HISTORICAL INTRODUCTION. 5 



Bargatzky in retaining for them the specific name of " cariosa,'' which Goldfuss 

 gave to them as a variety of 8. polymorpha. 



(b) A massive form having the surface covered with perforated nipple-shaped 

 eminences (' Petref. Germ.,' Taf. lxiv, fig. 8,/j, subsequently distinguished by 

 Bargatzky as 8. polyostlolata. This form is only imperfectly known, and it is not 

 at present possible to stato definitely what are its complete characters. Through 

 the kindness of Professor Schliiter I have been able to examine a thin section of the 

 original specimen, and I am able to say that it belongs to one of the groups of the 

 Stromatoporoids in which the skeleton is completely reticulated and the skeleton- 

 fibre is minutely porous. I have little doubt that the species (as based on the 

 original specimen) is really referable to Stachyodes, Barg., with which it agrees 

 entirely in the minute structure of the skeleton-fibre. In any case it is entirely 

 distinct from the other forms included by Goldfuss under the name of 8. poly- 

 morpha. 



(c) The form for which Goldfuss used the varietal name of " ostiolata " 

 ('Petref. Germ.,' Taf. lxiv, fig. 8, e), and which Bargatzky subsequently raised to 

 the rank of a distinct species under the name of 8. monostiolata. The single 

 original specimen has never been sectioned, and it is therefore impossible to come 

 to any positive conclusion as to its internal structure or its real affinities. 



It would appear from the above that Goldfuss included probably three distinct 

 forms under the name of 8. polymorpha. If one were disposed to retain the 

 specific title of "polymorpha" at all, it would be probably best to do so for the 

 forms which Bargatzky has called 8. curiosa, but it would appear to be best to 

 drop the name altogether. An additional reason for following this course is that 

 Goldfuss himself, in the ' Petrefacta,' ultimately referred his Tragos capitatum to 

 8. polymorpha, the former thus becoming the first described example of S. poly- 

 morpha, and therefore the type of the species. Goldfuss also ultimately referred 

 his Ceriopora verrucosa to 8. polymorpha. Upon the whole, therefore, any attempt 

 to retain the species would be sure to lead to confusion. 



Prof. Ferd. Roemer has expressed the opinion (' Rhein. Uebergangsgebirge,' 

 p. 57, 1844) that Stromatopora concentrica, Goldf., and 8. polymorpha, Goldf., are 

 identical. I have examined in the Bonn Museum the specimen upon which 

 Roemer relied in making this statement, and it seems certainly (so far as can be 

 judged without thin sections) to belong to the true S. concentrica, Goldf. As, 

 however, the specimen in question is not one of the originals upon which Goldfuss 

 founded his 8. polymorpha, and as it does not agree in any of its obvious 

 characters with any of these originals, it cannot be accepted as throwing any light 

 upon the validity of this species. 



Having now dealt at some length, as the importance of the subject demanded, 

 with the species of Stromatoporoids described and figured by Goldfuss, I may 



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