Harmothoe pulchella (Kinberg 1856)

Harmothoe pulchella (Kinberg, 1856)

Antinoe pulchellus Kinberg, 1856:385.—Hartman, 1959:62 [catalog].

Antinoe pulchella.—Kinberg, 1858:20, pl. 6: fig. 29, pl. 10: fig. 56.

Antinoe (?) pulchella.—Hartman, 1949:29, pl. 2: figs. 10–14 [examination of syntypes].

MATERIAL EXAMINED.—ARGENTINA: South Atlantic Ocean, south of La Plata River, Eugenie Expedition, 90 m, 4 syntypes (NRS 399).

MEASUREMENTS.—Type Material: Four syntypes in poor condition; anterior fragment in best condition consisting of 13 segments, 4 mm long, 4 mm wide with setae; pharynx has been removed, jaws figured by Kinberg, 1958, pl. 10: fig. 56; complete syntype with 35 segments, 17 mm long, and 6 mm wide. All elytra missing except for one free in vial.

DESCRIPTION.—Elytrophores 15 pairs, on usual segments. Elytra large, oval, with papillae on lateral border and some on surface, with conical microtubercles throughout and single oval macrotubercle near posterior margin (on single elytron remaining) (Figure 17B; Kinberg, 1858, pl. 6: fig. 29H). Prostomium bilobed, with distinct cephalic peaks; ceratophore of median antenna large, oval, in anterior notch, with style missing; lateral antennae with distinct ceratophores inserted ventrally, with styles short, subulate, papillate; palps stout, tapered; 2 pairs of eyes, anterior pair slightly larger than posterior pair, located laterally in greatest width of prostomium, smaller posterior pair posterolateral; tentaculophores lateral to prostornium, each with small acicular lobe, 2 notosetae on inner side, and pair of papillate dorsal and ventral tentacular cirri, with subterminal enlargements and filamentous tips, tentacular cirri slightly shorter than palps (Figure 17A; Kinberg, 1858, pl. 6: fig. 29B).

Segment 2 with first pair of elytrophores, biramous parapodia, and long ventral buccal cirri, similar to tentacular cirri (Figure 17A); notosetae similar to following notosetae; neurosetae more slender than following neurosetae, with long spinous regions; upper neurosetae with bifid tips, lower neurosetae with slender, entire tips.

Parapodia biramous, with notopodia short, conical, on anterodorsal side of larger neuropodia; neuropodial acicular lobe subconical, with supraacicular digitiform process; postsetal lobe shorter, rounded; notosetae very numerous, forming radiating bundle; neurosetae numerous, forming fan-shape bundle (Figure 17C; Hartman, 1949, pl. 2: fig. 10). Notosetae slightly stouter than neurosetae, with numerous spinous rows and short, tapered, bare, blunt tips, sometimes worn, appearing slightly bifid (Figure 17D; Kinberg, 1858, pl. 6: fig. 29S; Hartman, 1949, pl. 2: fig. 13). Upper neurosetae more slender and with longer spinous regions than middle neurosetae, all with bifid tips (Figure 17E; Kinberg, 1858, pl. 6: fig. 29U; Hartman, 1949, pl. 2: figs. 11, 12, 14); few lower neurosetae with entire tips. Dorsal cirri with cylindrical cirrophores on posterior sides of notopodia, with papillate styles extending beyond neurosetae (Kinberg, 1858, pl. 6: fig. 29F); dorsal tubercles nodular. Ventral cirri short, tapered. Pharynx with 9 pairs of border papillae and 2 pairs of hooked jaws (Kinberg, 1858, pl. 10: fig. 56).

DISTRIBUTION.—South Atlantic Ocean, Argentina, mouth of La Plata River, in 90 meters.