Eunice northioidea Moore 1903

Eunice northioidea Moore, 1903

Eunice northioidea Moore, 1903:433–435, pl. 25: figs. 36–38.

MATERIAL EXAMINED.—Holotype, USNM 15728, Albatross sta 3718, Japan, 1.2 miles off Ose Zaki, Honshu Island, (~35°02′N, 138°47′E) 11 May 1900, 117 m, volcanic sand, shells and rock, beamtrawl.

DESCRIPTION.—Holotype incomplete with 86 setigers; length 58 mm; maximal width 2.5 mm; length through setiger 10, 7 mm. Body cylindrical; only slightly dorsoventrally flattened posteriorly.

Prostomium (Figure 80g) distinctly shorter and narrower than peristomium, less than as deep as peristomium. Prostomial lobes frontally rounded, dorsally inflated; median sulcus deep. Eyes at bases of A-II, reddish. Antennae in a horseshoe, with A-I isolated by a gap, similar in thickness. Ceratophores ring-shaped in all antennae, without articulations. Ceratostyles slender and tapering; A-II and A-III with cylindrical articulations; A-I with distally drop-shaped and proximally cylindrical articulations; maximum 9 articulations in A-III. A-I to posterior peristomial ring; A-II to setiger 4; A-III to setiger 6. Peristomium cylindrical, with a distinct muscular lower lip. Separation between rings distinct dorsally and visible ventrally; anterior ring ~ of total peristomial length. Peristomial cirri to middle of anterior peristomial ring, without articulations.

Maxillary formula 1+1, 6+6, 8+0, 5+8, and 1+1. Mx III part of distal arc with left Mx IV.

Branchiae (Figure 80h) present, pectinate, distinctly longer than notopodial cirri, not reduced in mid-body region, erect. Branchiae from setiger 3 to end of fragment. First 3 and last 45 pairs single filaments; maximum 3–4 filaments between setigers 10–20. Filaments slender, digitiform, about as long as notopodial cirri.

Anterior neuropodial lobes symmetrically bluntly pointed; median and posterior acicular lobes (Figure 80m) conical; aciculae emerging at midline. Pre- and postsetal lobes low, transverse folds. First 4 ventral cirri thick, tapering. Ventral cirri basally inflated from about setiger 5 to about setiger 25. Inflated bases ovate; narrow tips digitiform. Posterior ventral cirri tapering, conical. Anterior notopodial cirri slender, filiform, with 6 to 7 articulations. Notopodial cirri decreasing gradually in length, retaining same shape in all setigers; articulations lost in first part of branchial region.

Limbate setae marginally serrated. Pectinate setae (Figure 80j,l) tapering, flat. One marginal tooth much longer than other teeth; 7 teeth in anterior setigers; ~12 teeth in posterior setigers. Shafts of compound falcigers (Figure 80i) slightly inflated, marginally smooth. Appendages long, tapering, bidentate. Proximal teeth very much shorter than distal teeth, triangular, directed laterally. Distal teeth distinctly hooked. Guards symmetrically bluntly pointed; mucros absent. Pseudocompound falcigers and compound spinigers absent. Aciculae paired in anterior parapodia, single in median and posterior parapodia, with brown cores and clear sheaths, tapering, bluntly pointed, straight; cross-section round. Subacicular hooks (Figure 80k) with dark brown cores and clear sheaths, bidentate. Hooks first present from setiger 25, present in all setigers thereafter, always single (except for replacements). Hooks tapering, slightly bent. Proximal teeth larger than distal teeth, triangular, directed laterally. Distal teeth short, nearly erect.

UNKNOWN MORPHOLOGICAL FEATURES.—All features associated with posterior setigers and pygidium.

EXPECTED STATES OF UNKNOWN MORPHOLOGICAL FEATURES.—None.

CHARACTERS USED IN PREPARATION OF KEY NOT SCORED.—Inappropriate Characters: 56, 58, 59. Unknown Characters: 1, 2.4, 6, 36–40, 47, 50, 63.

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