i8o Cjncmnati Society of Natural History. 



Chtvtetes fldchcri, Nich. Quart. Jour. Geo). Soc, XXX., 504, 

 1874; Pal. Ohio, II., 197, 1875; Ann. Nat. Hist. ser. 4, XVIII., 

 90, 1876. 



Dckayella ulric/ii, Nich. Ulrich, Jour. Cin. S. N. Hist., YI., 



9ir i53> 1883- 



D. obscura, Ul. Ibid, YI., 89, 1883. 



Corallum ramose, of cylindrical or sub-cylindrical branches, 

 dividing at irregular intervals, and from less than two lines to about 

 4 lines in diameter. Surface smooth ; calices sub-polygonal or 

 rounded. Walls of corallites thickened. Interstitial corallites 

 numerous, angular, interspersed with the ordinary corallites. 



Obs. Externally this species somewhat resembles andrcwsii, but 

 that species is generally more robust, and has but few interstitial 

 corallites. The surface, too, shows macule, with many corallites 

 of a larger size than the average. Maculae of idrichi, if developed, 

 are made up of rather smaller cells than the average. Some spec- 

 imens show low, rounded monticules. 



Formation and Locality: Lower Silurian, Cincinnati Group, 

 Cincinnati, O. 



27. M. SEPTOSA, Ulrich. 



Atactopora septosa, Ul. Jour. Cin. S. N. Hist. II., 125, 1879. 



Amplexopora septosa, Ul. Ibid, V., 255, 1882. 



Corallum ramose; branches cylindrical or sub-cylindrical. 

 Surface with broad, low monticules, about one line apart and occu- 

 pied by groups of cells larger than the average. Calices polygonal, 

 rather regularly arranged; walls of corallites thin; no interstitial 

 corallites. Worn specimens show peculiar projections from the 

 cell walls into the cell cavity. 



Obs. This is rather a poorly defined species, but it will prob- 

 ably be distinguished by the low monticules, the absence of inter- 

 stitial cells and the peculiar appearance presented by the walls of 

 worn specimens. 



Formation and Locality: Lower Silurian, Cincinnati Group, 

 Cincinnati, O. 



28. M. KENTUCKENSis, U. P. James. 

 The Palaeontologist, 57, 1883. 



Corallum dendroid; branches cylindrical; about one line, more 

 or less in diameter, branching dichotomously or anastomosing. 

 Surface with low monticules irregularly distributed. Calices poly- 



