PARTE CHAZYAN AND RELATED BRACHIOPODS—-COOPER IOI 
is probably a shaly part of the Ridley. This seems to be the case in northwestern 
Georgia where the Ridley is partially a shaly facies. Fascifera appears in all the 
shaly facies, and F. stonensis is identified in the Wardell formation which is cor- 
related with the Ridley. 
Ridley formation.—This consists of about 93 to 115 feet of dark cherty 
limestone containing an abundance of fossils, often beautifully silicified. In places 
the coral Tetradium is common, and Opikina occurs in countless numbers at 
the top of the formation. Brachiopods identified are: 
Ancistrorhyncha costata Ulrich and Cooper 
Camerella varians = C. plicata (Schuchert and Cooper) 
C. pulchra Cooper 
Chaulistomella superlata Cooper (in Georgia) 
Dinorthis deflecta = Chaulistomella ridleyensis Cooper 
Doleroides crassus Cooper (Georgia) 
D. extensus Cooper (Georgia) 
Fascifera subcarinata Ulrich and Cooper 
Glyptorthis multicostellata Cooper (Georgia) 
Heberiella bellarugosa = Glyptorthis assimilis Cooper 
Mimella biconvexa Cooper 
M. globosa (Willard) (Georgia) 
Opikina maja Cooper 
O. quadrata Cooper 
O. speciosa Cooper 
Orthis tricenaria Conrad = Hesperorthis australis Cooper 
Petrocramia sp. 1 (Georgia) 
Pianodema subaequata (probably a misidentification) 
P. stonensis (Safford) = Fascifera stonensis (Safford) 
Protorhyncha rideleyana (Safford) = Ancistrorhyncha costata Ulrich and Cooper 
Protozyga rotunda Cooper 
Rafinesquina incrassata (Hall) = ? 
Rostricellula rostrata Ulrich and Cooper 
R. variabilis Cooper 
Strophomena filitexta = S. basilica Cooper 
S. planobesa Cooper (in Sequatchie Valley) 
Correlation of Ridley formation—tThe correlation of the Ridley formation is 
with the Wardell of the Southern Appalachians. This is based on the common 
presence of Fascifera, Hesperorthis australis, Opikina speciosa, and Ancistro- 
rhyncha costata. The Ridley of the Central Basin of Tennessee with its scattered 
and light-colored chert cannot be correlated lithologically with the “Lenoir” of the 
Appalachians which has black chert. Furthermore, the “Lenoir” of the Appa- 
lachians includes a variety of formations, none of which is faunally like the Rid- 
ley. Certainly the Lenoir as now restricted has no species in common with the 
Ridley. Correlation of the Ridley of northwestern Georgia is discussed under the 
Chickamauga. 
Lebanon formation.—This formation consists of approximately 100 feet of 
thin-bedded limestone separated by thin beds of shale often containing exquisite 
fossils. Camarocladia markings are frequent and conspicuous. A thick bed of 
calcarenite (about 3 feet thick) containing abundant Cryptophragmus occurs 
