Beresellids from the Carboniferous of the Russian Platform

The classification of the tribe Bereselleae of the family Dasycladaceae is discussed in some detail. The genera Beresella, Samarella and Dvinella are placed in the tribe with Trinodella, being treated as a subgenus of Dvinella. A number of new species are described: four in Beresella, six in Dvinella subgenus Dvinella and two in Dvinella subgenus Trinodella. The stratigraphic occurrence of the tribe in the Carboniferous at a number of localities on the Russian Platform is represented and a strong generic-facies association is pointed out. A pattern of variation in morphological form with sediment type is also discussed. — W. Adey.