A Review of the Genus Eunice - Smithsonian Institution Libraries

76
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY
mium, short, posteriorly overlapped by nuchal fold. Prostomial
lobes frontally rounded, dorsally inflated; median groove deep.
Antennae slender, tapering. A-I and II articulated with long
basal articulation and shorter distal articulations; A-III without
articulations. A-I with 5 articulations; A-I I with 4. A-I to setiger
1; A-II and III to setiger 5. Peristomium cylindrical; anterior
ring 4 /5 of total peristomial length. Separation between rings
distinct dorsally and ventrally. Peristomial cirri to front edge of
peristomium, digitiform, without articulations.
Maxillary formula (rewritten from Mclntosh) 1+1,7+6,8+0,
2+3, and 10+11. Mx-III part of distal arc with left Mx-IV;
Mx-VI missing.
Branchiae absent.
Neuropodial acicular lobes symmetrically triangular. All
presetal lobes low folds; postsetal lobes about as long as
acicular lobes, rounded. Ventral cirri tapering through setiger 8,
thereafter basally swollen in remaining setigers. Notopodial
cirri basally inflated, without articulations, less than half as
long as width of body.
Limbate setae present. Pectinate setae with -15 teeth.
Aciculae black, single. Subacicular hooks not present in
anterior fragment.
Median fragment not matching anterior end; at least 20
setigers missing. Fragment abranchiate, with relatively short,
tapering notopodial cirri; ventral cirri basally inflated. All
segments with black, bidentate subacicular hooks in addition to
tapering black aciculae and limbate and pectinate setae.
REMARKS.—The anterior fragment may belong to the same
specimen as the median fragment, but too many segments are
missing to justify describing the median fragment as belonging
to the same species. The distribution of the subacicular hooks
remains unknown. Eunice balfouriana differs clearly from all
other abranchiate species in having short second ring on the
peristomium and in the development of the antennae. In
abranchiate species (often described as Nicidion) the two
peristomial rings are similar in length and antennae are short,
barely projecting beyond the tip of the prostomium.
The jaw apparatus is currently missing. The very high
number of teeth reported by Mclntosh for Maxilla V is, as far
as known, completely unique in the family. Eunice balfouriana
is here considered indeterminable.
23. Eunice barvicensis Mclntosh, 1885
FIGURE 18b-d; TABLES 24,26
Eunice barvicensis Mclntosh, 1885:292-294, figs. 52, 53. pi. 39: fig. 12, pi.
21A: figs. 1-3.
MATERIAL EXAMINED.—One syntype, BM(NH) ZK
1885.12.1.203a, Bermuda, between tidemarks, June 1873.
DESCRIPTION.—Syntype incomplete with 112 setigers;
length 41 mm; maximal width 3.5 mm at setiger 10. Length
through setiger 10, 6 mm. Syntype frontally dissected, at one
time desiccated. Body apparently cylindrical, anteriorly truncate.
Prostomium (Figure 18b) distinctly shorter than peristomium,
about as wide as peristomium, less than x h as deep as
peristomium. Prostomial lobes large, frontally rounded, dorsally
flattened; median groove deep. Eyes large, lensed,
between bases of A-I and A-II. Antennae poorly preserved, in
a horseshoe, evenly spaced, similar in thickness. Ceratophores
long in all antennae, without articulations. Ceratostyles
tapering, apparently not articulated (but see Mclntosh,
1885:292-293). A-I to posterior margin of peristomium; A-II
to setiger 1; A-III to setiger 3. Peristomium short, tapering
towards anterior end (artefact); anterior ring ~ 3 A of total
peristomial length. Separation between rings distinct dorsally
and ventrally. Peristomial cirri to front edge of pcrisiomium,
tapering, without articulations.
Jaws present in vial. Maxillary formula 1+1, 5+5, 5+0, 5+8,
1+1. Mx III very short and forming distal arc with left Mx IV
and V. Only 3 teeth on left Mx IV well developed; others low
tubercles.
Branchiae present, pectinate, about as long as notopodial
cirri, not reduced in mid-body region, erect. Branchiae from
setiger 6 to setiger 65, terminating well before the posterior
end. First 3 and last 10 pairs single filaments; maximum 4
filaments at setigers 25-30. Branchial stems short, tapering.
Filaments shorter than notopodial cirri, short, flattened.
Anterior neuropodial acicular lobes symmetrically rounded,
becoming distinctly conical by setiger 60; aciculae emerging at
midline. Pre- and postsetal lobes low folds. Ventral cirri
digitiform through setiger 4. Ventral cirri basally inflated from
setiger 5 through about setiger 25. Inflated bases ovate; narrow
tips digitiform. Posterior ventral cirri without basal inflation,
digitiform. All notopodial cirri digitiform, without articulations.
Far posterior notopodial and ventral cirri similar in shape
and size.
Limbate setae present. Up to 10 pectinate setae in a
parapodium in posterior setigers. Shafts of pectinate setae
slender, cylindrical; blades flat, flared. Both marginal teeth
longer than other teeth; number of teeth 15. Shafts of
compound falcigers (Figure 18d) distally inflated, without
serrations; distal beak distinct. Appendages short, tapering;
head large, bidentate. Proximal teeth triangular with narrow
base, directed laterally; distal teeth as large as proximal teeth,
tapering, directed laterally. Guards symmetrically bluntly
pointed, marginally serrated; mucros absent Pseudocompound
falcigers and compound spinigers absent. Aciculae single in
anterior and posterior parapodia, paired in median parapodia,
light brown in anterior and posterior setigers, dark brown in
median setigers, pointed, straight; cross-sections round. Subacicular
hooks (Figure 18c) with dark brown cores and clear
sheaths, bidentate. Hooks first present from setiger 19, present
in all setigers thereafter, paired in some setigers. Hooks
distinctly bent distally, with narrow necks and large heads.