Manual of the Paleontology of the Cincinnati Group. 



75 



53. — M. prolifica Ulrich (sp.), 1890. 



Corallum frondescent or sub-ramose, with flattened branches 

 varying from four to twelve mm. thick; surface with low rounded 

 monticules arranged in irregularly intersecting lines, composed of 

 cells a little larger than the average, commonly surrounding a cluster 

 of interstitial cells ; corallites curved in the axial but direct in the 

 peripheral region, where walls are thickened ; calices sub-polygonal, 

 eight in two mm., the interspaces occasionally with a few interstitial 

 cells, although these are mostly in the clusters; tabulae in the axial 

 region few, but closely set and more or less funnel-shaped in the 

 cortical region ; interstitial cells more closely tabulate than the 

 ordinary corallites; spiniform corallites about one-third more numer- 

 ous than the ordinary corallites, and when not at the angles causing 

 an inflection of the wall. (Geol. Sur, Ills., vol. 8, 1890, p. 413 as 

 Heterotrypa prolifica. Pal. of Minn., vol. 3, Geol. and Nat. Hist. Sur. 

 Minn., 1893, P- 268.) 



Locality. — Blanchester, O.. Wilmington, Ills. 



54. — M. flaIjELLaris Ulrich (sp.), 1890. 



Corallum frondescent, fan-shaped ; surface smooth with obscure 

 maculae about four mm. apart and with calices from one-third to one- 

 half larger than the average ; walls of corallites flexuous or crenulated 

 in the axial region and very thin in the cortical region ; calices angu- 

 lar, slightly oblique eight to ten in two mm.; interstitial cells few, 

 gathered into clusters in the maculae ; tabulae straight and few in 

 the axial region, moderately numerous in the smaller cells; vesicular 

 diaphragms forming a short series in each tube; spiniform corallites 

 few and very small. (Geol. Sur. Illinois, vol. 8, 1890, p. 411, as 

 Homotrypa flabellaris .) 



Locality. — Wilmington, Illinois. 



55. — M. compressa Ulrich (sp.), 1879. 



Corallum small, thin, frondescent, celluliferous on both sides, 

 varying from one-half to one line thick ; surface smooth ; calices 

 slightly oblique to the surface with somewhat elongate apertures, 

 nearly equal in size, circular or oval, arranged in diagonal lines and 

 eight to ten in one line ; interstitial cells few ; corallites short, 



