264 Life of a Fossil Hunter 



the other layers It is literally packed with casts of 

 straight and coiled shells related to our living nau- 

 tilus. They are mingled in great confusion. I be- 

 lieve some of the coiled shells are a foot in diameter. 

 This stratum is not so compact as the others, and 

 seems to contain more lime. No. 4 is a very solid 

 gray sandstone, eight inches thick, its upper surface 

 crossed at various angles by elevated ridges of 

 harder material. 



From these observations, I am led to the con- 

 clusion that the pervious nature of the red beds, 

 which in the valley of the Wichita are about three 

 hundred feet thick, allows the water to sink rapidly 

 down through them until it reaches the impenetrable 

 gray sandstone ; from which it runs off at whatever 

 angle the rocks may be tilted. 



