230 PALAEONTOLOGY OF OHIO. 



CORALS OF THE CORNIFEROUS LIMESTONE. 



Genus FAVOSITES, Lamarck, 18 ll. 

 (Hist, des An. sans Vert., Vol. II., p. 204.) 



Favosites tuebinata, Billings. 



Favosites turbinata, Billings; Canadian Journal, new ser., Vol. IV., p. 109, and Vol. 



v., p. 258, fig. 7. 

 Favosites turbinata, Nicholson ; Canadian Journal, new ser.. Vol. XIV., No. 1, p. 48. 

 Favosites turbinata, Nicholson ; Report on the Palaeontology of Ontario, pi. 8, figs. 1, 2. 



Corallum massive, usually turbinate, with a more or less spirally 

 twisted base, sometimes straight and cylindrical, or at other times more 

 or less irregular in shape. Corallites nearly equally sized, prismatic or 

 sub-prismatic, from half a line to one line in width. Tabulte flat or flex- 

 uous, usually complete. Mural pores of large size, disposed in a single 

 row upon each of the flat surfaces of the corallites. The entire surface 

 is occupied by the calices, but only those in the upper portion of the 

 coral remain open, the remainder being completely closed by a thicker 

 or thinner epitheca. 



The specimens of this remarkable species differ much both in shape 

 and in size, being usually more or less in the form of an inverted cone, 

 and varying from less than an inch to two feet in length. The upper 

 portion of the colony is usually thick and broad, sometimes cup-shaped, 

 and here the calices are open. Owing, however, to the fact that the cor- 

 allites radiate in all directions from an imaginary central line, the entire 

 surface is really occupied by the calices ; but those which are placed on 

 all parts of the surface beneath the summit of the mass have their 

 mouths completely sealed up by the development of an epitheca. As a 

 general rule, the epitheca is thin and delicate, and allows the old calices 

 beileath to be distinctly seen ; but at other times it may be thick enough 

 to almost conceal from view the calices. 



The form and mode of growth of F. turbinata sufficiently distinguish 

 it from all other recorded forms. The species, however, is further distin- 

 guished by the small size of the corallites, their thick walls, their nearly 



