0)1 the Monticuliporoid Corals of the Cincirmati Group. 23 



Nebulipom papillata, McCoy. Ann. & Mag. Nat Hist. ser. 2, 

 VI, 248, 1850; Brit. Pal. Foss. , p. 266, 1850. 



Chcetetes ttiberculatits, Ed. & H. Pol. Foss. des Terr. Palae. 

 C/icetetfs papillatus, McCoy. Nicholson, Pal. Ohio II, 210, 



1875- 



Monticulipoya pLirasitica, I'lrich. Jour. Cin. S. Nat. Hist., V, 

 238, 1882. 



Corallum forming a thin crust, parasitic on shells of Brachio- 

 pods, Orthoceras, and^ other foreign bodies, generally about one- 

 half a line thick. Surface with small, rounded monticules, ar- 

 ranged more or less regularly, and generally occupied by corallites 

 of a larger size than the average. Calices polygonal, thin walled, 

 bearing in well preserved examples a small number of spiniform 

 corallites. No interstitial cells. 



Obs. — The genus Ncbiilipora, McCoy, is undoubtedly a syno- 

 nym for Monticulipora. The present species is recognized by the 

 more or less regular arrangement of the rounded monticules and 

 the polygonal calices. 



Formation and Locality. --Lower Silurian, Cincinnati Crroup, 

 Cincinnati and Hamilton, O. 



45. — M. CRUSTULATA, V . P. James. 



Nicholson, Genus Montic, 27, 1881. 



Chcetetes cnistulatus, James. The Palseon. ,p. i, 1878, p. 20, 1879. 



Lcptotrypa or/iata. LHrich. Jour. Cin. Soc. Nat. Hist., VI. 

 160, 1883. 



L. clavis, Ul. Ibid, p. 161. 



L. cortex, IT. Ibid, p. 162. 

 . Spatiopora aspcra, Ul. Ibid, p. 166. 



.v. maculosa, Ul. Ibid, p. 167. 



S. lineata, LT. Ibid, p. 167. 



Atactoporella typicalis, \]\. Ibid, p. 248. 



Corallum forming a thin crust, parasitic on shel's of OrtPtoceras 

 and other substances, and from one-eighth of a line to one-fourth of 

 a line thick. Surface generally smooth, sometimes with a few 

 small elevations. Calices sub-polygonal, rounded or (jblong, vary- 

 ing in form and size: at intervals of about two lines are groups of 

 larger cells, sometimes the center one larger than the rest. Walls 

 of corallites very thin, sometimes bearing numbers of spiniform 

 corallites. No interstitial cells. (Plate i, figs. 2, 2a.) 



Obs. — This is mainly distinguished by the smooth or nearly 

 smooth surface. It is similar to the following, from which, per- 



