184 Cincinnati Society of Natural History. 



Ohs. This species is mainly distinguished by the robust form 

 of the corallum, together with the conspicuous monticules, both of 

 which are marked features. 



Formation and Locality: Lower Silurian, Cincinnati Group, 

 Cincinnati, Ohio. 



34. M. woRTHENi, U. P. James. 



The Palaeontologist, 50, 1882. 



Corallum dendroid, of cylindrical or flattened Stefns, branch- 

 ing irregularly, from one to two lines in diameter. Surface with 

 small, prominent monticules, arranged in alternating, longitudinal 

 rows about one line apart. Apices apparently solid, the slopes oc- 

 cupied by cells of ordinary size or larger. Calices sub-circular or 

 angular, margins thick. No interstitial coralliles. (Plate 2, 

 figs, za, b.) 



Obs. This resembles somewhat M. ramosa, var, dalii, but the 

 small, interstitial tubes are absent. 



Formation and Locality: Lower Silurian, Cincinnati Group, 

 Lynchburg, Highland Co., Ohio, and other localities in upper beds 

 of Cincinnati Group. 



[to be concluded.] 



