| That is, sperm are created, concentrated and sent out the excurrent openings, sometimes in masses so dense that the sponges appear to be smoking. |
| Trabs rise upward parallel to or slightly oblique to excurrent canals and form regular ladder-like structure. |
| The opercular is more often made up of one or more immobile bones which channel the excurrent from gills with individual covers. |
| Very similar structures, observed on living sponges of the genus Astrosclera, represent excurrent canal systems. |
| Most conifers and a few hardwoods, such as sweetgum and tuliptree, have excurrent forms. |
| Colonies with greater than 12 individuals across, may have fixed water excurrent chimneys reflected in the skeleton. |
