No. 1621. LATE NIAGARAN STRATA—PATE AND BASSLER. 415 
Feet 
Blue shale with bryozoa and a few corals_-_-___--_____--_-~- : 1 
Purple shale and argillaceous limestone, containing many 
bEyozZoaman de ag hewa COLA S Saekee= teeen eS eee eee ee 17 
Bob formation. 
Conechidium zone. Nodular, cherty, crinoidal blue and gray lime- 
stone with Conchidiwm in upper part especially. Other fossils 
HOW, sete Se ee a Se ee 15 
Dictyonella zone. Blue shales with rather numerous brachiopods_ 5) 
Uncinulus zone. Grayish, cliff forming limestone breaking into 
BETS TEES GNA EY fee San a ra ne a Re eae gf cake Sel cg gi 16 
Beech River formation. 
Eucalyptocrinus zone. Blue and yellow shales with Hucalypto- 
crinus and other characteristic fossils. At one point in the near 
vicinity this bed has thickened to 40 feet____________________ 20 
Troostocrinus zone. Yellow shales and thin white limestone_____ 24 
Coccocrinus zone. Only topmost layer exposed_______--_-----~ — 
MOUSETAIL, PERRY COUNTY, TENNESSEE. 
The local variability of the beds comprised in the late Niagaran 
is brought out in a comparison of the Lady’s Bluff section and that 
at Mousetail, 1 mile south. The absence of the Bob formation in_ 
the Mousetail section is particularly noteworthy. 
Section at Mousetail, Perry County, Tennessee. 
Decatur limestone. ; Feet. 
Massive gray and white coarsely crystalline limestone with few fossils_ 8 
Lobelville formation. 
b. Coral zone. Yellowish clays and thin limestones with numerous 
specimens of Favosites, Heliolites, and other corals____________ 8. 
a. Bryozoan zone. Soft shales holding many bryozoa and a few corals 
of the genera Favosites and Heliolites. 
Tunis wala Gey Shy ail eS teeta eee an Sa eet ee rE RN Te ely 2 
Up lish: Slvall esas ees Pete Grates Mase ean ists Senne OA LE 2 7 
Beech River formation. 
ec. EKuecalyptocrinus zone. Yellowish shales with crinoids and other 
HOSS CeereancCreawgnie Or Wis INORVOMNs Le ee 27 
b. Troostocrinus zone. Thin limestone and shales with 7. rein- | 
CU BXOMP OR Bs ON so OL 8 re ae ee ia Boa 45 
LEC OCCOCLAINUTS eZ Oa Cece a aoe a erin eg rps TEES a es 15 
Dixon formation. 
Red shales. Top only exposed = 
In the remaining sections studied by us the differences in lithology 
and in fauna were so slight that it was deemed best to arrange these 
in tabular form. In this table the bottom and top of each section is 
indicated by the lowest and uppermost figures, or <<, while blank 
spaces within these limits show the absence of formations. The 
' various thicknesses are given in feet when accurately determined, 
but by & when only noted. 
