1895.] NATURAL SCIENCES OF PHILADELPHIA. 103 



smaller in the upper than the lower beds. Westward from the 

 Neches the gypsum crystals are, however, almost exclusively confined 

 to the fifty or sixty feet at the base. 



The base of these clays may be seen in a bluff on the Brazos 

 River about 500 yards south of the mouth of the Little Brazos, with 

 the following section : 32 



1. Black soil 2 feet 



2. Brown loam with limy concretions . . .25 feet 



3. Fine brownish-yellow sand with occasional 



streaks or pockets of gravel 15 feet 



4. Gravel, with unknown cretaceous shells . 2 to 4 feet 

 Yegua clays 5. Pale blue clay unfossiliferous 5 feet 



6. Dark green sand showing fossils in lower 



portion 2 to 5 feet 



7. Dark colored laminated sandy clay containing 



Terebra houstonia Harris; Levlfusus trabeatoides 

 Harris n. sp. ; Pseudoliva vetusta var. ; Pseudo- 

 lira vetusta var. pica; P. vetusta, var. clausa; Tri- 

 r§ gonarca corbuloides, Con. ; Pleurotoma (Pleuroto- 



<U 



pq mella) quasites, Harris; Nucula magnified, Con.; 



2 Leda opulenta, Con. ; Latirus moorei, Gabb. ; 



Corbula alabameiisis, Lea; Venericardia plani- 



S costa, Lam ; Phos texana, Gabb., var. ; Natica 

 arata, Gabb. ; Natica semilunata, var. janthinops 

 new var. ; Sigaretus inconstans, Aid. ; Yoldia 

 aldrichiana 33 4 feet 



8. Ferruginous sandstones 8 inches 



9. Same as No. 7. 



In this section the gypseous clays are not seen nor do they appear 

 anywhere in the river banks. This, however, may be expected as 

 their position there is obscured by broad, deep deposits of river 

 alluvium which cover wide areas and form the bottom lands of the 

 Brazos. East of the Little Brazos these clays are found occupying 

 their proper position at several places. A section seen on the line 

 of the Houston and Texas Central Railway near Elm Creek, on the 

 south side of Robertson County, shows : 3t 



32 Fourth Annual Report Geol. Survey of Texas, 1892, p. 



33 Harris M. S., Monograph of Texas Tertiary Fossils. 



34 Fourth Annual Report Geol. Survey of Texas, 1892, p. 50. 



