Summary: In the Dahomeyan of the western Accra Plains mafie gneisses, amphibolites, and ortho-amphibolite dykes in granitic gneiss occur. During the latest recrystallization, metamorphic conditions ranged (north to south) from oligoclase-epidote amphibolite subfacies through andesine-epidote amphibolite subfacies to at least the medium or upper part of the amphibolite facies. Chemical analyses of hornblende, garnet, and clinopyroxene from two mafic gneiss specimens supplement data from the Mampong specimen (Knorring and Kennedy, 1958) and indicate that mineral compositions are largely controlled by rock compositions.