Chapter I: Introduction: TO PART I. (Spongillidæ) 27

The Phylum Porifera 27
General Structure 29
Skeleton and Spicules 33
Colour and Odour 35
External Form and Consistency 37
Variation 39
Nutrition 41
Reproduction 41
Development 45
Habitat 47
Animals and Plants commonly associated with Freshwater Sponges 49
Freshwater Sponges in relation to Man 50
Indian Spongillidæ compared with those of other Countries 51
Fossil Spongillidæ 52
Oriental Spongillidæ not yet found in India 52
History of the Study of Freshwater Sponges 54
Literature 55

GLOSSARY OF TECHNICAL TERMS USED IN PART I. 61

SYSTEMATIC LIST OF THE INDIAN SPONGILLIDÆ 63