Ceratocephale
Prostomium with anterior margin indented. Maxillary ring of pharynx without paragnaths. Oral ring papillae present; solitary. Area V papillae present; 3 papillae (close togetehr); VI papillae absent; VII-VIII papillae present. Comprising a single row. 7 papillae. Oral ring paragnaths absent. In Ceratocephale spp, Area V and VI contain up to 3 papillae in total; these are here interpreted as all occurring in Area V, with VI=0,0. Transverse dorsal lamellae present (in all species except C.abyssorum); commencing chaetiger 4–10. Prechaetal notopodial lobe present. Neuropodial postchaetal lobe present, at least on some anterior chaetigers. Ventral neuropodial ligule on posterior chaetigers reduced, up to half length of acicular neuropodial ligule. Ventral cirri paired. Commencing chaetiger 1–3. Notopodial homogomph spinigers present; sesquigomph spinigers present, or absent. Notopodial homogomph falcigers absent. Neuropodial dorsal fascicle fused falcigers absent.
Distinguished from other Nereididae genera by: Transverse dorsal lamellae Present; Area VI papillae Absent (Wilson, RS, Bakken, T & Glasby, CJ 20014. Nereididae (Polychaeta)–A DELTA database of genera, and Australian species. 2nd edition. 1st edition previously published In RS Wilson, PA Hutchings & CJ Glasby (eds) Polychaetes: An Interactive Identification Guide. CSIRO Publishing, Melbourne.)
The following characters states are implicit in all Nereididae species unless indicated otherwise in the description below:
Maxillary ring of pharynx without papillae. Maxillary ring divided into discrete Areas. Maxillary ring of pharynx with paragnaths; paragnaths arranged in discrete areas; Areas II, III and IV paragnaths not in regular comb-like rows (but may be arranged in irregular rows). Area I minute rod-like paragnaths in a compact cluster absent; II minute rod-like paragnaths in a compact cluster absent; pectinate paragnaths absent; minute rod-like paragnaths in a compact cluster absent; pectinate paragnaths absent; minute rod-like paragnaths in a compact cluster absent; smooth bar-like paragnaths absent; pectinate paragnaths absent. Oral ring papillae absent. Ring of oral ring paragnaths present as irregular rows, not crown-shaped. Smooth bars absent; pectinate rows absent; pectinate paragnaths absent; arranged in one or more irregular lines forming a continuous band; Area VII-VIII paragnaths similar in size, or irregular mix of large and small paragnaths in a single band. Transverse dorsal lamellae absent.
Dorsal notopodial ligule not markedly elongate on posterior chaetigers. Not markedly broader on posterior chaetigers.
Ventral cirri single.