The existence in the British Isles of a rock essentially composed of garnet and omphacite, and answering therefore to Hauy's' definition of eclogite, does not appear to have been hitherto recorded.

The following description of such a rock from Totig Ferry, Loch Dutch, is therefore of some interest. The specimen was collected by the Director General, who informs me that he believes it to be a part of the Archæan gneiss which in the region of Loch Alsh and Loch Carron has been thrust bodily from the east over the Torridon sandstone.

The rock is of a dull green eolour, and contains numerous reddishbrown garnets. Under the microscope the principal constituents are seen to be garnet and omphacite—a pale green pyroxene without any definite crystalline form. Green hornblende, plagioclase, rutile, ironores, quartz, and epidote occur as accessories.