Main Characteristics of MolluscaBasic body plan: bilateral symmetry, unsegmented and coelomate, but the coelom is small and reduced to a small cavity around the heart.Ventral body is specialized as a muscular foot for creeping locomotion;Dorsal body wall forms a mantle, which encloses the mantle cavity containing gills (aquatic forms) or lungs (terrestrial forms);Some species have a calcareous shell, which protects the soft body and internalorgans; the shell is lost in more derived forms.The mantle cavity is small which only occupies a little space in the visceral mass.
49. What is the larva of Xiphosura called?
50. What is the larva of Cirripedia called?