107 August 16. Friday. Port au Choix, Dumbaus mts. Dumbaus mts are as follows: One by an oval on the south side of the south side of outer Port au Choix. There is an estimated interval of 50 feet not exposed occupied by the neck of Port au Choix Bay. These strata belong in the upper part of Lagan Division H. The lowest strata on the south side are of light gray dolomite in large beds 2 to 6 feet thick. Small grades of dolomite and quartz are common at various times. Only rare traces of marine fossils are seen. The lithology remains uniform for a thickness of 90 feet and then there is an unexposed interval for about 1/4 mile across a very shallow curve. The strata here have a very low dip so that the lost interval may be only 50 feet or less. All of these strata are of Lagan Division I. At the first point of the cliff about 1/2 mile to the south west of the outer edge of Port au Choix Bay the section begins again with light bluish-gray argillaceous li. that weathers crisp and finely like the Chazy. Fossils are at once common. Raf. Proctori, Hemitoma augusta (new), Retiresquim (can not warn) and depressed footprints. Also Macaulis transitorius. These layers are entirely different from the bearing beds of dolomite below but the exact contact could not be seen. The bare slope on top of the cliffs (about 30 feet above the face of the Chazy) are repeta with Macaulis acuminate, Mr. transitorius,