100 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
CENTRAL BASIN OF TENNESSEE 
The formations of interest here in the Central Basin are the Stones River 
group and the Hermitage formation. The Stones River group, as redefined by 
C. W. Wilson (1949, pp. 24-75) consists of five formations from the bottom: 
Murireesboro, Pierce, Ridley, Lebanon, and Carters limestones. 
Murfreesboro formation.—This formation consists of about 70 feet of dark- 
gray, cherty, moderately heavy-bedded limestone on the outcrop. Collins and 
Bentall (1945) report approximately 400 feet of this formation in wells drilled 
in central Tennessee. Fossils are common but are usually silicified and enclosed 
by chert. The fauna abounds in gastropods, but a few brachiopods have been 
reported by Bassler, as follows: Dinorthis deflecta (Conrad), Orthis tricenaria 
Conrad, Pianodema (sic) subaequata (Conrad), and Strophomena filitexta Hall. 
In four visits to the Central Basin the writer has been unable to verify this list ex- 
cept for the presence of an abundant strophomenoid. No specimens from the Mur- 
freesboro formation in the National Museum or in the Schuchert Collection at 
Yale University corroborate the first three species. Murfreesboro brachiopods 
are: 
Camerella nuda Cooper Protozyga untplicata Cooper 
Murinella sp. 1 Strophomena planobesa Cooper 
Plectorthis sp. 2 
Correlation of Murfreesboro formation—The Murfreesboro formation is gen- 
erally correlated on fossils other than brachiopods. It contains a scaphopod, Poly- 
lopia billingsi (Safford) in abundance. B. N. Cooper (1944, pp. 69-71) correlates 
the Murfreesboro formation with the Peery formation of Tazewell County. As ex- 
plained under the Chickamauga limestone, the Murfreesboro formation is present 
in northwestern Georgia but its correlation elsewhere is not clear. A representa- 
tive of it may occur in Missouri in the Rock Levee formation. The Blackford 
has nothing to do with Murfreesboro. 
Pierce formation.—This formation consists of 27 feet of thin-bedded lime- 
stone separated by shaly partings. Fossils, particularly bryozoans, are abundant. 
The following brachiopods are known: 
Ancistrorhyncha costata Ulrich and Cooper Opikina ? planulata Cooper 
Bellimurina concentrica Cooper Philhedra minor Cooper 
Doleroides regularis Cooper Protozyga sp. 
Doleroides sp. I Rostricellula rostrata Ulrich and Cooper 
Fascifera stonensis (Safford) R. variabilis Cooper 
Glyptorthis irregularis Cooper Strophomena planobesa Cooper 
Mimella biconvexa Cooper 
Pionodema subaequata has also been reported but was not seen by the writer. 
The report is probably erroneous. A small Mimella may have been confused 
with the punctate genus, an error that is frequently made. 
Correlation of Pierce formation—The Pierce formation is closely related to 
the Ridley formation which overlies it, and the two may be only facies of each 
other. In Sequatchie Valley, Tenn., Pierce has been identified, but there, too, it 
