1895.] NATURAL SCIENCES OF PHILADELPHIA. 105 



The base of these beds is seen at Alabama bluii' some twenty 

 miles farther up the river, where a bed of blue elay with gypsum 

 crystals occurs iu coutact with the underlying fossiliferous sands of 

 the Marine beds. This section shows : 3ti 



1. Black sandy loam 5 feet 



Y egua 2. Gravelly conglomerate 2 feet 



^ a y s 3. Laminated blue clay with gypsum 2 to 5 feet 



4. Fossiliferous greenish-blue clay 4 feet 



d w 5. Green sand 5 feet 



a pq 6. Clay ironstone 10 inches 



7. Fossiliferous clay, to water 5 feet 



No. 3 of this section shows the base of the Yegua clays as found 

 on the Trinity River. 



Eastward towards the Neches River the deposits belonging to this 

 stage assume more and more the same structure and conditions of 

 deposition as found in Angelina and the other counties in the east- 

 ern portion of the area. 



The positions of the sections given show approximately the north- 

 ern boundary of the area occupied by these Yegua clays. The line 

 may be traced by the outcroppings of the gypseous clays and sands 

 from the Sabine River, near Sabine Town, in a generally northwest- 

 ern direction as far as the Angelina River, near the mouth of the 

 Atoi Creek, in Cherokee, and thence southwesterly, crossing the 

 Neches near Weches Post Office , passing through the eastern side of 

 the town of Crockett, crossing the Trinity at Alabama Bluff, the 

 Navasota River near the northwest corner of Madison County and 

 the Brazos at the locality shown in the section already given. To 

 the south they are circumscribed by the overlying Fayette sands. 



Unlike the rough, hilly region occupied by the Fayette sands, the 

 country occupied by the Yegua clays is generally flat. Sand hills 

 and ridges occur in several localities, but throughout the greater 

 portion level, prairie-like conditions prevail. 



The fauna of these deposits throughout east Texas is scanty in 

 the extreme. Of the vertebrates only one specimen, the portion of 

 the lower jaw of a species of Crocodilus, lias been obtained, and that 

 from a well at Bryan, while no invertebrate fossils have been found 

 anywhere east of the Brazos except at the base of the beds on that 



36 Third Annual Report Geol. Survey of Texas, 1891, p. 15. 

 8 



