1895.] NATURAL SCIENCES OF PHILADELPHIA. 141 



Hill. The basal Tertiary of the region while in its principal 

 feature? undoubtedly lignitic and in places correspond to the 

 Texas beds, his Camden series is only partially so, a portion belong- 

 ing to the middle Tertiary or Claiborne and a still greater portion 

 being of much younger age. At the base of this series Prof. Hill 

 has also included as Tertiary some beds of cretaceous deposits. His 

 Cleveland "red lands" are, according to Harris, of Claiborne and 

 Jackson age. fis It may also be stated that in some parts of Arkan- 

 sas the Eocene is represented by a still lower phase than the Lignitic. 



In Louisiana these beds are represented in the northwestern por- 

 tion of the State. They have been described by Hilgard 69 and Hop- 

 kins 70 as the Mansfield group and recently by Dr. Otto Lerch as the 

 Lignitic. 71 These beds are, in their main characteristic's, similar to 

 the lignitic of Texas and along the State line in Cass and Harrison 

 Counties in Texas and Caddo Parish in Louisiana I have found them 

 passing in unbroken continuity. 



It would thus appear that the lignitic beds of East Texas can be 

 directly connected with those of almost the whole of the Gulf States. 

 A number of variations in structure undoubtedly occur between 

 them and the corresponding beds of Alabama and Mississippi, where 

 heavy beds of green sand, carrying numerous fossils form no incon- 

 siderable portion of the series, and where the lignites are few and 

 poorly developed. In Texas the lignites are very extensively repre- 

 sented by many beds of different thickness and make up a very fair 

 proportion of the aggregate thickness of the lignitic stage and no 

 trace of a single deposit of glauconite or green sand occurs any- 

 where. In fact, with the exception of petrified or silicified wood a 

 few dicotyledonous leaves and stems of plants, all much broken, the 

 entire series of the Texas Lignitic is wholly unfossiliferous. 



If we follow Mr. Harris' division 72 and restrict the Alabama lig- 

 nite to the first 600 feet of the beds considered by Smith and John- 

 son as belonging to that stage, we find constantly recurring changes 

 from periods of low marshy coastal flats, during which the extensive 

 beds of lignitic clays and shales and sands were laid down to periods 

 in which the abundant fauna now buried in the glauconitic fossilifer- 



<w Geol. Survey of Ark.. Vol. II of 1892, pp. 04-110. 



69 Am? J. of Sci., Vol. XL VIII, No. 144, Nov., 1869, p. 340. 



7 " First Annual Report Geol. Survey of La., 1870, p. 83. 



71 Geol. and Agr. of North Louisiana. La. Exp. Sta. Bull., 1892, p. 9. 



72 Am. J. Sci., Vol. XLVII, April, 1894, p. 304. 



