146 CivcitDiali Society of Naiura/ His for v. 



referred to the genu?, some of them from our own section, 

 but there does not seem good reason for making more than 

 one from the Cincinnati group. It has also been questioned 

 whether it is not the same as Petraia described by Munster in 

 1837. Billings and others have so considered it, but we shall 

 here regard it as distinct. 



I. — S. coKxicTLr.M, Hall, 1.S47. 



Corallum conical, slightly curved or nearly straight, aver- 

 aging from one to four inches long, and from ten lines to i^ 

 inches in diameter; septa from 90 to 160, alternately large 

 and small ; smaller ones rarely extending much beyond the 

 margin, but the larger ones reaching to the center, where 

 they become more or less twisted and united with one an- 

 other, forming a mass of vesicular tissue : calice moderately 

 deep; septa very thick, often appearing as if double; tabulae 

 remote and irregular, sometimes elevated toward the center 

 of the visceral chamber ; no dissepiments ; epitheca with 

 longitudinal ridges corresponding to the septa within ; other- 

 wise smooth, or, rareh', with a few encircling folds. (Pal. of 

 N. Y., vol. I, i<S47, p. 69; Nicholson, Pal. of Ohio, vol. 2, 

 1875, p. 218. 



Loca/iiy. — Oxford, Waynesville, Lebanon, Loveland, Cincin- 

 nati and other places in Ohio and Indiana. 



Remarks — One of the most common of the fossils of the 

 Cincinnati group, and generally known as the " bull's horn 

 coral." It varies greatly in size— from ]2 inch to 4 inches in 

 length. It may be nearly straight or considerably curved, 

 and with a sharp, or a rounded, blunt point. The description 

 above is from the Pakcontology of Ohio. It is possible that 

 Zaphrentis (.^) ohioensis may be only a small variety of this 

 species. 



(lenus 3.— P.\L.v:()i'iivi,i,rM, Billings, 1857. 



Corallum fasciculate or aggregate ; corallites surrounded b\' 

 a thick wall ; radiating sej^ta extending the whole length ; 

 transverse diaphragms either rudimentary or none ; increasing 

 by lateral budding. (Geol. Sur. of Canada, Kept. Prog, for 

 ''^53. 54' '55> '5^^' '^57' P- ''^•'^; Nicholson, Pal. of Ohio, vol. 2, 

 1875, p. 219.) 



