In work on fossil brachiopods the present writer has found that descriptions and more particularly figures of the musculature of living froms are insufficiently explicit for parallels to be drawn with fossil specimens. These notes are the result of dissections of specimens of the living Terebratulinid Gryphus vitreus (Born) from the Marine Biological Station at Naples, and are intended primarily to elucidate the accompanying figures, which it is hoped might be of some value to palaeontologists.