The present report deals with microfossils mostly of organic matter from the Silurian of Estonia and the Isle of Ösel. There are several groups met with: Chitinozoa, the most frequent ones, Foraminifera, Melanoskleritoidea, Annelida, Hystrichophyta and Algae. Other groups are only briefly mentioned.The annelids have yielded some new forms of mandibles and carriers; the maxillae are not dealt with here. In stratigraphical view there is a good correspondence with the equivalent strata of Gotland and for the higher zones of Ösel with the Beyrichian limestone, a well known and fossiliferous kind of glacial boulders of Downtonian age.