The fourth sub-kingdom, that of _Mollusca_, includes, besides snails and slugs, various kinds of shell-fish; and the lower sub-kingdoms—including _Echinodermata_, which may be typified by starfishes and sea urchins, the _Cœlenterata_, or Zoophytes, and the _Protozoa_—will be found to be just entered on sufficiently to show their place in the scale. The clear descriptions, made still more instructive by the numerous and good figures, will speak for themselves to all readers; but I should like to add a few lines to point out the serviceableness of a handbook in which the reader may turn at pleasure to the history of any common farm animal—as a weasel or a vole, a wood-pigeon or a pheasant, a blindworm or a common frog. And, in regard to the insect infestations, to which it will be seen more than a hundred pages of the book are devoted, I can bear witness to the great amount of valuable information which I constantly derive myself from the study of the writings of Dr. Ritzema Bos on this subject; and I trust this little manual of “Agricultural Zoology” may take the place in our farm and school libraries which I believe it to be excellently fitted to fill. ELEANOR A. ORMEROD, _Late Consulting Entomologist of the Royal Agricultural Society of England_. TORRINGTON HOUSE, ST. ALBAN’S, _May 24, 1894_. CONTENTS. PAGE INTRODUCTION— I. Subdivision of the Animal Kingdom 1 II. Review of the Structure and Vital Phenomena of Animals 3–16