Spicules image: a) Tylostyles; b) ends of tylostyles; c) spirasters. Sample from the Bahamas. Photos and image composite by Angela Marulanda (U. Javeriana, Cali, Colombia).
Tissue image: a) Perpendicular section (surface above) of an encrusting specimen, over the substratum (upper) and over a subdermal space (lower); b) enlargement. Sample from the Bahamas.