Corallum relatively light; base quite extensive; spreading fan-like; 12.5 cm long, 8.5 cm across, around 7 cm high. Valley open, meandroid, 2.5-3 cm deep; narrow at constriction (1 cm or less) but expanded (2.5 cm) where calicinal centers are present. A single, continuous, very meandering valley can be discerned from where side branches issue forth.

Septa uniformly thin; subequal, roundly arched over wall; primary septa narrow at upper half, then expanded gradually at lower portion to join columellar tangle, the expanded portion not set off with a notch from rest of septa. This expansion exhibited to limited degree by some secondaries. Septa of higher cycles narrow, without expansion. Over calicinal wall, septal edges marked with regularly spaced teeth, termination of ridges across septal surface. On primaries, teeth unequally spaced on narrow upper portion, lost on expanded portion so that latter is entire, except close to bottom of fossa where it produces tall spines similar to those of columella. Septa of higher cycles bear tall spines throughout length, contrasting with those of lower cycles. Septal surfaces spinulous; marked with transverse ridges, which are wider, distant towards calicinal rim, becoming narrower and crowded below.

Costae prominent, corresponding to septa; in some areas thicker and thinner ones alternating. Costal spines abundant very slender, some in clusters, few big blisters among them.

Columella a tangled but relatively lax mass of slender, tall trabeculae.

Remarks:The genus Trachyphyllia is credited with only one species by Vaughan and Wells in their Revision. Crossland (1952) expressed doubt in the correctness of Matthai’s view that there is only one species, saying “There may be even three species ….” From the only species, T. geoffroyi, recognized by most students of this group, the present one described above may be distinguished by its relatively lighter corallum, absence of well- marked paliform lobes which gives the fossa an open appearance; the nature of the dentation on both costae and septa; and the taller less crowded trabeculae composing the columella.

Source:Nemenzo F (1971) Systematic studies on Philippine shallow water scleractinians: VII. Additional forms. Nat. Appli. Sci. Bull. 23:141-209.p pls