348 The American Geologist, June, 1896 
pearance of a saw-log with the bark removed and the ends 
flat as if cut with a saw. The wavy lamination imitated 
closely the curly grain sometimes seen in wood. Further ac- 
quaintance with the region showed like phenomena very com- 
mon. In cut banks more or less transverse to the axes of the 
concretions they were seen to project like logs from a flood 
deposit. 
Some of the variations observed are the following: Some- 
times these concretions are only a few feet in length with 
rounded ends, and occasionally, where their length equals their 
diameter, they become globular. Sometimes there is a repe- 
tition of the log-like feature in a lateral direction, and they 
are often cemented to each other. Plate XII, figure 2, shows 
an example of this sort. At other points this variation passes 
into a regularly formed stratum of sandstone of limited ex- 
tent. Though often showing almost perfect cylindrical form, 
more frequently their form and surface are somewhat irregu- 
lar. They commonly show more or less iron present, as is in- 
dicated by their rusty appearance. Sometimes this is suffi- 
cient to make them black. No fossils were found in them at 
any time. They are sometimes associated with concretions of 
the more common biscuit-shape. The sizes more commonly 
represented are from one to two and a half feet in breadth, 
while the sections separated by joints are from two to five feet 
in length, and the series lying in very direct course sometimes 
attained a length of 100 or 150 feet. Not only is there the 
tendency of repetition in a lateral direction but also in a 
longitudinal. While any one system rarely exceeds a breadth 
of two rods, the length sometimes may be measured by miles. 
Not infrequently by climbing to the top of a conical hill and 
ascertaining the direction indicated by the axes of the con- 
cretions, the system can be traced for miles on the same level. 
These longer series frequently show curves and sometimes 
angles. Sometimes in the same hill several series may be 
noted, one above another, which eonimonly show different 
directions for their axes. 
So far as I am aware this is the first time that attention 
has been called to these novel formations. Opportunity did 
not permit me to make a systematic or exhaustive study of 
them, but it seems not improbable that some such explanation 
