Conodonts of the Dounans Limestone, Highland Border Complex, Scotland

Abstract. A meager collection of conodonts recovered from the Dounans Limestone near Aberfoyle, Perthshire, consists for the most part of species with North American affinities. This fauna reaffirms correlation of the Dounans with part of Zone J (Cassinian) of the biostratigraphic succession in western United States. The conodonts indicate that the Dounans is equivalent to part of the zone of Didymograptus nitidus (middle Arenig) in the graptolite sequence for the Ordovician.