THE LATE NIAGARAN STRATA OF WEST TENNESSEE. 
oo 
By Wituiam F. Parts, 
Of Lebanon, Kentucky. 
and 
Ray S. Basser, 
Curator, Division of Invertebrate Paleontology, U. S. National Museum. 
Probably nowhere in America is a more complete and _ better 
exposed section of Niagaran strata than that shown along the Paleo- 
zoic geanticline of West Tennessee. This section is well exposed 
along the Tennessee River and its tributaries, but the many fine 
fossils that have made this classic ground for the paleontologist have 
come almost entirely from the conspicuous white-capped, rounded 
hills or “glades” scattered through portions of Decatur, Perry, 
Wayne, and Hardin counties. A portion of this Niagaran section 
contains rather thick beds of white clays and clayey limestones, 
which weather into soils unfavorable to the growth of much vegeta- 
tion. Therefore, when these particular strata happen to occupy the 
top of the hills or are exposed along their slopes, spaces almost 
entirely barren of vegetation occur in otherwise well-wooded areas, 
and because of their white clayey soil, such bare spots or glades, as 
they are locally known, are visible for considerable distances. The 
strata whose disintegration primarily gave rise to these spots are 
usually very fossiliferous. In process of erosion the fossils are left 
behind, so that in the course of time most of the glades become ideal 
collecting grounds. Indeed, fossils are sometimes so abundant on 
the glades that specimens can be shoveled up literally by the bushel 
measure. : 
Despite the fine fossils and good sections afforded by the area, 
comparatively little has been done on its paleontology, and but one 
writer has published on its stratigraphy in any detail. The present 
contribution is based upon several short seasons of study and collect- 
ing by Mr. Pate, and upon a joint study of the rocks by both authors 
during two weeks of the summer of 1907. Much of the senior 
PROCEEDINGS U.S. NATIONAL MUSEUM, VOL. XXXIV—No. 1621. 407 
