384 E. T. DUMBLE — CRETACEOUS OF TEXAS AND MEXICO. 



decided that the}^ belong to the Ripley. In the East Texas section the 

 Navarro or Glauconitic beds are the highest beds recognized. In the 

 Rio Grande section the corresponding beds are near the middle of the 

 section, being overlaid by nearl}^ 4,000 feet of deposits of Cretaceous age. 

 This 4,000 feet I separated into two stages, the Coal series and the 

 Escondido beds, and grouped all of the beds above the Pinto limestone 

 as the Eagle Pass division. Under the names proposed and used by Dr 

 White ^ for the divisions of the Upper Cretaceous the section given would 

 be as follows : 



Montana division = Eagle Pass division. 



Colorado division =-- Pinto limestone and Val Verde flags. 



Dakota division. Not observed here. 



It is, of course, entirely possible that the basal portion of the Val Verde 

 flags represent a part of Dakota time. 



While it may be impossible to draw the line closely between the repre- 

 sentatives of the Fox Hills and Fort Pierre stages in this region, I have 

 placed it provisionally at the contact of the Coal series and Escondido 

 beds, where we have the final disappearance of the Exogyra costata, Say, 

 which extends in its varieties throughout the beds thus defined as Fort 

 Pierre, and the first appearance of Sphenodiscus lenticiUaris, Owen.f This 

 is the characteristic fossil of the Escondido beds in this section and is 

 found in large numbers along the Rio Grande, from just below Eagle 

 Pass to the southern line of Maverick county. Such a division places all 

 of the Texas Cretaceous coals, whose horizons have been determined, in 

 the Fort Pierre stage or subdivision. 



DAKOTA DIVISION. 



My first reference X of certain sandstones in the vicinity of Eagle Flat 

 to this horizon has since been verified by the fossils found in them and 

 extended by Taff in his Carpenter Spring section.§ No other exposures 

 have been recognized. On Soro creek, in northern Coahuila, the Eagle 

 Ford flags rest directly on the Vola limestone. 



COLORADO DIVISION. 



The Eagle Ford clays were found by Taff and the writer in the Eagle 

 mountains, as has been noted in the First and Second Annual Reports 

 of the Texas Survey. 



xr Bulletin 82, U. S. Geological Survey. 



t Cragin : Fourth Ann. Rep. Geol. Survey of Texas, part ii, p. 245. 



X First Ann. Rep. Geol. Survey of Texas, p. xlviii. 



§ Second Ann. Rep. Geol. Survey of Texas, p. 734. 



