New pre-Paleozoic nannofossils from the Stoer Formation /Torridonian/, northwest Scotland.

The nature of the sph eroidal unicellular fossils 10 to 62 micrometers in diameter that are abundant in black shales referred to the Stoer Formation of lower Torridonian age at Stoer Bay, in northwest Scotland, is examined. It is shown that their biological affinities are obscure; it is, however, not unlikely that many or most of them are independent unicellular members of the marine phytoplankton.