Polyodontes atromarginatus Horst 1917

Polyodontes atromarginatus Horst, 1917

Polyodontes atromarginatus Horst, 1917:133, pl. 29: figs. 5–7.

Panthalis melanotus [sic].—Ehlers, 1920:22. [Not Panthalis melanotus Grube, 1876.]

Panthalis adumbrata Hongland, 1920:606, pl. 46: figs. 9–14.—Hartman, 1938b:126 [includes Panthalis helleri in synonymy]. [Not sensu Treadwell, 1937:147 (= Polyodontes panamensis).]

Polyodontes melanonotus.—Monro, 1931:8. [Not Polyodontes melanonotus (Grube, 1876) (= Acoetes melanonota).]

Panthalis helleri Holly, 1934:148, figs. 1, 2.

Polyodontes adumbrata.—Hartman, 1939b:82, 87.

Polyodontes maxillosus.—Gibbs, 1971:127. [Not Polyodontes maxillosus (Ranzani, 1817).]

Polyodontes aurorea.—Strelzov, 1972:283, figs. 2A–K, 3A. [Not Eupompe aurorea Grube, 1876.]

MATERIAL EXAMINED.—INDONESIA. Six syntypes of P. atromarginatus from 6 Siboga stations: Bay of Labuan Tring, Lombok, 08°44.5′S, 116°02.5′E, 18–27 m, sta 19 (RNHL 1290); Bima Anchorage, 13–31 m, sta 47 (ZMA 1169.1); Makassar, up to 32 m, sta 71 (ZMA 1169.2); between Loslos and Broken Islands, west off Salawatti, 18 m, sta 162 (ZMA 1169.3); Banda Anchorage, 9–45 m, sta 240 (RNHL 1291; Sapeh Bay, east coast of Sumbawa, up to 36 m, sta 311 (ZMA 1169.4). Amboina, Brach, collector, 1 specimen (ZMH 192, as Panthalis melanotus [sic] by Ehlers, 1920).

PHILIPPINE ISLANDS. Tinakta Island, Sulu Archipelageo, 05°12′N, 119°54′E, 18–33 m, coral sandy and fine sandy bottoms, Albatross sta 5157–5159, 21 Feb 1908, holotype and 4 paratypes of Panthalis adumbrata (USNM 18944–18946).

SOLOMON ISLANDS. Guadalcanal, Graham Point, silty sand with shell and coral fragments, low water, P.E. Gibbs, collector, 1 specimen (BMNH 1970:159, as Polyodontes maxillosus by Gibbs, 1971). New Georgia, Marovo Lagoon, coarse sand, sta ML 204, 3 Nov 1965, P.E. Gibbs, collector, 1 specimen (BMNH 1970:162, as P. maxillosus by Gibbs, 1971).

AUSTRALIA. Great Barrier Reef, west side of Low Isles, 15 m, mixed bottom, 1 specimen (BMNH 1931.7.1.16, as Polyodontes melanonotus by Monro, 1931).

TYPE MATERIAL.—All six syntypes of Polyodontes atromarginatus consist of anterior fragments, 3 with pharynx extended, the largest, from Siboga station 311 (ZMA 1169.4), with 80 segments, 55 mm long, and 12 mm wide with setae; the parapodia in the anterior ventral region were thickly covered with entoprocts (referred to as “strange organisms” by Horst, 1917:134), The smallest syntype, from station 162 (ZMA 1169.3), has 36 segments, 20 mm long, and 10 mm wide with setae; it appears to be the specimen figured by Horst and the one figured here.

The holotype and four paratypes of Panthalis adumbrata (USNM) are all incomplete posteriorly: holotype with 51 segments, 47 mm long, and 9 mm wide with setae; larger paratype with 55 segments, 58 mm long, and 13 mm wide. The type of P. helleri Holly from the Philippines was not available; it was referred to P. adumbrata by Hartman (1938b:136). A specimen from the Solomon Islands, collected by P.E. Gibbs (BMNH), is complete, with 113 segments, 120 mm long, and 8 mm wide with setae.

