54 DHE JOURNAL, OF (GEOLOGY: 
cross-stratification, and at one locality great wave marks are 
found. Near the top of the Trenton are often seen rounded peb- 
bles of limestone distributed in thin beds for a number of miles. 
They are mentioned from Garrard, and also from Clark and 
Montgomery counties. 
Lower Fludson.—These beds are considered by Mr. E. O. 
Ulrich as being in large part equivalent to the Utica. Mention 
of wave marks is made from the following counties: Shelby, 
Spencer, Washington, Marion, Mercer, Garrard, Madison, Clark, 
Montgomery, Bath, Fleming, and Mason. The wave marks 
occur in the upper beds of this division. In Mercer county they 
are stated to occur 140 to 170 feet above the base. Their occur- 
rence in the upper beds is more or less directly inferred from 
statements made with reference to these layers in Spencer, 
Washington, Mercer, Garrard, Madison, Bath, and Mason 
counties, and this is presumably their horizon also in the other 
counties. Cross-stratification occurs in the upper beds in 
Mason county. 
Rounded limestone pebbles are stated to occur only in the 
case of one county, Washington. Here the lowest layer of the 
Lower Hudson is said to be about one foot in thickness, and to 
contain usually some rounded limestone pebbles. The occur- 
rence of pebbles in Clark and Montgomery counties seems to be 
warranted by the following statement made, under the title of 
‘‘ Disturbances in Clark and Montgomery,” in one of the reports: 
‘In the Lower Hudson beds, where the alternations of hard lime- 
stones and shales are so constant, the intervals were produced by 
corresponding changes of condition, and in these hard layers are 
sometimes seen large pebbles of limestone, which have been 
worn until half round and then consolidated with finer material.’ 
In this case no particular horizon is mentioned. 
Middle Hudson—Wave marks are mentioned from Nelson, 
Washington, and Mason counties. In Washington county they 
are said to occur at the base. Those from Mason county are 
not located, and the reference to them is suspicious, as though 
the wave marks belonged to the well-known waved beds of the 
