Description of the Impressions and Foot-prints of the Protichnites from the Potsdam Sandstone of Canada

Of the extensive series of foot-prints found under the circumstances described in the preceding communication, the originals of some and good plaster-casts of more have been brought over with much labour and expense by their discoverer, Mr. Logan, and of these I have selected the best-marked and most intelligible portions for the following descriptions.