Willeysthenelais heterochela (Horst 1917)

Sthenelais heterochela Horst, 1917:113, pl. 23: figs. 3–6

MATERIAL EXAMINED.—Sanana Bay, east coast of Sula Besi, 22 meters, mud, Siboga station 193, 13/14 September 1899—holotype (ZMA 1383).

TYPE MATERIAL.—The holotype consists of an anterior fragment of 53 segments, 30 mm in length and 5 mm in width, including setae. It is a female having numerous eggs in the body cavity.

DESCRIPTION.—Wide middorsal ridge on anterior segments, with few pairs of small ctenidia alongside (Figure 14a). Ventral surface smooth. Elytra delicate, transparent, subreniform, smooth except for areas along anterior borders furnished with small rounded microtubercles; lateral borders with long papillae; elytra of anterior and middle regions with lateral notch (Figure 14l–n).

Prostomium with median antenna with large rounded auricles on ceratophore and moderately long tapered style; lateral antennae short, subulate; four eyes arranged in square, moderate in size, anterior pair much largfer than posterior pair, hidden by antennal auricles; palps extending about to segment 7; nuchal organs prominent (Figure 14a,b). Tentacular parapodia with dorsal tentacular cirri subequal in length to median antenna; ventral tentacular cirrus about half as long as dorsal cirrus; inner tentacular lobe not extending beyond tip of ventral tentacular cirrus, fused to shorter, rounded inner palpal sheath; dorsal ctenidium elongate-oval (Figure 14a–c).

Parapodia of segments II and III directed anteriorly, slightly modified from following segments, with more numerous and longer papillae or stylodes. (Figure 14a,d,e). Neurosetae compound falcigerous with blades of 1–4 articles, with elongated terminal inner tooth; stems smooth or with 3–5 spinous rows (Figure 14f); upper simple spinous neurosetae beginning on segment III. Additional small ctenidia located medial to elytrophores of segment II (Figure 14a).

Parapodia of anterior (Figure 14g,h) and middle regions similar. Cirriform branchiae beginning on segment IV. Clavate notopodia with stylodes and fimbriated bracts—few posterior papillae and few papillae or stylodes on lower anterior part. Neuropodial acicular lobes with single oval stylode. Bilobed posterior bracts fimbriated—papillae longer on upper and lower parts. Anteroventral bracts fimbriated, with row of short papillae. Extra papillae (2–4) on lower sides of neuropodia medial to anteroventral bracts. C-shaped group of stout neurosetae with blades short, with greatly elongated inner curved distal tooth; stems smooth (Figure 14j). Upper anterior group simple spinous neurosetae (Figure 14i). Anteroventral slender neurosetae similar to those of middle group (Figure 14k). Ventral cirri tapered, with small outer basal knob; long papillae on medial bases of ventral cirri beginning on segment III (single one), usually 2, sometimes 3.

DISTRIBUTION.—Indonesia. In 22 meters.

Fimbriosthenelais, new genus

TYPE-SPECIES.—Sthenelais longipinnis Grube, 1870. Gender: feminine.

DIAGNOSIS.—Body elongate, vermiform, with numerous segments; broad middorsal ridge on some anterior segments, bordered by few pairs of small ctenidia. Elytra numerous pairs, on segments 2, 4, 5, 7, alternate segments to 27, and continuing on all segments. Elytra large, covering dorsum, with microtubercles or papillae and lateral fringes of papillae [absent in F. laevis (Kinberg) ?]. Dorsal tubercles on segments 3, 6, 8, and alternate segments to 26. Prostomium rounded, fused to first or tentacular segment; median antenna with stout cylindrical ceratophore furnished with lateral auricles and terminal style; lateral antennae fused to inner dorsal sides of tentacular parapodia; four eyes; palps emerging ventral to tentacular parapodia; paired oval nuchal organs (sometimes inconspicuous). Tentacular parapodia extending anteroventral to prostomium, each with pair of tentacular cirri, single aciculum, two bundles of capillary setae, L-shaped inner tentacular lobe with ciliated ridge and fused to inner palpal sheath; ciliated dorsal ctenidium. Parapodia of second or buccal segment extending anteriorly, with ventral buccal cirri longer than those following; small ctenidia on lateral lips and medial to ventral cirri of some anterior segments. Third segment with dorsal tubercles fused to posterior sides of elytrophores of segment II. Neurosetae of segments II and III compound falcigerous with articulate blades and bifid tips.

Branchiae cirriform, ciliated, on external borders of all elytrophores and dorsal tubercles except few anterior ones. Parapodial ctenidia cup-shaped, ciliated, three per parapodium, beginning on segment II. Parapodia with accessory bracts and papillate stylodes. Notopodia clavate, with bracts nearly encircling acicular lobes. Notosetae numerous, arranged in semicircular row and directed posterodorsally, finely spinous, and tapering to capillary tips. Neuropodia with conical acicular lobes; truncate or bilobed C-shaped posterior bracts directed anteriorly on upper and lower margins; crescent-shaped anteroventral and anterior upper bracts. Neurosetae arranged in three groups: upper group within anterior upper bracts, C-shaped group of stouter neurosetae within posterior bracts, and lower arched group of more slender neurosetae within anteroventral bracts. Neurosetae simple spinous (in upper group; sometimes absent) and compound falcigerous with some blades articulate and tips bifid; distal parts of stems smooth or spinous. Ventral cirri subulate, with outer basal knobs (without long papillae on medial bases). Pharynx with eleven or thirteen pairs of papillae and two pairs of jaws.

ETYMOLOGY.—The genus is named for the characteristic fimbriated or papillated parapodial stylodes.

The following species of Sthenelais are referred herein to Fimbriosthenelais, new genus:

1. S. laevis Kinberg, 1858. Society Islands, Central Pacific. See F. laevis (Kinberg).

2. S. longipinnis Grube, 1870. Red Sea. See F.longipinnis (Grube).

3. S.? zetlandica McIntosh, 1876a. North Atlantic off Shetland Islands. See F. zetlandica (McIntosh).

4. S. atlantica McIntosh, 1876b. North Atlantic off Great Britain. See F. zetlandica (McIntosh).

5. S. minor Pruvot and Racovitza, 1895. France. See F. minor (Pruvot and Racovitza).

6. S. sarsi McIntosh, 1897. Norway. See F. zetlandica (McIntosh).

7. S. variabilis var. glabra Potts, 1910. Maldives. See F. longipinnis (Grube).

8. S. variabilis var. hirsuta Potts, 1910. Maldives. See F. hirsuta (Potts).

9. S. calcarea Potts, 1910. Maldives. See F. hirsuta (Potts).

10. S. dubiosa Horst, 1917. Indonesia. See F. longipinnis (Grube).

11. S. minor var. digitata Fauvel, 1919. Red Sea. See F. longipinnis (Grube).

12. S. dahli Augener, 1927. New Britain, Bismark Archipelago. See F. hirsuta (Potts).

13. S. papillosa Day, 1960. South Africa. See F. zetlandica (McIntosh).

14. S. vachoni Rullier, 1964. Cape Verde Islands, off NW Africa. See F. zetlandica (McIntosh).

The following species of Fimbriosthenelais, new genus are recognized:

1. F. laevis (Kinberg).

2. F. longipinnis (Grube).

3. F. zetlandica (McIntosh)

4. F. minor (Pruvot and Racovitza).

5. F. hirsuta (Potts).

6. F. hobbsi new species.