Brachiopods belonging to the superfamily Davidsoniacea have been collected from localities in the Visean and Namurian rocks (Lower and Upper Limestone Groups and Passage Group) of Central Scotland- Additional material from museum collections has also been investigated. The specimens obtained have been subjected to numerical taxonomic analysis using the English Electric KDF9 computer of Glasgow University. The superfamily Davidsoniacea is briefly considered, and an accoimt given of the aims of this work. The classification and distribution of the superfamily are also considered. An account is given of the program used in the numerical work, the results it provides and their use and interpretation. The brachiopods collected fall into four known genera, namely Orthothetina Schellwien 1900, Schellwienella Thomas 1910, Brochocarina Brunt on 1968 and Serratocrista Brunt on 1968. In addition a new genus is described. A total of twelve species in these five genera is described, of which four are new and a fifth was formerly described as a variety. The species are described and compared both verbally and by the use of the statistical results provided by the computer. The implication of the various patterns of ornament is discussed, and a brief account of some repairs given. The relationship between shell shape and mode of life is also discussed. Finally the existing classification is reconsidered in the light of possible patterns of evolution suggested by the taxonomic work. A new subfamily, the Schellwienellinae, is suggested. It is concluded that the existing classification should not be modified.