14 THE GENUS MONTICULIPORA. 



Nat. Sci. Phil., 1866, p. 113). In this memoir Dr Rominger 

 expresses the opinion that Chcstetes, Fischer (under which he 

 includes Monticidipora, D'Orb., and various allied types), is 

 really referable to the Polyzoa, and not, as at that time gen- 

 erally believed, to the Actinozoa. He regards the interstitial 

 corallites of the Monticuliporoids — which he rightly recognises 

 as being more closely tabulate than the normal corallites — not 

 as " real tubules," but as " merely vertical rows of independent 

 cells, which, being crowded in between tubes, assumed them- 

 selves the form of tubules." He notices the existence of oper- 

 cula in M. rugosa, E. and H., M. ramosa, D'Orb., and M. 

 frondosa, D'Orb., pointing out that in the latter these structures 

 (which, I may add, are morphologically only the last formed 

 tahdcE) are concave and have an excentric opening. He also 

 alleges that septal ridges sometimes occur, and instances some 

 specimens of M. frojidosa, D'Orb., from Cincinnati ; but it is 

 probable that in this case he has been misled by the inward 

 protrusion into the visceral chambers of the large corallites of 

 the " spiniform corallites" in the substance of their walls. In 

 addition to describing various species of Monticulipora proper, 

 Dr Rominger further describes a number of types of Fishili- 

 pora (and Callopora^ Hall) ; but as the descriptions are short, 

 and are unaccompanied by any figures, it will probably be 

 difficult to identify many of these in future. 



In the second edition of the 'Acadian Geology,' published 

 in 1868, Principal Dawson figures and briefly describes two 

 small Monticuliporoids from the Carboniferous rocks 

 of Nova Scotia under the names of Chcstetes t7imidtts, 

 Phill., and Stenopoi'a exilis, n. sp. Dr Dawson was good 

 enough to send me specimens of these, but the material was 

 unfortunately insufficient for a satisfactory examination by 

 thin sections ; while in the case of the latter form, the few 

 specimens at my disposal were preserved so badly (appar- 

 ently in dolomite) that I failed to prepare any workable 

 slides from them. I should not, therefore, wish to express 

 any opinion as to their precise nature. 



