In Chile and adjacent regions of South America, Mr. Darwin, in his “Geological Observations,” has described a great series of Mesozoic rocks, which he calls the “porphyritic formation,” and which shows an interesting resemblance to certain rocks in British Columbia. These I had provisionally designated in my report in connexion with the Geological Survey of Canada for 1875, as the Porphyrite series, without at the time remembering Mr. Darwin's name for the Chilian rocks. Many of Mr. Darwin's descriptions of the rocks of Chile would apply word for word to those of British Columbia, where the formation would also appear to bear a somewhat similar relation to the Cascade or Coast Range, which that of Chile does to the Cordillera.