The writer has recently been engaged in the investigation of a 'Lewisian' inlier within the Moine series of Glen Dessarry, at the head of Loch Arkaig, Inverness-shire. The inlier is largely composed of a series of hornblendic and felspathic gneisses but includes small lenses of marble and calc-silicate rocks. All these are to be reported later in two separate communications. There are in addition, however, some steeply inclined and impersistent ribs of mica-schist, granulite, and diopside-epidote-rocks, which will only be incidentally mentioned in those accounts in so far as they bear upon certain specific problems. In themsclves they are apparently of little petrographic interest except for the occurrence of an unusual copper-bearing recta-sediment. This it seems convenient to record in a separate note.