CORALS OF THE CINCINNATI GROUP. 



COELENTERATA. 



ACTINOZOA. 



Genus FAVOSITES, Lamarck, 18li!. 

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



The genus Fawsites comprises branched or massive corals, composed of 

 numerous more or less polygonal corallites, the walls of which are not 

 amalgamated with one another, and which have the visceral cavity par- 

 titioned off by transverse diaphragms'or " tabulae," which are sometimes 

 more or less rudimentary.. The walls of the corallites are perforated by 

 one, two, three, or more rows of " mural pores," by which the separate 

 corallites are placed in communication with one another. The septal 

 system is entirely unrepresented, or is quite rudimentary, consisting at 

 most of short spiniform projections or tubercles. 



The genus Favosites (including under this name Emmonosia, Edw. and 

 H., and Astrocerium, Hall) has a vast development in the Upper Silurian 

 and Devonian periods, but is compiaratively poorly represented in Lower 

 Silurian deposits. This arises in part from the fact that the genus had 

 at this early period undoubtedly not attained its full development, and 

 in part from the diflBculty which is often experienced in separating im- 

 perfectly preserved examples of the genera Columnaria and Favistella 

 from Favosites proper. So far as the Cincinnati group of Ohio is concerned, 

 I have only seen two examj^es which I could refer with certainty to the 

 genus Favosites, and in both of these it was not possible to arrive at an 

 absolutely certain specific determination. 



Favosites Gtothlandica, Lamarck (?). 



(For the synonymy of this species, see its description later on.) 



The determination of the different species of Favosites depends upon 

 the diameter of the corallites, their general form, and their equality or 

 inequality in point of size; the completeness or incompleteness of the 

 tabulae, and the form of these structures and their number in a given 



