Murrindisyllis San Martín, Aguado & Murray 2007

Original diagnosis by San Martín et al. (2007: 40): "Body long, slender to filiform, with up to about 50–60 chaetigers; most specimens incomplete. Body surface with transverse ciliary bands. Prostomium triangular in shape, with two eyes and 3 smooth antennae. Median antenna very long, coiled, inserted on posterior part of prostomium; lateral antennae much shorter, originating on anterior margin, latero-ventrally situated. Palps completely fused to each other and also fused to prostomium. Two pairs of tentacular cirri similar in length to lateral antennae. Antennae, tentacular and dorsal cirri smooth. Anterior segments (about 9–10) fused in single piece, including proventricular segments; midbody segments forming groups of 2 or 3 fused chaetigers. Dorsal cirri anteriorly short, longer after proventricle, very long on midbody, presenting differences in length but without a fixed alternation pattern. Dorsal cirri of midbody ending in wide expansion with five longitudinal rows of internal vacuolated cells forming a ‘‘hand-like’’ structure, and joined by a membrane (‘‘webbed’’), distal end with five rounded shallow projections. Dorsal cirri of posterior parapodia short, papilliform. Ventral cirri digitiform, not projecting beyond parapodia, inserted basally. Parapodia with distal papilla. Anterior and midbody parapodia with compound, heterogomph chaetae. Blades and shafts partially fused towards posterior part of body. Posterior parapodia with simple chaetae resulting from fusion of blade with shaft. Solitary capillary dorsal and ventral chaetae on posterior parapodia. Pharynx short, unarmed, with 10 terminal papillae. Proventricle very long, about 5–7 segments. Pygidium with two long anal cirri."