New species of cheilostomatous Bryozoa from subantarctic Marion and Prince Edward Islands

Fifteen new species of cheilostomatous Bryozoa are described from the subantarctic Marion and Prince Edward Islands: Pyriporoides judyae, Valdemunitella dianae, Cornucopina elongata, Cornucopina bryonyae, Cornucopina antlera, Paracellaria elizabethae, Filaguria lithocrustata, Celleporella marionensis, Catenicella glabrosa, Ipsibuffonella hyalina, Parkermavella corrugata, Calloporina spinosa, Fenestrulina pumicosa, Microporella mandibulata, and Reteporellina berylae. Two species originally described from the region, Sclerodomus myriozoides and Reteporella gigantea, are here reported for only the second time, while three others, Celleporella alia, Celleporella bougainvillei, and Talivittaticella frigida, represent new records for Marion Island. Phonicosia jousseaumei was previously recorded from Marion Island as P. circinata.


Introduction
The phylum Bryozoa is one of the most numerically abundant and species-rich zoobenthic taxa in the waters around subantarctic Marion and Prince Edward Islands (MPE), which are situated at 46u509S, 37u509E in the Southern Ocean. The bryozoan fauna of these islands has never been the subject of a dedicated study, although there was sporadic collecting through the second half of the 19th century. For example, Busk (1854) described ''Smittia'' marionensis from material given to the British Museum by J. Hooker. Three stations were sampled in the relatively shallow area between Marion and Prince Edward Islands by the HMS Challenger expedition in 1873, at 80-150 m; a few new species from these collections were described in a small paper by Goldstein (1882), while Busk (1884) recorded a total of 23 species and two ''varieties'' from the same three samples. RRS Discovery II visited the islands in 1935, and in her Discovery report on the cellularine families Hastings (1943) recorded seven species, from three stations, between 90 and 100 m depth. D 'Hondt (1984) listed seven taxa collected by a French cruise in 1976, but gave no further details. The bulk of the collections originating from Discovery Investigations elongate oval, smooth-surfaced, imperforate; a narrow, longitudinal area of endooecium exposed frontally, the edges of the ectooecium developing as a pronounced ridge; 0.17 mm long60.19 mm wide. An irregularly shaped kenozooid is always present distal to the ovicell, with a portion of membranous frontal wall underlain by a granular cryptocyst ( Figure 2B). Avicularia not observed. Basal pore chambers present in vertical walls.

Etymology
Named for the first author's sister, Judy Maré.

Remarks
Pyriporoides was introduced by Hayward and Thorpe (1989) for the Antarctic species Membranipora uniserialis Waters, 1904. The autozooids of P. uniserialis are shortly clavate, without the proximal cauda seen in P. judyae; they are characterized by a broad cryptocystal shelf, but bear only a distal circlet of six short spines. The ovicell has a short longitudinal ridge, perhaps indicative of an occluded endooecial fenestra. The genus Daisyella was introduced by Gordon (1989) for two species of calloporids with encrusting, uniserial growth form, from deep waters off south-east New Zealand. Rosso and Taylor (2002) described a third species from two localities off southern Iceland, also in deep water, and provided a review of known calloporid genera with uniserial growth habit. Most of the species attributed to the seven genera reviewed by Rosso and Taylor (2002) are known from comparatively few samples and, as they note, data on ancestrula morphology, early astogeny and budding patterns may lead to a re-evaluation of generic distinctions.

Description
Colony an encrusting, unilaminar sheet. Autozooids elongate-oval, separated by deep grooves marking the incurving lateral walls; 0.5-0.6560.3-0.35 mm. Gymnocyst reduced, smoothly calcified; cryptocyst developed as a narrow, coarsely granular rim bordering an elongate oval opesia. Four stout distal oral spines present, the distal-most pair obscured in ovicelled zooids; an additional 9-12 slender, tapered spines evenly spaced around the frontal membrane, slightly curved medially. Avicularia absent in all four specimens. Ovicell distinctly bipartite, with a conspicuous longitudinal, median suture; frontal fenestrae, on each side of the suture, large, occupying most of the frontal surface of the ovicell, tapered proximo-laterally, with thickened rims. Vertical walls of autozooids deep, with multiporous septula.

Etymology
Named for Diana Gianakouras, leader of the University of Cape Town offshore sampling group.

Remarks
The type species of Valdemunitella, V. valdemunita Hincks, 1885, was described from Napier, New Zealand. It has been recorded from a number of other localities in New Zealand, and from Sydney Harbour, New South Wales (Gordon 1986). The few other species presently assigned to the genus are distributed in the New Zealand region, and northwards to south-east Australia. However, Valdemunitella has only recently been detached from the synonymy of Crassimarginatella Canu, 1900, and it is possible that other species presently accommodated in the latter genus may prove to belong to Valdemunitella, which may then be found to have a far wider geographical distribution. All species of Valdemunitella have in common the medially sutured ovicell with paired frontal fenestrae. Valdemunitella dianae sp. nov. and V. fraudatrix Gordon, 1986, from New Zealand, have a similar number of spines, but the ovicellular fenestrae of the latter are smaller in relation to the rest of the ovicell, and narrower than in V. dianae, and while Gordon (1986) reported large vicarious avicularia in his species, none has been discovered in V. dianae sp. nov. All specimens found were encrusting biogenic carbonates, namely worm tubes and bryozoans.  Other material. St. 45 Marion Island (47u009S,37u559E), 420-540 m, SAM A27532.

