156 



Cincinnati Society of Natural History. 



live to twelve or more equally depressed ra\^s. Between the rays the 

 surface is elevated into small ridges, which are occupied by the aper- 

 tures of proper zooecia. Depressed portions of "maculae" occupied b} T 

 interstitial cells. True tubes cylindrical, with thick walls and remote 

 diaphragms. Interstitial tubes angular with numerous diaphragms. 

 Cincinnati. 



Sub-genus Constellaria, Dana. — Zoarium ramose or sub-frond 

 escent; in other respects like Stellipora. 



Family Fistuliporidce, Ulrich. 



Zoarium massive, ramose or frondescent. Cell-apertures circular 

 or ovate, with or without a slightly projecting lip, and separated by 

 one or more series of angular interstitial cells. Tubes with straight 

 diaphragms. Walls of interstitial cells not continuous, but form a 

 loose vesicular tissue between the proper zooecia. 



Fistulipora, McCoy. — Zoarium massive, ramose, or forming free or 

 attached expansions. When ramose the branches are large, often 

 irregular, and sometimes hollow. In tangential sections the proper 

 zooecia are regularly circular or elliptical. Niagara to Carboniferous. 



Didymopora, Ulrich. — Proper zooecia with two delicate longitudinal 

 lamellae springing inwardly from the walls of the tubes; or they are 

 simply contracted by two inflections of the wall. In other respects 

 like Fistulipora. 



Besides Fistulipora and Didymopora, and several undescribed 

 genera, I believe that Bhinopora, Hall, Lichenalia, Hall, and 

 Coscinium, Keyserling (as identified by Prout), will be found to be 

 long to the Fistuliporidai. 



Fam. Ceramoporidai, Ulrich. 



Zoarium usually incrusting, in other cases ramose, with the branches 

 hollow (i. e., provided with an "axial tube") or flabellate. Cell-aper- 

 tures triangular or ovate, with a prominent and arched "lip" usually 

 on one side. Interstitial cells from very few to numerous. Connect- 

 ing foramina sometimes present. Diaphragms (if at all developed) 

 straight. 



Ceramopora, Hall. — Usually incrusting. Cells angular, with the 

 "lip" strongly arched, the aperture oblique, and radiating from one or 

 more centers. Insterstitial cells sometimes absent; always few. Con- 

 necting foramina usually present. Diaphragms occasionally devel- 

 oped. Cincinnati to Lower Helderberg. 



Ceramoporella, Ulrich. — Incrusting; composed of a single thin 



