234 The Ohio Journal of Science [\^ol. XVII, No. 7, 



fourth row of primary plates, a partial row of accessory plates, a 

 third row of secondary plates, another partial row of accessory 

 plates, a fifth row of primary plates, and a broken end beyond 

 which there may have been additional rows of primary plates. 

 The surface of the plates probably was marked by low pustules. 

 The interior of the plates evidently was traversed by numerous 

 coarse pores, more or less perpendicular to the surface. 



With this group of Ilolocystites, from the Racine limestone 

 of the Silurian of Wisconsin, Holocystites greenvillensis is corre- 

 lated chiefly on account of the presence of horizontal rows of 

 plates, successive rows alternating, and consisting of eight 

 plates each. The anal protuberance is located between the first 

 and second rows of the distinctly outlined plates. The general 

 outline is similar, and there appears to have been a similar 

 absence of arms. 



The specimens of Holocystites greenvillensis here figured were 

 found in the Cedarville dolomite, about four and a half miles 

 east of Greenville, Ohio, at Brierly's quarry, on Greenville 

 Creek. No exposures exist here at present, the site having long 

 been covered by soil washed in by rains, and rising waters. The 

 elevation here is 980 feet above sea level. At the Lewisburg 

 Limestone Quarry, a mile northwest of Euphemia, the base of 

 the Cedarville limestone is about 975 feet above sea level. For 

 19 miles south of Euphemia the Brassfield limestone dips 

 between 4 and 5 feet toward the north. Euphemia being 

 about 17 miles south of the Brierly quarry, east of Greenville, 

 this suggests a dip of fully 70 feet northward within that 

 interval, provided the amount of dip does not change. Hence, at 

 the Brierly quarry, the base of the Cedarville dolomite should 

 be about 905 feet above sea level, and the strata formerly 

 exposed in the Brierly quarry should be about 75 feet above 

 the base of the Cedarville limestone, and therefore above the 

 level of the highest strata exposed at Cedarville, Ohio. The 

 Brierly quarry in former days furnished a large number of 

 crinoids and cystids, some of which were listed by A. C. Linde- 

 muth in his Report on the Geology of Darke County, in Volume 

 III, of the Ohio Geology, (p. 515) in 1878. Here the species 

 described in this paper as Holocystites greenvillensis was identi- 

 fied as Holocystites abnormis. 



Most of the species described by S. A. Miller from the 

 Osgood formation of Indiana as Holocystites evidently belong to 



