LETTER OF TRANSMITTAL.

Hon. L. L. Foster, Commissioner of Agriculture, Insurance, Statistics, and History, Austin Texas:

DEAR SIR— The accompanying Bulletin No. 4, "A Preliminary Annotated Check List of the Cretaceous Invertebrate Fossils of Texas," was prepared at my request by Mr. Robert T. Hill, in order that the different field parties engaged in actively prosecuting the work of the survey might have at hand a concise statement of our present knowledge of this system, not only as an aid to the proper understanding and interpretation of its various horizons as they come upon them in their work, but in order that work already done may be fully verified or corrected without unnecessary duplication, and each be prepared to add such new discoveries as may be made from time to time.

I may add that in this bulletin is exemplified the typical co-operation of State and National surveys, i. e., the working out and preparation by the National survey of such purely scientific matters as is contained herein, which, while it is absolutely necessary to the proper prosecution of the work of the State survey in the discovery and description of the economic materials contained within the system, yet lacks that direct interest to the people of the State that obtains in the economics themselves.

Our thanks are therefore due to the Director of the United States Geological Survey for the assistance thus afforded us, as well as to Mr. Hill for his valuable services in its preparation.

Yours, respectfully,

E. T. DUMBLE,
State Geologist.