THE LATE NIAGARAN STRATA OF WEST TENNESSEE. By William F. Pate, Of Lebanon, Kentucky. and Ray S. Bassler, Curator, Division of Invertebrate Paleontology, U. 8. 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 foi; 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 Avhite 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 vlisintegration jn-imarily 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
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