FIGURE 9 in Deep-sea serpulids (Annelida: Polychaeta) in tetragonal tubes: on a tube convergence path from the Mesozoic to Recent

FIGURE 9. Tube ultrastructures of Bathyvermilia gregrousei sp. nov. A–D and F–J: PIN 5485/13, A—general view of longitudinal wall section, B—enlarged outer wall part consisting of elongated crystals positioned parallel to direction of tube growth, C—enlarged middle wall part consisting of elongated loosely oriented crystals, D—details of inner wall part with clearly visible cavities and thin inner layer, F—transverse section, G—enlarged edge showing inner layer with cavities, Hdetails of outer wall part, I—middle part of tube wall with unoriented crystals, J—details of wall inner part, including cavities and innermost layer. E: PIN 5485/14, empty tube of (?)Bathyvermilia gregrousei sp. nov. identified by ultrastructure only, longitudinal section of anterior tube end showing diagnostic inner layer with cavities. Arrows indicate direction of tube growth. Abbreviations: g. l.—growth lamellae, o. s.—outer tube surface.