Alitta succinea

Prostomium with entire anterior margin. Longest tentacular cirri extend back to chaetiger 5–7. Maxillary ring divided into discrete Areas. Maxillary ring of pharynx with paragnaths; paragnaths arranged in discrete areas. Area I paragnaths present; conical paragnaths present; 1–7 conical paragnaths on Area I; minute rod-like paragnaths in a compact cluster absent; II present; II conical paragnaths present; 9–41 conical paragnaths on Area II; II minute rod-like paragnaths in a compact cluster absent; pectinate paragnaths absent; III present; conical paragnaths present; 13–47 paragnaths; minute rod-like paragnaths in a compact cluster absent; pectinate paragnaths absent; IV present; conical paragnaths present; 15–37 conical paragnaths; minute rod-like paragnaths in a compact cluster absent; smooth bar-like paragnaths absent; pectinate paragnaths absent. Oral ring papillae absent. Oral ring paragnaths present. Area V and VI present as distinct groups. Area V conical paragnaths present, or absent; 0–4 paragnaths (usually 1–3); arranged in a longitudinal line; not arranged in a triangular pattern; VI present; arranged in a roughly circular group; cones present; 4–19 conical paragnaths; smooth bars absent; pectinate rows absent; VII-VIII present; conical paragnaths present; 40–74; Band of conical paragnaths on Areas VII-VIII discontinuous, present only as a ventral band; pectinate paragnaths absent; arranged in one or more irregular lines forming a continuous band; 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 markedly elongate on posterior chaetigers. Markedly broader on posterior chaetigers. Dorsal notopodial ligule not markedly reduced on posterior chaetigers. Prechaetal notopodial lobe present. Dorsal cirrus not terminally attached to dorsal notopodial ligule on posterior chaetigers. Dorsal cirrus length about 1–1.5 times ventral notopodial ligule at chaetiger 10-20. Neuropodial postchaetal lobe present, at least on some anterior chaetigers. Ventral neuropodial ligule on posterior chaetigers similar to length of acicular neuropodial ligule. Ventral cirri single. Notopodial homogomph spinigers present; sesquigomph spinigers absent. Notopodial homogomph falcigers absent. Neuropodial dorsal fascicle fused falcigers absent. Notoaciculae present on chaetigers 1 & 2 and thus moved from Alitta back to Neanthes (correction following Sato, 2013)

Distinguished from other Australian Nereididae by: Dorsal notopodial ligule breadth on posterior chaetigers markedly broader on posterior chaetigers; Areas II, III and IV paragnaths not in regular comb-like rows (but may be arranged in irregular rows)
Areas II, III and IV paragnaths Not in regular comb-like rows (but may be arranged in irregular rows).

Australia (introduced), northern Europe, North America (Atlantic coast)