Paratetilla arcifera from Indonesia RMNH.POR.11266. A in situ photograph. B preserved specimen showing the porocalices (scale bar 1 cm) C skeleton D spicules E, F oxea, end detail G, H natriaene, cladus. and rhabd end I-L anatriaene, different types M Protriaene N-Q different calthrops R thin microxea, detail S thin microxeas, full length T sigmaspires. Scale bars: 1 cm (B), 500 μm (C,D), 100 μm E,F); 40 μm (G,H); 20 μm (I–M); 200 μm (N–Q); 5 μm (R, T); 50 μm (S).