During the last fifteen years, a renewed attack has been made upon the difficult problems presented by the complicated fold and thrust structures in the older Paleozoic strata of northwestern Vermont. The campaign led by Arthur Keith bids fair to resolve the difficulties which baffled such eminent and acute geologists as Sir William Logan, Elkanah Billings, James Hall, Jules Marcou, and Charles D. Walcott. Like Sir William, Keith realized that fossils might be the master key for opening the secrets of this chamber of mysteries, and at an early date induced Charles Schuchert to collaborate in the work. Schuchert has been kind enough to turn over for study such Upper Cambrian and Lower Ordovician trilobites as he and his associates have collected during visits to the area over a long period, and several years ago the writer described such fossils as had then been collected from what . . .