PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 949 
tached to the median ridge, to forms in which the fulcral plates are nearly or 
quite obsolete. 
DALMANELLA CRASSICGSTELLATA Cooper, new species 
Plate 121, B, figures 2-8; plate 146, C, figures 24-30 
Shell small, rectangular in outline, wider than long; hinge slightly less than 
the greatest width which is at the middle; sides gently rounded; anterior margin 
broadly rounded; anterior commissure somewhat narrowly sulcate; costellae 
strong, 2 to the millimeter at the front margin. 
Pedicle and brachial valves about equal in depth; pedicle valve with gentle 
convexity in lateral profile; narrowly convex in anterior profile and with long, 
steep lateral slopes; umbo subcarinate, the carina extending to the front margin 
as a strong fold. Flanks bounding fold sloping moderately steeply to the mar- 
gins. Beak low, slightly incurved. 
Brachial valve with gentle convexity in lateral profile; anterior profile with 
narrowly depressed middle bounded by 2 low humps; umbo sulcate, sulcus nar- 
row and deep from beak to margin; flanks bounding sulcus moderately swollen ; 
lateral slopes long and gentle to the margins. Interior with long brachiphore 
plates uniting with the median ridge; cardinal process with long shaft and small 
myophore. 
Measurements in mm.— 
Brachial Hinge 
Length length Width width Thickness 
HIGIOtYDE)) Wives. ce ea cats 9.2 8.9 Tit 9.0 3.4 
Paratype (117361a).... 6.7 6.2 8.3 7.2 3.6 
- (TI7Z60 ees 8.8 7.8 10.1 8.0 3.3 
« GrT7SGIC Dh. «05).°0:4 8.7 10.6 0.5 3.4 
Types.—Holotype: 117361d; figured paratypes: 117361a,e,f; unfigured para- 
types: 117361b,c,g-i. 
Horizon and locality—Lower Hermitage formation in Tennessee: Along 
Tennessee Highway 53, 0.7 mile south of Woodbury, Woodbury (15’) Quad- 
rangle. 
Discussion——This species is common in the lower part of the Hermitage 
formation in West Tennessee. It can be recognized by its wide hinge, deep 
sulcus, and fairly thick contour when compared to Onniella planoconvexa Cooper 
with which it occurs. It has about the same size as D. rara but generally is not 
as thick as that species, is somewhat more finely costellate, and has a less promi- 
nent sulcus than the East Tennessee form. This species is much smaller in size 
than D. sulcata and has a much shallower sulcus. 
DALMANELLA RARA Cooper, new species 
Plate 126,1, figures 46-51; plate 157, B, figure 4; plate 158, A, figures 1-5; 
plate 161, B, figures 17-22; plate 162, C, figures 13-18 
Shell of about medium size for the genus, subrectangular in outline; wider 
than long, with a wide hinge; greatest width at the middle; sides gently rounded ; 
