939 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
way 70N, just east of Round Lick Creek, Rome, Smith County; F. B. Cooper 
farm 2 miles southeast of Pikeville, Pikeville Special (15’) Quadrangle ; Auburn, 
Cannon County. 
Carters formation in Alabama: Quarry 4 mile northeast of Gate City, Leeds 
(15’) Quadrangle; ? Birmingham, Birmingham (30’) Quadrangle. 
Discussion.—This subspecies is distinguished from other members of the 
species by the narrowed and nasute front. This is especially seen in the pedicle 
valves. 
STROPHOMENA BASILICA Cooper, new species 
Plate 258, A, figures 1-17 
Shell of about average size for the genus, wider than long; subrectangular in 
outline; hinge equal to the midwidth or forming the greatest shell width; sides 
nearly straight but generally indented more or less strongly just anterior to the 
cardinal extremities; anterior margin strongly rounded; cardinal extremities 
varying from nearly a right angle to auriculate. Surface finely costellated, the 
costellae of 2 sizes, I to 3 of the finer ones alternating with the stronger ones; 
18 costellae may be counted in the space of 5 mm. at the front, the figure includ- 
ing 5 of the stronger costellae. 
Pedicle valve gently concave in lateral profile; umbonal region slightly con- 
vex, the convexity continued anteriorly for a short distance only; cardinal ex- 
tremities flattened and deflected slightly toward the brachial valve; greatest con- 
cavity in the median region with the sides gently deflected toward the pedicle 
valve. Pseudodeltidium long, subcarinate ; foramen minute ; interarea moderately 
long. 
Brachial valve unevenly convex in lateral profile, the posterior third flat and 
the anterior two-thirds moderately convex; anterior profile broadly and moder- 
ately convex. Posterior third flattened but with umbo concave, the concavity 
extended anteriorly nearly to the middle as a shallow and narrow sulcus ; median 
half fairly strongly swollen; anterior slope convex, long, and steep. Lateral 
slopes shorter than the anterior one and moderately steep. 
Interior of pedicle valve with variably shaped muscle field ranging from nearly 
circular to elongate oval; teeth small; dental ridges slender, flaring; ridges sur- 
rounding sides of muscle field low and not elevated anterior to the middle of the 
field. Interior of brachial valve with brachiophores nearly obsolete; sockets 
formed by short, delicate cups; cardinal process small and delicate. Median 
ridge low but long, extending for about a third the length. 
Measurements in mm.— Brachial 
Hinge 
Length length Midwidth width Thickness 
PIONOLY DE ce ceeh see wane stain 27.8 26.5 34.5 32.6 4.0 
Paratype: (117705b)2 3...4 ee ? 26.1 32.0 31.1 ? 
‘ (1177050) 2 v22.. KIN 227, ? 26.9 26.5 ? 
i (BE7FOSA) ohh» 5 antes ? 22.0 25.8 26.7 ? 
ih CEIZ7O5E ) cto ok bua 5 24.2 22.1 26.2 26.7 3.6 
Types.—Holotype: 117705a; figured paratypes: 117705b-e,g,h, unfigured 
paratype: 117705f. 
Horizon and locality —Ridley formation in Tennessee: In the lower third of 
