MOLLUSCA. 231 



6. What is the nature and what the source of the fol- 

 lowing: Sepia? Cuttle-fishbone? Tyrian dye? 



7. Write of the pearl industry. Location and methods. 



8. The manufacture of pearl buttons. 



9. The color of shells in mollusks. ' Location. 



10. A report on all the mollusks found in your locality; 

 their habits, distribution, etc. 



11. Some special spring studies on the habits and 

 behavior of some members of this group. 



