553; " Rhabdopleura and Graptolites," Neues Jahrb.
Since no graptolites are known living, or, indeed, since palaeozoic times, the interpretation of their structure and affinities must of necessity be extremely conjectural, and it is by no means certain that they are Hydrozoa at all.
In the Maecuru, another northern affluent, graptolites of Ordovician age have been discovered, and Silurian fossils are said to have been found in the Maraca.
The typical graptolites are, in the upper part, Dicellograptus anceps and D.
Here they contain numerous graptolites, including Tetragraptus, Dichograptus and Didymograptus.