E. W. Hilgard—Geological History of the Gulf of Mexico. 395 
by Tuomey as the Buhrstone group (‘‘Siliceous Claiborne” of 
my Miss. Report). The lithological continuity of the bed- 
supported to some extent by paleontological evidence, sinchgle 
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€ river, so far as I know; and the oceurrence of somewhat 
extensive marine Tertiary outliers on the Cretaceous territory 
of Arkansas, as well as of lignitic beds on that of Texas (e. g., 
the Cross Timbers, as approximately laid down on the map), 
deg that although the deeper water of the embayment fol- 
Owed substantially the lines of trend shown on the map, 
_ there still existed at that time a connection, in a northwesterly 
- ection, of the Gulf waters with those of the great interior: 
__ basin of the West. 
: ; ecting troug! 
Inconsiderable thickness of the deposits, that of course — 
avored their removal by the subsequent events of the Quater- 
hary period. Nevertheless, enough seems to remain of these 
§ deposits to form a chain by which, with the aid of paleobotany, 
_ "Me equivalents in time of the Buhrstone and Claiborne marine 
_ Stoups, at least, can be determined among the fresh or brackish- 
_ * Miss, Rep., 1860, $$ 162 and ff. 188, ete. 
