Neue Forschungsergebnisse von gotlandischen Graptolithen

Summary

For the first time we succeeded in photographing in ultra-violet light graptoliths, the predominating fossils of the Silurian. These were mono- and diprionitic graptoliths such as occur in the alum and silica slates of the Gotlandium in Central Germany. Additional floating apparatuses not visible in ordinary light and exhibiting various constructions were ascertained photographically besides the already familiar floating bladders. From this investigation it is apparent that the graptoliths must be located in the vicinity of theScyphozoa orSiphonophores in the palæozoological system. Only the familiar ontogenesis of the graptoliths creates difficulty with regard to this allocation. A planctonic and a pseudoplanctonic manner of living could be proved beyond all doubt, however, for the gotlandic graptoliths of Central Germany. This fact holds good also for the graptolithic fauna spread over the entire world.