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Contents

Foreword ............................................................................ viii
How to use this book ........................................................ xi
Advisory board ................................................................... xiii
Contributing writers.......................................................... xv
Contributing illustrators.................................................... xvii

Volume 1: Lower Metazoans and Lesser Deuterostomes

What are lower metazoans and lesser deuterostomes?.... 3
Evolution and systematics ................................................. 7
Reproduction, development, and life history ................... 15
Ecology............................................................................... 24
Symbiosis............................................................................ 31
Behavior.............................................................................. 37
Lower metazoans, lesser deuterostomes, and humans..... 44
Conservation ...................................................................... 47

Phylum: PORIFERA
    Class: CALCAREA..................................................... 57
    Class: HEXACTINELLIDA ..................................... 67
    Class: DEMOSPONGIAE......................................... 77

Phylum: PLACOZOA....................................................... 87

Phylum: MONOBLASTOZOA ....................................... 91

Phylum: RHOMBOZOA.................................................. 93

Phylum: ORTHONECTIDA .......................................... 99

Phylum: CNIDARIA
    Class: ANTHOZOA................................................... 103
    Class: HYDROZOA................................................... 123
    Class: CUBOZOA ...................................................... 147
    Class: SCYPHOZOA ................................................. 153

Phylum: CTENOPHORA................................................ 169

Phylum: PLATYHELMINTHES
    Class: ACOELA.......................................................... 179
    Class: TURBELLARIA.............................................. 185
    Class: TREMATODA................................................ 197
    Class: MONOGENEA............................................... 213
    Class: CESTODA....................................................... 225

Phylum: NEMERTEA
    Class: ANOPLA.......................................................... 245
    Class: ENOPLA.......................................................... 253

Phylum: ROTIFERA......................................................... 259

Phylum: GASTROTRICHA ............................................ 269

Phylum: KINORHYNCHA ............................................. 275

Phylum: NEMATODA
    Class: ADENOPHOREA........................................... 283
    Class: SECERNENTEA............................................ 293

Phylum: NEMATOMORPHA......................................... 305

Phylum: ACANTHOCEPHALA..................................... 311

Phylum: ENTOPROCTA ................................................ 319

Phylum: MICROGNATHOZOA.................................... 327

Phylum: GNATHOSTOMULIDA ................................. 331

Phylum: PRIAPULIDA..................................................... 337

Phylum: LORICIFERA..................................................... 343

Phylum: CYCLIOPHORA ............................................... 351

Phylum: ECHINODERMATA
    Class: CRINOIDEA................................................... 355
    Class: ASTEROIDEA ................................................ 367
    Class: CONCENTRICYCLOIDEA......................... 381
    Class: OPHIUROIDEA............................................. 387
    Class: ECHINOIDEA................................................ 401
    Class: HOLOTHUROIDEA..................................... 417

Phylum: CHAETOGNATHA ......................................... 433

Phylum: HEMICHORDATA .......................................... 443

Phylum: CHORDATA
  Subphylum: UROCHORDATA
    Class: ASCIDIACEA.................................................. 451
    Class: THALIACEA................................................... 467
    Class: APPENDICULARIA ...................................... 473
    Class: SORBERACEA................................................ 479
  Subphylum: CEPHALOCHORDATA
    Class: CEPHALOCHORDATA ............................... 485

For further reading............................................................ 495
Organizations ..................................................................... 498
Contributors to the first edition ....................................... 499
Glossary.............................................................................. 506
Lower metazoans and lesser deuterostomes order list...................................... 512
Geologic time scale............................................................ 514
Index ................................................................................... 515