PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 97 
Correlation of Wardell formation—The Wardell formation appears to be the 
equivalent of the Ridley limestone in the Appalachian Valley. This equivalence 
is shown in the common presence in the two formations of Fascifera stonensis, 
Ancistrorhyncha costata, and Opikina speciosa. The Wardell and Ridley also 
see establishment of the genus Strophomena which appeared in Murfreesboro. 
The Wardell is the level at which Doleroides appears in abundance and virtually 
displaces Mimella, which is commonest below. The Wardell thus contains a 
more modern fauna than that of the Benbolt below, and the New York—Canada 
elements become conspicuous. Most of the genera of the Benbolt suite fail to 
pass over into the Wardell. 
Wassum formation (B. N. Cooper and G. A. Cooper).—The Wassum for- 
mation consists of Solenopora- and Stromatocerium-bearing calcarenites and 
buff crumbly shales with Receptaculites, which underlie the red sandy mudstones 
of the Bays formation and which succeed the black petroliferous limestones of 
the Chatham Hill formation. The type locality is 4 miles northwest of Marion, 
Marion (T.V.A. 218-SE) Quadrangle, Smyth County, Va. In the type locality 
the formation is about 125 feet thick and composed principally of variegated 
marble or calcarenite. On Walker Mountain south of Chatham Hill, Smyth 
County, Va., the Wassum formation is fully exposed with a total thickness of 
about 150 feet. The fossils and position of the Wassum formation place it oppo- 
site the upper part of the Wardell and part of the Dryden formations of middle 
and western belts of the Appalachian Valley. The formation extends northeast- 
ward in one persistent belt of outcrop to Sinking Creek Valley, Giles County, 
Va., where it carries Favistella halli and Stromatocerium in abundance. 
Whistle Creek formation.—This name is applied by Cooper and Cooper 
(1946, p. 74) to dark, cherty limestones underlying the Lincolnshire or its equiva- 
lent along U. S. Highway 60 and Whistle Creek, northwest of Lexington, Va. 
The full extent of this formation is not yet known. Fossils are abundant in 
many places and often weather out of the limestone by solution, The known 
brachiopods are: 
Atelelasma perfectum Cooper ? Multicostella quadrata Cooper 
Camerella globularis Cooper Murinella parva Cooper 
Dactylogonia sp. 7 Opikina sp. 5 
Dinorthis holdem (Willard) Oxoplecia costellata Cooper 
Hesperorthis longirostris Cooper Protozyga nasuta Cooper 
Macrocoelia elegantula Cooper Rhipidomena 
Mimella intermedia Cooper Valcourea austrina Cooper 
M. virginiensis Cooper 
Correlation of Whistle Creek formation—The Whistle Creek formation is 
related to the Elway formation by virtue of the common presence of Dinorthis 
holdent. 
Whitesburg formation.—This formation was so ambiguously defined that 
the name is no longer of any use outside its type locality. At the type section 
24 miles southeast of Whitesburg, on Bulls Gap (T.V.A. 171-SE) Quadrangle, 
siliceous limestones about to feet thick rest on the Maclurites beds of the Lenoir 
formation. The siliceous limestones contain Christiania and other fossils char- 
