viii CONTENTS 



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PondSnails(Viviparidce) — Valvatidce — Ampullariidce — Cyclophoridce — Cyclostomatidce—^ 

 Truncatellidce — Hipponychidai — Calyptrceidce — Xenophoridce — Naticidce — Section Pteno^ 

 ylossa— Violet Snails (lanthinidce)— Wentle-Traps (Scalariidce) — Section Gymnoglossa — I 

 Eulimidce — Pyramidellidce — Suborder Heteropoda — Pterotracheidce — Atlantidce — Sub- 

 order Scutibranchiata — Section Rhipidoglossa — Helicenidce — Neritidce — Turbinidce — 

 Trochidce — Delphinulidce— Ormers {Haliotidoz) — Pleurotomariidce — Keyhole Limpets 

 (Fissurellidce)— Section Docoglossa — Acmceidce — Limpets (Patellida?) — Lepetidce,. . 341 



CHAPTER XL — Molluscs, — concluded. Classes Amphineura, Scaphopoda, and Pelecypoda. 



The Chiton Group (Class Amphineura) — Chitons (Order Polyplacophora) — Order Aplacophora 

 — The Tooth-Shells (Class Scaphopoda) — The Bivalves (Class Pelecypoda)— Order Proto- 

 branchiata — Order Filibranchiata — Order Pseudolarnellibranchiata — Order Eulamelli- 

 branchiata— Suborder Submytilacea — Suborder Tellinacea — Suborder Veneracea — Sub- 

 order Cardiacea — Suborder Myacea — Suborder Pholadacea — Suborder Anatinacea 

 — Order Septibranchiata, . . . . . . . ., : . 398 



CHAPTER XII. — Moss- Animals and Lamp-Shells, — Subkingdom Molluscoidea. 



The Moss-Animals (Class Bryozoa) — Characteristics of the Group — Subclass Ectoprocta — Order 

 Phylactolmmata— Order Gymnolmmata — Subclass Entoprocta — The Lamp-Shells (Class 

 Brachiopoda) and their Characteristics — Hinged Group (Order Testicardines) — Hinge- 

 less Group (Order Ecardines), . . . . . . . 419 



CHAPTER XIII. -The Worm-Like Animals,— Subkingdom Vermes. 



Characteristics of Worms — Bristle- Worms, or Annelids (Class Annelida) — Their Distinctive 

 Features — Many-Bristled Group (Order Polychaita) — Sparsely-Bristled Group (Order 

 Oligochceta) — The Leeches (Class Hirudinea) — The Gephyrean Worms (Class Gephyrea) 

 The AVheel- Animalcules (Class Rotifera) — The Thread-Worms, or Round-Worms (Class 

 Nematohelminthes) — Spiny-Headed Thread-Worms (Order Acanthocephala) — Typical 

 Thread-Worms (Order Nematoidea) — Arrow-Worms (Order Chcetognatha) — The Nemer- 

 tine Worms (Class Nemertinea) — The Flat- Worms (Class Platyhelminthes) — Tape- 

 Worms (Order Cestoda) — Trematode Worms (Order Trematoda) — Many-Suckered Group 

 (Suborder Polystomeai) — Two-Suckered Group (Suborder Distomew) — Turbellarian 

 Worms (Order Turbellaria) — Suborder Rhabdocoela — Suborder Dendrocala — Group of 

 Uncertain Position (Orthonectidos and Dicyemidce), ..... 432 



CHAPTER XIV. — Jelly-Fish, Corals, and Sea- Anemones, — Subkingdom Cailenterata. 



Distinctive Features of Ccelenterates — The Ctenophores (Group Ctenophora) — Stinging Series 

 (Group Cnidaria)— The Jelly-Fish and their Allies (Class Polypomedusas) — Order 

 Siphonophora— Order Hydromedusa — Fresh-water Forms — Order Scyphomedusm — The 

 Sea- Anemones and Corals (Class Anthozoa) — Six-Rayed Polyps (Order Hexactinia)— 

 Horny Corals (A ntipatharia) — Eight-Rayed Polyps (Order Octactinia) — Coral-Reefs and 

 Islands, . . . . .'■■•. . , . 474 



CHAPTER XV.— The Sponges— Subkingdom Porifera. 



Distinctive Characters of the Group — Reproduction— The Calcareous Sponges (Class Calcarea) 

 — Six-Rayed, or Glass-Sponges (Class He;cactinellida) — The Common Sponges (Class 

 Demospongia) — Four-Rayed Sponges (Order Tetractinellida) — The Fleshy Sponges 

 (Order Carnosa) — Single-Rayed Sponges (Order Monaxonida) — Fresh-Water Sponges — 

 Horny Sponges (Order Ceratosa), . . . . - . . . •. f>26 



