148 PROCEEDINGS OF THE ACADEMY OF [1895. 



Half a mile below the contact of the Cretaceous and at the foot of 

 Blue Shoals we have another section : 



(c.) Section at foot of Blue Shoals Half a Mile Below Tertiary — 

 Cretaceous Contact on Brazos River : — 



1. Brown sand river alluvium 10 feet. 



2. Blue indurated clay with boulders of limestone 



containing Ostrea pulaskensis Harris, and 



other fossils 5 " 



3. Laminated blue almost black fossiliferous clay 



with thin seam of indurated clay on top . . 4 " + 



The fossils obtained here with the addition of Turritella 

 alabamensis Whitf, Pecten alabamensis Aldr. , and a species of 

 Cerithium are the same as those occurring in (b.) a few miles down 

 the river and most of them occur at the Tertiary-Cretaceous contact 

 half a mile farther up. These have already been shown. 



These beds as shown in the river section undulate to such a degree 

 that many of them dip sharply and pass beneath the river level only 

 to rise again in some small exposures farther down. These undula- 

 tions are not uniform in their length as the usual condition appears 

 to be a long gentle slope, succeeded by a sharply abrupt descent 

 which is repi'esented in a much slower rise where the same beds 

 appear again. On this account we have two different rates of dip 

 towards the southeast with one towards the northwest, although the 

 whole series has a gentle slope or lowering towards the southeast; 

 That is, the farther we go up the river the longer and higher the 

 folds become. 



These beds have been traced westward in Falls and Milam counties 

 for some distance by Messrs. Taff and Stone of the Texas Geological 

 Survey. They do not, however, appear to occur anywhere along the 

 Cretaceous border east of Hopkins county. At least they are not 

 known in that region nor do they appear to be known anywhere east 

 as far as Rockport near Malvern and near Alexander Station on the 

 St. Louis and Iron Mountain Railroad in Arkansas, where a small 

 outcrop of the limestone belonging to them appears carrying Osbrea 

 I'u/askensis Harris, and some other fossils of the same age. 



Whether these beds ever formed a continuous belt along the 

 cretaceous border through this region and that this belt has long 



