HISTORICAL INTRODUCTION. 7 



pora (as understood by him) among the Corals ; and he described and figured, 

 under the name of Goscinopora placenta, the singular fossil subsequently and 

 better known as Gaunopora placenta. 



Michelin (' Iconographie Zoophytologique,' p. 190, pi. 49, fig. 4,1840 — 47) 

 described and figured a Stromatoporoid under the name of Stromatopora concen- 

 trica, Goldf. The figure given would answer fairly for this species, but without 

 an examination of the original specimen it would be of little use to hazard a con- 

 jecture as to the precise form which he had before him. 



In 1841, Professor Phillips described and figured certain Stromatoporoids from 

 the Devonian formation of Devonshire (' Paleozoic Fossils of Cornwall,' &c, 

 p. 18). The two forms identified respectively as Stromatopora concentrica, Goldf., 

 and 8. polymorpha, Goldf., are certainly not identical with the forms described by 

 Goldf uss under these two names. What they really are could only be determined 

 positively by an examination of the specimens which Phillips had under investiga- 

 tion. The extraordinary fossil described by Lonsdale under the name of Coscinopora 

 placenta is here referred to a new genus, viz. Gaunopora. Under the name of 

 Gaunopora ramosa Phillips also describes and figures the remarkable form which 

 now constitutes the type of the genus Amphipora of Schulz. 



In 1843, Fr. Ad. Romer referred certain fossils to the Stromatoporoids, and 

 placed the genus Stromatopora itself among the Corals (' Versteinerungen des 

 Harzgebirges '). Judging from his figures, however, the forms to which he 

 assigns the names of S. concentrica and S. polymorpha are not really referable to 

 the Stromatoporoids at all. 



In the same year, Count von Keyserling (' Reise in das Petschora-Land ') 

 expressed the opinion that the genus Stromatopora is referable to the Corals, and 

 that it is nearly related to Alveolites, Lam. 



In 1844, Prof. Ferdinand Roemer first brought forward the highly important 

 conjecture that the genus Caunopora, Phill., is really based upon specimens of 

 Syringopor a growing parasitically along with Stromatopora; or, to use his own words, 

 that Caunopora is " nichts anderes als Stromatopora polymorpha von Syringoporen 

 durchwachsen " — (' Das rheinische Uebergangsgebirge '). At the same time he 

 expressed the opinion, as previously noted, that Stromatopora concentrica, Goldf., 

 is only a form of S. polymorpha, Goldf. ; and he arrived at the conclusion that 

 almost all the species of Stromatoporoids described by former observers might 

 be regarded as variations of a single type. 



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

 briefly some more or less obscure fossils from tho Carboniferous Limestone of 

 Ireland, to which he gives the names of Gaunopora placenta, Phill., Stromatopora. 

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

 structure and nature of these must remain at present doubtful. 



