Eunice segregata (Chamberlin 1919)

Eunice segregata (Chamberlin, 1919)

Leodice segregata Chamberlin, 1919a:237–240, pl. 54: figs. 1–4 [in part].

Eunice segregata.—Fauchald, 1969:6–8. fig. 3a-g.

MATERIAL EXAMINED—USNM 19153, Albatross sta D5695, off southern California 33°33′N, 120°17′30″W, 26 Apr 1911, 977 m, green sand, Globigerina, beam trawl.

COMMENTS ON MATERIAL EXAMINED.—As indicated by Fauchald (1969), none of the original specimens remaining fit the description given by Chamberlin (1919a); these specimens were described as a new species by Fauchald (1969). The specimen here described is the one Fauchald (1969) used in the re-description of this species.

DESCRIPTION.—Specimen incomplete female with 92 setigers; length 60 mm; maximal width 4 mm at setiger 15; length through setiger 10,5 mm; width at setiger 10,3.5 mm. Anterior body dorsally convex with flattened ventrum, becoming cylindrical by about setiger 25.

Prostomium (Figure 103a) distinctly shorter and narrower than peristomium, less than as deep as peristomium. Prostomial lobes frontally truncate, dorsally flattened; median sulcus shallow. Palpal region marked by horizontal grooves. Eyes between bases of A-I and A-II, hidden by peristomial fold, faded purple. Antennae in a nearly straight line, with A-I only slightly in front of other antennae, with A-I isolated by a gap, similar in thickness. Ceratophores ring-shaped in all antennae, without articulations. Ceratostyles slender, slightly tapering, but basically digitiform, with up to 10 indistinct, cylindrical articulations in A-III. A-I to setiger 1; A-II to setiger 5; A-III to setiger 8. Peristomium cylindrical with slightly inflated posterior ring, ∼ wider than prostomium; lower lip distinct, muscular. Separation between rings distinct on all sides; anterior ring of total peristomial length. Peristomial cirri to middle of anterior peristomial ring, slender, tapering to slender tips, with 5 to 6 long, cylindrical articulations.

Maxillary formula 1+1, 7+8, 9+0, 6+10, and 1+1. Mx III long, straight and located behind left Mx II. Mx VI absent.

Jaws very badly decalcified; very soft.

Branchiae (Figure 103e) present, pectinate, distinctly longer than notopodial cirri, not reduced in mid-body region, erect. Branchiae from setiger 3 to setiger 39. Branchiae terminating well before posterior end, present on less than 55% of total number of setigers. First 2 pairs single filaments; all other branchiae with at least 2 filaments; maximum 15 filaments present between setigers 25 and 30. Filaments slender, tapering to fine tips, about as long as notopodial cirri.

Anterior neuropodial acicular lobes (Figure 103b) symmetrically conical, retaining same shape through branchial region, becoming lower and more flattened posteriorly (Figure 103h); aciculae emerging at midline. Postbranchial neuropodial acicular lobes flattened conical with tip associated with inferior aciculae. Presetal lobes low, transverse folds. Pre-branchial and branchial postsetal lobes high, rounded free lobes; postbranchial postsetal lobes follow outline of acicular lobes closely. First 7 ventral cirri tapering. Ventral cirri with inflated bases from about setiger 8, gradually lost from about setiger 30. Inflated bases nearly spherical; narrow tips digitiform. Postbranchial ventral cirri digitiform. Anterior notopodial cirri long, slender, tapering to fine tips, about as long as peristomial cirri in first few setigers. Notopodial cirri less prominent in branchial region, retaining about same shape. Postbranchial notopodial cirri long, basally slightly inflated and distally digitiform. Anterior notopodial cirri with up to 5 cylindrical, indistinct articulations; articulations gradually lost in branchial region. Postbranchial notopodial cirri without articulations.

Limbate setae slender, tapering with narrow, marginally smooth limbation, longer than compound falcigers in all setigers. Anterior pectinate setae (Figure 103d) slender, tapering, furled. One marginal tooth large, rather thick; ∼5 teeth present. Median and posterior pectinate setae (Figure 103 g,l) flat, distally slightly flaring. One marginal tooth distinctly longer and thicker than other teeth; ∼10 teeth present. Shafts of anterior and posterior compound falcigers (Figure 103 c,i) tapering; distal beaks present, marginally smooth. Shafts of median falcigers (Figure 103f) inflated; distal beaks present, marginally indistinctly serrated. Appendages similar in all setigers, long, tapering to small heads, bidentate. Proximal teeth smaller than distal teeth, reduced triangular, directed laterally. Distal teeth nearly erect, tapering. Guards sharply and asymmetrically pointed, without mucros. Pseudocompound falcigers and compound spinigers absent Aciculae (Figure 103j) paired, yellow, tapering, pointed. Most aciculae distally straight with both aciculae similar; in posterior setigers superior aciculae with distinct core and sheath construction and thicker than inferior acicula, gently curved; cross-sections round. Subacicular hooks (Figure 103k) yellow, bidentate. Separation between cores and sheaths indistinct in all subacicular hooks. Hooks first present from setiger 36, present in all setigers thereafter, always single (except for replacements). Hooks tapering towards small heads. Proximal teeth nearly twice as large as distal teeth, directed laterally. Distal teeth nearly erect.

UNKNOWN MORPHOLOGICAL FEATURES.—Pygidium and anal cirri.

EXPECTED STATES OF UNKNOWN MORPHOLOGICAL FEATURES.—None

CHARACTERS USED IN PREPARATION OF KEY NOT SCORED.—Inappropriate Characters: 56, 58, 59. Unknown Characters: 1, 2, 47, 50, 63.

ASSUMED STATES FOR PURPOSE OF PREPARING KEY.—None.