INTRODUCTION—NATURE OF CESTODES—OCCURRENCE OF CESTODES—THE TAPE-WORMS OF MAN AND DOMESTIC ANIMALS—TABLE OF LIFE-HISTORIES OF PRINCIPAL CESTODES OF MAN AND DOMESTIC ANIMALS—STRUCTURE AND DEVELOPMENT OF CESTODES—TABLE FOR THE DISCRIMINATION OF THE MORE USUAL CESTODES OF MAN AND DOMESTIC ANIMALS—CLASSIFICATION 74 CHAPTER IV MESOZOA DICYEMIDAE—STRUCTURE—REPRODUCTION—OCCURRENCE: ORTHONECTIDAE—OCCURRENCE —STRUCTURE: _TRICHOPLAX: SALINELLA_ 92 NEMERTINEA CHAPTER V NEMERTINEA INTRODUCTORY—EXTERNAL CHARACTERS—ANATOMY—CLASSIFICATION—DEVELOPMENT —HABITS—REGENERATION—BREEDING—GEOGRAPHICAL DISTRIBUTION—LAND, FRESH-WATER, AND PARASITIC FORMS—AFFINITIES 99 NEMATHELMINTHES AND CHAETOGNATHA CHAPTER VI NEMATHELMINTHES INTRODUCTION—NEMATODA—ANATOMY—EMBRYOLOGY—CLASSIFICATION—ASCARIDAE —STRONGYLIDAE—TRICHOTRACHELIDAE—FILARIIDAE—MERMITHIDAE—ANGUILLULIDAE —ENOPLIDAE—PARASITISM: NEMATOMORPHA—ANATOMY—CLASSIFICATION —LIFE-HISTORY: ACANTHOCEPHALA—ANATOMY—EMBRYOLOGY—CLASSIFICATION 123 CHAPTER VII CHAETOGNATHA STRUCTURE—REPRODUCTION—HABITS—FOOD—CLASSIFICATION—TABLE OF IDENTIFICATION [see also p. 534] 186 ROTIFERA, GASTROTRICHA, AND KINORHYNCHA CHAPTER VIII ROTIFERA, GASTROTRICHA, AND KINORHYNCHA ROTIFERA—HISTORY—EXTERNAL FEATURES—MOVEMENTS—ANATOMY—REPRODUCTION —EMBRYOLOGY—CLASSIFICATION—DISTRIBUTION—AFFINITIES: GASTROTRICHA: KINORHYNCHA 197 ARCHIANNELIDA, POLYCHAETA, AND MYZOSTOMARIA CHAPTER IX THE CHAETOPODOUS WORMS—THE ARCHIANNELIDA—ANATOMY OF _NEREIS_, AS TYPICAL OF THE POLYCHAETA 241 CHAPTER X CLASSIFICATION OF THE POLYCHAETA—SHAPE—HEAD—PARAPODIA—CHAETAE—GILLS —INTERNAL ORGANS—JAWS—SENSE ORGANS—REPRODUCTION—LARVAL FORMS —BUDDING—FISSION—BRANCHING—REGENERATION 257 CHAPTER XI NATURAL HISTORY OF POLYCHAETES—GENERAL HABITS—CHARACTER OF TUBE AND ITS FORMATION—COLOURING—PROTECTIVE AND MIMETIC DEVICES —PHOSPHORESCENCE—FOOD—USES—ASSOCIATED WORMS—WORMS AS HOSTS —DISTRIBUTION—FOSSIL REMAINS 284 CHAPTER XII CHARACTERS OF THE SUB-ORDERS OF POLYCHAETES—CHARACTERS OF THE FAMILIES—DESCRIPTION OF BRITISH GENERA AND SPECIES: THE MYZOSTOMARIA 303 OLIGOCHAETA (EARTHWORMS, ETC.), AND HIRUDINEA (LEECHES) CHAPTER XIII OLIGOCHAETA (EARTHWORMS AND THEIR ALLIES) INTRODUCTION—ANATOMY—REPRODUCTION—BIONOMICS—DISTRIBUTION —CLASSIFICATION—MICRODRILI AND MEGADRILI 347 CHAPTER XIV HIRUDINEA (LEECHES) INTRODUCTION—ANATOMY—REPRODUCTION—CLASSIFICATION—RHYNCHOBDELLAE AND GNATHOBDELLAE 392