GASTEROPODA 



8. Aplysia. Foot with lateral flaps (epipodia) projecting dorsalwards ; mantle with shell in nearly 

 closed sac ; single ctenidium ; spermatic groove leading from genital aperture to penis on head. 



9. Eolis. Dorsal cerata : without ctenidia and mantle folds. 



10. Doris. Dorsal view. Anus median and posterior; anal branchiag. 



68 



