notes 320 321 322 rhamphotheca en.wikipedia.org → Calcareous Sponges - Plate 5 from Ernst Haeckel ’s Kunstformen der Natur “Calcispongiae”, now called Calcarea, is a class of about 400 marine sponges that are found mostly in shallow tropical waters worldwide. Calcareous sponges vary from radially symmetrical vase-shaped body types to colonies