HISTORICAL INTRODUCTION. 23 



lias a reticulated skeleton, with the typical " curvilinear " structure, and belongs, 

 therefore, to an entirely different group of the Stromatoporoids to that which 

 includes the forms with a "rectilinear" structure (i.e. the Actinostromidai). It 

 follows, therefore, that Stromatopora concentrica, Barg., has no relationship with 

 Stromatopora concentrica, Goldf. Of the other forms placed by Bargatzky under 

 the genus Stromatopora, S. verrucosa, Goldf., is likewise a typical Actinostroma, 

 with continuous "radial pillars " and a well-marked hexactinellid structure; and 

 this is also the case with the forms named by Bargatzky 8. papillosa, n. sp., and 

 8. astroites, Rosen. The latter of these has really nothing to do with the form 

 described by Rosen as 8. astroites, but it is a well-marked and perfectly distinct 

 species of the genus Actinostroma, of which the former is probably only a variety. 

 On the other hand, the form described as 8. Beuthii, Barg., is a genuine Stroma- 

 topora, as above defined, and appears to be a good species. The forms included 

 by Goldf uss under the head of 8. polymorpha are broken up by Bargatzky into the 

 three species 8. curiosa, 8. monostiolata, and 8. polyostiolata. The two forms 

 included by Bargatzky under the names of Gaunopora placenta, Phill., and G. 

 Ilupschii, Barg., appear to me to be undoubtedly the same; and as I shall subse- 

 quently give reasons for not retaining the name of "placenta," Phill., the species 

 should stand as Stromatopora Ilupschii, Barg., sp. The specimen in the Bonn 

 Museum labelled Gaunopora bucheliensis, Barg., appears to me also to be identical 

 with the preceding. As, however, Dr. Bargatzky sent me authentic specimens of 

 his Gaunopora bucheliensis, which are quite different from his G. Hilpschii, and as 

 these specimens belong to a form of common occurrence in the Devonian Rocks of 

 Germany and of Britain, I shall retain this specific name, placing the species 

 under Stromatopora. Of the species referred to Parallelopora, Barg., P. ostiolata 

 is a remarkable form, which I shall notice later on ; but P. stellaris, and P. Gold- 

 fussi are not so clearly distinct, and the latter may be only the Stromatopora 

 capitata of Goldfuss. P. eifeliensis, Barg., appears to be a Fistulipora. Finally, 

 as regards the systematic position of the Stromatoporoids, Bargatzky agrees with 

 Steinmann and Carter in placing these organisms in the neighbourhood of the 

 Ilydractiniidce . 



In a second paper (' Zeitschr. der deutscher geol. Gesellschaft,' Jahrg., 

 1881), Dr. Bargatzky describes a singular Stromatoporoid from the Devonian 

 Limestone of Hebborn, near Paffrath, under the name of Stachyodes ramosa. The 

 characters of the new genus Stachyodes I shall consider in detail later on. The 

 species is identical with the Stromatopora verticillata of M'Coy. 



In the ' Eleventh Report on the Geology of Indiana,' 1881, p. 400, Prof. 

 James Hall figures a Stromatoporoid under the name of Stromatopora pustuli- 

 fera?, Winchell, and quotes a previously published description of the same by 

 "Winchell. 



