WILLIAMS AND 
KINDLE. 
| KENSSEL^ERIA AND BLOCK SHALE FAUNAS. 49 
It will be observed by reference to the descriptive part of this paper 
that the zones 1376 A2, 1376 B2, 1379 Al, 1379 X, 1380 A2, 1382 B2, 
1381 A2 are at present sandstone, often coarse grained; the other 
zones are more or less calcareous. 
The species which are peculiar to the Oriskany in New York are 
generally confined to the sandstone, but this is not always the case, nor 
are peculiar Helderbergian fossils restricted to the calcareous beds. In 
the New York sections Aspidocrinus appears in the " Shaly limestone " 
or " Scutella limestone" of the early reports, while in both sections in 
which it occurs in Virginia (Bigstone Gap 1376 B2 and Rocky Gap 
1379 X) it is found in sandy beds. At Rocky Gap (1379 X) it occurs in 
a coarse sandstone similar to the typical Oriskany of New York. 
It is evident that the subdivisions of the Rensselaeria fauna, which in 
the northern Appalachian region have determined the division of the 
strata into numerous separate formations, are not universal. Future 
investigations probably will show that the composition of the local 
faunules is determined rather by environmental conditions recorded 
by the differing characters of the sediments than by actual epochs in 
their history. 
THE BLACK SHALE AND ITS FAUNA. 
By H. S. Williams. 
It will be noted that while the New Albany shale reaches a thick- 
ness of 100 feet in Indiana, it thins out and is often not represented 
along the axis of the Cincinnati-Nashville arch. On the eastern side 
of this arch it thickens again eastward, and along the Appalachian 
channel is very thick. The u Chattanooga '' shale attains a thick- 
ness of several hundred feet, and runs up into coarser and more 
irregular beds, known as the Grainger shale in southern, and as the 
Romney shale in northern, Virginia and West Virginia. The fauna of 
the pure black shale is very meager in both species and specimens. 
At Louisville (1357 A3) the black shale contains Lingula spatulata 
and Schizobolus concentricus. Northeast of Brooks, Ky. (1365 A3), it 
holds Leiorhynchus q uadricostatum, Chonetes scitidus, Lingula spatulata, 
and a small Pleurotomaria. In the Bigstone Gap region (1376 133) it 
contains Schizobolus concentricus and Lingula ligea. In Bland County, 
Va., along Kimberling Creek (1379 A 2), Schizobolus truncatus appears 
in rocks which are there classified as Romney shales, but which are only 
a few feet above the base of the Giles formation, which contains the 
Oriskany type of the Rensselseria fauna. The same species occurs 
in a similar black shale one-half mile north of Hicksville, Va., and 
is characteristic of the black shales of the White Sulphur Springs 
section (1380 A4). 
