242 PALAEONTOLOGY OF OHIO. 



their septa througliout their entire height. The number of the septa 

 appears to be about fifty, rising to fifty-six, and they carry arched striae 

 on their sides and spine-like processes on their edges, as is the case in 

 the genus Heliophyllum. 



All the examples I have hitherto seen of this species are more or less 

 imperfectly preserved, and do not show minute details of structure in a 

 satisfactory manner. The species is, however, readily distinguished 

 from its companion form, P. Verneuilli, Edw. and H., by its much larger 

 corallites. 



Position and locality : Corniferous limestone, Erie county, Ohio. 



