10 GUSTAF LINDSTRÖM. 



it has never since been mentioned *) under that denoinination until lately when it again 

 is registered amongst the corals by Prof. Duncan in the list of fossils appended t\> the last 

 edition of Siluria (p. 510) and named Heliolithes? discoideus. In the mean tinie this very 

 species, as far as I may judge from good figures and descriptions, had been confounded 

 with a Silurian fossil of quite another type and described several tiraes by various authors 

 under different names. As this coininixtion of the two distinct fossils may be iraced back 

 to the first author on closely allied Devonian fossils, Goldfuss, I may as well try to un- 

 ravel what he described in his grand work, Petrefacta Germanise. Under the naine of 

 Stromatopora polymorpha Goldfuss united (p. 215 Vol. I) three distinct types. One is 

 Stromatopora concentrica figured pl. 8 fig. 5 (pag. 21) which as far as the good figures 

 show is something widely different from the others. Then there is Ceriopora verrucosa 

 (p. 33 pl. 10 fig. 6) which fossil coincides with what since commonly is considered as 

 Stromatopora concentrica and is decidedly of the same genus with the Upper Silurian Stro- 

 matop. striatella Lonsdale (Siluria 4:th edit. pl. 41 fig. 31.) The third type is called by 

 Goldfuss Tragos capitatum (Pl. 5 fig. 6 pag. 26) which låter by him has been identified 

 with the fossil that he (p. 215, plate 64 fig. 8) gives as a variety of Stromatopora poly- 

 morpha, his own lucid descriptions as well as his excellent figures showing how widely 

 different this type is from the rest, although he considers them all only as mere varieties 

 of each other, and the starlike figures as due to weathering. The last mentioned Stroma- 

 topora polymorpha is so closely allied to the Silurian Coenostroma, that it must be 

 ranged in the same genus and considered one of the Montiporina^. In thus separating 

 the Stromatopora (Coenostroma) polymorpha from Stromatopora concentrica and striatella 

 and uniting it with Coenostroma discoideum, I only follow the arrangement of Prof. WiN- 

 chell, who in the Proceedings of the American Association, Aug. 1866 (printed at Cam- 

 bridge 1867) page 91, in a paper on the affinity of the Stromatoporidre creates the genus 

 Coenostroma out of Stromatopora, and I think lie is right in retaining that name for what 

 generally has been considered the typical form of Goldfusss genus. But I differ from 

 him in not considering Stromatopora a coral because it does not exhibit any characteri- 

 stics at all proper to that group. It may easily be seen that the body of this fossil 

 mainly consists of thin strata or plates regularly united by short connecting tubes running 

 vertically between them, and on the surface of the plates no cellulär openings nor star- 

 shaped calices are seen, only the heads of the thickly set small tubes, which give to the 

 surface a punctuated appearance (See fig. 15). It is more probable, as stated by Dr 

 Carpenter and other eminent english naturalists, that it is akin to the ancient Eozoon 

 canadense and another example of primeval, gigantic foraminifera. No doubt the man- 

 ner of growth being alike both in Coenostroma and Stromatopora with its concentric, 

 thin layers, and the occurence of both in large balls and inoreover the circumstance, that 

 strata of the one genus have grown on those of the other so as to be intimately com- 

 mingled in the same handpiece, has caused their being so long confounded. After all 

 Coenostroma is by far the most cornmon of the two fossils, at least in Gotland. It is only 



x ) MM. Milne-Euwauds ajid Haime only give it a passiug uotice in their work »Polypiers fossiles des ter- 

 mins paléozoiques» p. 470, where tliey say that it and some otliers »päraissent étre des Spongiaires». 



