A Review of the Genus Eunice - Smithsonian Institution Libraries

NUMBER 523 65
midline. Pre- and postsetal lobes low, transverse folds. Anterior
ventral cirri thick and tapering. Median ventral cirri basally
inflated from about setiger 5 through setiger 20. Bases ovate,
narrow tips tapering. Posterior ventral cirri increasingly
digitiform, increasing in length, nearly as long as notopodial
cirri in far posterior setigers. Anterior notopodial cirri thick and
tapering, decreasing in girth, but not in length posteriorly.
Limbate setae longer than all other setae, marginally
serrated. Pectinate setae unknown. Shafts of compound
falcigers (Figure 130 slender, distally tapering without distinct
marginal serrations; distinct distal beak absent. Appendages
long, narrow; head large, bidentate. Anterior proximal teeth
short, slender, becoming triangular in posterior setigers,
directed slightly basally. Distal teeth longer than proximal
teeth, curved, directed laterally. Guards narrow, symmetrical,
slender, terminating in distinct mucros. Most guards distally
rounded with mucro appended, but mucros appearing as
continuations of guards proper in some setae. Pseudocompound
falcigers and compound spinigers absent. Aciculae
single, yellow, tapering with straight, narrow tips; cross-section
round. Some aciculae with narrow sharply pointed guards
(Figure 13h). Separation between core and sheath indistinct in
aciculae, distinct in subacicular hooks. Subacicular hooks
(Figure 13g) yellow, tridentate with teeth in a crest. Hooks first
present from setiger 16, present in all setigers thereafter, always
single (except for replacements). Main fang curved, strongly
tapering; secondary fang curved, rather slender; distal fang very
poorly developed, blunt, indistinct in some posterior setigers.
UKNOWN MORPHOLOGICAL FEATURES.—Jaw structure;
pygidium and anal cirri.
EXPECTED STATE OF SELECTED UNKNOWN FEATURES.—Mx
III long, straight, located behind left Mx II.
CHARACTERS USED IN PREPARATION OF KEY NOT
SCORED.—Inappropriate Characters: 56, 58, 59. Unknown
Characters: 1,2, 13, 14, 65-68.
ASSUMED STATES FOR PURPOSE OF PREPARING KEY.—
None.
REMARKS.—A minor discrepancy with the original description
can be noted. Kinberg found that the antennae stretched to
segment 9 (corresponding to setiger 7); in both specimens the
longest antenna, A-III, reaches setiger 5. One specimen had
been dissected for the jaws, which are now missing. No
attempts were made at examining the jaws in the other, intact
specimen.
Eunice arenosa is listed with similar species in Tables 19
and 20. It can be characterized only by a combination of the
characters used, including relatively long antennae and peristomial
cirri, combined with a total lack of articulations of the
notopodial cirri.
17. Eunice argentinensis (Treadwell, 1929)
FIGURE 14; TABLES 27,29
Ltodice argentinensis Treadwell, 1929:3-5, figs. 7-12.
MATERIAL EXAMINED.—Three syntypes, USNM 19280,
Mar del Plata, Argentina, Felippone # 3008, coll. Florentino
Felippone.
COMMENTS ON MATERIAL EXAMINED.—One syntype is in
good condition, but is in posterior regeneration; another has
been frontally dissected for the jaw apparatus, the third
syntype, which is currently in overall the best condition, is
described in detail here.
DESCRIPTION.—Specimen incomplete, of unknown sex,
with 71 setigers; length 67 mm; maximal width 5 mm at setiger
10; length through setiger 10, 12 mm. Body cylindrical,
abruptly tapering frontally.
Prostomium (Figure 14a) distinctly shorter and narrower
than peristomium, as deep as 1 /2 of the peristomium. Prostomial
lobes frontally rounded, dorsally inflated; median sulcus deep.
Eyes absent. Antennae in transverse row, evenly spaced,
similar in thickness. Ceratophores ring-shaped in all antennae,
without articulations. Ceratostyles digitiform, with up to 7
short, slightly inflated articulations in A-III. A-I to posterior
peristomial ring; A-II to setiger 1; A-III to setiger 4.
Peristomium cylindrical. Separation between rings distinct
ventrally, less so dorsally; anterior ring 3 /4 of total peristomial
length. Peristomial cirri to front edge of peristomium, slender
and digitiform, with 3 articulations.
Maxillary formula 1+1,5+6,7+0,7+9, and 1+1 according to
Treadwell (1929:5 and his fig.11). Mx III part of distal arc with
left Mx IV; Mx VI missing.
Branchiae (Figure 14b) present, pectinate, distinctly longer
than notopodial cirri where best developed, not reduced in
mid-body region, erecL Branchiae from setiger 3 to near end of
body, present on more than 65% of total number of setigers. All
branchiae pectinate except in regenerating posterior end of a
complete syntype where branchiae are single filaments,
missing in last 15 setigers in this syntype. First branchia with 5
filaments, maximum 10 filaments, first reached at setiger 10.
Stems thick, tapering, shorter than notopodial cirri. Filaments
digitiform, shorter than notopodial cirri in all branchiae.
Number and length of filaments decreasing posteriorly, from
about setiger 30, 3-4 short filaments present.
Neuropodial acicular lobes truncate with aciculae emerging
dorsal to midline. Pre- and postsetal lobes low, transverse folds.
First 3 ventral cirri thick, digitiform. Median ventral cirri
basally inflated; inflated bases ovate; narrow tips tapering.
Ventral cirri basally inflated through rest of fragments, without
basal inflation only in regenerating posterior end in one
syntype. Notopodial cirri medially inflated, with at least 1 long
distal articulation; some anterior cirri with 2 or 3 articulations.
Notopodial cirri large, becoming dominant parapodial feature
in posterior segments.
Limbate setae distinctly longer than other setae, slender,
marginally serrated. Shafts of pectinate setae (Figure 14f) wide,
cylindrical. Blades tapering, flat. One marginal tooth distinctly
longer than other teeth, with -12 teeth. Shafts of compound
falcigers (Figure 14c) massive, smoothly tapering, with internal
striations (not shown), but without marginal teeth; distal beak