76 



Cincinnati Society of Natural History. 



approaching the surface in a regular curve, with remote tabulae in 

 the axial and more numerous ones in the peripheral region ; tabulae 

 horizontal and vesicular, in the latter event connected by horizontal 

 lines with the opposite side. (Jour. Cin. Soc. Nat. Hist., vol. 2, 

 1879, P- 2 7> as Chcctetes compressus and in Ibid., vol. 5, 1882, p. 244, 

 as Peronopora compi-essa.) 



Locality. — Cincinnati, O. 



56. — M. stidhami Ulrich (sp.), 1890. 



Corallum irregularly lobate or massive ; surface smooth with 

 clusters of somewhat larger cell apertures; corailites radiating in all 

 directions from a point at the base ; angular, irregular in shape and 

 thin-walled throughout; from eight to ten in two mm.; tabulae hori- 

 zontal, about a tube diameter apart; spiniform corailites rather large, 

 numerous, and situated at the angles of the corailites. ( Geol. Sur. 

 of Ills., vol. 8, 1890, p. 456, as Leptoirypa stidhami.) 



Locality. — Brown County, Ohio. 



57. — M. uniformis Ulrich (sp.), 1882. 



Corallum of erect, flattened, smooth or undulating expansions, 

 several inches in height, varying from one to three lines in thickness ; 

 composed of two layers of cells growing in opposite directions from 

 the median plate ; cells polygonal, sub-equal, thin-walled, averaging 

 ilu inch in diameter ; interstitial cells almost entirely wanting, usually 

 restricted to small clusters or irregularly scattered among the ordinary 

 cells; corailites thin-walled, lying prostrate at first but soon bending 

 and proceeding directly to the surface, the walls becoming there mod- 

 erately thickened ; straight tabulae in a few corailites, but wanting in 

 most of them, being replaced by vesicular diaphragms ; spiniform tabuli 

 few and small, mostly at angles of junction of cells. (Jour. Cin. Soc. 

 Nat. Hist., vol. 5, 1882, p. 244, as Peronopora uniformis.) 



Locality. — Cincinnati, O. 



58. — M. WILM1NGTONENSE Ulrich (sp.), 1890. 



Corallum compressed, sub-ramose ; surface smooth ; corailites 

 slightly inclined in the axial region, turning to the surface with a 

 sharp curve; calices four in one mm., circular, about 0.2 mm. in dia- 

 meter, nearly always surrounded by interstitial corailites about as long 



