Early growth of post-oral arms and evagination of coelomic sacs from the archenteron.

Early with two arms.

Ossicles of the lantern of Aristotle in formation at the oral region.

Oral region.

Larva with six arms.

Pluteus larva.

Larva with six arms.

Early with two arms.

Larva with four pairs of arms.

Stage with four pairs of arms.

Stage with three pairs of arms.

Anus of the larva.

Oral region.

Aboral surface (opposite to mouth).

Remnants of the larval skeleton in the aboral region of the juvenile.

Skeleton and digestive cavity.

Early eight-arm stage.

Growth of antero-lateral pair of arms (2nd pair).

Microalgae in the larval gut.

Embryos during early cellular divisions.

Early eight-arm stage.

Structure in the anal region.