Nicidion mutilata (Webster 1884)

Eunice mutilatoides Augener, 1922

Eunice mutilatoides Augener, 1922b:45.

MATERIAL EXAMINED.—Holotype, ZMB 6397, Bird Key, Dry Tortugas, coll. Hartmeyer, 1907.

COMMENTS ON MATERIAL EXAMINED.—Holotype has been partially dried out; its condition does not warrant illustrations of soft parts.

DESCRIPTION.—Holotype complete with 110 setigers; total length 32 mm; maximal width 1 mm; length through setiger 10, 5 mm.

Prostomium distinctly shorter and narrower than peristomium, as deep as of peristomium. Median sulcus shallow. Eyes posterior to bases of A-I, dark. Antennae in a straight line, evenly spaced, similar in thickness. Ceratophores ring-shaped in all antennae, without articulations. Ceratostyles thick and digitiform, without articulations. No antennae reaching beyond peristomium; A-I short; A-II and A-III similar in length. Peristomium cylindrical. Separation between rings distinct dorsally and ventrally; anterior ring of total peristomial length. Peristomial cirri to middle of anterior peristomial ring, ovate, without articulations.

Jaws not examined.

Branchiae present, palmate, distinctly shorter than notopodial cirri. Branchiae from setiger 8 to setiger 48. Branchiae terminating well before posterior end, present on less than 55% of total number of setigers. All branchiae short, stubby filaments; no more than 2 filaments apparently present in any setiger.

Anterior neuropodial acicular lobes rounded or truncate; posterior acicular lobes currently sharply pointed, possibly due to condition of type. Shape of pre- and postsetal lobes cannot be determined. First 7 ventral cirri tapering. Ventral cirri long ventrolateral ridge in median setigers; narrow tips tapering. Posterior ventral cirri tapering. Notopodial cirri apparently short, medially inflated. Notopodial cirri without articulations.

Limbate setae marginally smooth. Pectinate setae (Figure 78a) long, slender, tapering, furled. One marginal tooth distinctly longer than other teeth; ~10 teeth present. Compound falcigers (Figure 78c) small. Shafts inflated, marginally serrated. Appendages short with relatively large heads, bidentate. Proximal teeth tapering to sharp, curved tips. Distal teeth abruptly tapering, directed laterally. Guards asymmetrically bluntly pointed, following outline of hooks closely; mucros absent. Pseudocompound falcigers and compound spinigers absent. Aciculae tan-colored, tapering to blunt tips, straight; cross-sections round. Subacicular hooks (Figure 78b) light to dark tan color, bidentate. Hooks first present from setiger 19, present in all setigers thereafter, always single (except for replacements). Hooks with distinct heads. Proximal teeth large, directed laterally. Distal teeth about as long as proximal teeth, slender, directed obliquely distally.

UNKNOWN MORPHOLOGICAL FEATURES.—Jaw structure; some parapodial features; pygidium and anal cirri.

EXPECTED STATES OF UNKNOWN MORPHOLOGICAL FEATURES.—None.

CHARACTERS USED IN PREPARATION OF KEY NOT SCORED.—Inappropriate Characters: 22, 33, 34. Unknown Characters: 4, 6–8, 44–50, 74, 78.

ASSUMED STATES FOR PURPOSE OF PREPARING KEY.—None.

Eunice mutilata Webster, 1884

Eunice mutilata Webster, 1884:315–316, pl. 9: figs. 36, 36a–d, 37–40.

MATERIAL EXAMINED.—Holotype, USNM 4789, 1 specimen in 3 pieces, plus 5 mounted slides of parapodia, Bermuda, coll. G. Brown Goode.

COMMENTS ON MATERIAL EXAMINED.—The type lot consists of an anterior end, a median piece, and a long section with a posterior end; however, perhaps as much as 50 middle setigers are missing. The three pieces match in all characters and are here considered part of the holotype, but because an unknown number of setigers are missing, no overall measurements can be given.

DESCRIPTION.—Anterior end with 36 setigers; length 30 mm; maximal width 3.5 mm wide at setiger 10; length through setiger 10, 10 mm.

Prostomium (Figure 77f) distinctly shorter and narrower than peristomium, as deep as of peristomium. Prostomial lobes frontally rounded, dorsally strongly inflated; median sulcus deep. Eyes between bases of A-I and A-II, small, black. Antennae in a straight line, evenly spaced, similar in thickness. Ceratophores ring-shaped in all antennae, without articulations. Ceratostyles tapering, with up to 5–6 very indistinct, cylindrical articulations. A-I to posterior peristomial ring; A-II to setiger 1; A-III to setiger 2. Peristomium cylindrical. Separation between rings distinct on all sides; anterior ring of total peristomial length. Peristomial cirri to middle of anterior peristomial ring, digitiform, without articulations.

Jaws not examined.

Branchiae (Figure 77i) present, pectinate, distinctly longer than notopodial cirri, not reduced in mid-body region, erect. Branchiae from setiger 7, missing on last 15–20 setigers. Branchiae present to near posterior end, present on more than 65% of total number of setigers. First 3 pairs and last half of body with single filaments only; maximum 4 filaments at about setiger 25–30. Branchial stems short, tapering. Filaments in pectinate branchiae digitiform, much longer than notopodial cirri. Branchial filaments short on posterior half of body, digitiform, distinctly shorter than notopodial cirri.

Anterior neuropodial acicular lobes (Figure 77g) short and symmetrically rounded; median (Figure 77i) and posterior acicular lobes obliquely truncate with aciculae emerging from upper and higher ends. All presetal lobes low, transverse folds. Anterior postsetal lobes high narrowly rounded, symmetrical, becoming broadly rounded in median setigers, turning into low, transverse folds in far posterior setigers. Postsetal lobes recognizable as free lobes through at least setiger 35. Anterior ventral cirri thick, tapering, becoming basally inflated from about setiger 10. Inflated bases transverse welts along ventral side of neuropodia; narrow tips digitiform. Inflated bases missing in median fragment; posterior ventral cirri short, digitiform, increasingly slender. All notopodial cirri digitiform, without articulations, becoming increasingly slender posteriorly.

Limbate setae broadly limbate, marginally smooth. Pectinate setae (Figure 771) tapering, furled. One marginal tooth longer than all other teeth; 12–15 teeth present. Shafts of compound falcigers (Figure 77h,j,m) inflated, marginally smooth. All appendages tapering, nearly triangular in shape, bidentate. Two distinctly different kinds of heads present. In most heads both teeth directed distally (Figure 77h,m); proximal teeth smaller than distal teeth. Both teeth curved; distal teeth nearly erect. In other, rarer kind of heads proximal teeth triangular (Figure 77j), directed laterally. Distal teeth distinctly bent. Both kinds present in same parapodia; relative proportions of both kinds varying along length of body, with second kind becoming more common posteriorly. Both kinds of compound hooks with pointed guards, symmetrically and asymmetrically bluntly pointed, respectively; mucros absent. Pseudocompound falcigers and compound spinigers absent. Aciculae dark brown to nearly black, tapering, straight or gently curved; cross-sections round. Subacicular hooks (Figure 77k,n) dark brown, bidentate. Hooks first present from setiger 27, present in all setigers thereafter, always single (except for replacements). All hooks with narrowed, sometimes bent necks and distinct heads. Proximal teeth somewhat larger than distal teeth, curved distally. Distal teeth nearly erect.

UNKNOWN MORPHOLOGICAL FEATURES.—Jaw structures; features associated with far posterior setigers; 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, 4, 6, 40, 74, 78.

ASSUMED STATES FOR PURPOSE OF PREPARING KEY.—None.