32 AUG. F. FOERSTE 



In 1896 Harper and Bassler' adopted the division of the Cin- 

 cinnati group made by Winchell and Ulrich in the preceding 

 paper, written at an earlier date but still unpublished. The Lor- 

 raine is said to be terminated above by a widely distributed bed 

 containing rolled fragments and entire specimens of the large 

 form of Platystrophia lynx in great abundance. The Richmond 

 group comprises the overlying part of the Cincinnati group and 

 is, therefore, the exact equivalent of the Lebanon beds of Orton. 



In 1900 Nickles and Bassler^ adopted the division of the 

 Cincinnati group into the Utica, Lorraine, and Richmond. Their 

 lists of fossil bryozoa established still more definitely the line 

 between the Utica and the Lorraine, as identified by Ulrich. The 

 line between the Lorraine and the Richmond is apparently still 

 the same as that between the Cincinnati beds proper and the 

 Lebanon beds of Professor Orton. 



In 1902 J. M. Nickles 3 referred the lower 80 feet of the 

 Lebanon beds of Orton to the Lorraine, thus increasing the sec- 

 tion to be identified as Lorraine and diminishing the section to 

 be included in the Richmond. The strata including the thin 

 Dinorihis retrorsahtd are for the first time definitely* excluded 

 from the Richmond. The base of the Richmond was placed just 

 beneath the lowest beds containing Strophomeiia rugosa (the 

 Stroplwmeiia planumbona oi the Ohio Survey), Rhy?tchotrema capax, 

 Dalmanella jiigosa and Streptelasma rusticum (the Stroptelasma 

 corniculum of the Ohio Survey. The Lorraine of Ohio, as 

 extended by Nickles, was then subdivided into six sets of beds, 

 called, in descending order: the Warren beds, 80 feet thick; 

 Mount Auburn beds, 20 feet; Corryville beds, 60 feet; Bellevue 

 beds, 20 feet; Fairmount beds, 80 feet; and the Mount Hope 

 beds, 50 feet. The Warren beds include those formerly referred 

 to the Lebanon beds by Orton, but transferred to the Lorraine 

 by Nickles. The Mount Auburn beds include the highest strata 



' Catalogue of Fossils in Vicinity of Citicittnati, O. Private publication. 



^"Synopsis of American Fossil Bryozoa,'" Bulletin U. S. Geol. Stirv., No. 173. 



3"The Geology of Cincinnati," /<9«r. Cincinnati Sec. Nat, Hist., Vol. XX, No. 2. 



■» Ulrich, "Correlation of Lower Silurian Horizons," ^w. Geol., Vol. II (1888), 

 p. 41. 



