Page:The Habitat of the Eurypterida.djvu/152

146 The eurypterids do not occur in the beds with the marine fossils but always in distinct zones a few inches thick, their whole representation being confined to not more than a few feet in the entire Oesel series.

West of Rootziküll a distance of about 5 versts there is an exposure not far from Gesinde Wessiko Maddis along a little brook which rises near Lümmada, but is usually dried up. Here the lower rock is limey, not dolomitic and the eurypterids are not very abundant, but the rock above is crowded with Platyschisma helicites, Leperditia phaseolus, and the delicate fish scales of Coelolepis schmidti Pander together with fragments of seventeen other species of fishes (Schmidt, 241, 168, 248, 29). The upper beds are evidently the continuation of the brecciated limestone of Wita. Proceeding in the same south-westerly direction from Rootziküll towards the coast one comes to the Attel estates or Gut Attel where there is a small outcrop of yellow, coralline limestone which on exposure weathers white and which carries Stromatopora sp., Cyathophyllum, Favosites hisingeri, and F. fibrosa; similar brecciated inclusions occur as at Wita. A little farther to the west in the village of Attel may be seen on the west side of the deeply indented bay a coarsely crystalline yellow-dolomite and beneath this is the coral limestone of the Attel estates which here is not entirely composed of corals, but contains also Eurypterus fischeri, Lepeditia baltica, Orthoceras bullatum, and Murchisonia cingulata = M. compressa, the last being the same species which is found in zone VI in Gotland. It is clear that the eurypterid remains at Attel are found not in the plattenkalk beds, which here are barren of all organic remains, but in the overlying coral limestones (Nieszkowski, 197, 307; Schmidt, 241, 169, 170). The last section in this series is at the Soegi-ninna point about 12 versts from Rootziküll, where the rock walls rise from the sea to a height of 10 or 12 feet. In the upper part is seen the typical crystalline dolomite with nodular inclusions which here and there give place to thin, unaltered limestone beds with Leperditia baltica and Murchisonia compressa; the lower part of the rock walls consists of platten dolomites which appear to be the continuation of those of Wita, but which have not yet yielded any eurypterid remains after fifty years of patient search (Schmidt, 151, 169, 170).

The outcrops in the southeastern portion of Oesel show only traces of eurypterids here and there. For instance, between Uddafer and Ladjal, north of Arensburg, Schmidt found in small ditches along the roadside Phragmoceras sp., Spirigerina prunum, S. didyma,