Radiolaria

Haeckel says: The central capsule and the enclosed parts of the skeleton. The protoplasm is radially striped. The central nucleus (red) sends out numerous radial apophyses, which are protruded through the pores of the medullary shell.

Haeckel says, "Medullary shell."

Haeckel says, "A single radial spine."

Haeckel says, "A part of the two outer shells is removed."