On two previous occasions the writer has presented or assisted in presenting certain aspects of the geology of the Mingan Islands.2 He has made three visits to these islands. The first was in 1909, when some of them were studied by means of a fishing boat owned and sailed by Selas Poirer of Anticosti Island. On that trip the islets of the Parroquet group and Mingan, Harbour, Moutange (Big Romaine), Large, Quarry, and Niapisco islands were studied. During that same summer on the return from Anticosti the writer was compelled to remain for several days in Havre Saint Pierre (Eskimo Point), and the opportunity was taken to study Eskimo Island and the section on the west side of Clearwater Point. The second visit was in the summer of 1925, when Inner and Outer Birch, Harbour, Moutange (Big Romaine), and Moniac (Little Romaine) islands, Point des Morts, and the west . . .