20 Cincifviati Society of Natural Histoiy. 



with numbers of spines or granules on the walls of the interstitial 

 cells. 



Obs. — This species, we are told,* is readily distinguished by 

 its •' peculiar growth, circular cell apertures, and regular arrangement 

 of the cells and monticules. When in a good state of preservation 

 the most striking characteristic is found in the granular cell inter- 

 spaces." It is similar in some respects to the next. 



Formation and Locality. — Lower Silurian. Cincinnati (iroup, 

 Cincinnati and Waynesville, O. 



41. — M. CLiNTONENSis, U. P. James. 



Mflniiculipora i^Hctcrfltrypa) clintoncnsis, James. '!"he I'alasont., 

 45, 1882. 



Corallum variable, flattened, undulating, thickened or con- 

 torted, amorphous, and occasionally appearing as if branched. 

 Surface with rounded, more or less prominent monticules, or at 

 times nearly smooth. Cell apertures of various forms, the walls 

 indented or expanded irregularly. Interstitial corallites more or 

 less numerous at the angles of larger tubes. Spiniform corallites 

 few to numerous. (Plate i, figs i, la) 



Obs. — The indented walls of the calices, and the peculiar 

 mode of growth will generally distinguish this species. It is sim- 

 ilar in mode ot growth to M. zuiupeli and to M. varians, but these 

 possess other features which distinguish them. 



Formation and Locality.— Lower Silurian, Cincinnati Group, 

 Clinton and Warren Counties, O. 



Group V. — Incrusting species : forming patches or crusts grow 

 ing parasitically on shells of various kinds, or on corals. 



a. Corallum forming a thin crust. 



t Monticules prominent, elongated 42 



t Monticules rounded, arranged in regular lines. 



* Calices irregular, indented 43 



* Calices polygonal 44 



■f Surface nearly smooth 45, 46 



b. Corallum forming small circular patches 47 



c. Corallum growing in irregular masses about crinoid col- 



umns 48 



d. Corallum fusiform, cylindrical or clavate 49. 50 



e. Corallum nearly hemispherical 51 



"Jour. C. S. N. H., I.e. vi, S7. 



