8o 
Aug. F. Foerste 
5b, the reversal of curvature is due to crushing, common except 1 
in silicified shells; the cardinal area of the brachial valve should be : 
much higher, and the inclination of the cardinal area of both 1 
valves is incorrectly indicated. Errors of this nature are shown | 
also by other drawings accompanying this paper. |j 
Brownsport bed: glades southwest of Dixon Spring; Clifton,! 
west of Dr. Evans, west of Hope creek; south of Mr. Phillips, four j 
miles northwest of Martins mills; Bath Springs; Wells creek basin, 
Tennessee. 
jHebertella (Schizonema) celsa, sp. nov. | 
{Plate III, Figs. 53 A, B.) |j 
Brachial valve moderately convex, with a distinct but shallow j 
median depression as in Dalmanella. Cardinal area forming an |: 
angle of about 150° with the general plane of the valve. Upper ili 
margin of cardinal process narrow, projecting slightly beyond the I 
cardinal area, marked by a faint longitudinal groove. Anteriorly | 
the cardinal process is merged in the comparatively high median |j 
elevation which divides the muscular area. Crural plates strongly I 
developed, their base continuous with the straight postero-lateral 
border of the posterior adductor impressions. Anterior margin of 
the anterior adductor impressions extending slightly beyond the 
center of the valve. Muscular impressions resembling those of |j 
Hebertella insculpta. | 
Cardinal area of the pedicel valve flat, forming almost a right 
angle with the general plane of the brachial valve, broadly trian- , 
gular, high at the beak. The type specimen has a width of 16.5 j 
mm., the cardinal area has a length of 13 mm. along the hinge j 
line, and the height of the area is 4.3 mm. The width of the del- 
thyrium is about 2.5 mm. at the widest part, at the apex it appears | 
to possess a rather large apical plate, poorly preserved. Curvature | 
from the beak to the anterior margin of the shell slight, the shell (j 
sloping rather evenly but abruptly from the beak to the lateral and li 
anterior margins of the shell. j 
Radiating striae rather angular, the newer striae being implanted I 
among the older so as to produce a fasciculate arrangement; about j: 
8 or 9 striae in a width of 5 mm. Numerous fine concentric striae. 1 
Linden bed: above quarry along river north of Perryville,Tennes- j 
see. I 
