CORALS OF THE CINCINNATI GEOUP. 215 



oblique or transverse rows, two stars usually occupying a space of two 

 lines and a half. The central area of each star is very minutely pitted 

 or porous, being apparently composed of very minute tubuli, but appears 

 to be solid unless examined with a sufficiently high magnifying power. 

 The elevated rays of the stars, and all the comparatively depressed por- 

 tions of the surface between the stars, are covered with small circular 

 calices, of which ten or twelve occupy the space of one line. The calices 

 are sometimes in contact, but they are more usually separated from one 

 another by half their own width or more. The spaces between the 

 calices appear to be sometimes solid, but they are more commonly 

 minutely tubular, this latter condition almost certainly representing the 

 true structure of the coral. The coralites exhibit no traces of septa, but 

 well developed though delicate tabulae. 



On the one hand, C. antheloidea has close affinities with Chsstetes frondo- 

 sus, D'Orb., from which it differs in little that is essential, save the pecu- 

 liar star-like elevations of the surface. On the other hand, as already 

 pointed out, this species approximates closely to Fistulipora, and if it 

 could be proved that the minute interstitial tubuli were coenenchymal, 

 instead of being aborted corallites, then this approximation would be 

 converted into a true generic affinity. In the third! place, there is a de- 

 cided resemblance between this form and such species of Callopora as 

 C. incrassata, Nich., in which there are star-like spaces occupied by ex- 

 ceedingly minute tubes, but these spaces have no radiating ridges sur- 

 rounding them. 



Pos^ion and locality : Cincinnati group, Cincinnati, Ohio. 



CONSTELLARIA POLYSTOMELLA, Mcholson. 



Plate 22, flgs. 7, 7a. 



Corallum in all essential points of structure resembling the preceding, 

 consisting of erect, flattened, palmate expansions, the thickness of which 

 is from two to three lines. Surface covered with very prominent stars, 

 formed of a series of elevated ridges radiating from a central depressed 

 area, and surrounded by depressed interspaces. Each star is usually 

 composed of from eight to as many as thirteen elevated ridges, some of 

 which are smaller than the others. The ridge-like elevated rays are 

 occupied by comparatively large sized circular calices, which are also 

 present, though not so closely set, in the interspaces between the stars. 

 The central areas of the stars are occupied by innumerable excessively 



