2o8 Cincinnati Society of Natural History. 



region, and but few in the outer zone; tangential sections 

 show cells sub-oval or sub-circular, thick-walled, surrounded 

 by an open space ; there is some indication of spiniform 

 corallites at the angles of some of the larger tubes. (The 

 Paleontologist, No. 6, Sept. 12, 1882, p. 50.) 



Locality. — Lynchburg, Highland County, etc., Ohio. 



Remarks. — This species somewhat resembles M. ramosa var. 

 dalii, but the interstitial tubes are absent. 



40. — M. CRASSiMURALis Ulrich (sp.;, 1890. 



Corallum dendroid, dividing at intervals of 10 to 18 mm.; 

 branches with low, rounded monticules ; apertures circular, 

 arranged in regular curved series, about eight in 2 mm.; 

 interspaces thick, flattened centrally, sloping down to the 

 apertures and thickest on the monticules where a few illy- 

 defined interstitial tubes are found ; tangential sections vary- 

 ing, the interspaces sometimes with openings of varyinj^ form 

 and size, or again filled by a deposit of a light color ; walls in 

 the axial region very thin ; corallites regularly rhomboidal or 

 pentagonal ; tabuke complete and horizontal, wanting in the 

 axial and very few in the peripheral region ; numerous and 

 thick in the interspaces. (Geol. Sur. Illinois, vol. 8, 1890. p. 

 452, as Mojiotrypella crassimiiralis.) 



Locality. — Wilmington, Ills. 



Remarks. — This species presents many points of resem- 

 blance to M. ivortheni, but it seems best to arrange it pro- 

 visionally as a distinct species. It has not been recorded 

 from Ohio as yet. 



I TO BE CONTI.NL'ED. J 



