Figures, ectoderm cells and spongoblasts of Cacospongia by George Bidder Three figures, labelled figures 1-3, showing 'Ectoderm cells of Cacospongia, sp.', 'Ectoderm cells at the apex of a conulus of Cacospongia, sp.' and 'Spongoblasts near the apex of a conulus of Cacospongia sp.' Subject: Zoology Prints of these diagrams were published in volume 52 of the Proceedings of the Royal Society alongside the paper 'On the flask-shaped ectoderm and spongoblasts in one of the Keratosa'. 1892