1Introduction
8PART III. FRESHWATER POLYZOA (CTENOSTOMATA & PHYLACTOLÆMATA) .
2Freshwater Sponges, Hydroids & Polyzoa
9GLOSSARY OF TECHNICAL TERMS USED IN PART III.
3EDITOR'S PREFACE.
10APPENDIX TO THE VOLUME.
4PART I. FRESHWATER SPONGES (SPONGILLIDÆ) .
11ALPHABETICAL INDEX.
5GLOSSARY OF TECHNICAL TERMS USED IN PART I.
12PLATE I.