6 GULF TERTIARY OF TEXAS. 



volume comprises all of the little that was then known regarding the geology 

 of the Tertiary area of East Texas. 



Professor E. D. Cope, of Philadelphia, has published accounts of the fossil 

 vertebrates of Central and Eastern Texas,* and has added greatly to our 

 knowledge of the subject in those regions. 



In 1884 R. H. Loughridge published in the " Report on the Cotton Pro- 

 duction of the State of Texas, with a Discussion of the General Agricultural 

 Features of the State," Tenth Census of the United States, Vol. Y, 1884, pp. 

 653-831, a brief account of the Geology of Texas, and a much more detailed 

 account of the soils and the agriculture. It gives a great deal of valuable 

 data, collected over a large area, but mostly in Central and West Texas. 



In 1888 there appeared, as a congressional document, a report on "The 

 Iron Regions of Northern Louisiana and Eastern Texas," by Lawrence C. 

 Johnson, Assistant Geologist United States Geological Survey. This outlines 

 the iron ore area of Louisiana and Texas, and gives data respecting the geo- 

 logical formations of those sections. 



In the Report of Progress, for 1888, of Mr. E. T. Durable, State Geologist, 

 there is a short account of the iron ores of East Texas, by R. A. F. Penrose, Jr. 



Here ends the list of geological literature on East Texas. Though many 

 works on Central and Western Texas have been published, it is not necessary to 

 mention them here, as they do not refer to the question under consideration, 

 and have been already summarized by Mr. R. T. Hill.f 



It will be seen that what little is known of East Texas consists largely of 

 fragmentary and vague statements, made often in connection with and as sub- 

 ordinate to other interests. It is purposed in this preliminary report to make 

 as concise a statement as possible of the facts already noted, not only in East 

 Texas proper, i. e,, the country east of the Brazos, but also at various points 

 on the Colorado River and Rio Grande. The various data will be described 

 under two principal headings — Descriptive Geology, and Economic Geology. 



In conclusion, I wish to express most sincere thanks to Professor Angelo 

 Heilprin, of the Academy of Natural Sciences, Philadelphia, for much valuable 

 advice and information. I also wish to express the same thanks to Professor 

 R. T. Hill, of the University of Texas, for his kindly assistance and advice 

 during the prosecution of the work. 



* Bulletin of the United States National Museum, No. 1*7, "On the Zoological Position of 

 Texas," 1880, and elsewhere. 



f R T. Hill: "The Present Condition of Knowledge of the GTeology of Texas." Bulletin 

 ofU.-S. G-. S., No. 45, 188*7. 



