viii CONTENTS 



Page 



Order i. — Barnacles (Cirripedia) - 417 



Order 2. — Bivalve Crustacea (Ostracoda) — Mussel-Shrimps 419 



Order 3. — Fork-footed Crustacea (Copepoda) 420 



Order 4. — Leaf-footed Crustacea (Phyllopoda) 421 



Class 6.— KING-CRABS (Xiphosura) 422 



Structure of the King-Crab (Limulus). 



Class 7.— SEA-SPIDERS (Pycnogonida) 424 



CHAPTER IX 



STRUCTURE AND CLASSIFICATION OF SEGMENTED WORMS, 

 SIPHON -WORMS, WHEEL -ANIMALCULES, MOSS -POLYPES, 

 AND LAMP-SHELLS 



SEGMENTED WORMS (Annelida) 



Class I.— BRISTLE-WORMS (Chaetopoda) - 425 



Structure of the Sea-Centipede (Nereis), taken as a Type 425 



Order i. — Many-bristled Worms (Polychseta) 429 



Order 2. — Few-bristled Worms (Oligochaeta) — River- Worms, Earth- Worms 430 



Order 3. — SIMPLE Segmented Worms (Archiannelida) — Dinophilus, Poly- 



gordius 431 



Class 2. — LEECHES (Discophora) 432 



SIPHON-WORMS (Gephyrea) 

 Bristle-Tail (Echiurus), Siphon- Worm (Sipunculus) - 433 



WHEEL-ANIMALCULES (Rotifera) 

 Structure of the Rose-coloured Rotifer (Philodina roseola) 434 



MOSS-POLYPES AND LAMP-SHELLS (Molluscoida) 



Class I.— MOSS-POLYPES (Polyzoa or Bryozoa) 436 



Sea-Mat (Flustra), Lace-Coralline (Membranipora), Plume Coralline (Pluma- 

 tella), Lophopus. 



Class 2.— LAMP-SHELLS (Brachiopoda) 438 



Structure of a typical Lamp-Shell (Waldheimia). 



CHAPTER X 



STRUCTURE AND CLASSIFICATION OF FLAT-WORMS (Platyhelmia) 

 AND THREAD-WORMS (Nemathelmia) 



FLAT-WORMS (Platyhelmia) 



Class I.— Tape-Worms (Cestoda) 441 



Class 2. — Flukes (Trematoda) 443 



Class 3. — Planarian Worms (Turbellaria) 445 



