The Ohio T^aturalist, 



PUBLISHED BY 



The Biological Club of the Ohio State Uni'versity, 

 Volume XII. JANUARY, 1912. No. 3. 



TABLE OF CONTENTS 



FoERSTE— The Arnheim Formatiou within the Areas Traverseil by the Cincinnati 



Geanticline 429 



SCHAFFNER— New and Rare Plants of Ohio 457 



Metcalf — Meetiniis of the Biological Club 458 



THE ARNHEIM FORMATION WITHIN THE AREAS 

 TRAVERSED BY THE CINCINNATI GEANTICLINE. 



By Aug. F. Foerste. 



CONTENTS. 



1. Subdivisions of the Arnheim 429 



2. Eastern Kentucky, from Maysville to Stanford 431 



3. Central Kentucky, from Stanford to Lebanon 435 



4. Western Kentucky, from Nelson to Trimble Counties 437 



5. Indiana 439 



6. Ohio 440 



7. Nodular top of Arnheim in Ohio 443 



8. Arnheim includes first advent of Richmond fauna 445 



9. Adair County, with outcrops in Marion and Casey Counties, 



Kentucky 445 



10. Western Tennessee 446 



11. Southern Kentucky, along the Cumberland River 447 



12. Globular bryozoans in Casey and Lincoln Counties, Kentucky .... 447 



13. Diastrophic movements during the deposition of the Arnheim 448 



14. Origin of the Arnheim fauna 449 



1. Subdivisions of the Arnheim. 



Along the eastern line of outcrop of the Ordovician formations 

 in Kentucky, and in the immediately adjacent parts of Ohio, the 

 lower part of the Arnheim inember of the Richmond is compara- 

 tively unfossiliferous, while the upper part is abundantly supplied 

 with fossils. The transition is sufficiently abrupt to be traced 

 readily in the field. In fact, the line of separation between the 

 lower, comparatively unfossiliferous division and the upper 

 richly fossiliferous part of the Arnheim may be traced more 

 readily, with greater exactness, and for a greater distance than any 

 other horizon in the Richmond along its eastern line of outcrop. 

 For this reason, the line of separation between the upper and lower 

 Arnheiin is inore definitely known than any other horizon in the 

 Richmond of eastern Kentucky, and it has been found convenient 



429 



