Plakortis zyggompha (de Laubenfels, 1934)

Synonymy and references. Plakortis zyggompha (de Laubenfels, 1934): Diaz & van Soest (1994): 104.

Material. USNM 1228902, 1228903, 1228904, Carrie Bow Cay, back reef near reef crest, underside of Acropora palmata coral rubble, 0.3 m; K. Ruetzler col. 23 Apr 1974. USNM 1228905, Carrie Bow Cay south back reef, lower surface of coral rock, 1m; K. Ruetzler col. 13 Mar 0 9.

External morphology. Small crusts or cushions (to 5 mm thick), covering up to 5 cm 2. Small (1 mm) oscula, located on the thicker lobes. Smooth surface, firm-elastic consistency. Color cream to olive, brown, and blackish brown.

Skeleton structure. Spicules densely packed throughout.

Spicules. Diods, small but of considerable size range: 18–138 x 3–8 (85 x 5) Μm; triods, common: 38–110 (55) Μm.

Ecology. Under platy coral rubble in the back reef, 0.3–1 m, reported from below 100 m.

Distribution. Gulf of Mexico and Caribbean.