Acritarchs (organic-walled phytoplankton) are described from the siliciclastic rocks of the Buen Formation. A total of 52 form taxa are reported from a small number of extremely fossiliferous samples from th deeper shelf portion of the formation.

Phosphatised helically coiled microfossils are described from the Portfjeld Formation of Early Cambrian age in southem Peary Land, central North Greenland. SpirelIus Jiang in Luo et al., 1982, originally described from the Meishucunian Stage of China, is recorded from Greenland and interpreted as a filamentous cyanobacterium showing variable degrees of mineralisation of the sheath. Jiangispirellus groenlandicus gen. et sp. nov. is described, based on helically coiled naked trichomes with preserved cell structure. Both genera are compared to Obruchevella Reitlinger, 1948 which is also reported from Greenland for the first time.

Siliciclastic sediments of the Buen Formation of North Greenland yield the earliest Cambrian fossils known from North Greenland, with the exception of cyanobacteria described from dolomites of the underlying Portfjeld Formation (see Peel, this report). The fauna is dominated by olenellid and nevadiid trilobites indicating an Early Cambrian age (Poulsen, 1974; Blaker, this report) but hyolithids, bradoriids, sponges and other fossils also occur. Bergstrom & Peel (this report) described trace fossils from the Buen Formation. Of particular interest is the recent discovery of lightly skeletised arthropods comprising an assemblage similar to that of the Middle Cambrian Burgess shale of Canada (Conway Morris et al., 1987).

Field work in 1985 revealed that the Aleqatsiaq Fjord Formation (Ordovieian-Silurian) can be traced from Washington Land to westernmost Peary Land, and that a tripartite subdivision of the formation can be achieved throughout most of this area (units AFI-3). Five mapping units (WGI-5) were recognised within the overlying Washington Land Group of Silurian age between Hall Land and westernmost Peary Land. These are described and correlated with sequenees in Washington Land and elsewhere in Peary Land. Deposition was uniform in the lower part of the sequenee (units AFI-WG1) throughout the mapped area. Lateral lithologieal variation in the upper part (units WG2-5) refleets differential regional subsidenee, the presence of intrashelf mounds and the development of huge mound complexes along the shelf margin.

There is broad agreement from genomic and morph o logical studies of present day bivalves that the Ordo vician-Recent members of the Class Bivalvia Linnaeus, 1758 form a monophyletic group, although some relation ships within the group remain unresolved (