In the following readings the story of lower animal life has been presented on broad lines, divested of technicality, and at almost every step supplemented by forceful and explanatory illustrations as ocular aids to the reader. The subject has been divested of dry detail, and I have introduced notes and incidents, the results of personal observation and investigation in various lands and seas, and have given attention to the often neglected fauna of the Pacific coast as well as that of other regions. While the volume is a supplementary reader, the matter is so arranged that it can be used by the teacher as a text-book, and the pupil who undertakes the various "half-hour readings" of this series will have covered in the main the ground of the ordinary text-book for intermediate grades in the form of readings. In a word, I have endeavored to make this volume a popular combined review and supplemental reader on the lower forms of animal life from the Amœba to the insects inclusive, and the series to follow will present the entire subject of animal life or zoölogy, voluminously illustrated, on a similar plan. CHARLES F. HOLDER. PASADENA, CALIFORNIA. CONTENTS CHAPTER PAGE I. INHABITANTS OF A DROP OF WATER 7 II. THE SPONGES 18 III. THE JELLYFISHES 26 IV. THE SEA ANEMONES 38 V. THE CORALS 44 VI. THE STONE LILIES 56 VII. THE STARS OF THE SEA 60 VIII. OCEAN HEDGEHOGS 65 IX. THE SEA CUCUMBERS 70 X. THE WORMS 73 XI. THE TWO-VALVED SHELLS 89 XII. THE UNIVALVES 103 XIII. THE CUTTLEFISHES 117 XIV. THE CRUSTACEANS 128 XV. FROM BARNACLES TO LOBSTERS 134 XVI. THE CRABS 145 XVII. LUMINOUS CRABS 156 XVIII. THE INSECTS 159 XIX. LOWER FORMS OF INSECTS 164 XX. THE SPIDERS 168 XXI. SOME SIX-LEGGED INSECTS 178 XXII. SOME MIMICS 186