A new calcareous alga is described from the Norian limestones of Lime Peak, Yukon, Canada. The algae-bearing limestones were formed in a low-energy environment below the storm wave base, as indicated by the abundance of carbonate mud. Clypeina? pamelareidae n. sp. usually appears in the form of separate laterals scattered in the sediment. The laterals are pyriform, with the tip slightly curved upwards. Sometimes they are arranged around a non-calcified axial cavity. The lack of calcification of the connection between the main axis and the laterals led to the detachment and scattering of the latter in the sediment. The shape of the laterals and their arrangement are reminiscent of the genus Clypeina (Michelin). Still, the lack of completely preserved specimens leads us to attribute it with uncertainty to this genus. Almost certainly, the alga in question is individualised as a new distinct species, basically different from other Mesozoic or Cenozoic species of the genus, as well as from the only species of Clypeina known from the Triassic (Clypeina besici Pantic).