DESCRIPTION.—Body long, vermiform, transversely banded dorsally with brown pigmentation. Anterior 3 elytra rounded, covering dorsum, following ones transversely elliptical, with shallow lateral pouch, leaving middorsum uncovered; elytra dotted with black pigmentation, with darker band on posterior and medial borders, with surface compactly areolate (Figure 75B; Horst, 1917, pl. 29: fig. 6; Hoagland, 1920, pl. 46: fig. 10; Holly, 1934, fig. 1a,b).

Prostomium bilobed, with bulbous ommatophores with long necks and small distal lenses; median antenna with rounded ceratophore on middle of prostomium, with 1–2 minute lateral papillae, extending posteriorly as middorsal ridge, with style extending to tips of ommatophores; posterior pair of small eyes anterolateral to ceratophore of median antenna; lateral antennae inserted ventrally with tips extending slightly beyond ommatophores; palps stout, long, tapered, with 2 rows of brown spots or transversely banded, with small papillae and longitudinal rows of extra long curved papillae (Figure 75A; Horst, 1917, pl. 29: fig. 5; Hoagland, 1920, pl. 46: fig. 9; Strelzov, 1972, fig. 2A). Tentacular segment distinct dorsally; tentaculophores lateral to prostomium, each with row of papillae on inner side, 2 acicula, 2 small rounded projecting acicular lobes, 2 bundles of capillary setae, and pair of dorsal and ventral tentacular cirri, similar to but slightly longer than median antenna (Figure 75A,C).

Second segment with first pair of elytrophores, ventral buccal cirri much longer than following ventral cirri, and biramous parapodia; notopodium conical, on anterodorsal side of larger neuropodium, with bundle of long, finely spinous, capillary notosetae; neuropodium rounded, with ventral bract; neurosetae slender, slightly enlarged basally, tapering to long finely spinous capillary tips (Figure 76D–F; Strelzov, 1972, fig. 2B). Distal border of extended pharynx with 13, 15, or 17 pairs of border papillae, middorsal and midventral ones on broad bases and longer than other papillae, midventral one sometimes not as elongated as dorsal one; 2 pairs of hooked jaws, each with 3–6 lateral teeth (Horst, 1917, pl. 29: fig. 5).

Third segment with first pair of dorsal cirri, with short cirrophores and tapered styles extending beyond setae; ventral cirri about half as long; notopodium and notosetae similar to those of segment 2; neuropodium with 3 groups of neurosetae: upper ones lanceolate, spinous, with tapered tips; middle ones stouter, acicular, aristate; lower ones curved, lanceolate, with large spines basally and closely packed smaller ones distally, with fine tips (Figure 75G–I). Parapodia of segments 4–8 becoming larger, with fewer and shorter notosetae (Figure 76A,B).

Beginning with segment 9, notopodium wide, rounded, flattened, on anterodorsal half of larger neuropodium, with notoaciculum, spinning glands, and few short notosetae emerging from lower side of notopodium; neuropodium with truncate presetal acicular and postsetal lobes, and more or less developed anteroventral bract; lower group of neurosetae, within anteroventral bract, numerous, similar to more anterior neurosetae; middle row of stout acicular aristate neurosetae; upper group of neurosetae, emanating from low anterodorsal bract, hidden by notopodium, of 2 types: (a) long, lanceolate, with very long hairs basally, tapering to fine hairy tips; (b) short, slender, bipinnate, with sharp tips (Figure 76C–F; Strelzov, 1972, fig. 2C,G).

Middle parapodia becoming larger, with more numerous neurosetae of same types; dorsal cirri with wide, inflated cirrophores and short subulate styles; some of middle stout acicular aristate neurosetae with subdistal spines on one side (Figure 76G–J; Horst, 1917, pl. 29: fig. 7; Hoagland, 1920, pl. 46: figs. 11–14; Holly, 1934, fig. 2a–d; Strelzov, 1972, fig. 2D,I,K). Some indication of blister-like branchiae on few anterior segments, indistinct posteriorly; ventrally, with 2 or 3 translucent bulbous extensions medial to ventral cirri, beginning on segment 12.

DISTRIBUTION.—Indonesia, Philippines, Gulf of Tonkin, Solomon Islands, Australia (Queensland). In low water to 45 meters.

黑边多齿鳞虫（学名：Polyodontes atromarginatus）为蠕鳞虫科多齿鳞虫属的动物。分布于印度尼西亚、所罗门群岛、澳大利亚以及中国南海等海域。