Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. The first Edition of the following work was prepared by request of the Local Committee of the British Association at Glasgow, in order to serve as a guide to the Geologists attend ing the meeting in 1855. A sketch of the geological structure of Clydesdale was the main feature of that edition. In the second Edition the portion treating of Clydesdale was much extended, while that relating to ‘arran and the other Islands was entirely new, and founded on observations of the Author made during the intervening summers. It appeared to him, however, that as Arran is a highly interesting field in other departments as well as in Geology, the wishes of many students would be met by combining an account of the Botany and Marine Zoology with that of the Geology. At his request the Rev. Dr. Miles, to whom a special grant had been entrusted by the British Association for dredgings in the Clyde, drew up an account of the more remarkable objects of the Marine Fauna to which was added a complete list of the species then known, as well for the guidance of students as a basis for future enquiry. An account of the Flora of Arran was drawn up by the Author’s eldest son, Mr. James Bryce, now of Lincoln’s Inn, and Begins Pro fessor of Civil Law at Oxford. In preparing the list appended to it, advantage was taken of Professor Balfour’s kind permission to make use of his catalogue of Arran plants. For this edition, which was published in 1859, notices of the rarer Lepidopterous insects of Arran were most kindly supplied by the distinguished entomologist, Mr. Henry T. Stainton.