Erinaceusyllis opisthodentata (Hartmann-Schröder, 1987) n.comb.

Fig. 37A–E

Sphaerosyllis (Sphaerosyllis) erinaceus opisthodentata Hartmann- Schröder, 1987: 40, figs. 13–16; 1990: 54.

Material examined. AUSTRALIA:VICTORIA. 3PARATYPES, HZM P-18882, Warrnambool, coralline algae, G. Hartmann-Schröder, 22 Dec 1975.

Description. Body small, 2.2 mm long, 0.17 mm wide, 26 chaetigers. Small, scattered papillae on dorsum, more abundant on lateral margins of segments, longer on chaetiger 2 (Fig. 37A). Prostomium oval to pentagonal, much wider than long; 4 eyes linearly arranged, on posterior margin of prostomium, and 2 anterior eyespots; antennae with welldeveloped bulbous bases and moderate, slender tips, median antenna slightly shorter than combined length of prostomium and palps, inserted in front of eyes, lateral antennae distinctly smaller and shorter than median antenna, inserted near lateral margins of prostomium, near to eyespots (Fig. 37A). Palps shorter than prostomium, fused along their length, forming a bilobed structure. Peristomium shorter than following segments (Fig. 37A); tentacular cirri similar to lateral antennae but smaller. Dorsal cirri similar in length to median antenna, longer than tentacular cirri, with bulbous bases and short tip, provided with conspicuous internal, dark gland, absent on chaetiger 2 (Fig. 37A), more elongate on midbody segments. Compound chaetae heterogomph, blades provided with short, straight marginal spines, unidentate, distally slightly hooked (Fig. 37C); anterior parapodia each with 6–7 compound chaetae with slight dorsoventral gradation in length, about 26–20 µm long, diminishing in number to 4 on posterior parapodia, similar to those of anterior parapodia but shorter, 22–15 µm long (Fig. 37C). Dorsal simple chaetae from chaetiger 1, unidentate, provided with short marginal spines (Fig. 37B). Ventral simple chaetae from midbody, slender, unidentate, with short marginal spines (Fig. 37D). Acicula solitary, acuminate, with short tip (Fig. 37E). Pharynx proportionally wide, long, through 5–6 segments when retracted, without papillae on opening; pharyngeal tooth rhomboidal, small, located anterior to middle of pharynx (Fig. 37A). Proventricle long and wide, similar in length to pharynx, barrel-shaped, through 5 segments, with about 17–20 muscle cell rows. One paratype is a female carrying eggs dorsally by means of capillary notochaetae.

Distribution. Australia (Victoria, New South Wales).

Habitat. Algae, encrusting coralline algae. Intertidal.