﻿American Palaeozoic Fossils. 



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tial tissue; and from that family, in being without any non -poriferous 

 margins or ridges, and the consequent peculiarities of the form or 

 growth of the zoaria, and in having the interstitial vesicles open 

 throughout, or the secondary interstitial deposit, when present, more 

 superficial. 



After a careful study of perhaps half of the described species, 

 doubtlessly belonging to this family, I must still confess that I have 

 not been successful in dividing it up into genera thoroughly satisfac- 

 tory to me. But in the hope that future researches will prove my 

 conclusions to be in the main correct, I propose the following 

 divisions: Fistulipora, McCoy, Lichenalia, Hall (Didymopora, 

 Ulrich), Fridopora, Ulrich, and Cheilotrypa, n. gen. In my scheme 

 of classification (vol. v., p. 157), I placed Fridopora, provisionally, 

 with the Ceramoporidw, as the superficial characters greatly resemble 

 those of species of Ceramoporella. But now, while I still regard 

 Fridopora as being, in a measure, the connecting link between the 

 Ceramoporidai and Fistuliporidce, I can see that the possession of a 

 vesicular interstitial tissue, proves the affinities of the genus to be 

 nearer the latter. The genus differs from Fistulipora in forming only 

 thin and delicate parasitic expansions, in the form of the cells, which 

 are triangular or ovoid, and in the oblique, often imbricating, cell aper- 

 tures, one margin being much more elevated than the other. 



Fistulipora, McCoy. 1849. 



(Ann. and Mag. Nat. Hist., 2nd ser., vol. 3.) 



Zoaria massive, lamellate, attached to foreign bodies, or free, with a 

 wrinkled epitheca below; less commonly ramose or subramose, branches 

 large, irregular, often hollow; the central cavity large, irregular, and 

 lined with a plicated epithecal covering. Zocecia with circular or 

 elliptical apertures, surrounded by a more or less distinct peristome; 

 internally with complete straight diaphragms; tube wall thin, the 

 anterior portion often corrugated or flexuous. Interstitial spaces with 

 shallow pits, or smooth, flat or concave; internally occupied b}^ one or 

 more series of vesicular cells. 



Type: F. minor, McCoy. Carboniferous. 



From my investigations I find that the genus is represented in 

 American deposits by at least six species, which range in time from 

 the Niagara group to the Upper Coal Measures. These are distributed 

 as follows: a lamellar species (F. neglecta, Bominger) in the Niagara 



