April, 1917] Sihii'iiui Fossils from Ohio 109 



From the Lilley member, forming the upper part of the 

 West Union bed, in the Zink or Corporation quarry, in the 

 eastern part of Hillsboro, Ohio. Named in honor of Henry 

 Pavey, an eminent member of the bar of southwestern Ohio, 

 who has also given considerable attention to the geology of 

 the area surrounding Hillsboro. 



Grabauphyllum johnstoni, gen. et sp. nov. Plate XI; Fig. 9. 



Corallum composite, composed of large polygonal corallites from 

 20 to 30 millimeters in diameter. Calices comparatively shallow, 

 varying from 10 to 12, occasionally 15 millimeters in depth. Walls 

 separating the corallites with vertical ribs, evidently corresponding to 

 the septal ridges of other corals. Outer part of the corallites coarsely 

 vesiculate. Near the lower part of the calices this vesiculate tissue 

 extends to a distance of 3 to G millimeters from the walls between the 

 corallites toward the center of the calices, leaving a circular or elliptical 

 space, in the center, having diameters varying from 15 to 20 millimeters, 

 in which this coarsely vesicular tissue is absent. On their lower surfaces, 

 the plates forming this vesicular tissue are smooth; on their upper 

 surfaces they frequently show septal lines, more or less denticulate as 

 in some species of CystiphyUum. In the outer zone of the central 

 circular area, for a distance of 3 to 4, sometimes 5 millimeters, radiating 

 septa are numerous and well defined. The number of these septa 

 varies from 45 to ob in the difterent corallites. They are connected 

 laterally by numerous short dissepiments. Tabulae are abundant 

 in the central parts of the corallites. These are chiefly elliptical in 

 outline in the specimen at hand, and vary from 6 to 10 millimeters in 

 width, and from 10 to 15 millimeters in length. Viewed from the 

 lower side they appear smooth, but it is probable that septal ridges 

 extended over their upper surfaces for some distances toward the 

 center; how far, can not be determined from the specimen at hand. 



Found in the Niagaran dolomite near McCook, 5 miles west 

 of Chicago, Illinois, by William Johnston. Genus named in 

 honor of Prof. Amadeus Grabau, of Columbia University in 

 recognition of his valuable contributions to our knowledge of 

 corals. 



The distinguishing features of GraiihauphyUmn are the 

 composite corallum, the outer coarsely vesicular zone, the 

 intermediate septate zone, and the central tabulate area. 



It is not unlikely that Acervidaria clintonensis, Nicholson, 

 may prove to be congeneric. This species was described (Ohio 

 Pal. II, 1875, p. 227, PI. 23, Figs. 2, 2a) as coming from the 

 Clinton group at Yellow Springs, Ohio. Fortunately, it is 

 known that specimens of fossils from the Cedarville dolomite in 



