74 



Cincinnati Society of Natural History. 



Locality. — Clinton and Warren counties, Ohio. 



Remarks. — The indented walls of the calices and the peculiar 

 mode of growth will generally distinguish this species. In the last 

 respect it resembles M. varians and M. raupeli, but in other respects 

 it is different. 



51. — M. cumulata Ulrich (sp.), 1890. 



Corrallum irregular, sometimes sub-massive and again sub- 

 ramose, consisting of one or more superimposed layers from 0.7 to four 

 mm. thick, the inner side generally with an epitheca or loosely attached 

 to some foreign body ; surface sometimes smooth, but generally with 

 low, rounded, rather irregularly arranged monticules, two mm. or more 

 apart, with the calices scarcely larger than in the intermediate spaces, 

 but separated by greater intervals ; corallites slightly curved near 

 their origin in each layer and then proceeding direct to the surface; 

 crossed by horizontal tabulae one or two times their diameter apart; 

 calices sub-circular with a faintly elevated and minutely spinulose 

 margin when perfect ; seven in two mm.; interspaces usually narrow, 

 with small, closely tabulated, angular, interstitial corallites, which just 

 below the aperture are filled with a dense deposit of material. 

 (Geol. Sur. of Illinois, vol. 8, 1890, p. 423, as Nicholsonella cumulata.) 



Locality. — Wilmington, Ills. 



52. — M. contexta Ulrich (sp.), 1890. 



Corallum frondescent, formed of a mass of irregular, coalescing 

 branches varying from three to six mm. thick; surface smooth, with 

 spaces having larger cells than the average ; walls of corallites scarcely 

 thicker in the cortical than in the axial region ; calices sub-circular or 

 oval, eight to ten in two mm., occasionally in contact but ordinarily 

 separated by the angular, thin-walled interstitial tubes which are very 

 numerous and nearly the same size as the ordinary cells ; tabula? 

 few in the axial region, becoming more numerous toward the surface, 

 where they are abundant and extend from the vesicular tabulae to the 

 opposite wall ; closely set tabulae in the interstitial cells, approximately 

 upon the same level in all : spiniform corallites small, but conspicu- 

 ous in the tangential section, three to five around each corallite. 

 (Geol. Sur. of Ills., vol. 8, 1890, p. 412, as Homotrypella contexta.) 



Locality. — Wilmington, Ills. 



