IN spite of its relatively small land area, New Zealand contains a remarkably complete fossil record. Up to the present the Carboniferous and the Silurian have been the only two Phanerozoic geological periods not known to be represented by fossils. The apparent absence of Silurian fossils has been considered strange because upper Ordovician and lower Devonian fossils are present in sedimentary sequences in north-west Nelson, South Island, which do not seem to be interrupted by regional unconformity, and which therefore presumably contained sediments of Silurian age1. The conclusive identification of Silurian fossils from north-west Nelson is therefore of considerable interest. © 1970 Nature Publishing Group.