366 GEOLOGY OF NORTHWESTERN TEXAS. 



Just how much time there was between the deposition of the limestones and 

 the sandstones we do not know. But we do know that there are hundreds 

 of feet of strata below the sandstone along the Brazos (which is the equivalent 

 of the sandstones in San Saba County) and the limestones found in this dis- 

 trict. A diamond drill taking out a two inch core has been put down one 

 thousand feet, beginning at Coal Seam No. 1 , at Thurber. The entire dis- 

 tance has been through blue slate, thin beds of gray sandstone, and blue lime- 

 stone, all of which evidently belong to the Coal Measures, and that belong 

 in the series between the Richland sandstone of Mr. Tarr and the blue shales 

 of the Bend Beds. 



A comparison of the Colorado and Brazos sections, as illustrated on Plate 

 VII, shows that the unconformity at this place is caused by the absence of the 

 entire Millsap series, including Coal Seam No. 1, from its rightful position 

 between the shales and limestones of the Bend series and the Strawn (Rich- 

 land) sandstone. 



No list of fossils is given by Mr. Tarr as the basis of his reference of the 

 Bend series to the Sub-Carboniferous The following is a list of those taken 

 by myself and assistants from these beds: 



LIST OF FOSSILS FOUND IN THE BEND DIVISION. 

 VERTEBRATES. 



Edestus minor, Newberry. 



INVERTEBRATES. 



Hadrophyllum aplatus, sp. nov., Cum- Myalina subquadrata, Shumard. 



mins. Synocladia biserialis, Swallow. 



Chceletes radiens, . Bellerophon carbonarius, Cox. 



Spirifer cameratus, Morton. Productus semireticulatus, Martin. 



Pleurotomaria turbiniformis, Meek and P. punctatus, Morton. 



Worthen. Nuculana bellistriata, Stevens. 



Bellerophon crassus, Meek and W. C honetes mesoloba, Norwood and Prat- 

 Spiriferina kentuckensis, Shumard. ten. 



Productus nebrascensis, Owen. Productus costatus, Sowerby. 



Platyceras nebrascensis, Meek. Zaphrentis gibsoni, White. 



Euomphalus rugosus, Hall. Nunstroceras parallelumf, Hyatt. 



These fossils seem to me to fully warrant the retention of the Bend series 

 in the Coal Measures. 



Professor George G. Shumard, Assistant State Geologist, in a report writ- 

 ten in 1855 and 1856, but not published until 1886, says he found the Sub- 

 Carboniferous in Texas. He says: " On the San Saba River, at a point about 



