PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 895 
Measurements in mm.— 
Brachial Hinge 
Length length Width width Thickness 
Figlotypen sisi be Ns ATO LY 60.0 56.7 78.6 84.0 ? 7.5-+ 
Hypotype (117777)......... 61.2 57.7 73.6 61.2 11.5 
sf QuI77 Sia) eset 46.5 43.9 55.2 49.1 6.7 
Types.—Holotype: 98199; figured hypotypes: 117778, 117779a, 117780a, 
117781a,b,d; unfigured hypotype: 117777. 
Horizon and locality—Benbolt formation in Tennessee: Along the road 
1.6 miles northeast of Heiskell, Powell Station (T.V.A. 137-SE) Quadrangle ; 
100 yards west of the store, junction of Tennessee Highway 33 and Flint Creek, 
Maynardville (T.V.A. 145-SE) Quadrangle ; 14 miles northeast of Halls School, 
Howard Quarter (T.V.A. 162-NW) Quadrangle; 4 mile southwest of Fleanor 
Mill, Powell Station (T.V.A. 137-SE) Quadrangle; hillside south of Dutch, 
Maynardville (30’) Quadrangle; 4 mile west of Dodson Creek on road from 
Tennessee Highway 33 to Acuff, Maynardville (T.V.A. 145-SE) Quadrangle ; 
west side of the sharp loop on the road down Flint Creek, Powder Springs 
(T.V.A. 154-SW) Quadrangle. 
Benbolt formation in Virginia: 100 to 150 yards north of the triangular in- 
tersection at Rye Cove and elsewhere in the vicinity of Rye Cove, Clinchport 
(T.V.A. 188-NW) Quadrangle; § mile south of Gate City, Gate City (T.V.A. 
188-NE) Quadrangle; on Virginia Highway 74, 0.2 mile southwest of New 
Bethel Church, Hilton (T.V.A. 197-NW) Quadrangle; Mount Hagan School, 
Hilton (T.V.A. 197-NW) Quadrangle; 0.67 mile south of Tumbez, Moll Creek 
(T.V.A. 196-SE) Quadrangle. 
Discussion.—This species is best identified by its large size; it is the largest 
known brachiopod occurring in the Southern Appalachians. As identified herein 
the shell is variable and shows considerable range in its convexity and shape. 
It is quite probable that more collecting will ultimately lead to the separation of 
more species from it. The species can be recognized in small pieces by its ap- 
parent flatness and the thin body cavity. In its complete form, however, the 
species is strongly convex. A good deal of the variability is due to flattening by 
compression. It will be noted that some of the specimens figured show fractures 
from compression with a consequent flattening of the shell. 
Macrocoelia magna is approached in size by M. duplistriata (Willard) of the 
Lincolnshire, Hogskin member, but is much less concave in the brachial valve 
and is more convex in the adult form than the stratigraphically lower species. 
MACROCOELIA OBESA Cooper, new species 
Plate 230, C, figures 14-19 
Shell moderately large for the genus, semielliptical in outline; wider than 
long with the greatest width slightly anterior to the hinge. Strongly concavo- 
convex in lateral profile. Lateral margin gently rounded; anterior margin 
broadly rounded. Surface multicostellate, with 2 to 6 costellae separating the 
