LIMESTONES OF WESTERN TENNESSEE 563 



sists chiefly of hard, reddish-purple limestone. Its thickness 

 has not been determined at this locality. No attempt has been 

 made as yet to identify the Waldron bed within the town limits 

 at Clifton. However, the Waldron bed is well exposed along 

 the river bank, a quarter of a mile above the old cement mill. 

 It is here about 3 feet thick, and consists, in ascending order, of 

 whitish clay, about 8 inches thick ; white, very dense limestone, 

 about 8 inches thick ; and indurated clay, white below, red above, 

 containing most of the fossils collected. Attached to the top of 

 the white limestone bed were found eight specimens of Eucalyp- 

 tocriims magnus, and six specimens of Eucalyptocrinus elrodi, fossils 

 characteristic of the Waldron bed, and found in great abundance 

 at this horizon at Newsom. Only 16 feet of limestone belong- 

 ing to the top of Laurel bed are exposed beneath the Waldron 

 at this locality. It is very hard and has a reddish-purple color. 

 The total thickness of the Laurel bed at this locality is unknown. 

 At Swallow Bluff, about half-way between the mouths of 

 Hardin and Indian Creeks, on the north side of the Tennessee 

 River, the Saltillo limestone is directly overlaid by the Silurian. 

 At the base of the Silurian section there is hard, whitish lime- 

 stone, 18 inches thick, with scattered specks of black chert, fol- 

 lowed by a layer of black chert, 2 to 8 inches thick; both are 

 fossiliferous, and are referred to the Clinton bed. The layer of 

 chert is overlaid by hard, massive white limestone, 8^ feet 

 thick, followed by thin-bedded white limestone, 9^ feet thick, 

 and a softer, more clayey rock, partly tinged with red, 5^ 

 feet thick. The softer, clayey limestone, partly tinged with red, 

 occupies in a general way the horizon of the Osgood bed. It is 

 overlaid by hard limestone, 28 feet thick, referred to the Laurel 

 bed. The lower part, 6 feet thick, is white and crackled. The 

 middle and upper part is more reddish-purple. The most massive 

 layers are near the top. Above the Laurel bed is the Waldron, 

 31^ feet thick, well exposed along the upper part of the bluff 

 below the landing, immediately above the broad shelf formed by 

 the top of the Laurel bed. The Waldron bed consists, in ascend- 

 ing order, of soft whitish clay, 14 inches thick, containing small 

 fragments of rubble limestone ; very fossiliferous, hard, white, 



