Transcriber’s Notes: Underscores “_” before and after a word or phrase indicate _italics_ in the original text. Small capitals have been converted to SOLID capitals. Illustrations have been moved so they do not break up paragraphs. Old or antiquated spellings have been preserved. Typographical errors have been silently corrected but other variations in spelling and punctuation remain unaltered. [Illustration: THE FIVE CLASSES OF INVERTEBRAL ANIMALS DESCRIBED IN THIS VOLUME] THE BOOK OF SHELLS; CONTAINING THE CLASSES MOLLUSCA, CONCHIFERA, CIRRHIPEDA, ANNULATA, AND CRUSTACEA. PUBLISHED UNDER THE DIRECTION OF THE COMMITTEE OF GENERAL LITERATURE AND EDUCATION, APPOINTED BY THE SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE. THE SECOND EDITION. LONDON: JOHN W. PARKER, WEST STRAND. M.DCCC.XXXVII. TO THE READER. In describing that portion of the system of Natural History which embraces the VERTEBRAL ANIMALS,—namely, the Mammalia, the Birds, the Reptiles, and the Fishes,—the arrangement of the BARON CUVIER was adopted. In the present little volume, as well as in two others that are to follow, and which, together, will comprise the INVERTEBRAL ANIMALS, the method of M. LAMARCK will be adhered to. It is true, that, since the works of that naturalist were published, many deviations from certain parts of his system have taken place, some of which have received the sanction of the highest names; but still, _as a whole_, Lamarck’s System remains unrivalled, and the young naturalist can readily add to the information it contains, by reference to the works of more recent authors, in case he has sufficient inclination and industry to follow out the subject. CONTENTS. Page Introductory Chapter 9 Class MOLLUSCA 14 Order HETEROPODA 15 The Glassy Carinaria 15 Order CEPHALOPODA 16 The Cuttle Fish 17 Argonaut 20 Pearly Nautilus 22