246 BULLETIN: MUSEUM OF COMPARATIVE, ZOOLOGY. 
formations may in former times have extended across this north- 
ern region. In Dalecarlia, however, which is well to the north, 
the Trinucleus shales are well developed, and contain the typical 
southern fauna. The Kegel and Wesenberg are certainly older than 
the Trinucleus shales. 
The Chasmops limestone of Sweden has been little studied except 
for the work of Olin on the trilobites in Scania, and the time is not yet 
ripe for accurate correlations. The Upper Chasmops or Macrourus 
limestone of Dalecarlia contains such species as Chasmops maxima 
Schmidt, found in Russia in the Jewe and Kegel, while the lower 
Chasmops limestone of the same region contains such typical Kuckers 
and Itfer fossils as Echinosphaerites aurantium, Chasmops odini, and 
Oxoplecia dorsata. 'The Chasmops limestone is therefore correlated 
as indicated by these fossils. As mentioned above, there are certain 
trilobites which serve to connect the Chasmops limestone with the 
shales in Scania containing Dicranograptus clingant and Pleurograptus 
linearis. Between the zone of Nemagraptus gracilis and that of 
Dicranograptus clingant, there is, it seems, a considerable gap, so that 
the section in Scania is far from complete. 
ZONE OF DICRANOGRAPTUS CLINGANI. 
In southern Sweden the zone of Nemagraptus gracilis is succeeded 
by the zone of Dicranograptus clingani, or as it is sometimes called, 
the Middle Dicellograptus beds. 
These beds, have recently been studied in great detail on Born- 
holm, politically an apanage of Denmark, but geologically in the 
Scanian province. Hadding (61) has recognized four subzones on 
this island. These are in descending order: 
4 Zone with Climacograptus styloideus Lapworth. 
3. Zone with Dicranograptus clingani Carruthers. 
2. Zone with Amplexograptus vasae (Tullberg). 
1. Zone with Climacograptus rugosus Tullberg. 7 
Among the fossils of zone 4 may be mentioned, beside the name 
fossil, Glossograptus quadrimucronatus, Diplograptus truncatus, Dicello- 
graptus pumilis, Leptograptus flaccidus macer, and inarticulate brachio- 
pods. 
Zone 3 has a large fauna, including among others, Amplexograptus 
vasae, Climacograptus brevis, Dicellograptus forschammeri, D. pumilis, 
and Corynoides curtus. There are also several inarticulate brachio- 
pods and Dalmanella argentea. 
