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below the Ostrea cortex ledge. All of the coal (or lignite) along this stream occurs above the oyster ledge and in all probability is Eocene. This coal is discussed under the Eocene coals or lignites (pp. 61 and 62). One other occurrence of coal is reported in the Eagle Pass formation. Mr. Robert Thomson states that a 4-foot seam of coal was penetrated in a well bored by him on the line between Maverick and Zavalla counties, about 4 miles north of the northern line of Dimmit County. The writer has no further information in regard to this occurrence.
MINES.
Two mines are at present being worked in the Eagle Pass coal bed, in the vicinity of Eagle Pass. One is that of the Maverick County Coal Company, situated on the east side of Elm Creek, 4 miles north of Eagle Pass. A section of this mine is given on page 25. It was opened in 1895. The other mitre was opened by L. F. Dolch & Co. in 1898, and is about a mile south of the mine of the Maverick County Coal Company. The shipping of coal from the Dolch mine was begun in January, 1899. It is now owned by the Rio Bravo Coal Company. A section in this mine is given on page 24. The old Hartz mine, about 5 miles above Eagle Pass, on the Rio Grande, was worked on a slope, and is now abandoned.
CHARACTER OF COAL.
Specimens of the Eagle Pass coal were collected, and on them the following notes are based:
The coal is dark, does not air slack, is lustrous or brownish black in color, has a brown streak and subcubical cleavage. Usually no woody structure is apparent.
Two analyses, made by Dr. Peter Fireman, of Columbian University, showed a rather low percentage of water, a ratio of fixed carbon to volatile hydrocarbon of 1.11 and 1.05. The percentage of ash was high.
The following is one of the analyses:
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