130 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



from those in the territory nearer the Rio Grande. The 

 Carrizo is less dominant, in fact between the Salado and the 

 Pesqueria and along the railroad we observed no beds cer- 

 tainly referable to the Carrizo, although it doubtless occurs. 

 While the exposures of the Wilcox are still limited, the Mid- 

 way shows much greater development. 



On the road from Mier to Cerralvo, we find 2)4 miles 

 west of La Masa, a range of hills trending northwest and 

 southeast and having a northeast dip. The section shows: 



Feet. 



Sandstone 8 



Yellowish clay 10 



Fine-grained, smooth, yellow sandstone 10 



Blue clays weathering yellow --. 20 



Alternating clays and sandstones in thin beds. 



The character of these beds and their stratigraphic posi- 

 tion warrant their reference to the Midway. They occur 

 again at a creek crossing 10 miles south of Cerralvo on the 

 Herreras road and a hill in this vicinity is capped with fos- 

 siliferous sandstone showing Midway forms. They also have 

 a wide development in the valley of the Pesqueria River be- 

 tween Ramones and Herreras. 



A hill north of La Masa gives us a section of the Wilcox 

 clays overlain by the Carrizo, and similar beds were ob- 

 served southeast of Cerralvo. 



The town of Ramones is located on the blue shale of 

 the Papagallos and exposures are seen in the river bed for 

 two or three miles east of the town, underlying the yellow 

 clays of the Midway and the calcareous conglomerate of the 

 Reynosa. 



A quarry 2^ miles north of Ramones gives the following 

 section : 



Feet. 



Thin soil 1 



Thin bed of ferruginous sandstone contain- 

 ing Venericardia alticostata, Ostrca pnl- 



askensis, etc 1 to 1^ 



Thinly laminated shale, gray and black 4 to 12 



Soft gray sandstone 10 



