203 



parallel. The stone in wliieli all the markings spoken of in this paper 

 occur is the blue, abundantly fossiliferous limestone, so characteristic of 

 the lower and middle Hudson formation in the region of the Cincinnati 

 geanticline. The fossils found in the A^arious ripple marked limestones 

 vary with the horizon in which they occur. 



The thickness of the stratum containing tlie upper Wolf Run marks 

 is from two to three inches, while that of the lower is from one and a 

 half to two inches. The distance from crest to crest or wave length is in 

 the upper series twenty-one inches, and in the lower eighteen inches, 

 approximately. The depth of trough in tlie upper is one and a half inches, 

 and in the lower one to one and a half inches. 



The Cliffy Creek series of markings occur in the bed of that stream at 

 a point about one and one-fourth miles above the bridge on tlie INIadison 

 and Hanover pike. The ripple marks are exposed in this place at intervals 

 for a distance of 200 yards. The trend of the crests here is N. 10°-15° E., 

 quite a little irregularity being noticed. The distance from crest to crest 

 is from thirty to thirty-six inches, and the depth of trough three inches. 

 The thickness of stratum five to seven inches, and the approximate verti- 

 cal distance below the Clinton limestone, 190 feet. 



In the bed of the West Fork of Indian Kentucky Creek, one-third of a 

 mile above Manville, a series of ripple marks are found extending some 

 seventy-five yards where the stratum is unbroken. This series I shall call 

 the \"an Buren, since they are found but a short distance from the house 

 of John Van Buren. The trend of crests here is N. 40° E. : wave length, 

 thirty inches; depth of trough one and a half to two and a half inches; 

 thickness of stratum, two to three and a half inches. The approximate 

 vertical distance below the Clinton limestone is 342 feet. 



In the creek bed, beneath the bridge across the east fork of Indian Ken- 

 tucky Creek, and within 200 yards of Manville postofBce, a ripple marked 

 layer of limestone from four to six inches thick is exposed at intervals for 

 a distance of 130 yards. At low water the marks are here exposed over a 

 space of 150x25 feet and as many as sixty consecutive crests may be 

 counted. The trend here is approximately N. 10° B., the wave length 

 thirty inches, the depth of trough two and a half inches, the vertical dis- 

 tance below the Clinton formation 350 feet. At this place the wide ex- 

 posure, amounting at times to 300 or more square yards, affords an ex- 

 cellent opportunity for the study of the relations which the marks bear 



