Malmgreniella pettiti Pettibone 1993

Malmgreniella pettiti

MATERIAL EXAMINED.—SOUTH PACIFIC OCEAN: New Guinea: Papua, Bootless Inlet, about 4 mi NE of Raine Point, 28 May 1981, removed from Alcyonacea, G.R. Pettit, collector, holotype (USNM 80508).

DESCRIPTION.—Holoptype 5 mm long, 1.5 mm wide including setae, and 34 segments. Body flattened, tapered posteriorly, colorless. Elytra 15 pairs, on usual segments, large, oval, covering dorsum; mottled brownish pigmentation on medial two-thirds and scattered microtubercles on anterior part (Figure 15B).

Prostomium oval, bilobed, with anterior lobes truncate, without peaks; anterior pair of eyes anteroventral, larger than posterodorsal pair, ceratophore of median antenna bulbous, in anterior notch, style missing; ceratophores of lateral antennae inserted terminoventrally, with styles short, subulate, minutely papillate; palps stout, tapered; tentaculophores lateral to prostomium, each with single seta on inner side; dorsal and ventral tentacular cirri about length of palps, with short papillae (Figure 15A). Segment 2 with first pair of large elytrophores, biramous parapodia, and long ventral buccal cirri similar to tentacular cirri (Figure 15A).

Biramous parapodium with notopodium short, rounded, with projecting acicular lobe on lower side; longer neuropodium with subconical presetal acicular lobe with digitiform supraacicular process; postsetal lobe shorter, rounded (Figure 15C,D). Notosetae numerous, of several lengths, forming radiating bundle. Notosetae about equal in width to neurosetae, with numerous spinose rows, shorter ones with tips entire and pointed or notched, longer ones mostly with notched tips (Figure 15E). Neurosetae numerous, forming fan-shape bundle, all with rather long, bare, bifid hooked tips, upper ones with longer spinose regions (Figure 15F). Dorsal cirri with cylindrical cirrophores and papillate styles extending to tips of neurosetae; dorsal tubercles nodular; ventral cirri short, subulate (Figure 15D).

BIOLOGY.—Associated with Alcyonacea.

ETYMOLOGY.—The species is named for the collector, G.R. Pettit.

DISTRIBUTION.—South Pacific Ocean, New Guinea.

Malmgreniella phillipensis (Knox and Cameron, 1971), new combination

Malmgrenia phillipensis Knox and Cameron, 1971:22, figs. 1–6.—Kudenov, 1977:85, pl. 1a–n.

Harmothoe phillipensis.—Hanley, 1987:153, fig. 31.

MATERIAL EXAMINED.—PACIFIC OCEAN: Australia: Victoria, Port Phillip Bay Survey, 1957–63, area 14 (175), 2 paratypes (NMV G1737).

DESCRIPTION.—Two paratypes examined, consisting of anterior fragments, 9 and 11 mm long, 6 and 7 mm wide including setae, with 18 and 22 segments (up to 20 mm long, 6 mm wide, with 38 segments in original description). Middorsum reddish brown to cream, ventrum pale cream; according to Kudenov (1977), posterior ventral half of each posterior segment with transverse brown bands. Elytra 15 pairs, on usual segments, large, overlapping, covering dorsum. Elytra oval to subreniform, stiff, slick and shiny, sometimes showing 1–3 indistinct parallel longitudinal ridges (due to preservation, according to Kudenov, 1977:88), with wide band of numerous microtubercles on anterior region and some scattered on surface; brownish pigmentation in form of large anteromedial patch, continuing as narrow band along medioposterior border (Figure 16C,D; Knox and Cameron, 1971, figs. 2, 3; Kudenov, 1977, pl. 1d–g).

Bilobed prostomium with anterior lobes truncate, without peaks; anterior pair of eyes anterolateral, anterior to widest part of prostomium, larger than posterodorsal pair; ceratophore of median antenna large, in anterior notch, style about length of prostomium; ceratophores of lateral antennae distinct, inserted terminoventrally, with styles short, subulate; palps large, stout, tapering; tentaculophores lateral to prostomium, with 0–1 seta on inner sides and pair of dorsal and ventral tentacular cirri similar to median antenna; antennae and tentacular cirri with scattered micropapillae; subconical facial tubercle between ventral bases of palps; antennae, tentacular cirri, facial tubercle, and anterior lip of ventral mouth showing brownish pigmentation (Figure 16A,B; Knox and Cameron, 1971, fig. 1; Kudenov, 1977, pl. la; Hanley, 1987, fig. 3I). Segment 2 with small, slightly bilobed nuchal fold, first pair of large elytrophores, biramous parapodia, and long ventral buccal cirri similar to tentacular cirri; notosetae similar to following notosetae; neurosetae more slender than those following, upper ones with bifid tips, lower ones ending in rounded blunt tips (Figure 16A,E,F).

Notopodia of biramous parapodia rounded, with projecting acicular processes on lower side; larger neuropodia with subconical presetal lobes with projecting supraacicular processes and shorter, rounded postsetal lobes (Figure 16E,G,H; Knox and Cameron, 1971, fig. 4; Kudenov, 1977, pl. 1b,c). Notosetae very numerous, of 3 lengths, slightly curved, moderately stout, slightly stouter than neurosetae, forming radiating bundles. Notosetae with numerous rows of fine serrations, with rounded to tapered pointed tips, showing verying degrees of wear (Figure 16I; Knox and Cameron, 1971, fig. 5; Kudenov, 1977, pl. 1h–j). Neurosetae numerous, forming fan-shape bundle, upper ones with longer spinose regions, with tips entire or with small secondary tooth; middle ones with shorter spinose regions and bifid tips; lower ones with entire tips or slight indication of secondary tooth (Figure 16J; Knox and Cameron, 1971, fig. 6; Kudenov, 1977, pl. 1k–n). Dorsal cirri with cylindrical cirrophores, with long, tapered styles extending to about tips of neurosetae, with scattered micropapillae; dorsal tubercles slightly inflated to nodular; ventral cirri short, tapered (Figure 16H; Knox and Cameron, 1971, fig. 4; Kudenov, 1977, pl. 1c).

DISTRIBUTION.—South Pacific Ocean, SE Australia. Low water to 24 meters.