A Review of the Genus Eunice - Smithsonian Institution Libraries

NUMBER 523 303
smaller specimens. Most species that become as large as this
species does tend to have modified occurrence and structure of
the subacicular hooks, and the fact that the hooks in these large
specimens are unidentate is not here considered to be of great
importance. The species is compared to similar species in
Tables 27 and 28 and with other species with simple, spine-like
subacicular hooks in Table 50.
Of the four species in Table 28 with very short antennae, E.
aphroditois and E. suviensis have bidentate subacicular hooks,
as far as known at all times; E. unidentata always has simple,
spine-like subacicular hooks and E. sebastiani may have both.
Eunice unidentata was described with long, articulated
ceratophores; the ceratophores of E. sebastiani are long in A-I;
they are short and ring-shaped in A-I I and A-I II; they all lack
articulations. Eunice sebastiani also resembles E. scombrinis
and is discussed above in relation to that species.
179. Eunice segregata (Chamberlin, 1919)
FIOURE 103; TABLES 19. 20
Ltodice segregata Chamberlin, 1919a:237-240, pi. 54: figs. 1-4 [in pan].
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 l /2 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-I I, 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-I 11. A-I to setiger 1; A-II to setiger 5; A-III to
setiger 8. Peristomium cylindrical with slightly inflated
posterior ring, ~ x h wider than prostomium; lower lip distinct,
muscular. Separation between rings distinct on all sides;
anterior ring 3 A 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 seugers 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 103g,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 103c j)
tapering; distal beaks present, marginally smooth. Shafts of
median falcigers (Figure 1030 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