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when used in the field. Especially is this the case in the location and windings of streams. This is the natural consequence of the character of work from which they are compiled, which is intended to show only the position of streams with regard to survey lines. This could be obviated by meandering and mapping the streams, provided there was no conflict in survey lines, but, unhappily, such is not always the case.

Besides these and the work now being done by this Survey in the effort to prepare such maps as we need, based on accurate surveys, we have the topography of twenty to twenty-four thousand square miles (about one-twelfth of our entire area) in the center of the State, which has been done under the United States Geological Survey. While these maps are by far the best we have of this district, beautifully executed and very useful indeed, it is nevertheless a fact that they have proved so inaccurate in detail in many localities that we have been compelled to add a topographic corps to that of the geologists proper, wherever we have essayed to use them in anything like thorough work, such as that in the Central Mineral Region. These United States topographic maps cover only a certain belt of country, and they do not give us exactly the areas which are of most service to us. Thus the sheets take in part of the Central Mineral Region, part of the Central Coal Field, and part of the Eastern Cretaceous Belt; and they are now working eastward into a comparatively level country, in which, if anywhere, the geologist could manage to prosecute his studies without them, leaving those portions of the regions mentioned where they are most needed unfinished, and thereby increasing our work instead of helping us.

All geologic work heretofore done in Texas has been of such a disconnected character that we are unable to formulate any general results from it, although many of the observations will be of great assistance in working out the local geology. The several expeditions made along the boundaries of the State and across it in various directions, were too hurried to give anything more than sketches of a few localities. Dr. Ferdinand Ræmer gave an excellent section of one district as he saw it, and for his opportunities a remarkably comprehensive view of the geology of the State, but this has subsequently been somewhat modified by other observers. Of the first State survey of Dr. Shumard we