Fenestrulina pumicosa, Branch & Hayward, 2005

Branch, M. L. & Hayward, P. J., 2005, New species of cheilostomatous Bryozoa from subantarctic Marion and Prince Edward Islands, Journal of Natural History 39 (29), pp. 2671-2704 : 2697-2698

Fenestrulina pumicosa sp. nov.

( Figure 11 A–C)

Material

Holotype: St. 16 Marion Island (46 ° 51 9 S, 30 ° 04 9 E), 160–170 m, SAM A27362 . Paratype: St. 39 Marion Island (46 ° 60 9 S, 38 ° 65 9 E), 360–376 m, SAM A27268 .

Description

Colony encrusting on rock, forming small, unilaminar patches. Autozooids large, oval to hexagonal, convex, separated by deep grooves; 0.68–0.72X 0.55–0.6 mm. Frontal shield thickly calcified, coarsely textured with fine radiating, reticulate ripples; central area imperforate; marginal pores large, circular, and closely spaced around the entire periphery; two larger pores on either side of the ascopore. Primary orifice with straight proximal edge, lacking condyles; slightly wider than long; 0.16X 0.13 mm. Six short, thick and slightly flattened, oral spines, four of which persist in ovicelled autozooids. Ascopore about 0.1 mm diameter, separated from the proximal rim of the orifice by a distance equivalent to twofifths orifice length; crescentic, with finely toothed rim, set within a smooth, round to transversely oval dished plate. Ovicell distinctive, with a deep, thick, ectooecial rim and a flat, ridged frontal entooecium bordered by pores; wider than long, 0.45X 0.4 mm.

Etymology

Latin, pumicosus, resembling pumice, with reference to the frontal shield calcification of the zooids.

Remarks

Species of Fenestrulina occur in all the seas of the world, and the genus seems to be especially speciose in Antarctica and the subantarctic realm ( Hayward and Ryland 1990; Hayward 1995). Each species is readily distinguished by the size and proportions of the primary orifice, number of spines, morphology of the ascopore and its position relative to the primary orifice, and to some extent by its frontal shield calcification, and perforation. Fenestrulina pumicosa sp. nov. is especially characterized by its unusual ovicell, the broad border of ectooecial calcification being perhaps unique within the genus.

Superfamily CELLEPOROIDEA Johnston, 1838 Family PHIDOLOPORIDAE Gabb and Horn, 1862

Figures

Figure 11. (A–C) Fenestrulina pumicosa sp. nov., SAM A27362: (A) ovicelled autozooid, X70; (B) autozooids, X45; (C) primary orifice and ascopore, X110. (D–G) Microporella mandibulata sp. nov., SAM A27554: (D) autozooid, X100; (E) ascopore, X180; (F) avicularium, X180; (G) avicularium with long mandible, X150.