566 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
sloping sides. Sulcus shallow, originating about 9 mm. anterior to the beak and 
occupying about half the width. Floor of sulcus convex and with a short tongue. 
Flanks bounding sulcus moderately convex. Median septum supporting a nar- 
row spondylium and extending to the center. 
Brachial valve nearly as deep as the pedicle valve, moderately convex in lateral 
profile but with an inflated umbo; anterior profile strongly arched and with pre- 
cipitous sides. Fold low and inconspicuous, originating at or near the middle; 
flanks swollen. Umbonal and median regions inflated. Cruralium short, mod- 
erately deep ; septum short. 
Measurements in mm.— 
Brachial Hinge 
Length length Width width Thickness 
PAECIE VETS: pate ohn’ ne ruaigshattie weet pin idle s\n ins 12:7 12.3 14.9 4.0 10.2 
Paratype (pedicle valve IIIII3a)..... 12.8 ? 13.6 ? 3.0 
ef (brachial valve 111113b).... ? 11.3 14.4 ? 2.6 
Types.—Holotype: 117131; figured paratypes: I111113a,b. 
Horizon and locality—Elway formation in Tennessee: $ mile southwest of 
Mount Eager Church, Powder Springs (T.V.A. 154-SW) Quadrangle; U. S. 
Highway 25E, north of Evans Ferry, Howard Quarter (T.V.A. 162-NW) 
Quadrangle. 
Elway formation in Virginia: At Eggleston, Giles County. 
Discussion.—This species is characterized by its broadly elliptical outline and 
the nearly completely costate shell. The species is suggestive of C. elliptica, but 
that species attains a considerably greater size and differs in having much more 
strongly defined costae, a more erect beak on the pedicle valve, and the sulcus 
originating posterior to the middle. Camerella multiplicata is another Elway 
species, but it is more triangular in outline and the ornamentation is more strongly 
etched into the shell. 
CAMERELLA EDMUNDSONI Cooper, new species 
Plate 115, F, figures 35-42; plate 115,1, figures 50-52 
Shell small, pentagonal in outline, with the length slightly greater than the 
width. Greatest width at about the middle. Beak varying from a right angle to 
an acute angle. Lateral margins straight and divergent to the anterolateral ex- 
tremities which are moderately rounded. Surface marked by closely crowded, 
rounded costae, 2 or 3 (occasionally 4) in the sulcus and 4 forming the fold. 
Flanks marked by 3 costae. 
Pedicle valve evenly convex in lateral profile with the maximum convexity at 
about the middle; sulcus originating about one-third the length anterior to the 
beak, shallow, and occupying about half of the width. Tongue short, generally 
truncated. Umbonal region smooth, gently convex. 
Brachial valve generally more circular in outline than the pedicle one and with 
length and width about equal, slightly deeper than the pedicle valve. Moderately 
convex in lateral and anterior profiles. Fold originating about one-third the 
