April, \\)lt\ Siliiriau Fossils from Ohio 191 



which does not resemble the softer clay sections of more 

 southern areas. The same lithological appearances are pre- 

 sented by the exposures on following the stream westward from 

 the first exposures of the Crab Orchard formation, half a mile 

 west of Port William, 18 miles northwest of Leesburg. They 

 characterize the exposures also west of Cedar ville, west of 

 Clifton, and at Yellow Springs. At Centerville, the more or 

 less indurated clayey strata, overlying the Dayton limestone, are 

 interbedded with thin layers which are sufficiently calcareous 

 to suggest impure limestones. Near the Soldiers' Home, west 

 of Dayton, the limestone layers interbedded with the more 

 shaly courses in the equivalent of the Crab Orchard section are 

 more calcareous, and thicker, frequently attaining a thickness 

 of three or four inches, or more, and resemble the underlying 

 Dayton limestone, which is softer and less white here than 

 southeast of Dayton, and at Centerville. At Lewisburg, Lud- 

 low Falls, and Covington, the equivalent of the Crab Orchard 

 section has become a continuous succession of limestones no 

 longer to be readily differentiated from the typical Dayton 

 limestone beneath. 



In the present state of our knowledge it seems probable that 

 the Osgood clay of the Lewisburg section belongs above the 

 Crab Orchard clay section of Highland and Adams Counties, 

 in Ohio, and is not merely an attenuated equivalent of the latter. 



The Dayton limestone is regarded as forming merely the 

 base of the Crab Orchard formation. The Liocalymene clintoni 

 horizon, at the top of the Crab Orchard formation, may belong 

 below the Rochester shale, rather than be equivalent to the 

 latter. 



The discrepancies between the Niagaran sections east and 

 wfest of the present Cincinnati geanticline suggest an origin at 

 least as early as the early Niagaran. 



Holophragma calceoloides Lindstrom. 

 Plate VIII, Figs. 3A-K. 



1865. Hallia calceoloides, Lindstrom. Ofvers. Vet. Akad. Forhandl., XXX, 



L. C, p. 289, pi. 31, figs. 9-11. Id. Nomina Foss. Sil. Gotl. p. 7. 

 1879. Cvathophvllum calceoloides, Quenstedt. Petrefactenkunde Deutsch- 



lands. Pt. I. vol. 6, p. 410, pi. 156, figs. 90-92. 

 1885. Cvathophvllum calceoloides, Lindstrom. List of Fossils of Gotland, p. 19. 

 1888. Cvathophvllum calceoloides, Lindstrom. List of Fossil Faunas of Sweden, 



Pt. IL p". 21. 

 1896. Holophragma calceoloides, Lindstrom. Bihang t. K. Sv. Vet. Akad. 



Handl. vol. 21, Afd. IV, No. 7, pi. VI, figs. 74-86. 



