DESCRIPTION OF SPECIES 155 



x 



"The second radial plates present the strong specific features of 

 the species, and are large and spine-bearing, as in Zeacrinus mucrospinus 

 McChesney. The spines are long, much thickened, and bulbous in the 

 lower part, presenting in this respect a strong contrast with those of 

 that species. The cicatrix for the attachment of the arm plates is very 

 large, showing that the plates above were of large size. 



"The species has been quite abundant, as the spines are found in 

 great numbers, and vary considerably in size, according to the width^ 

 of the first radial plates upon which they have rested. But all are 

 thickened and bulbous, and many of them are more than an inch in 

 length. They are seldom found attached to the calyx, but are scat- 

 tered through the shale in the bed where found. " 



Remarks. -At no locality in the Pottsville formation from which 

 collections were made for the present paper, do these spines occur as 

 abundantly as they are found at the Carbon Hill locality. 1 The close 

 resemblance of the spines in question to those described above, com- 

 bined with stratigraphic and geographic evidence, points to identifica- 

 tion with the Carbon Hill species, although with the exception of a 

 few fragments of plates no other portions of the calyx have been dis- 

 covered. The figured specimen of a calyx of E. mooresi from Carbon 

 Hill is included to show the attachment of the second radial plates and 

 spines to the first radial plates. 



Horizon and locality. Boggs limestone: Muskingum County, Lo- 

 cality 27, c; of general distribution in the Lower Mercer limestone, c. 



Crinoid Segments 

 PI. VI, figs. 9-13 



Description. That crinoids were very abundant during the 

 deposition of Pottsville strata is evinced by the abundance of stems 

 which characterize the marine limestones. In the Lower Mercer and 

 in the limestone phase of the Upper Mercer members they are par- 

 ticularly abundant and characteristic. They vary in diameter from 

 only a few millimeters to over one-half inch. The specimens figured 

 form the most abundant types. 



Horizon and locality. Widely distributed in the marine lime- 

 stones of the Pottsville formation, aa. 



ir The exact stratigraphic position of the horizon from which the Carbon Hill 

 fauna described by Whitfield came, has not been determined definitely, although 

 it is known to be either upper Pottsville (probably McArthur) or basal Allegheny 



