15" Cincinmili Society of Aahaa/ Hist or v. 



coral, composed of irregular concentric lamina^ ; cells vertical 

 to the laminae ; openings upon the surface nearly circular, 

 with internal vertical lamellae, which reach one-half way 

 to the center." (Pal. of N. Y., 1.S47, vol. i, p. 71.) The 

 form described by Edwards and Haime as Protaraa verneuili 

 (1. c. p. 209) does not show any characters sufficient to sepa- 

 rate it, even as a variety. The description is as follows : 

 " Corallum forming a convex, elevated ma.ss; calices polygonal, 

 somewhat unequal, separated by walls that are rather thin, 

 and show at their angles small, slender columns; a score 

 of the septa somewhat unequal, rather fine; size of the 

 calices three mm. in diameter. — Alexanderville, Ohio." 



Genus 3. — Calapceci.\, Billings, 1865. 



" Corallum composite, forming hemispherical or sub-spheri- 

 cal colonies ; corallites slender, tubular, perforated as in 

 Favosites, and with their outside striated by imperfectly de- 

 veloped costse ; radiating septa {in the species at present 

 known), about twenty-four; tabulae thin, and apparently, in 

 some instances, not complete. When the corallites are not in 

 contact, the space between them is filled with a variously 

 formed vesicular tissue. This genus resembles Heliolites, but 

 differs therefrom in having double the number of septa and 

 the walls perforated." (Canad. Naturali.st, 2d .ser., vol. 2, 

 i(S65, p. 425). {CohoiDwpora Nicholson, Geol. Mag. new ser., 

 vol. I, 1874, p. 253; Hoiig/itonia Rominger, Foss. Cor. Michi- 

 gan, 1S76. p. 17.) 



Remarks.— Vox a discussion of the affinities of this genus 

 .see Nicholson's " Palaeozoic Tabulate Corals," 1.S79, pp. 159- 

 164. Since that volume was written Dr. Nicholson has aban- 

 doned his genus in favor of that given above. (See Manual 

 of Pakeontology, vol. i, 18S9, j). 317.) 



I.— C. CKiHKiKOKMis, Nicliolson, 1S74. 



Corallum massive, hemispheric or pyriform, var}ing from 

 ten lines to six inches in diameter, and from eight lines to 

 three inches or more in height; corallites spreading from base 

 ot attachment, polygonal, generally in close contact and the 

 walls thick and fused together; occasional!)- sub-circular, 



