vi CONTENTS 



PAGE 



Trochithr — Delphin ulidce— Ormers (Ualiotidoe) — Pleurotomariidce — Keyhole Limpets 

 (Fissurellidce)— Section Docoglossa — Acmceidce — Limpets (Patellidce) — Lepetidce, . • 341 



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



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

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

 branchiata — Order Filibranchiata — Order Pseudolamellibranchiata — 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 

 Phylactolcemata — Order Gymnolcemata — 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 Polychceta) — Sparsely-Bristled Group (Order 

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

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

 Nematohdminthcs) — 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 Polystomece) — Two-Suckered Group (Suborder Distomece)- — Turbellarian 

 Worms (Order Turbellaria) — Suborder Rhabdoccela — Suborder Dendrocada — Group of 

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



CHAPTER XIY. — Jelly-Fish, Corals, and Sea-Anemones, — Subkingdom Ccelenteruta. 



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

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

 Siphonophora — Order Hydromedusce — Fresh-water Forms — Order Scyphomedusce — The 

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

 Horny Corals (Antipatharia) — Eight-Rayed Polyps (Order Oetactinia) — 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 Hexactinellida) — The Common Sponges (Class 

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

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

 Horny Sponges (Order Geratosa), ...... . 526 



CHAPTER XVI. — The Lowest Animals, — Subkingdom Protozoa. 



Characteristics of Protozoans— The Root-Footed Group (Class Rhizopoda)— The Amsebas 

 (Order Lobosa) — Order Foraminifera — Sun- Animalcules (Order Heliozoa) — Order 

 Eadiolaria The Infusorial Animalcules (Class Infusoria)— Flagellated Infusorians 

 (Order Flagellata) Ciliated Infusorians (Order Ciliata), .... 550 



Index to Sixth Volume, comprising Sections XL and XII. .... 569 



