Polarized light highlights the calcareous skeleton showing the structure of spines, podia, and remnants of the larval skeleton.

Aboral surface (opposite to mouth).

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

Lantern of Aristotle and sphaeridium.

Aboral surface (opposite to mouth).

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

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

Oral region with the lantern of Aristotle in formation.

Oral region.

Aboral surface (opposite to mouth).

Aboral surface (opposite to mouth).

Aboral surface (opposite to mouth).

Detail of teeth in the lantern of Aristotle.

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

Aboral surface.

Spines.

Oral region with the lantern of Aristotle in formation.

Aboral surface (opposite to mouth).

Aboral surface (opposite to mouth).

Aboral surface (opposite to mouth).

Oral region.

Bright spots are spicules being secreted which will originate the post-oral arms.

Lantern of Aristotle in the oral region.

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

Spine on the posterior region.

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

Sphaeridia and spines.