Since so many species of invertebrates are found on the beach that a complete enumeration of them is impracticable, only the most conspicuous ones have been selected for description in Part II; but the attempt has been made to designate the various classes and orders with sufficient clearness to enable the collector to identify the objects commonly found on the shore, and to follow the subject further, if he so desires, in technical books. It is hoped that this book will suggest a new interest and pleasure to many, that it will encourage the pastime of collecting and classifying, and that it will serve as a practical guide to a better acquaintance with this branch of natural history, without necessitating serious study. Marine organisms are interesting acquaintances when once introduced, and the real purpose of the author is to present, to the latent naturalist, friends whom he will enjoy. Grateful acknowledgment is here made to the following persons who have kindly assisted and advised the author and have also extended valued courtesies to her in the preparation of this book: Smith Ely Jelliffe, M.D., Ph.D.; Herbert M. Richards, A.B., Ph.D., Professor of Botany in Barnard College; Marshall A. Howe, A.B., Ph.D.; the Rev. George A. Holst; the Long Island Historical Society of Brooklyn for the use of its fine herbarium, containing the collections of Mr. John Hooper, Mr. A. R. Young, and others, from which most of the illustrations of algæ in this book were photographed; Miss Toedtleberg, Librarian of the Long Island Historical Society; Miss Ingalls, in charge of the Museum of the Long Island Historical Society; Dr. Theodore Gill; James A. Benedict, Ph.D., Assistant Curator of Marine Invertebrates in the Smithsonian Institution; Miss Mary J. Rathbun, second Assistant Curator of Marine Invertebrates in the Smithsonian Institution; Miss Harriet Richardson; and especially to Mr. John B. Henderson, Jr. * * * * *