8 CONTENTS. 



Order of Gasteropoda Cyclobranchiata. — Patella — Chiton. 



Order of Gasteropoda Inferobranchiata. 



Order of Gasteropoda Tectibranchiata. — Plcurobranchus — Aplysia — Dola- 



bella—Bullea— Bulla. 

 Order of Gasteropoda Nudibranchiata. — Eolidia — Glaucus. 

 Order of Gasteropoda Heteropoda. — Carinaria. 

 Class of Mollusca Pteropoda. — Clio borealis. 



LESSON V. 



Class of Mollusca Acephala, or Lainellibranchiata. — Organization — Classi- 

 fication. 



Family of Ostracea. — Classification — Oysters — Gryphaea — Pecten — Lima — 

 Malleus — Anomia — Spondylus — Perna — Etheria — Avicula — Pearls — 

 Pearl Fishery —Pinna — Area — Pectunculus — Trigonia. 



Family of Mytilacea, — Mussels, (Mytilus) — Modiolus — Anodonta — Unio. 



Family of Chamacea. — Tridacna — Cliama — Isocardia. 



LESSON VI. 



Family of Cardiaeea. — Cardium — Donax — Cyclas — Corbis — Tcllina — Ve» 



nus — Petricola — Venerupis — Mactra. 

 Family of Inclusa. — Lutraria — Mya — Byssoniia — Hiatella — Solen — San- 



guinolaria — Pholas — Teredo — Fistulana — Gastrochaena — Clavigella — 



Aspergillum. 

 Class of Mollusca Brachiopoda. — General Characters — Lingula — Terebra- 



tula — Orbicula. 

 Class of Mollusca Tunicata, or Acephala Nuda. — Biphora — Ascidia — Botryl- 



lus — Pyrosoma — Parts of Shells, 



