OLIGOCHAETA (pp. 241, 347) | +—— MICRODRILI (p. 373) | | | +—— Aphaneura (p. 374). | +—— Enchytraeidae (p. 375). | +—— Discodrilidae (p. 376). | +—— Phreoryctidae (p. 376). | +—— Naidomorpha (p. 377). | +—— Tubificidae (p. 378). | +—— Lumbriculidae (p. 379). | +—— Moniligastridae (p. 380). | +—— MEGADRILI (pp. 373, 374). | +—— Perichaetidae (p. 380). +—— Cryptodrilidae (p. 382). +—— Acanthodrilidae (p. 384). +—— Eudrilidae (p. 385). +—— Geoscolicidae (p. 386). +—— Lumbricidae (p. 388). HIRUDINEA (p. 392) RHYNCHOBDELLAE (p. 405) ——+ | +—— Ichthyobdellidae (p. 406). +—— Glossiphoniidae (p. 406). GNATHOBDELLAE (p. 407) ———+ | +—— Gnathobdellidae (p. 407). +—— Herpobdellidae (p. 407). GEPHYREA (p. 411) SIPUNCULOIDEA (pp. 412, 420). PRIAPULOIDEA (pp. 412, 430). ECHIUROIDEA (pp. 412, 434). EPITHETOSOMATOIDEA (pp. 412, 444). _PHORONIS_ (p. 450) POLYZOA (p. 465) ENTOPROCTA (pp. 475, 487) ECTOPROCTA (p. 475) | +—— GYMNOLAEMATA (p. 476) | | | +—— CYCLOSTOMATA (p. 477) | | | | | +—— Articulata (p. 517). | | +—— Inarticulata (p. 517). | | | +—— CHEILOSTOMATA (p. 477) | | | | | +—— Cellularina (p. 518). | | +—— Flustrina (p. 518). | | +—— Escharina (p. 518). | | | +—— CTENOSTOMATA (p. 477) | | | +—— Alcyonellea (p. 518). | +—— Vesicularina (p. 518). | +—— PHYLACTOLAEMATA (pp. 476, 493) PLATYHELMINTHES AND MESOZOA BY F. W. GAMBLE, M.Sc. (VICT.) Demonstrator and Assistant-Lecturer in Zoology in the Owens College, Manchester. {3}CHAPTER I TURBELLARIA INTRODUCTION: DESCRIPTION OF THE POLYCLAD _LEPTOPLANA TREMELLARIS_— APPEARANCE—HABITS—STRUCTURE: POLYCLADIDA—CLASSIFICATION—HABITS— ANATOMY—DEVELOPMENT: TRICLADIDA—OCCURRENCE—STRUCTURE—CLASSIFICATION: RHABDOCOELIDA—OCCURRENCE—HABITS—REPRODUCTION—CLASSIFICATION.