COMPARISONS. 



With two columns, as before, for Clam, Oyster, and 

 Squid, answer the folio wing questions: 



(1) Is the body bilaterally symmetrical? 



(2) Is there a mantle? 



(3) Are gills present? 



(4) Is there a foot? 



(5) Do you find cerebral, pedal, and visceral ganglia? 



(6) Does the alimentary canal pass through the nervous 

 system? 



Read the whole section on the Mollusca (pp. 113 to 

 214). 



109 



