The following statements are based partly on observations made during a trip from Eagle Pass to Edinburg by row-boat in the months of May and June, 1889, and partly on work in the region between Del Rio and Eagle Pass during the summer of 1891.*
A portion of the area having been described by Dr. R. A. F. Penrose, Jr., in the first annual report of the Geological Survey of Texas, in the present article I propose to confine myself to that part of the river between San Felipe creek, near Del Rio, and Webb bluff, three miles below the southern line of Maverick county. A line joining the two points has a direction S. 27° E., and a length of 81.7 miles. The distance by the river is probably half as much more, or one hundred and twenty miles. The general direction of the dip is about S. . . .