Nulariidae, Syringoporidae, B, Diagrammatic longitudinal section Tubi oridae and Favosi- of a corallite, showing two platforms, t i dae In the first-named p,and simple and cup-shaped tabulae, t.
In the Tubiporidae the spicules of the proximal part of the body-wall are fused together to form a firm tube, the corallite, into which the distal part of the zooid can be retracted.
The corallites are connected at intervals by horizontal platforms containing solenia, and at the level of each platform the cavity of the corallite is divided by a transverse calcareous partition, either flat or cup-shaped, called a tabula.
- Portion of a colony of Coral- of the corallite, give it the lium rubrum, showing expanded and appearance of a madreporcontracted zooids.
Thus the architecture of the Helioporid colony differs entirely from such forms as Tubipora or Favosites, in which each corallite has its own distinct and proper wall.