CONTENTS ix 



CHAPTER PAGE 



and Autotomy — Fossil Relatives — Ancestry and Relationship to Other 

 Phyla — Economic Importance. 



XI— MoLLUscA 142 



Classification — Class i. Pelecypoda or Lamellibranchiata — Class 2. 

 Amphineura — Class 3. Gastropoda — Class 4. Scaphopoda — Class 5. 

 Cephalopoda — Characteristics — Natural History — Class i. Lamel- 

 libranchiata — Types of Group — Clams and Mussels — Natural History 

 of Lamellibranchiata — Class 2. Gastropoda — Natural History of Gas- 

 tropoda — Class 3. Scaphopoda — Value of Dentalium — Class 4. Ceph- 

 alopoda — Natural History — Pearls — Composition — Source and Value 

 — Culture Pearls — Coated Glass Substitutes for Pearls — References — 

 General Consideration of the Mollusca— Distribution— Physiology- 

 Nervous System — Regeneration — Growth Studies of the iVIollusca — 

 Embryology — Care of the Young — Fossil Relatives — Ancestry and 

 Relationship to Other Phyla — Economic Importance of Mollusca — 

 Positive — Negative. 



XII — Arthropoda '°3 



Classification— Characteristics— Natural History— Class i. Crustacea 

 — Types— Crayfish and Lobster— Class 2. Onychophora— Class 3. 

 Myriapoda— Class 4. Insecta (Hexapoda)— Type of Group— Lubber 

 Grasshopper— Characteristics of More Important Races of Honey Bees 

 —Methods of Insect Control— Class 5. Arachnida— Bibliography on 

 Venomous Spiders— Other Classes— Xiphosura—Pycnogonida-Tardi- 

 grada— General Consideration of the Arthropoda— Characteristics and 

 Distribution— Integument and Musculature— Digestive System— 

 Respiration— Circulatory System— Excretion— Nervous System and 

 Sense Organs — Fossil Relatives. 



XIII— Chordata ^°9 



Classification— Sub-phylum Hemichorda (Enteropneusta)— Sub-phy- 

 lum Urochorda (Tunicata)— Sub-phylum Cephalochorda (Adelochorda 

 or Acrania)— Sub-phylum Vertebrata or Craniata— Class i. Cyclo- 

 stomata— Class 2. Pisces— Class 3. Amphibia— Class 4. Reptilia— 

 Class 5. Aves— Class 6. Mammalia— Invertebrates versus Verte- 

 brates— Sub-phylum Hemichorda (Enteropneusta)— Type of Group— 

 Balanoglossus— Sub-phylum Urochorda (Tunicata)— Sub-phylum 

 Cephalochorda (Adelochorda or Acrania)— Type of Group— Amphi- 

 oxus— Theories of the Origin of Vertebrates— Amphioxus— Arthropod 

 —Annelid— Nemertean— Bibliography. 



221 



XIV — Cyclostomata 



Craniata— Classification— Characteristics— Cyclostomata— Character- 

 istics — Myxinoids — Petromyzontia. 



XV— Pisces ^^"^ 



Classification— Characteristics— Natural History— Sub-class Elasmo- 

 branchii— Type of Group— The Skate— Sub-class Teleostomi— Order I. 



