PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 507 
length from the beak, only slightly elevated above the flanks with are rounded 
and have steep slopes. Umbonal region moderately curved. 
Interior: Spondylium of pedicle valve in length equal to about one-third the 
valve length; septum short and thin. Cruralium and septum of brachial valve 
short. 
Measurements in mm.— 
Brachial 
Length length Width Thickness 
Holotype (pedicle valve) ............. 10.6 ? 9.9 3.0 
Patdtype -(idtthze) van is. oteinan. ox 9.2 ? 8.4 3.9 
ia (GAG Fer eRe, eee ey Tv 10.6 ? 10.1 2.6 
ne (brachial valve 111117a)..... ? 30.8 10.2 4.6 
# RUSEEIZO eee. we ke eet ce aoe ? 10.2 10.9 4.2 
s Cristea Went: ae Pee. ? 10.4 10.3 4.4 
Types.—Holotype: 111117b; figured paratypes: II111I7a,c-e, 117132a,b. 
Horizon and locality—Poteet formation (Yellow Branch member) in Vir- 
ginia: On the road along Yellow (Creek) Branch, 5 miles southeast of Rose 
Hill, Rose Hill (T.V.A. 161-NE) Quadrangle. 
Discussion.—This species is recognized by its elongate form and the nearly 
complete costation of the surface. It most nearly resembles some of the variants 
of C. plicata in which the valves are almost completely costate and the sulcus is 
occupied by 3 costae, but differs from them in having a more elongate fold and 
sulcus. The costation is similar to that of C. globularis, but that species is more 
rotund in profile and is wider than long. 
CAMERELLA ELLIPTICA Cooper, new species 
Plate 113, E, figures 32-43; plate 113, F, figures 44-48 
Shell large for the genus, wider than long with a broadly elliptical outline ; 
beak forming approximately a right angle, sides narrowly rounded and front 
margin nearly straight. Surface marked by 18 subangular costae of which 5 
occupy the fold and 4 occur in the sulcus. Flanks with 6 costae. 
Pedicle valve moderately convex in lateral profile with the greatest convexity 
slightly posterior to the middle; beak short, slightly curved; umbonal region 
gently convex. Fold originating about one-fifth the length anterior to the beak, 
shallow and occupying slightly less than half the width at the front. Tongue 
short, slightly rounded. Flanks gently convex and sloping moderately to the 
margins. 
Brachial valve slightly more convex than the pedicle valve in lateral profile 
and with the greatest convexity at about the middle. Anterior profile broadly 
but only moderately convex. Umbonal region strongly convex; fold low, only 
slightly elevated above the flanks which are moderately convex and slope steeply 
to the margins. 
Interior: Spondylium in the pedicle valve long and slender, extending to a 
point slightly posterior to the middle. Cruralium of brachial valve short but with 
long brachial processes. 
