. Bulletin of the Geological Society of America. Geology. BALTIC REGION 613 up occur Diplograptus foliaceus var. calcaratus Lapw. and Dicellograptus forchhammeri Gein. We have thus the Dicellograptus or Normanskill shales following almost directly on beds of Deepkill (Arenig) age, as in eastern North America, but with a thin limestone, probably representing the Megalaspis limbata beds, intervening. If this limestone is correctly identified, the break in the series comes above it, this break representing the greater part of the Arenig and of the Lower Llandeilo, or, in Ameri- can terms, most of
. Bulletin of the Geological Society of America. Geology. BALTIC REGION 613 up occur Diplograptus foliaceus var. calcaratus Lapw. and Dicellograptus forchhammeri Gein. We have thus the Dicellograptus or Normanskill shales following almost directly on beds of Deepkill (Arenig) age, as in eastern North America, but with a thin limestone, probably representing the Megalaspis limbata beds, intervening. If this limestone is correctly identified, the break in the series comes above it, this break representing the greater part of the Arenig and of the Lower Llandeilo, or, in Ameri- can terms, most of the Beekmantown and the whole of the Chazy. A nearly continuous section is exposed in the stream bank south of Tommarp, which I here reproduce from my notes (figure 9). The beds dip at a gentle angle to the north, this dip being lowest at the southern end of the section. Here a quarry has been opened in tlic "Orthoceras limestone," which here represents the Megalaspis limbata limestone. The N s. Figure 9.—Section in the Stream Bank south of Tommarp, Scania, in southern Sweden a, Megalaspis limbata limestone; b, Trinucleus coscinorhinus beds; e, black sbalc with Dicranograptus clingani; d, covered; e, Trinucleus shale limestone is in thin layers with shaly partings, the whole dipping about 20° to the north. Fossils are scarce, but I succeeded in finding a speci- men of the pygidium of Megalaspis limbata. This limestone is followed by thin-bedded, dark, mainly black, fine-grained calcarenites, from which Trinucleus coscinorhmus Aug. and some other fossils have been reported. We, however, did not succeed in finding any of these. Overlying this limestone are dark shales with Dicranograptus clingani, from which we also obtained some small brachiopods. After a covered interval, which may represent the zone of Pleurograptus linearis Carr. which we saw at Jerrestadt, a similar black shale with thin limestone beds completes the section. This is the zone of Trinucleus, the
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