Polycirrus hesslei Monro, 1930

Glasby, Christopher J. & Hutchings, Pat, 2014, Revision of the taxonomy of Polycirrus Grube, 1850 (Annelida: Terebellida: Polycirridae), Zootaxa 3877 (1), pp. 1-117 : 60

Polycirrus hesslei Monro, 1930

Fig. 30a–e

Polycirrus hesslei Monro, 1930:195–197 .

Type locality. Falkland Islands .

Material examined. SYNTYPES: BMNH ZK 1930.10.8.2911-15, St.WS 73, 51º02ʹ S, 58º5ʹ W to 51º00ʹ S, 58º53ʹ W, north of East Falkland , trawled 121–130 m, coll. 6.iii.1927, fine dark sand .

Description. Syntypes fairly well preserved with body walls mainly intact and chaetae mainly intact, pale yellow in colour. Three individuals of which only one is complete. Complete individual 50 mm long, 4 mm wide excluding buccal tentacles, with approximately 135 segments. Two individuals gravid.

Dorsum anteriorly smooth. Venter anteriorly with mid-ventral groove and discrete ventro-lateral pads; pads incised (transverse grooves), extending from segment 4 to 11. Mid-ventral groove from segment 4 ( Fig. 30a ).

Buccal tentacles numerous, of one type, cylindrical, uniformly thin and weakly grooved, some shorter than others, arising at junction between prostomium and upper lip. Prostomial ridge distinctly curved, extending laterally along anterodorsal base of upper lip. Upper lip trefoiled, small wing-like lobes laterally, margin of medial lobe convoluted, thin; oral surface glandular and ciliated. Inner lower lip oblong, ridged; outer region flat, shieldlike, inverted T-shaped (expanded posteriorly), tessellated, extending posteriorly to posterior margin of segment 3. Achaetous segments not visible ( Fig. 30a ).

Notochaetigerous segments 13, extending to segment 15. Notopodia more-or-less rectangular with expanded tips, lobes triangular, postchaetal lobe longer than prechaetal ( Fig. 30b ). Notochaetae within a chaetiger one type (chaetiger 4 and a mid-body chaetiger examined), gradually elongating from dorsal to ventral, hirsute (under high power), uniformly tapered, posteriorly same form as those anteriorly ( Fig. 30c ). Neurochaetae beginning on segment 15. Neuropodial tori erect rectangular pinnules, similar along body. Uncini with short neck and straight to convex base (Type 1), teeth above main fang arranged in single transverse series or arranged in double transverse series (MF:2–3 or MF:1:3–4) enlarged median tooth above main fang present or absent, subrostral process present as low, rounded protuberance ( Fig. 30d, e ).

Nephridial papillae present, globular, flattened. Pre-gular membrane nephridial papillae absent. Post-gular membrane nephridial papillae present, extending from segment 5 to 9; situated at base of notopodia. Pygidium simple cone with central depression.

Figures

FIGURE 30. Polycirrus hesslei Monro. Syntypes BMNH ZK 1930.10.8.2911-15. a. Anterior ventral view. b. Left side anterior lateral view of notopodium, chaetiger 4. c. Two types of notochaetae from chaetiger 18 (notochaetae illustrated at x40 and x100). d. Anterior views of uncini from anterior parapodia. e, f. Lateral and anterior views of uncini from posterior chaetiger.