Eunice dilatata Grube 1877

Eunice dilatata Grube, 1877

Eunice dilatata Grube, 1877:530–531.—Fauchald, 1986:248–249, figs. 29–34.

MATERIAL EXAMINED.—Holotype, ZMB 896, Salavatti, Timor, coll. Exp. Gazelle.

COMMENTS ON MATERIAL EXAMINED.—The prostomium had been laterally dissected, so the lower outline of the peristomium has been reconstructed in the illustration.

DESCRIPTION.—Holotype incomplete, of unknown sex, with 92 anterior setigers; length 70 mm; maximal width 10 mm at setiger 85; length through setiger 10, 16 mm; width at setiger 10, 5 mm. Anterior end cylindrical, becoming strongly dorsoventrally flattened by setiger 30; segments becoming very short and crowded near posterior end.

Prostomium (Figure 38b) distinctly shorter and narrower than peristomium, less than as deep as peristomium. Prostomial lobes frontally obliquely truncate, dorsally flattened; median sulcus deep. Eyes between bases of A-I and A-II, black. Antennae in a horseshoe; A-I and A-II separated by gap from A-III; A-III located well forward of other antennae; A-III half as thick as A-I and A-II. Ceratophores ring-shaped in all antennae, without articulations. Ceratostyles digitiform, without obvious articulations. A-I to posterior peristomial ring; A-II to end of setiger 1, and A-III to end of setiger 2. Peristomium about twice as long as prostomium, cylindrical. Separation between peristomial rings visible, but indistinct dorsally, possibly also ventrally, but specimen damaged; anterior ring of total peristomial length. Peristomial cirri short, digitiform, without articulations.

Maxillary formula 1+1, 5+5, 8+0, 6+7, and 1+1; Mx II with unusually large and heavy teeth compared to other maxillae.

Branchiae (Figure 38c) present, pectinate, distinctly longer than notopodial cirri, not reduced in mid-body region, flexible. Branchiae from setiger 19 to end of fragment. First 5 pairs single filaments; maximum 6 filaments; most branchiae with 5 filaments; this number of filaments continued to end of fragment. Branchial stems slender, longer than notopodial cirri. Filaments digitiform, longer than notopodial cirri, increasing in length posteriorly.

Anterior neuropodial acicular lobes (Figure 38a) symmetrically rounded; median and posterior acicular lobes distally truncate; aciculae emerging at midline. Presetal lobes low, transverse folds. Anterior postsetal lobes free, rounded, about as high as acicular lobes, reduced to low folds from median setigers. Median and posterior parapodia on high ridges thus all parapodial structures, including aciculae, free of body wall, resembling large, flattened paddles with parapodial features carried at distal end. Anterior ventral cirri large, tapering from a wide triangular base, nearly scoop-shaped. Ventral cirri basally inflated in branchial region; bases ovate; narrow tips tapering. Anterior notopodial cirri basally distinctly inflated with a narrowed attachment to body wall. Notopodial cirri decreasing in length in branchial region, retaining similar shape in all setigers. Notopodial cirri without articulations.

Limbate setae slender, nearly capillary. Pectinate setae (Figure 38f) in thick fascicles. Shafts wide, cylindrical. Blades narrow, tapering, furled. Both marginal teeth longer than other teeth; with ∼15 teeth. Prebranchial setigers with compound falcigers in thick fascicles; numbers of falcigers decreasing posteriorly; in last segments present only 4 or 5 in each parapodium. Shafts (Figure 38d) tapering and marginally serrated, with distinct beaks. Appendages large, head distinct, bidentate. Proximal teeth smaller than distal teeth, narrowly tapering, directed laterally. Distal teeth long, slender, blunt-tipped, directed obliquely distally. Guards symmetrically bluntly pointed, marginally coarsely serrated; mucros absent. Pseudocompound falcigers and compound spinigers absent. Aciculae single, dark yellow in anterior setigers, darkening to dark brown in last segments, tapering to smooth, sharp tips; cross-section round. Subacicular hooks (Figure 38e) brown, bidentate. Hooks first present from setiger 28, present in all setigers thereafter, always single (except for replacements). Hooks distally abruptly tapered. Proximal teeth larger than distal teeth, directed laterally. Distal teeth erect.

UNKNOWN MORPHOLOGICAL FEATURES.—Relationship between Mx III and left Mx IV; features associated with far posterior setigers, including branchial distribution; pygidium and anal cirri.

EXPECTED STATES OF SELECTED UNKNOWN FEATURES.—Mx III forms part of distal arc with left Mx IV; branchiae continued to near posterior end.

CHARACTERS USED IN PREPARATION OF KEY NOT SCORED.—Inappropriate Characters: 22, 56. Unknown Characters: 1, 2, 36, 38, 40, 42, 47, 50, 51, 57–60, 63, 74, 78.

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