dcsimg

Description

provided by NMNH Antarctic Invertebrates

3. Aglaoprimnoa Bayer, 1996

FIGURE 3M–S

?Amphilaphis.—Stibane, 1987:25, pl. 1, fig. 2.

Aglaoprimnoa Bayer, 1996a:516.

DIAGNOSIS. Colonies uniplanar, sparsely dichotomously branched, with long terminal branches. Calyces arranged in closely placed whorls of up to 10, the appressed calyces directed upward; calyces cylindrical to cone shaped; brood chambers common. Poorly developed, almost flat operculum present; inner face of opercular scales longitudinally keeled. Marginal scales not differentiated from other body wall scales, folding over bases of opercular scales (Figure 3r). Small calyces covered with eight longitudinal rows of scales, the adaxial rows somewhat shorter; however, larger calyces intercalate additional body wall scales, making the longitudinal row structure indistinct and even appear to spiral (Figure 3s). Outer face of body wall scales smooth but with radiating ridges near distal edge, which interlock with similarly sized ridges on inner distal face of the more proximal scale, preventing lateral displacement of scales as calyx opens and closes (Bayer, 1996a). Coenenchymal scales in two layers: outermost layer consists of highly concave, saucer-like plates (Figure 3q), the inner layer composed of small tuberculate spheroids (Figure 3m).

DISCUSSION. Bayer (1996a) stated that this genus does not have an operculum; however, calyces from the type series and even one figured by him (Bayer, 1996a: fig. 10, bottom) show a distinct, if somewhat ill defined, operculum composed of eight triangular, keeled, opercular scales.

DISTRIBUTION. South Georgia and Burdwood Bank, 70–686 m.

TYPE SPECIES. A. stefanii Bayer, 1996a, by original designation. The holotype is deposited at the USNM (81289).”

(Bayer and Cairns, 2009)

(Bayer, 1996)

(Stibane, 1987)

Aglaoprimnoa, new genus

?Amphilaphis.—Stibane 1987: pl. 1, fig. 2.

not Amphilaphis Studer [and Wright] 1887:50.

Diagnosis.—Large, sparsely dichotomously or laterally branched Primnoidae with long, stout terminal branches. Polyps in regular whorls, directed upward, bent inward and appressed to axis in contraction; sclerites of polyps numerous, placed around body in spirals, longitudinal arrangement obscured by intercalation of scales between original eight rows. Body scales externally concave, fan-shaped; outer layer of coenenchyme with small, saucer-shaped scales and tuberculate bod­ies with outwardly-directed crests; deeper coenenchyme and walls of stem canals with small tuberculate spheroids.

Type Species.—Aglaoprimnoa stefanii, new species.

Etymology.—From Greek αγλαος, splendid, stately + Primnoa, type genus of Primnoidae, named for Prymno, one of the Oceanids. Gender feminine.

Remarks.—The specimen illustrated by Stibane (1987: pl. 1, fig. 2) as "Gattung Amphilaphis . . . mit dichotomer Verzweigung" is strikingly similar to Aglao­primnoa. If the accompanying scale bar is correct, the branches are nearly 1 cm in diameter, much too stout for any known species of Amphilaphis (cf. Kükenthal 1924: 288).”

(Bayer, 1996)