CONTENTS. XI 



Oyster Banks. — Pearl-fishing in Ceylon. — How are Pearls formed? — The 

 Tridaena gigas. — The Teredo navalis.— The Braehiopods. — The Terebratuhe.— 

 The Polyzoa. — The Sea-Mats. — The Escharse. — The Lepraliae. — Bird's Head 



Processes. — The Tunicata. — The Sea-Squirts. — The Chelyosoma. The Botrylli. 



— The Pyrosomes. — The Salpse. — Interesting Points in the Organisation of the 

 Tunicata ........ Page 270 



CHAPTER XVL 



ECHINODERMATA. 



STAR-FISHES, SEA-URCHINS, AND SEA-CDCUMBERS. 



The Star-Fishes —Their Peet or Suckers. — Voracity of the Asterias. — The Eosy 

 Peather-Star. — Brittle and Sand-Stars. — The real Sea-Stars of the British 

 Waters. — The Sea-Urchins. — The Pedicellarise. — The Shell and the Dental Ap- 

 paratus of the Sea-Urchins. — The Sea-Cucumhers. — Their strange Dismember- 

 ments. — Trepang-fishing on the Coast of North Australia. — In the Feejee 

 Islands ...... ... 328 



CHAPTER XVII 



CCELENTEEATA. 

 POLYPS AND JELLY-FISHES. 



Thread-cells or Urticating Organs. — Sertulariae. — Campanulariadae. — Hydrozoie 

 Acalephse. — Medusidae. — Lucemariadse. — Calycophoridae. — The Velella. — The 

 Portuguese Man-of-war. — Anecdote of a Prussian Sailor. — Alternating Fixed 

 and Free- swimming Generations of Hydrozoa.— Actinozoa. — Ctenophora — Their 

 Beautiful Construction. — Sea-anemones. — Dead Man's Toes. — Sea-pens. — Sea- 

 rods. — Red Coral. — Coral Fishery. — Isis hippuris. — Tropical Lithophytes. — 

 History of the Coral Islands — Darwin's Theory of their Formation — The 

 progress of theii Growth above the level of the Sea . . . 345 



CHAPTER XVIII. 



PROTOZOA. 



The Foraminifera.— The Amcebse.— Their "Wonderful Simplicity of Structure.— The 

 Polycystina. — Marine Infusoria.— Sponges. — Their Pores — Fibres and Spiculse — 

 The Common Sponge of Commerce ..... 378 



CHAPTER XIX. 



MARINE PLANTS. 



The Alga?. Zostera marina.— The Ulvse and Enteromorphae. — The Fuci.— The 



Laminarise. — Macrocystis pyrifera. — Description of the Submarine Thickets at 

 Tierra del Fuego.— Nereocystis lutkeana.— The Sargasso Sea.— The Gathering 

 of edible Birds'-nests in the marine Caves of Java.— Agar-Agar.— The Floridese. 

 —The Diatomacea?.— Their importance in the economy of the Seas . 390 



