Eunice unidentata Rioja 1962

Eunice unidentata Rioja, 1962

Eunice unidentata Rioja, 1962:175–178, figs. 77–83.

COMMENTS ON MATERIAL.—Rioja did not leave any material of this or any of the other species he described from Mexico (Maria Elena Caso and Vivianne Solis Weiss, in litt.). The following description summarizes what is known about this species based on his description and illustrations.

DESCRIPTION.—Specimens 80–100 mm long and 2–3 mm wide.

Prostomium distinctly shorter than peristomium, about as wide as peristomium. Prostomial lobes frontally rounded; median groove shallow. Small eyes hidden below peristomial fold. Antennae in a horseshoe, evenly spaced, similar in thickness. Ceratophores long in all antennae, with 4 to 5 distinct, short articulations. Ceratostyles slender and tapering, not articulated. All antennae short; not outreaching peristomium; A-III longest, A-II slightly shorter and A-I shortest. Peristomium cylindrical. Separation between rings distinct at least dorsally. Peristomial cirri tapering, short, without articulations.

Maxillary formula unknown.

Branchiae present, pectinate, distinctly longer than notopodial cirri, not reduced in mid-body region, erect. Branchiae from setiger 23 absent on last or 1/4 of body. Branchiae terminating well before posterior end, present on less than 55% of total number of setigers. Maximum 5 filaments reached at about setiger 35 and lasting through setiger 70. Filaments long, digitiform.

Parapodial features not described in detail by Rioja. Median parapodium (Rioja, 1962, fig. 78) with truncate, possibly slightly excavate neuropodial acicular lobes; aciculae emerging at midline. Presetal and possibly postsetal lobes low, transverse folds. Ventral cirri basally inflated with large, thick, tapering tips in median parapodia. Notopodial cirri tapering, without articulations.

Pectinate setae flat, flaring. One marginal tooth longer than other teeth; ∼17 teeth present. Shafts of compound falcigers inflated, marginally smooth. Appendages short and triangular with very large heads, bidentate. Proximal teeth triangular and directed laterally. Distal teeth of about same size as proximal teeth, curved. Guards symmetrically rounded, mucros absent. Pseudocompound falcigers and compound spinigers absent. Aciculae with dark (black) cores and clear sheaths, distally straight, bluntly pointed; cross-sections round. Subacicular hooks with dark cores and clear sheaths, distally tapering, unidentate. Hooks first present from setigers 20–25.

UNKNOWN MORPHOLOGICAL FEATURES.—Many prostomial and peristomial features; jaw structure; many parapodial features; pygidium and anal cirri.

EXPECTED STATES OF SELECTED UNKNOWN FEATURES.—None.

CHARACTERS USED IN PREPARATION OF KEY NOT SCORED.—Inappropriate Characters: 22, 56. Unknown Characters: 1,4–6, 8, 12, 14, 24–26, 36, 39, 40, 45, 47, 48, 50–52, 57–61,63,64,81,82.

ASSUMED STATES FOR PURPOSE OF PREPARING KEY.—None.