A Review of the Genus Eunice - Smithsonian Institution Libraries

216 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY
nate. Pseudocompound falcigers and compound spinigers
absent. Aciculae (Figure 71e) paired, yellow, tapering, slightly
bent or straight; cross-sections round. Separation between core
and sheath indistinct in both aciculae and subacicular hooks.
Subacicular hooks (Figure 71c) yellow, tridentate with teeth in
a crest. Subacicular hooks first present from setiger 17, present
in all thereafter, occurring singly (except for replacements).
Hooks distally bent. Two distal fangs emerging from joint
bases.
UNKNOWN MORPHOLOGICAL FEATURES.—Pygidium and
anal cirri.
EXPECTED STATES OF UNKNOWN MORPHOLOGICAL FEA-
TURES.—None.
CHARACTERS USED IN PREPARATION OF KEY NOT
SCORED.—Inappropriate Characters: 56, 58, 59. Unknown
Characters: 4, 6, 17, 23, 32,42.
ASSUMED STATES FOR PURPOSE OF PREPARING KEY.—
None.
REMARKS.—Eunice medicina is listed with similar species
in Tables 41 and 42. In addition to E. medicina, two species
listed in Table 42 lack posterior simple branchiae; these are E.
indica and E. multicylindri. Subacicular hooks are always
single in E. medicina and E. multicylindri; in E. indica three or
more subacicular hooks are present in each segment. The
maximum number of branchial filaments is seven in E.
medicina and four in E. multicylindri. Other differences can be
seen by comparing illustrations and descriptions of the two
species.
120. Eunice megabranchia Fauchald, 1970
FIGURE 71f-m; TABLES 19.21,24,26
Eunice megabranchia Fauchald, 1970:33-36, pL 4: figs. a-e.
MATERIAL EXAMINED.—Holotype, AHF Poly 1056, Gulf of
California, Mexico, 27°03'N, 112°18"W, 894 m, coll. S.
Calvert, sta L-184.
DESCRIPTION.—Holotype incomplete mature female with
large eggs in body cavity with 74 setigers; length 68 mm;
maximal width 7 mm; length through setiger 10, 12 mm.
Anterior end of body cylindrical, becoming dorsally and
ventrally flattened towards posterior end of fragment; crosssection
nearly quadrangular posteriorly.
Prostomium (Figure 7If) distinctly shorter and narrower
than peristomium, as deep as */2 of peristomium. Prostomial
lobes frontally obliquely rounded; median sulcus shallow,
separation continued as distinct ridge to base of A-III. Surface
of prostomium rugose, palps distinctly marked frontolaterally
by shallow grooves. Eyes posterior to bases of A-I, hidden
under peristomial fold, purple. Antennae in a horseshoe, evenly
spaced, similar in thickness. Ceratophores ring-shaped in all
antennae, without articulations. Ceratostyles slender and
tapering, without articulations. A-I to setiger 1; A-I I to setiger
6; A-III to setiger 9. Peristomium cylindrical. Lower lip
scalloped. Separation between rings distinct on all sides;
anterior ring 3 /4 of total peristomial length. Peristomial cirri to
slightly beyond tip of prostomium slender and tapering,
without articulations.
Jaws not examined.
Branchiae (Figure 71m) present, pectinate, distinctly longer
than notopodial cirri, not reduced in mid-body region, erect.
Branchiae from setiger 3 to setiger 54. Branchiae terminating
well before posterior end, present on less than 55% of total
number of setigers. Last 7 pairs single filaments; all other
branchiae strongly pectinate with 47 or more filaments where
best developed, at setigers 15-20. Branchial stems erect,
strong, tapering to very narrow tips, and outreaching notopodial
cirri in all but last 7 branchial segments. Filaments filiform,
forming tangled masses on sides of specimen; some filaments
longer than notopodial cirri, but most distinctly shorter than
notopodial cirri.
Anterior ncuropodial acicular lobes obliquely truncate with
aciculae emerging dorsal to midline. Postcriormost ncuropodial
acicular lobes present (Figure 71i) symmetrically rounded with
aciculae emerging medially. Pre- and postselal lobes low,
transverse folds. Pre- and postbranchial ventral cirri tapering.
Ventral cirri modestly basally inflated in branchial region.
Inflated bases ovate; narrow tips tapering. Anterior notopodial
cirri, slightly inflated basally, becoming tapering with long,
slender, filiform tips in branchial region; postbranchial notopodial
cirri slender, tapering, very much shorter than in branchial
region. All notopodial cirri with distinct cirrophores; anterior
notopodial cirri with 3 to 4 irregular articulations; articulations
lost in first few branchial setigers.
Limbate setae narrow, marginally smooth. Shafts of pectinate
setae (Figure 71 h,l) wide, flattened. Blades slightly flaring,
flat or gently furled. One marginal tooth distinctly longer than
other teeth; 16 teeth present. Shafts of anterior compound
falcigers (Figure 71g) distally inflated, becoming tapering in
posterior setigers (Figure 71j), marginally smooth; internal
striation distinct, with distinct, narrow beaks. Appendages
tapering from base to very small distal heads, bidentate.
Proximal teeth smaller than distal teeth, forming low, triangular
lateral projections. Distal teeth erect, slender in anterior setigers
and thick in posterior setigers. Guards tapering to slender,
distinct mucros, marginally serrated. Pseudocompound falcigers
and compound spinigers absent. Aciculae single in anterior
setigers, up to 3 in posterior setigers, honey-colored, tapering to
blunt tips, straight; cross-sections round. Subacicular hooks
(Figure 71k) honey-colored, bidentate. Hooks first present
from setiger 35, present in all setigers thereafter, always single
(except for replacements). Hooks tapering to small heads.
Proximal teeth much larger than distal teeth; both teeth directed
distally.
UNKNOWN MORPHOLOGICAL FEATURES.—Jaw structure;
features associated with posterior parapodia; pygidium and
anal cirri.