Prostomium blunt, anteriorly truncate or rounded, anterior margin with entire anterior margin or bifid, with anterior margin indented (weakly). Lateral horns absent. Caruncle present, continuing back to chaetiger 3 (posterior margin), free from dorsum. Occipital antenna absent. Nuchal organ short, at most one segment long. Eyes present; 4 eyes. Palps simple, lacking basal sheath. Dorsal ridge connecting bases of branchiae on chaetiger 1 absent. Prominent dorsal collar on setiger 2 absent. Dorsal branchiae present, first present on chaetiger 2. Dorsal branchiae continue to near posterior end of body (absent for at most posterior one-third of body). Dorsal branchiae interrupted, (absent) on chaetigers 5. Dorsal branchiae free and separate from notopodial lamellae throughout, all simple. First branchiae without process at base on anterior face. Accessory branchiae arising from posterior part of notopodium absent. Ventral branchiae absent. Chaetiger 3 without filament at base of branchiae. Dorsal crests absent. Ventral crests absent. Chaetiger 1 notopodium present. Chaetiger 1 notochaetae present. Neuropodial lobe of chaetiger 2 rounded, approximately symmetrical. Neuropodial lobes of posterior chaetigers a single lobe. Interparapodial pouches absent. Chaetigers 2–4 similar, not strongly differentiated. Chaetiger 5 highly modified, enlarged and with specialised chaetae, with two types of modified spine present; simple, curved or subdistally inflated spines present; spines with subdistal tooth or flange absent; pennoned spines, with strongly asymmetrical tips absent; spines with flattened or cup-shaped tip present; spines with terminal or subterminal bristles present; companion chaetae absent. Posterior modified notochaetae absent. Notopodial hooded hooks absent. Neurochaetae of chaetiger 1 simple capillaries similar to those of subsequent chaetigers. Neuropodial hooded hooks present, first present on chaetiger 7. Neuropodial hooded hooks with accessory tooth or teeth above the main fang, 1 accessory tooth (bidentate), secondary tooth and main fang forming a prominent angle, about 90º or more. Shaft of neuropodial hooded hooks of constant thickness, lacking a constriction. Neuropodial sabre chaetae absent. Neuropodial spines absent. Embedded bunches of notopodial needle chaetae absent. Pygidium with 4 lobes, dorsal pair smaller than ventral.
Description generated from: Wilson, RS & McDiarmid, H 2013. Spionidae (Polychaeta)- A DELTA database of genera, and Australian species. Version 2; originally published as In RS Wilson, PA Hutchings & CJ Glasby (eds) Polychaetes: An Interactive Identification Guide. CSIRO Publishing, Melbourne.
Additional references:
Blake, JA and Kudenov, JD. 1978. The Spionidae (Polychaeta) from southeastern Australia and adjacent areas with a revision of the genera. Memoirs of the National Museum of Victoria 39, 171-280.
