Laonice papillibranchiae Ward, 1981

Prostomium blunt, anteriorly truncate or rounded, anterior margin with entire anterior margin or bifid, with anterior margin indented. Lateral horns absent. Caruncle present, continuing back to chaetiger 1. Occipital antenna present (long, thin). Nuchal organ short, at most one segment long. Eyes present; 2 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 absent from many median and posterior chaetigers (absent from posterior third). Dorsal branchiae free and separate from notopodial lamellae throughout, modified on some or all chaetigers, typically pinnate or flabellate. Modified dorsal branchiae with pinnules or papillae on one side giving them appearance similar to pinnate branchiae of Prionospio. 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 present; first dorsal crest present on chaetiger 17 (long dorsal ridges). Ventral crests absent. Chaetiger 1 notopodium present. Neuropodial lobe of chaetiger 2 rounded, approximately symmetrical. Neuropodial lobes of posterior chaetigers a single lobe. Interparapodial pouches present. Interparapodial pouches on chaetigers 12 (to within a few setigers of the end of body). Chaetigers 2–4 similar, not strongly differentiated. Chaetiger 5 unmodified, similar to subsequent chaetigers. Posterior modified notochaetae absent. Neurochaetae of chaetiger 1 simple capillaries similar to those of subsequent chaetigers. Neuropodial spines absent. Embedded bunches of notopodial needle chaetae absent. Pygidium consisting of 3 large lobes with 4 long, thin dorso-lateral cirri, easily lost.

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:
Ward, L.A. 1981. Spionidae (Polychaeta: Annelida) from Hawaii, with descriptions of five new species. Proceedings of the Biological Society of Washington 94: 713-730.