Eunice impexa Grube 1878

Eunice impexa Grube, 1878

Eunice impexa Grube, 1878b:159–160, pl. 9: fig. 6.

MATERIAL EXAMINED.—Holotype, ZMB 4001, Cape of Lapinig, Philippines, coll. Semper.

COMMENTS ON MATERIAL EXAMINED.—Four parapodia removed from the holotype were also available; two of these were previously examined by Grube, the other two by Augener.

DESCRIPTION.—Holotype incomplete, of unknown sex, with 101 setigers; length 63 mm; maximal width 5.5 mm at setiger 10; length through setiger 10, 11 mm.

Prostomium (Figure 57a) distinctly shorter than peristomium, distinctly narrower than peristomium, less than as deep as peristomium. Prostomial lobes frontally rounded, dorsally flattened; median sulcus shallow. Eyes present posterior to bases of A-I, faded purple. Antennae in horseshoe, evenly spaced, similar in thickness. Ceratophores ring-shaped in all antennae, without articulations. Ceratostyles tapering, with 1 or 2 irregular, cylindrical articulations. A-I to anterior peristomial ring; A-II to posterior peristomial ring; A-III to setiger 1. Peristomium massive, expanded anteriorly due to eversion of jaws; muscular lower lip present. Separation between rings distinct ventrally and visible dorsally; anterior ring of total peristomial length. Peristomial cirri to middle of anterior peristomial ring, digitiform, without articulations.

Maxillary formula 1+1, 5+4, 5+0, 2+5, and 1+1. Mx III short, forming a distal arc with very short left Mx IV and MX V. Mx VI absent.

Branchiae (Figure 57j, k) present, palmate, distinctly longer than notopodial cirri, not reduced in mid-body region, flexible. Branchiae from setiger 22 to end of fragment. First 10 branchiae short, button-shaped. From setiger 31 branchiae long, with slender filaments. Branchial distribution irregular with most branchiae having 4–5 filaments clustering at tip of short stems. Several branchiae with 6 to 7 long filaments and up to 3 short, truncate filaments emerging near bases. Some branchiae with filaments in 2 groups emerging from common stems. Relation between length of filaments and branchiae and notopodial cirri variable.

Neuropodial acicular lobes (Figure 57e, i) distally obliquely rounded with aciculae emerging above midline. Anterior presetal lobes high dorsally, forming rounded tabs visible dorsal to aciculae. At level of aciculae presetal lobes deeply cut away leaving bases of compound hooks exposed. Median and posterior presetal lobes low, transverse folds. Postsetal lobes low folds following outline of acicular lobes. First 4 ventral cirri thick, tapering. Ventral cirri basally inflated from setiger 5. Inflated bases thick; prominent ventrolateral ridges in all later setigers. Narrow tips short and button-shaped in median setigers, tapering in posterior setigers. Notopodial cirri short, basally distinctly inflated, tapering towards slender tips, without articulations.

Limbate setae stout, tapering, marginally smooth. Pectinate setae (Figure 57b, l) tapering, furled or funnel-shaped. One marginal tooth distinctly longer than other teeth; ~12 teeth present. First 30 setigers with compound spinigers (Figure 57c). Shafts distally inflated, marginally serrated. Appendages tapering, knife-shaped. Compound falcigers (Figure 57m) replacing compound spinigers from about setiger 30, considerably smaller than spinigers. Shafts inflated, marginally serrated. Appendages short, narrow, with nearly parallel sides, with small, distinct heads, bidentate. Proximal teeth larger than distal teeth, narrow, tapering, curved, directed laterally. Distal teeth gently curved, directed obliquely distally. Guards longer than appendage, symmetrically rounded, marginally smooth; mucros absent. Pseudocompound falcigers absent. Aciculae (Figure 57d) single or paired, with chestnut to copper-colored cores and clear sheaths, tapering, gently curved dorsally; cross-sections round. Separation between core and sheath distinct in both aciculae and subacicular hooks. Subacicular hooks (Figure 57f–h) honey colored anteriorly, becoming darker posteriorly, but always lighter in color than aciculae, bidentate or tridentate, the latter with teeth in a crest. Hooks first present from setiger 60, present in all setigers thereafter; three hooks in most setigers. Most hooks tapering distally towards tip with distinct inflated subdistal region. Proximal teeth large, directed laterally. Distal teeth short, nearly erect. Some hooks distally tridentate with small distal, medium-sized intermediate tooth and large main fangs.

UNKNOWN MORPHOLOGICAL FEATURES.—Pygidium and anal cirri.

EXPECTED STATES OF SELECTED UNKNOWN FEATURES.—None.

CHARACTERS USED IN PREPARATION OF KEY NOT SCORED.—Inappropriate Characters: 56, 60. Unknown Characters: 1-2, 36–38, 40, 42, 47, 50, 63.

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