184 PALEONTOLOGY OF OHIO. 



space ; the number of the rows of mural pores, and the position of these 

 openings on the fiat surfaces or the angles of the corallites ; and in the 

 presence or absence of rudimentary septa. Individual specimens rarely 

 exhibit more than a few of these characters, and it is, therefore, often a 

 matter of impossibility to determine with absolute accuracy to what 

 species of Favosites a given example should be referred. Hence I am not 

 prepared to assert positively that the specimen here referred to F. Goth- 

 landica, Lam., really is of this nature, though it has all the external 

 characters of this species. 



The specimen in question is a small, rounded, depressed-hemispheric 

 mass, composed of sub-equal polygonal corallites, which have an average 

 diameter of about one line. The walls of the corallites are thin, there 

 are no traces of septa, and the characters of the tabulae and mural pores 

 can not be determined. The specimen is beyond all question a true 

 Favosites, and it may with the greatest probability be regarded as the 

 young of F. Gothlandica, with which it agrees in form and in its general 

 proportions. 



Position and locality : Cincinnati group, Cincinnati, Ohio. 



Genus FAVISTELLA, Hall. 



(Pal. N. Y., Vol. I., p. 275, 1847.) 



Corallum aggregate, massive, hemispheric, pyriform, or sub-globose, 

 composed of prismatic corallites, with compact imperforate walls, which 

 are usually completely amalgamated with one another. Septa well de- 

 veloped, lamellar, of unequal sizes, the primary ones extending nearly 

 or quite to the center of the visceral chamber. No columella. Tabulae 

 well developed and complete. 



This genus is more nearly allied to Oolumnaria than to Favosites; but 

 it appears to be sufficiently distinct from both. From the latter of these 

 genera, Favistella is distinguished by the absence of mural pores, the 

 well-developed septal system, and in Favistella stellaia, at any rate, the 

 amalgamation of the walls of the corallites. On the other hand, whilst 

 agreeing with Oolumnaria in the possession of imperforate walls and by 

 distinct septa, Favistella is separated from the former genus, as usually 

 understood, by the fact that the septa extend to, or near to, the center of 

 the theca, instead of being comparatively rudimentary, the walls of the 

 corallites being at the same time usually inseparably united with one 

 another. Lastly, from Columnopora, Nich., the present genus is distin- 

 guished by the absence of mural pores and the better developed septa. 



