1 82 Cincinnati Society of Natural History. 



surrounded by smaller ones in a single row and often isolating the 

 large ones; variable in size and shape. 



Obs. A very common and variable species, the variety a 

 being the more marked of the two following, while b may perhaps 

 be scarcely worthy of even varietal prominence. 



a var. rugosa, Edw. and Haime. 



Nicholson, Genus Montic, 113, 1881. 



Monticidipora rugosa, Ed. and H. Brit. Foss. Cor., 265, 

 note, 1854, Dybowski, Die Chaetetiden, 92, 1877. 



ChcEtetes rugosus, Ed. and H. Pal. Foss. des Terr. Pal., 268, 

 1851; Nicholson, Pal. Ohio, II., 193, 1875. 



Monticulipora {Hcterotrypa) rugosa, Ed. and H. Nicholson, 

 Ann. Nat. Hist. ser. 4, XVIII., 88, 1876. 



Callopora ramosa, var. mgosa, Ulrich. Jour. Cin. S. Nat. H., 

 v., 252, 1882. 



Differs from the type in the surface having transversely elongated 

 monticules, forming in many cases transverse ridges ; these varying 

 in length, sometimes extending round the stem, usually with sharp 

 edges, and about one-half a line apart. Calices and interstitial 

 tubes, as in the type 



b var. DALii, Ed. and H. 



Nicholson, Genus Montic, ir5, 1881. 



Monticidipora data, Edw. and Haime. Brit. Foss. Cor., 265, 

 1854. 



Chcetetes dalii, Ed. and H. Pol. Foss. des Terr. Pal., 266, 

 1851. Nicholson, Ohio Pal., II., 192, 1875. 



Chcctetes approximatiis, Nicholson. Quar. Jour. Geol. Soc, 

 XXX., 502, 1874; Pal. of Ohio, II., 193, 1875. 



Differs from the type in the smaller sized monticules, and small- 

 er number of interstitial tubes. The monticules are gently rounded, 

 or somewhat transversely elongated. This is almost too close to 

 the type to retain even a varietal name. 



Formation and Locality : Lower Silurian, Cincinnati Group, 

 Cincinnati and vicinity. 



31. M. NODULOSA, Nicholson. 



Monticulipora {Heterotrypd) nodulosa, Nich. Genus Montic, 

 116, 1881. 



Chcetetes (?) nodulosus, Nich. Quart. Jour. Geol. Soc, XXX., 

 506, 1874. 



C/io'tetes nodulosus, Nich. Pal. Ohio, II., 200, 1875; Ann. 

 and Mag, Nat. Hist. ser. 4, XVIII. , 87, 1876. 



