Finally, a cyclopygid faunule described from further south in Malaysia (Kobayashi and Hamada, 1971) probably also belongs within the mid-Or- dovician time interval. Cyclopygid biofacies is a deep-water association almost independent of palaeocontinent distribution, but invariably as- sociated with sites near former continental mar- gins (Cocks and Fortey, 1990). The brachiopods in general are poorly known from Sibumasu at this time: the fauna described by Hamada (1964) from calcareous shales near Satun on the west coast of southern Thailand is recorded as three different species of Cyrtonotella, Multicostella? sp. and new species of Rafinesquina and Oepikina? and needs revision, for example one of the .Cyrtonotella. is a plectambonitoid and the .Rafinesquina.is a glyptomenid.