Fig. 13
Pachyzoon pulvinaris sp. nov. Histological details. a Basal colony side with non-kenozooidal cystid appendages, unrestricted in contact with the main body cavity (arrow). Note the thick cuticle of the appendages following the remaining cuticle. b Basal colony area showing multiple layers of zooidal generations from basal to frontal, with degenerated polypides. c Apertural papilla with cross-section of vestibular wall. d Zooid with several large oocytes. Abbreviations: bb brown body, bbw basal body wall, cy cystid appendage, fbw frontal body wall, l lophophore, oz old zooid, v vestibulum, vw vestibular wall