MINUTE STEUCTUEE OF STEOMATOPOEA AND ITS ALLIES. 189 



mosfc fully and from the best-preserved specimens, it must be 

 abandoned in favour of the previously described S. concentrica. 

 Still it follows from this that the type of the genus iStromatopora 

 is not the entirely vague and undeterminable form which palaeon- 

 tologists have been in the habit of calling S. concentrica, but the 

 well-marked and sharply characterized S. polymorpha. 



De Blainville (' Manuel d'Actinologie,' 1834) refers Stromato- 

 po7'a, with doubt, to the Corals. 



Steininger (Mem. de la Soc. Geol. de France, t. i., 1834) de- 

 scribes several species of Stromatopora from the Eifel limestone, 

 and refers the genus to the Sponges. 



Lonsdale (Trans. Greol. Soc. Lond. ser. 2, vol. v., 1840) places 

 Stromatopora among the Corals ; and he describes and figures a 

 Stromatoporoid fossil under the name of Coscinopora placenta. 



Professor Phillips (' Palaeozoic Possils of Cornwall,' &c., 1841) 

 describes and figures some Stromatoporoids from the Devonian 

 of Devonshire. He also founds the genus Caunopora for Lons- 

 dale's Coscinopora placenta, and describes a new form of the same 

 under the name of C. ramosa. As so many subsequent observers 

 have done, Phillips regards the " radial " elements of the skeleton 

 of Stromatopora as being tubes, a belief which is unequivocally 

 disproved by microscopic examination, as first satisfactorily shown 

 by Yon Eosen. 



In 1 843, Ad. E-oemer (' Die Yersteinerungen des Harzgebirges ') 

 described some Stromatoporoids, placing one among the Sponges, 

 and the rest among the Corals. In the same year Keyserling 

 ('Eeise in das Petschora-Land ') expressed the opinion that the 

 genus Stromatopora should be placed among the Corals, and that 

 it is nearly allied to Alveolites, Lam. 



In 1844, Ferdinand Eoemer ('Das rheinische Uebergangsge- 

 birge') published the opinion that Coscinopora placenta, Lonsd. 



= Caunopora placenta, Phill.), is founded upon specimens of 

 Stromatopora attached parasitically to a coral. 



In 1844, Prof M'Coy ('Synopsis Carb. Limestone Foss. of 

 Ireland') described briefly some more or less obscure fossils from 

 the Carboniferous Limestone of Ireland, to which he gives the 

 names of Caunopora placenta, Phill., Stromatopora concentrica, 

 Lonsd., S. polymorpha. Gold., and S. suhtilis, M'Coy. The true 

 structure and nature of these must remain at present doubtful. 



In 1847, Hall ('Pal. New York,' vol. i. p. 48, pi. xii.) founded 

 the genus Stromatocerium for a Stromatoporoid from the Trenton 



14* 



