In accordance with the original plans of the Survey, while keeping steadily in view the economic features, the first year of each biennial term is devoted mainly to stratigraphical geology. Therefore the report of the work which has been done in the year just closing will deal largely with the details and descriptions of the character and extent of the rock material of the different formations over which we have worked, although many very important facts regarding the resources of the regions will also be presented for the first time.

The lack of accurate maps, which has been a great disadvantage to the Survey since its commencement, is being supplied as rapidly as possible by the work of the United States Geological Survey, the. United States Coast and Geodetic Survey, and by our own field parties. There is, however, very much yet to be done in this direction, owing to the great area covered by the State; and several portions of Texas, of which it is necessary to know the accurate topography before certain important geological questions can be satisfactorily settled, lie outside the present limits in which the United States Surveys are able to work, and are too large a task to be undertaken by this Survey under the present appropriations. For this reason general conclusions must sometimes be made on data which are not as complete as they should be, and in consequence the details, when determined, may prove the real conditions to be somewhat different from our present understanding of