1 Gastropod anatomy. Side view of Berthella plumula.

1 Gastropod anatomy.  Side view of  Berthella plumula.

1: underside of mantle. 2: genital opening. 3: rhinophore. 4: oral veil. 5: foot. 6: gill.
Much anatomy can be observed on molluscs lacking external shells.
Full article of Anatomy of marine gastropods without dissection. below image 2 2 Gastropod anatomy. Transparent sole of Janolus hyalinus on undersurface of water.