Ceratocephale abyssorum

Prostomium with anterior margin indented. Longest tentacular cirri extend back to chaetiger 1–2. Maxillary ring of pharynx without paragnaths. Oral ring papillae present; solitary; 6–8 papillae present in total. Area V papillae present; 0–2 papillae; VI papillae absent; VII-VIII papillae present. Comprising a single row. 0–6 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 (as ridges, in larger specimens on anterior segments). Prechaetal notopodial lobe present. Dorsal cirrus length about 1.5–2 times ventral notopodial ligule at chaetiger 10-20. Neuropodial postchaetal lobe absent. Ventral neuropodial ligule on posterior chaetigers reduced, up to half length of acicular neuropodial ligule. Ventral cirri paired. Commencing chaetiger 1. Notopodial homogomph spinigers present; sesquigomph spinigers present. Notopodial homogomph falcigers absent. Neuropodial dorsal fascicle fused falcigers absent

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.

Distinguished from other Ceratocephale spp by having Basal cirrophore of dorsal cirrus; barely expanded more cylindrical throughout
and transverse dorsal lamellae present

North America, Atlantic coast, or South America, Atlantic coast.