How To Study Living Animals


5. MOLLUSCA: REVIEW AND LIBRARY EXERCISE
Characteristics herunterladen.

1. What are the general characteristics of mollusks?

2. Name the principal classes and give the characteristics of each.

Morphology herunterladen.

1. What is peculiar about the structure of a clam’s heart? What is its position? Contrast with the heart of a crayfish.

2. Make cross-sectional diagrams to show the arrangement of parts in a clam: (a) in the region of the umbone; (b) in the region just in front of the posterior muscle; (c) in the region of the anterior muscle microsoft office kostenlos downloaden vollversion deutsch chip.

3. Describe the various types of eyes found in mollusks, and their location.

4. Describe the tongue or lingual ribbon of the snail, and its use.

5. What is the operculum of snails? its use?

Physiology.

1. Describe the circulation of water through the siphons and mantle cavity of a clam. How is it caused? What three uses has it?

2. What are the principal facts about the development of fresh-water clams?

3. Describe the circulation of blood in a clam.

4. What various methods of locomotion are found among mollusca?

Economics.

Write a short account of the following:—

1. Oyster culture.

2. Typhoid-fever and oysters.

3. Clams, scallops, and other edible shellfish.

4. Pearls and pearl fisheries.

5. Fresh-water clams and the button industry.

6. Sepia, Tyrian dye, etc.

7. Harmful and useful mollusks.

8. The work of U. S. Fish Commission in propagating clams.

Natural history.

1. Give the class, habitat, and some important fact about each of the following: Pectens; wing shells; Tridacna gigas; abalones; limpets; oyster drill; periwinkle; mussel; cuttle fish; octopus; nautilus; argonaut.