Market formation (in the top 12 feet) in Wil- 
liamsport (15’) Quadrangle, Maryland: 4 mile southwest of Hicksville; 3 miles 
N. 10° E. of Wilson; 3 mile north of St. Pauls Church, west of Wilson. 
Same formation in Pennsylvania: 1 mile west-southwest of Marion, Cham- 
bersburg (15’) Quadrangle. | 
