A Review of the Genus Eunice - Smithsonian Institution Libraries

NUMBER 523 159
indistinct in both aciculae and subacicular hooks. Subacicular
hooks (Figure 5Id) yellow, bidentate. Hooks first present from
setiger 63, present in all setigers thereafter, always single
(except for replacements). Hooks distally strongly curved;
heads small. Proximal teeth larger than distal teeth, triangular,
directed laterally. Distal teeth less than half as massive as
proximal teeth, nearly erect.
UNKNOWN MORPHOLOGICAL FEATURES.—Jaw
pygidium and anal cirri.
structure;
EXPECTED STATES OF SELECTED UNKNOWN FEATURES.—
Mx III long and located behind left Mx II.
CHARACTERS USED IN PREPARATION OF KEY NOT
SCORED.—Inappropriate Characters: 56, 58, 59. Unknown
Characters: 13, 14.
ASSUMED STATES FOR PURPOSE OF PREPARING KEY.—
None.
REMARKS.—Presumably through a lapsus, E. gracilicirrata
was referred to E. armillata by Hartman (1956). Eunice
gracilicirrata belongs to group A-2 (Fauchald, 1970).
It is a very long, slender species with long, slender
ceratostyles and notopodial cirri. The aciculae are hooded in
some anterior setigers. It is listed with similar species in Tables
22 and 23. Of the species listed in Table 23, only E.
gracilicirrata and E. stigmatura have articulated peristomial
cirri. The latter has tridentate subacicular hooks, in addition to
bidentate ones; E. gracilicirrata has only distinctly bidentate
subacicular hooks.
77. Eunice gracilis Grube, 1866
FIGURE 51h-m; TABUES 46-48
Eunice antennata gracilis Grube, 1866a:65.
Eunice gracilis.—Grube, 1866c: 174.
Eunice gracilis Gr. var. antennata.—Grube, 1867:9-11, pi. 1: fig. 2.
MATERIAL EXAMINED.—Two syntypes, ZMB 1856 and
ZMH V-787, Tahiti, Novara Exp.
COMMENTS ON MATERIAL EXAMINED.—Both specimens are
now rather flaccid, but are otherwise in good condition; but the
shape of the parapodial lobes is difficult to describe in detail.
The description is based on the Berlin syntype with notes where
the Hamburg syntype differs.
DESCRIPTION.—Berlin syntype complete, of unknown sex,
with 81 setigers; total length 66 mm; maximal width 2 mm at
setiger 10; length through setiger 10, 6 mm. Hamburg syntype
incomplete, of unknown sex, with 31 setigers; length 25 mm;
maximal width 3 mm at setiger 10; length through setiger 10,7
mm.
Prostomium (Figure 51h) distinctly shorter and narrower
than peristomium, as deep as l /2 of the peristomium, sloping
steeply ventrally. Prostomial lobes frontally obliquely truncate,
dorsally flattened; median sulcus shallow. Eyes between bases
of A-I and A-II in Hamburg syntype, reddish. Antennae in
horseshoe, evenly spaced; A-I thicker than other antennae.
Ceratophores ring-shaped in all antennae, without articulations.
Ceratostyles digitiform with up to 23 moniliform articulations;
styles articulated to bases. A-I to middle of anterior peristomial
ring; right A-II to setiger 2; left A-II and A-III incomplete. A-I II
probably longest antenna, in incomplete condition as long as
right A-II. Peristomium cylindrical. Separation between rings
faintly visible dorsally, indiscernible ventrally and laterally.
Anterior ring 4 /s of total peristomial length. Peristomial cirri to
front edge of peristomium, very slender and digitiform, with 6
articulations.
Maxillary formula 1+1, 6+7, 8+0, 5+10, and 1+1. Teeth
slender and delicate. Mx III long and located behind left Mx II.
Mx VI missing.
Branchiae (Figure 511) present, pectinate, distinctly longer
than notopodial cirri, reduced in mid-body region, erect.
Branchiae from setiger 5 (4 in Hamburg specimen) to setiger
81. Branchiae present to near posterior end, present on more
than 65% of total number of setigers. First branchia with 3
filaments, maximally 6 filaments present. Number of filaments
decreasing rapidly from setiger 20, by setiger 35 single
filaments. At setiger 65 number of filaments increasing to 2;
last 10 branchiae with 3 filaments. Anterior and posterior
branchiae longer than notopodial cirri; median and posterior
branchiae shorter than notopodial cirri. Stems tapering, about
as long as notopodial cirri. Anterior and posterior filaments
digitiform; median filaments filiform; anterior and posterior
filaments shorter than notopodial cirri.
Anterior neuropodial acicular lobes apparently rounded;
posterior acicular lobes triangular or perhaps conical; aciculae
emerging at midline. Pre- and postsetal lobes apparently low,
transverse folds. Anterior ventral cirri thick and tapering. Bases
inflated base from about setiger 10. Bases ovate; narrow tips
tapering. From setiger 30 ventral cirri reduced to short, sharply
tapering lobes (Figure 51i). Anterior notopodial cirri long,
tapering or digitiform, with 4 or 5 articulations. Number of
articulations decreasing posteriorly, and completely lost at
about setiger 50. Posterior notopodial cirri retaining shape but
shorter than in anterior part of body.
Limbate setae slender. Shafts of compound falcigers (Figure
51k) distally gently inflated, marginally smooth. Appendages
short, tapering; head distinct, bidentate. Proximal teeth shorter
than distal teeth, tapering, directed distally. Distal teeth
tapering, directed obliquely distally. Guards asymmetrically
bluntly pointed, marginally finely serrated; mucros absent.
Pseudocompound falcigers and compound spinigers absent.
Aciculae (Figure 51m) paired, yellow, tapering to bluntly
pointed, straight tips; cross-sections round. Separation between
core and sheath indistinct in both aciculae and subacicular
hooks. Subacicular hooks (Figure 51j) yellow; tridentate with
teeth in a crest. Hooks first present from setiger 28, present in
all setigers thereafter, always single (except for replacements).
Hooks very large; fangs in a row, decreasing evenly and rapidly
in size from large main fangs to small tertiary fangs; all fangs
curved.