Figure 2. A–B in Ultrastructure and mineral composition of serpulid tubes (Polychaeta, Annelida)

Figure 2. A–B, Pseudovermilia madracicola, spherulitic irregularly oriented prismatic structure. A, cross section. B, longitudinal section. C–E, Crucigera zygophora. C, transition between irregularly oriented prismatic and spherulitic irregularly oriented prismatic structure in cross section. D, spherulitic irregularly oriented prismatic structure, cross section. E, spherulitic irregularly oriented prismatic structure, longitudinal section. F, Spiraserpula caribensis, spherulitic irregularly oriented prismatic structure. All sections were polished and treated with 1% acetic acid for 2 min. Abbreviations: IOP, irregularly oriented prismatic structure; SIOP, spherulitic irregularly oriented prismatic structure.