lxXXViii REPORTS OF GEOLOGISTS. 



across Wise, Montague, and Cooke counties, to Red River, north of Marys- 

 ville — 70 miles. 



The basal contact of Lower Cross Timber sand was then traced from Red 

 River, north of Gainesville, Cooke County, across Cooke, Denton, Tarrant, 

 Hill, and Johnson counties to Brazos River at west line of McLennan County — 

 175 miles. 



The Upper contact of Lower Cross Timber sand was determined from Red 

 River, near Gordonville, across Grayson, Denton, Tarrant, Dallas, Johnson, 

 Hill, and McLennan counties to Ross, McLennan County — 175 miles. 



In addition, Mr. McCulloch's services have been employed in delicate pale- 

 ontologic determinations and editorial work for my division. His services 

 have been of great value in many important branches. 



Mr. J. S. Stone relieved Mr. Drake in November, and was placed with Mr. 

 Taff upon the eastern line of the region. His training in surface geology has 

 been of great service to the work. 



R. T. HILL, 

 Geologist. 



REPORT OF MR. THEO. B. COMSTOCK. 



Austin, Texas, March 31, 1890. 

 Mr. E. T. Dumble, State Geologist, Austin, Texas: 



Sir — In accordance with my original engagement with you, I reported for 

 duty at Austin, June 20, 1889, and started next day for Burnet, with Charles 

 Huppertz and C. H. Shamel as aids, under your instructions to make a rapid 

 review of the Central Mineral Region for the purpose of outlining a plan of 

 survey. Employing Richard Maxwell, of Bluffton, as cook and teamster, I 

 spent sixteen days (owing to delays by floods in the rivers) in traveling 

 through parts of Burnet, Llano, Mason, Gillespie, and Blanco counties. Upon 

 my return to Austin, plans were matured for the complete survey of the dis- 

 trict, which, it was then supposed, would comprise about the area of three full 

 counties. Your instructions gave me "the charge of the study of all the 

 territory within the Central Paleozoic Area, from the earliest rocks to the base 

 of the Carboniferous System, with such further work in other terranes as 

 may be necessary in your judgment to a clear understanding of the struc- 

 ture of the district." It was thought that this limited field could be covered 

 fairly in the three months for which I had been engaged, and at the expira- 

 tion of that period, in September, enough work had been done to enable a 

 report to be prepared embodying all that was originally contemplated, although 



