August 10. Port au Choix, Duntan's nts. seen in section. The rock is so dense and heavy that almost none of the fossils could be determined. Lst 3 f foss. It is a puzzle to what great period the layer of pelecypods could belong since they seem far later than any of the gastropods present. About 2/5 of a mile from the north point of the peninsula we find a layer full of large trilobites and a little ostracod. This layer continues near the upper part of the ridge to the point where it is at the top of the strata in the high cliffs. These fossils are limited to a thin zone of not one foot thick. At some point 10 feet lower and almost none fossil thick is more muddy and weathered gillmore. It shows severally. Once again about it and again a few feet higher than intraplanatorial conglomerate. This closes Division 1st. Below the big trilobite layer it is just as perfect down to the lowest strata exposed at the farthest north point of the Port au Choix peninsula. Below the intraplanatorial cong. layer noted above fossils quickly become rare and some are absent. At the same time the strata become more dolomitic with more tendency to weather smooth. Many layers are marked by a pattern that may be due to sun-cracking. The beds have the appearance of shallow water deposits. Near the base is a heavy layer that is dimorph and uneven, suggesting Cryptozoon. Below this there is what of dark gray more coarsely crystalline and porous dolomite that breaks with conchoidal fracture and