Buccal mass and radular apparatus are present, but ctenidia are entirely wanting.
P, foot; o, mouth (at the other end of the foot is seen the anus raised on a papilla); kr, oral fringe; br, the numerous ctenidia (branchial plumes); spreading beyond mentum which is porcellaneous, quite compact, and entirely covered by the tegmentum.
Br, Ctenidia (branchial plumes).
The body chamber (reduced pallial chamber, conis worm-like and cylindritaining the concealed_pair of ctenidia) cal, the posterior half a to the right.
The characteristic organs of Mollusca are the mantle and shell, the foot, the ctenidia and the radula, of which all but the last are external.