Three new dinocyst genera, 14 new dinocyst species, and one new acritarch species are described from the upper Miocene to lowermost Pliocene Site 646 in the Labrador Sea. The new genera described are Habibacysta, Cristadinium, and Muraticysta. The new dinocyst species described are Capillicysta gloriana, Cerebrocysta? namocensis, Corrudinium? labradori, Cristadinium cristatoserratum, Cristadinium diminutivum, Gongylodinium serratum, Habibacysta tectata, Impagidinium fenestroseptatum, Muraticysta microornata, Nematosphaeropsis major, Operculodinium? eirikianum, Operculodinium janduchenei, Selenopemphix dionaeacysta, and Selenopemphix? indentata. A new acritarch species, Cymatiosphaera? invaginata is also described.

Species abundance: A = abundant, C = common, R = rare, - = not presented.

Supplement to: Head, Martin J; Norris, Geoffrey; Mudie, Peta J (1989): New species of dinocysts and a new species of acritarch from the upper Miocene and lowermost Pliocene, ODP Leg 105, Site 464, Labrador Sea. In: Srivastava, SP; Arthur, M; Clement, B; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 105, 453-466