SECTIONS OF THE WASIITTA DIVISION. 381 



The Exogyra avietina clays were not found at this locality, unless 

 they be rej)resented here by the beds containing the very similar form 

 of Exogyra plexa, Cragin. 



In the bed of a stream a few miles southwest of Kent there is an ex- 

 posure of a fine white marble with reddish spots, which is lithologically 

 similar to the Vola limestone. It contains great numbers of a large fossil 

 which in general shape, size and appearance closely resembled the Vola 

 roemerl of Hill, but they were all so worn that certain identification could 

 not be made. In the upper portion of the beds were two or three bands 

 which were simply masses of Ncrinea volana. Crag., beautifully preserved 

 in calcite. A good collection of these was made by Mr W. F. Cummins 

 and myself. The stratigraphic relation of these beds to those of the Kent 

 section was not traced, but beyond doubt they are referable to the Vola 

 limestone. The thickness is much greater here than in the eastern ex- 

 posures. 



Devils River Section. — In the Devils River section, at the base of the 

 Washita, there is a very sandy limestone, which in places carries con- 

 siderable bituminous matter, especially in its upper portion. This sandy 

 limestone is water-bearing and furnishes many good wells. It is over- 

 laid by a semicrystalline, heavy bedded limestone, which carries, together 

 with such characteristic fossils as Schloenbachia leonensis, Con., and Kingena 

 {Terehratula) icacocnsis, Roem., a bed of Caprina crassifibra, Roem., which 

 in size of individual fossils greatly exceed any I have seen in the Caprina 

 beds of the Fredericksburg. The exact relationship of these beds is well 

 shown in some of the bluffs of Devils river northwest of Del Rio. One 

 of them, by barometer measurement over 200 feet high, had at its base 

 the large Pecten texana, Roem., of the Washita, about 70 feet above this a 

 band of fossiliferous limestone containing Kingena {Terehratnla) ivacoensis, 

 Roem., and Schloenbachia leonensis, Con., while at the top of the bluff there 

 is a massive bed of Caprina crassifibra, Roem., with an echinoderm which, 

 although badly weathered, seemed to be a Pyrina. Succeeding the Caprina 

 bed, as shown by exposures southeast of this locality, the limestones are 

 more marly and carry an abundant fauna of species characteristic of the 

 Washita, and are finally succeeded at Del Rio by the Exogyra arietina 

 clays and their capping of the Vola limestone. 



In the San Lorenzo Section. — In the San Lorenzo section, in Coahuila, 

 the Washita forms the surface rock of a large part of the area, lacing over- 

 laid by the Ui)per Cretaceous only in phxces very near the river. The 

 Washita has the sand}^ water-bearing bed at its base, and this is capped 

 in places by asphaltic limestones. The overlying linn'stono is semi- 

 crystalline and very li-ht in color. TIio only fossil found was Ostrea 

 carinatn, Lain. 



