DESCRIPTIONS OF FORMATIONS 



463 



and sulphur seams. For this upper stage the name Manning is proposed 

 from the station of that name on tlie St. TjOuis & Santa Fe Eailway, 

 where they are well exposed. 



In this area the Jackson belt has a width of 8 to 14 miles and a prob- 

 able thickness of 400 to 500 feet. East of Corrigan a well beginning in 

 the base of the Catahoula passed through the Jackson and Yegua beds 

 and reached the fossiliferous Marine beds at 1,300 feet. This would give 

 the Jackson a thickness of about 600 feet in this locality. The beds are 

 not only thicker tlian on the Sabine, but they become more anrl more 

 sandy toward the west. 



West of the Houston, East & West Texas Railway we find the Caddell 

 clays with fossiliferous calcareous concretions on Tar Kiln Creek some 

 5 miles southwest of Diboll, at which place well preserved fossils were 

 collected, and it outcrops again about 12 miles northeast of Groveton, on 

 the Groveton, Lufkin & Northern Eailway. This was as far west as we 

 could trace it. 



Fossils are of more frequent occurrence in this terrane than in any 

 other in east Texas except the Marine beds. Those near the base occur 

 in connection with the calcareous concretions. Sometimes the shells are 

 present in the concretions or weathered out from them, but more often 

 the shell material has been leached out, leaving only the imprint. 



From the Tar Kiln Creek, 4 miles southwest of Dil)oll, the following 

 forms were identified : 



Ostren frag, like contracta 

 Area sp. V 



Yencricm'dia planicosta Lam. 

 Venericardia rotunda Lea. 

 I'cctKnciilns idoneus Con. 

 PcctuHCuIus sp. ? 

 Crassatclla texana Heilp. ? 

 CrassatclJa flexura 

 Corhula alaharnicnsis Loa. 

 Corbiila oniscus ? 

 Cytherea tornadonis Har. ? 

 Tcllina mooreana 



Tellina sp. 

 Turricula sp. 

 Bulinella Icellogii Gabb 

 Turritella nasuta Gabb 

 Turritclla hotistonia Har. 

 Solarinm alveatum Con. 

 Solarium huppcrtsi Har. 

 Vohitilithes pctrosus 

 Cax-'^hlaria sp. 

 Calijptrca sp. 

 Dcntaliuni dumblci Har. 

 FlabeUum wailesii Con. 



In tbe yelluw, sandy euncretions are many large Pinna, Pholodomya, 

 Echinoderms, .sni;ill l/aminea grandis, etcetera. 



In connection witb tbcso bods north of Manning a fragment of a verte- 

 bra was found, wbicli is probably Zeuglodon. 



At a somewbat biglier horizon tbe brown sands carry a number of 

 fossils in tbe form of casts. This appears to be the special horizon of 

 Haminea grandis. 



