Various classifications of the coals have been proposed by different authors, but none have come into general use, or taken the place of that which is based upon their geological age, which is this:

The coal of the Coal Measures in Texas is of the bituminous variety, of the same general character as the coal of the Indian Territory, and much of it yields a fair quality of coke when burned in ovens.

According to the classification given above, the coal of our Cretaceous area belongs under the head of brown coal, and it is true that in a few places small quantities of lignitic coal are found among the beds of this age. This occurs principally in the sands of the Bosque and Red River divisions, but nowhere, so far as yet determined, in workable quantities. The greater part of the coal of this age, as it is developed in the vicinity of Eagle Pass, resembles the bituminous coal of the Carboniferous much more closely in every characteristic than it does any of the varieties found in the Tertiary. In addition to this, certain portions of this bed yield a good coke in the crucible in the laboratory, and thereby give promise, at least, of coking on a larger scale.

When we come to a critical study of the deposits of the Tertiary, we find that the varieties of brown coal occurring in them are numerous, and correspond closely with those recognized in Europe, including true lignites and lignitic coals. Therefore, while it has been-customary in this country to use the term Lignite as synonomous with brown coal, and to apply the term to deposits of Secondary as well as Tertiary age, I have concluded, on account of the marked dissimilarity of the coals of these periods, as they occur here, to adopt the definition and classification of Zincken for the purposes of this report, and to include under the general