Review of Orbiniidae (Annelida, Sedentaria) from Australia Author Zhadan, Anna text Zootaxa 2020 2020-10-14 4860 4 451 502 journal article 8231 10.11646/zootaxa.4860.4.1 1f5ee6c2-2635-44a8-8469-49319b7a8c62 1175-5326 4414137 876F1085-5296-4340-A951-41420C011917 Protoariciella (?) sp. B Figure 29 Material examined. Western Australia : Fremantle , Arthur Head , off end of South Mole , 32°03’S , 115°44’E , depth 6 m , 25.12.1983 , coll. J.K. Lowry , AM W.43258, 1 specimen on SEM stub . Description. Specimen complete; body length about 2.5 mm, 45 chaetigers, width 270 µm ( Fig. 29A ). Transition from thorax to abdomen indistinct ( Fig. 29A ). Prostomium short, round; two peristomial segments ( Fig. 29B, C ). Branchiae starting from chaetiger 14, first triange-cirriform, then oval; shorter than notopodia ( Fig. 29B, E ). Notopodial postchaetal lobes digitiform; neuropodial lobes similar, but shorter; both lobes becoming shorter in abdomen ( Fig. 29 B–E). Pygidium with four short cirri ( Fig. 29F ). Notochaetae crenulated capillaries in all segments; forked chaetae absent ( Fig. 29 C–E). Neurochaetae crenulated capillaries in thorax, capillaries and one curved serrated hook in abdomen ( Fig. 29 C–E, G–J). FIGURE 29. Protoariciella (?) sp. B, AM W.43258, SEM. A. General dorsal view; B. Anterior end, dorsal view; C. Anterior end, lateral view; D. Anterior parapodia, lateral view; E. Posterior parapodia, lateral view; F. Posterior end, ventro-lateral view; G–J. Abdominal neurochaetae. cc, crenulated capillaries; sh, serrated hook. Remarks. This specimen is similar to Protoariciella (?) sp. A owing to chaetal shape and arrangement, while it differs owing to shorter thicker body and well developed neuropodial lobes. The specimen studied here likely represents a new species; but due to the few poorly preserved specimens and the limited knowledge of the important taxonomic characters in this genus, it is not described as a new species.