| Clathrinoid cormus of regularly anastomosed tubes, forming a more or less equally thick (around 350 um in diameter) wall around a large pseudatrium (about as wide as thickness of the wall). The tubes are lined by choanoderm and open into the pseudatrium, which likewise is lined by choanocytes. The pseudatrium opens to at least two complete wide oscula (specimen is incomplete on one side). The surface appears smooth because of triactines, which are lying tangentially to the sponge surface. |
| white |
| Two complete osula as openings of the pseudatrium. |
| smooth by tangential triactines. |
| The anastomosed tubes and the wall of pseudatrium are supported by tetractines, whose basal system lies tangentially to the tube wall and the apical actine protruding into the lumen of the tube or the pseudatrium, respectively. The apical rays of the tetractines are spined, and spines are parallel to the basal system of the tetractines. |
| Triactines lying in tangentially to the sponge surface. |
| Triactines and tetractines with spined apical rays |
