Eurypon gracilis Bertolino, Calcinai & Pansini

All the specimens were encrusting on the surface of coralligenous blocks, covering surfaces up to 2 cm2. The sponge surface is corrugated, hispid. The colour in life is brick red (Fig. 9A). Skeleton. The skeleton consists of a basal layer of spongin in which the spicules are vertically positioned, perpendicular to the substrate. Both the categories of acanthostyles are close one another (Fig. 9C) with the heads embedded in the basal spongin layer. Styles and oxeas–with the same vertical arrangement–are grouped in bundles which are faintly echinated, in their lower part, by the smaller acanthostyles (Fig. 9B). Oxeas are positioned in the basal part of the bundles. The styles protrude trough the sponge surface making it hispid. Spicules. Long styles to tylostyles, curved or flexuous (Fig. 9D), 788 (1101) 1280 × 5 (6.8) 10 µm; oxeas thin, almost straight or with a slight curvature (Fig. 9E), 365 (483) 650 × 2.5 µm; acanthostyles without head and uniformly spined, in two sizes categories: I) large acanthostyles, straight or slightly curved with rather small spines (Fig. 9F), 200 (253) 320 × 5 (6) 7.7 µm; II) small acanthostyles straight, with spines more robust than in the previous category (Fig. 9G), 90 (119.5) 160 × 2.5 (3.8) 5 µm.

So far known only from the Ligurian Sea.