142 



Cincinnati Society of Natural History. 



In Callopora, Hall, the interstitial tubes are not so numerous, and 

 spiniform tubuli are wanting. In Fistulipora, McCoy, the intertubu- 

 lar spaces are occupied by a vesicular tissue, and the interstitial cells 

 do not form tubes. Besides, spiniform tubuli appear to be entirel}* ab- 

 sent. From Batostomella, Ulrich, Leioclema is distinguished by the 

 much greater number of interstitial tubus in the latter. 



The only other Monticuliporoid deserving mention in this connection, 

 is the one described by the author under the name of Callopora 

 cincinnatiensis (Jour. Cin. Soc. Nat. Hist., vol. i., p. 93.) This 

 species is not a Callopora, nor do I know of any described genus to 

 which it may be properly referred. It appears to be related to certain 

 Upper Silurian and Devonian species, and until these have been fully 

 examined I prefer to leave the species as first described, with the 

 exception of adding an interrogation point to the generic name. In 

 Callopora ( ?) cincinnatiensis, we have an irregularly ramose z^arium. 

 The true cells are nearly circular, and surrounded by a single row of 

 angular and rather large interstitial cslls. In a tangential section we 

 find that the two sets of tubes are more or less rounded, and not dis- 

 tinguishable from each other except by their size, their walls are moder- 

 ately thick, and composed of concentrically arranged laminse with no 

 distinct line of demarcation between them, the spaces intervening 

 between the walls of both sets of tubes being filled by structureless 

 sclerenchyma. A few spiniform tubuli may also be detected in sections 

 of this kind. Longitudinal sections show that the tubes in the axial 

 portion of the branches are thin-walled, and crossed by remote, 

 diaphragms. In the peripheral region, the walls, as usual, become 

 thickened ; the diaphagms in the true tubes are often entirely absent 

 in this region, and when present the}' are from one to two tube-diame- 

 ters apart. In the interstitial tubes the diaphragms are about one and 

 a half times an interstitial tube-diameter distant from each other. 



In Heteropora neozelanica, Busk, we have a frequently branching 

 zoarium, the branches smooth and with a diameter varying from .1 inch 

 to .2 inch. In the axial region the tubes are thin-walled, and crossed 

 by a few diaphragms. In the cortical ("mature") region the walls 

 of the tubes are much thickened, and are here pierced by numerous 

 connecting foramina. In a tangential section we find that the two sets 

 of tubes are rounded and not distinguishable from each other except 

 by their size; their walls are thick, and composed of laminas arranged 

 concentrically around the cavity, with no distinct line of demarcation 



