FIELD INVESTIGATIONS IN 1 92 1 845 



Sainte Genevieve limestone. Feet 



Ohara member. 



Limestone, rather massive and impure, gray, varying in thickness, 

 with few recognizable fossils, among them the thickened sup- 

 port of a species of Lyropora like L. quincunciulis or L. ran- 

 osculum, 4-8 



Calcareous shale and argillaceous limestone, with abundant and 

 well preserved, though fragmentary, remains of Platycrinus 

 huntsvilkc, especially in the upper 6 inches 4-6 



Limestone, semioolitic, containing usual Sainte Genevieve Pen- 

 tremites 1-5 



Shaly limestone with Ohara fossils and locally in basal foot 



colonies of crinoids preserving calyx and arms' 0-1 



Fredonia member. 



Oolitic and fine-grained light-colored limestone, usually in thick 

 ledges, with considerable chert 15 to 30 feet beneath top ; 

 fossils of kinds usually found in this member, but not very 

 plentiful, to base of Chester series and to top of underlying 

 Saint Louis limestone, about 125 



Total thickness of Sainte Genevieve limestone, about 150 



Though some doubtless will find it difficult to locate exactly the bound- 

 ary between the Sainte Genevieve and Gasper limestones in the hills to 

 the east and south of Huntsville, Mr. Butts and I experienced little 

 trouble and agreed perfectly in recognizing the line of contact between 

 them. It is simply a matter of knowing what to look for and where to 

 look for it. Immediately beneath the Gasper, as indicated in the de- 

 tailed section, is a bed of solid gray limestone varying greatly in thick- 

 ness in different places, sometimes absent entirely and in one exposure 

 varying from less than 4 feet to 8 feet. It is only sparingly fossiliferous 

 and the fossils observed are imperfect and badly preserved. However, 

 we welcomed one find, the U-shaped thickened support of a Lyropora, 

 that at once suggested the top zone of the Ohara in western Kentucky 

 and with the other data procured here seemed a veritable cap sheaf to 

 the evidence on which I have now convinced myself that the Sainte 

 Genevieve limestone here, as in western Kentucky, not only includes rep- 

 resentatives of the Upper Ohara, but that the same species of Dizygo- 

 crinus and Platycrinus that I claimed to have found in the Upper Ohara 

 near Princeton, Kentuck} T , occur also in Alabama practically to the top 

 of the beds which I am correlating with the Upper Ohara. We found not 

 only Dizygocrinus and Platycrinus liuntsvillce in these upper beds, but 

 associated on the same slabs is "Glolocrinus" unionensis, which Weller, 

 no less than I, regards as a guide fossil of the Upper Ohara in western 

 Kentucky and southern Illinois. The same slabs also contained a number 



