Panthalis mutilata (Treadwell 1906)

Panthalis mutilata (Treadwell, 1906)

Polynoe mutilata Treadwell, 1906:1152, figs. 12–15.

Eupanthalis oahuensis Treadwell, 1906:1155, figs. 19–23.

Eupanthalis evanida Treadwell, 1926:186, figs. 6–12.

Eupanthalis mutilata.—Hartman, 1938b: 123, fig. 40a–f; 1966a:177.

Panthalis evanida.—Hartman, 1938b:127.

Panthalis mutilata.—Bailey-Brock, 2987:239, fig. 33.II.10a–c.

MATERIAL EXAMINED.—HAWAIIAN ISLANDS. North coast of Molokai Island, Mokapu Inlet, 600 m, fine gray sand, Albatross sta D3892, 18 Apr 1902, 3 paratypes and part of tube of Polynoe mutilata (AMNH 343). Vicinity of Kauai Island, Ukula Point, 584 m, fine gray sand, rocks, Albatross sta D4027, 24 Jun 1902, holotype of Polynoe mutilata (USNM 5204).

PHILIPPINE ISLANDS. Balicasag Island, 09°12′45″N, 123°45′30″E, 1472 m, green mud, globigerina, Albatross sta D5526, 11 Aug 1909, holotype of E. evanida (USNM 19208).

TYPE MATERIAL.—Holotype of Polynoe mutilata consists of anterior and middle fragments, with 73+ segments, 54+ mm long, 6 mm wide with setae; the prostomium is in very poor condition; the pharynx was fully extended, the right lower jaw had been cut out. The three paratypes of P. mutilata are in rather poor condition; a complete female with large yolky eggs has 122 segments, measures 56 mm long, 6 mm wide. The holotype of Eupanthalis evanida consists of an anterior fragment of 44+ segments, 25+ mm long, 12 mm wide; the elytra are mostly missing, the remaining ones soft and crumpled. The type of Eupanthalis oahuensis is missing; it is not in the USNM collections where it was supposed to have been deposited. It was reported from the same Albatross sta D3892 as the 3 paratypes of P. mutilata; based on the description of E. oahuensis, it was referred to E. mutilata by Hartman (1938b:123) when she examined the types in the USNM collections and found E. oahuensis missing.

DESCRIPTION.—Elytra delicate, smooth, oval, with lateral pouch, leaving middorsum uncovered.

Bilobed prostomium with colorless globular ommatophores on anterior half of prostomium; median antenna with small ceratophore on middle of prostomium, with style extending beyond ommatophores; lateral antennae inserted ventrally on ommatophores, with tips extending far beyond ommatophores; ventral palps long, tapered, smooth. Tentacular segment visible dorsally; tentaculophores lateral to prostomium, with small bundle of capillary setae and 2 pairs of dorsal and ventral tentacular cirri, longer and thicker than lateral antennae (Figure 39A; Treadwell, 1926, fig. 6).

Second segment with first pair of elytrophores, long ventral buccal cirri similar to tentacular cirri, and biramous parapodia; notopodium long, digitiform, with numerous long, finely spinous, capillary notosetae extending beyond neurosetae; neuropodium larger, subconical, with prominent anteroventral bract; neurosetae long, spinous, with capillary tips, lower ones shorter with more prominent spines (Figure 39B–D; Treadwell, 1906, figs. 19, 20; Treadwell, 1926, fig. 7). Distal border of extended pharynx with 15 pairs of papillae, middorsal one much longer than others, midventral one slightly longer; two pairs of jaws, each with about 18 lateral teeth (Hartman, 1938b, fig. 40e).

Third segment with pair of dorsal cirri with short cirrophores and styles extending to tips of neurosetae, inflated basally; notopodium short, rounded, with few short notosetae; neuropodium with upper and lower neurosetae similar, lanceolate, spinous; middle row of neurosetae stout, acicular, aristate; ventral cirri tapered, almost as long as dorsal cirri (Figure 39E–G; Treadwell, 1906, figs. 12, 13, 21, 22; Treadwell, 1926, fig. 8–11). Parapodia of segment 4 with few short notosetae, absent more posteriorly (Figure 39H). Segment 8 with dorsal and ventral cirri about equal in length; upper few neurosetae slender, with large spines basally, fine spines distally on tapering curved tip; middle acicular neurosetae with slightly hooked tip with distal hairs, with or without aristae (Figure 40A–C).

Beginning with segment 9, notopodium wide, rounded, flattened, anterodorsal to upper half of neuropodium, with notoaciculum and spinning glands; neuropodium with slightly bilobed presetal acicular lobe, prominent anteroventral bract, and truncate postsetal lobe; three groups of neurosetae: lower group numerous, within anteroventral bract, curved, longer spines basally, tapering to capillary, finely spinous tips; middle group stout acicular neurosetae with slightly hooked tips, hairy distally and subdistally on one side, aristate; upper group, emerging from low anterodorsal bract hidden by notopodium, of 2 types: (a) few (3–5), long, slender, with brush-like tips; (b) more numerous, short, slender, with widely spaced spines and tapered tips (Figure 40D–K; Treadwell, 1906, figs. 14, 15, 23; Treadwell, 1926, fig. 12; Hartman, 1938b, fig. 40a–d,f). Without parapodial branchiae.

TUBE.—The tube is soft, flabby, composed of several layers forming a fibrous mat. According to Treadwell (1906:1153) the outer surface of the thick-walled mud tubes were covered with deposits of thick brown mud.

DISTRIBUTION.—Hawaiian and Philippine Islands. In 584 to 1472 meters.