192 



PROF. H. A. NICHOLSON AND DR. J. MURIE ON THE 



a true coral closely allied to the existing Poritid86 ; and he justly 

 points to the close resemblance in appearance and general struc- 

 ture between Ccenostroma and Psammocora. While admitting this 

 resemblance, the passage between Ccenostroma and Stromatopora 

 proper is easily effected by means of forms like Syringostroma ; 

 and the minute structure of tlie former forbids our acceptance 

 of the view that it can really be a coral. Stromatopora itself is 

 regarded by Lindstrom as probably Foraminiferal. 



Tn a paper on the affinities of the Anthozoa Tabulata (CEfver- 

 sigt af Kongl. Yetenskaps-Akad. Forhandl. 1873, translated in 

 Ann. & Mag. Nat. Hist. 1876), Dr. Lindstrom indicates that 

 Ccenostroma, Winch ell, which is an undoubted Stromatoporoid, 

 presents certain affinities to Labechia, E. & H. ; and he regards 

 this latter genus as Hydrozoal, and as related to the recent 

 dractinia. On this point, however, we shall have more to say 

 hereafter. 



In the ' Twenty-third Annual Keport on the State Cabinet,' 

 dated 1873, but, we believe, not actually pubHshed till 1874, Prof. 

 Hall describes several species of Stromatopora from the Devonian 

 rocks of the United States. In describing a species of Caunopora, 

 Phill., he expresses some doubt as to the propriety of separating 

 Caunopora and Ccenostroma from Stromatopora proper, upon the 

 ground that both, when carefully examined, " prove to be made up 

 of a series of vertical columns " (our " radial pillars ") " connected 

 by lateral filaments, which radiate more or less regularly at given 

 intervals, and unite the several columns to each other, just as in 

 the typical Stromatopora ; and it is these lateral processes which 

 in a vertical section give the appearance of horizontal plates." 



In 1873, Salter expressed the opinion that Stromatopora is " a 

 very solid calcareous sponge " (* Cat. Sil. Foss.' p. 99). 



In 1873 (Ann. & Mag. Nat. Hist. ser. 4, vol. xii.) one of the pre- 

 sent writers described several species of Stromatopora from the 

 Upper Silurian and Devonian strata of Canada, indicating in one 

 of them {S. ostiolata,'N\ch.) the presence of large apertures believed 

 to correspond to the " oscula " of sponges. 



In 1874, the same writer (Ann. &Mag. Nat. Hist. ser. 4, vol. xiii.) 

 discussed the affinities of the genus Stromatopora upon general 

 grounds, referring it to the Calcispongise, and indicating the pre- 

 sence in examples of various species of large " oscular " openings. 

 The skeleton was regarded as composed of an amalgamated sys- 

 tem of horizontal spicules separated by interspaces and kept 



