98 TABULATE CORALS. 



enter into the discussion raised by Meek and Worthen (Geol. 

 Survey of Illinois, vol. iii. p. 368, 1868), as to whether Dr Dale 

 Owen is entitled to priority, in the sense that Hall's name of 



Striatopora should give way to 

 Cyathopora. There is no doubt 

 at all that Cyathopora lowensis, 

 Dale Owen, is a genuine Stria- 

 topora ; but the fact that Dr Owen 

 gave no separate description of 



Fig. 18. Fragment of Striatopora flexu- the genUS Cyathopora, COUpled With 

 osa, Hall, of the natural size. Niagara 1 i . M . - . . 



formation. After Hail. the close similarity of this name 



to the entirely different Cyatho- 

 pora of Michelin, would render it highly undesirable to 

 supplant the well -recognised title of Striatopora, even if 

 it were demonstrable that strict justice would require this 

 change. 



The genus Striatopora was very briefly defined by Hall 

 (loc. citl), and its zoological relations are left undecided ; but 

 Dr Rominger (Foss. Cor. of Michigan, p. 57) has correctly seized 

 its true affinities, and has placed it in the family of the Favo- 

 sitidce, a position to which I had independently and simulta- 

 neously assigned it (Art. " Corals," Encyclopaedia Brit., 9th ed., 

 vol. vi. p. 377). Microscopic examination, in fact, by means 

 of thin sections, places it beyond a doubt that Striatopora , 

 Hall, is an immediate relative of Favosites itself, and that it 

 agrees so closely with Packypora, Lindst, that the two may 

 be safely regarded as mere offshoots of a common stem. All 

 the known species of Striatopora possess a ramose corallum, 

 composed of cylindrical stems, which divide in a dichotomous 

 manner, but are not known to inosculate. The corallites 

 diverge in an obliquely -curved manner from a central axial 

 line, and open by large irregularly-sized polygonal calices on 

 all parts of the free surface. The general form and structure 

 of the corallum are thus precisely those of any dendroid species 

 of Favosites ; and the close relationship of the two genera is 

 shown by the existence in Striatopora of numerous circular mural 



