Eunice pycnobranchiata

Eunice pycnobranchiata McIntosh, 1885

Eunice pycnobranchiata McIntosh, 1885:294–297, figs. 54, 55, pl. 39: figs. 13–15, pl. 21A: figs. 4, 5.—Fauchald, 1986:253–255, figs. 56–61.

Eunice tentaculata.—Fauvel, 1917:269 [in part, not Eunice tentaculata Kinberg, 1865, nor Eunice tentaculata Quatrefages, 1866].

MATERIAL EXAMINED.—Three syntypes, BM(NH) ZK 1921.5.1.1997, Challenger sta 162, off East Moncoeur land, Bass Strait, 39°10′30″S, 146°37′E, 69 m, dredged, sand and shells, 2 Apr 1874. One syntype, BM(NH) ZK 1921.5.1.1998, Challenger sta 163A, Twofold Bay, between Melbourne and Sydney, 36°59′S, 150°20′E, 274 m, trawled, green mud.

COMMENTS ON MATERIAL EXAMINED.—The syntype from Twofold Bay was the one examined in detail by McIntosh; most of the description is based on this specimen. The specimen has been frontally dissected and the jaws are now missing.

DESCRIPTION.—Syntype described incomplete with 63 setigers; length 50 mm; maximal width 8 mm; length through setiger 10, 12 mm. Other syntype incomplete with 76 setigers; length 55 mm; maximal width 10 mm; length through setiger 10, 10 mm.

Prostomium (Figure 95a,b) distinctly shorter and narrower than peristomium, less than as deep as peristomium. Prostomial lobes frontally rounded, dorsally inflated; median sulcus deep. Antennae in a horseshoe, with A-III isolated by a gap, with A-I slimmer than other 3. Ceratophores ring-shaped in all antennae, without articulations. Ceratostyles tapering, with up to 15 irregular, cylindrical articulations. Antennae reaching posterior peristomial ring; A-II and A-III similar in length; A-I somewhat shorter. Peristomium cylindrical with distinct muscular lower lip. Separation between rings distinct dorsally and ventrally; anterior ring about of total peristomial length. Peristomial cirri to middle of anterior peristomial ring, with 3 articulations.

Maxillary formula according to McIntosh (1885, fig. 54) 1+1, 5+5, 6+0, 6+8, 1+1. Mx III part of distal arc with left Mx IV and V.

Branchiae present, pectinate, about as long as notopodial cirri, not reduced in mid-body region. Branchiae from setiger 5–6 to end of fragments. Where best developed branchiae with 4 short thick filaments.

All neuropodial acicular lobes (Figure 95c) rounded; aciculae emerging dorsal to midline. Presetal lobes low, transverse folds. Anterior postsetal lobes forming collars around dorsal edge of acicular lobes. Median postsetal lobes low, transverse folds. Anterior ventral cirri digitiform. Median ventral cirri with barely visible inflated bases. Inflated bases ovate; narrow tips digitiform. Anterior notopodial cirri digitiform, with 2 to 4 irregular articulations. Median notopodial cirri basally somewhat inflated, without articulations.

Limbate setae slender. Pectinate setae (Figure 95f) flat, flaring. Both marginal teeth slightly longer than other teeth; ~15 teeth present. Shafts of compound falcigers (Figure 95e) tapering, marginally smooth with internal striations. Appendages short, bidentate. Proximal teeth shorter than distal teeth, triangular, directed laterally. Distal teeth tapering, nearly erect. Guards distally asymmetrically bluntly pointed; mucros absent. Pseudocompound falcigers and compound spinigers absent. Aciculae single in first few setigers, thereafter paired, black, tapering, straight; cross-section round. Subacicular hooks (Figure 95d) black, bidentate. Hooks first present from setiger 28 or 29, present in all setigers thereafter, always single (except for replacements). Proximal teeth much larger than distal teeth; both teeth directed obliquely distally.

UNKNOWN MORPHOLOGICAL FEATURES.—Relationship between Mx III and left Mx IV; all features associated with posterior setigers; pygidium and anal cirri.

EXPECTED STATES OF UNKNOWN MORPHOLOGICAL FEATURES.—Mx III short, forming part of distal arc with left Mx IV.

CHARACTERS USED IN PREPARATION OF KEY NOT SCORED.—Inappropriate Characters: 56, 58, 59. Unknown Characters: 1, 2, 4, 6, 13, 14, 34, 36–40, 42, 47, 50, 51, 60, 63, 74.

ASSUMED STATES FOR PURPOSE OF PREPARING KEY.—37,1; 38,1.