PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 207 
to the middle. Posterior bluntly pointed; lateral margins broadly rounded but 
with a strongly rounded anterior margin. Gently convex in anterior and lateral 
profile. Surface preserved in the posterolateral region where it is marked by 
regular, fine, elevated concentric lines. 
Measurements in mm.—Length 27.1, width 15.6, thickness 1.5? 
Figured specitmen.—116771. 
Horizon and locality—Oil Creek formation (60 feet above the basal sand) 
in Oklahoma: Sec. 12, T. 3 S., R. 3 E., 13 miles northwest of Sylvan, Carter 
County. 
LINGULELLA ? sp. 3 
Plate 8, H, figures 17, 18 
Represented by a single brachial valve which is large for the genus, oval in 
outline with the length about 14 times the width. Beak prominent, narrowly ele- 
vated and protruding posterior to the posterior margin which is somewhat 
broadly rounded. Ornamentation consisting of fine, crowded, faintly elevated 
lines shown in 2 small patches preserved at the posterior on both sides of the beak. 
Evidence of an elongated central muscle track is indicated on the exfoliated 
specimen. 
Measurements in mm.—Length 22.6, width 15.8. 
Figured specitmen.—109312. 
Horizon and locality—Little Oak formation in Alabama: 4 mile south of 
Newala, Montevallo (15’) Quadrangle. 
LINGULELLA ? sp. 4 
Plate 5, A, figures 1-5 
Fairly large for the genus, elongate elliptical in outline with nearly parallel 
sides; valves subequally biconvex ; length twice the width. Surfaces badly ex- 
foliated but a patch showing the exterior indicates elevated concentric lines as 
the surface ornament. Brachial valve showing indications of a median ridge 
extending nearly the full length. 
Measurements in mm.—Length 16.3 (not complete), width 8.3, thickness 4.0. 
Figured specimen.—109304. 
Horizon and locality—Arline formation (middle to upper) in Tennessee: On 
Sevierville Pike, 5 miles southeast of Knoxville, Knoxville (T.V.A. 147-NW) 
Quadrangle. 
LINGULELLA ? sp. 5 
Plate 5, C, figures 7, 8 
This also is an elongate species which measures 14.3 mm. in length by 7.7 mm. 
in width. It may be related to or the same as Lingulella sp. 4 but seems a deeper 
shell. The brachial valve is moderately deep and moderately convex in lateral 
profile but is fairly strongly convex in anterior view. The surface is marked by 
fairly regular concentric elevated lines, finer and more crowded on the sides than 
on the median portion of the shell. 