Description
Colony erect, branching, delicate; made up of two alternating rows of club-shaped zooids. Autozooids with broad distal portion, 0.4-0.5560.25 mm, projecting from the branch axis, and a slender, proximal (axial) portion 0.8-1.0 mm long; opesia elongate-oval, occupying two-thirds of frontal surface of distal portion. Four to five curved, cylindrical spines spaced along the disto-basal wall of the autozooid, up to 1 mm long, and two or more spines on the lateral, axial side of the autozooid; one shorter, proximo-lateral spine. A short, pedunculate avicularium present, fronto-lateral in position, close to the border of the opesia; up to 0.2 mm long and 0.12 mm across the top with hooked, triangular rostrum. Ovicell not observed.

Etymology
Named with reference to the disposition of the disto-basal spines of the autozooid.

Remarks
Cornucopina antlera sp. nov. is characterized by the combination of a short frontal avicularium, the lack of a disto-lateral process and the antler-like arrangement of the spines. Several other species of Cornucopina are known in which the spines arise directly from the disto-basal wall of the autozooid, rather than from an elongate dorso-lateral process.
Cornucopina antlera may be distinguished from all of them by its short, oval opesia, which does not extend close to the colony axis, and in its small, fronto-laterally situated avicularia. The samples were obtained from depths of 200-540 m; that from St. 45 lacked avicularia.

Description
Colony erect, branching, delicate; each branch made up of two alternating rows of clubshaped zooids. Autozooid with a broad distal portion, 0.560.2 mm, projecting from the axis of the colony, and a slender proximal (axial) portion, 0.7-0.8 mm long; opesia elongate oval, occupying entire frontal surface of distal portion. A long, slender disto-lateral process extends from the frontal side of each autozooid, 0.5 mm long with a maximum thickness of 0.1 mm, bearing a group of two to four articulating, curved, cylindrical spines at the tip (up to 1 mm long) and two spines along its length; two more, short, spines present on the distobasal side of the autozooid. Avicularia sparse, arising from the basal surface of the autozooid, close to the branch axis; very long and slender, abruptly widening distally to resemble a straight coach-horn shape, up to 1 mm long and 0.18 mm across the top, with a terminal, hooked rostrum bearing a short triangular mandible. Ovicell slightly longer than wide, 0.4160.40 mm; smoothly calcified, with a frontal lip.

Etymology
Latin, elongatus, prolonged: with reference to the elongate disto-lateral process of the autozooid.

Remarks
The lax, feathery colonies of Cornucopina species are frequently damaged by collection, and taxonomically informative structures, such as avicularia, are readily lost. Thus, it is possible that this new species may possess more than one type of avicularium. In its elongate distolateral process, with two to four terminal spines, and its slender coach horn-shaped avicularia, Cornucopina elongata sp. nov. most resembles C. moluccensis (Busk, 1884), recorded from the Malay Archipelago (Busk 1884;Harmer 1926), off Somalia (Hasenbank 1932) and from Three Kings Island, northern New Zealand (Hastings 1943). However, in C. moluccensis the opesia is irregularly triangular in outline, extending disto-laterally along part of the spine-bearing process, quite unlike the oval opesia of C. elongata sp. nov. Further, judging from the figures of Busk (1884) and Harmer (1926), the avicularia of C. moluccensis are proportionately far stouter, and broader distally, than the slender avicularia of C. elongata sp. nov. D 'Hondt (1984) listed C. moluccensis from Marion Island, but provided neither a figure nor description of his material.

Description
Colony erect, branching, delicate; made up of two alternating rows of club-shaped zooids. Autozooids with a broad distal portion, projecting from branch axis, 0.5-0.5560.25 mm, and a slender, proximal (axial) portion, 0.6-0.7 mm long; opesia elongate oval, occupying entire frontal surface of distal portion. A thick disto-lateral process extends from the frontal side of each autozooid, 0.5-0.660.1 mm, typically no longer than the broad distal portion, slightly broadened at its tip where it bears five to six curved, cylindrical spines, up to 1 mm long; an additional spine present on the disto-basal side of each autozooid. Three types of avicularia present, each with a terminal rostrum, bearing a short, triangular mandible: a short pedunculate type, up to 0.2 mm long and 0.07 mm across the top, frontal in position and proximal to the frontal membrane; a larger, stouter, trumpet-shaped avicularium present latero-basally, midway along the length of the distal portion of the autozooid, 0.3 mm long, 0.12 mm across rostrum; this may be replaced by an even larger type, almost clavate in form, up to 0.7 mm long and 0.2 mm across the rostrum. Ovicell globular, flexed towards axis, wider than long (0.4360.4 mm), smooth, with faint striations radiating from the frontal lip.

Etymology
Named for the first author's daughter, Bryony Branch.

Remarks
Cornucopina bryonyae sp. nov. is characterized by the combination of three types of avicularia and an unusually stout disto-lateral process, bearing spines along the distal third of its length. Polymorphic avicularia are characteristic of many species of Cornucopina, and their variety, morphology and point of origin on the bearing autozooid are taxonomically significant characters. The very stout, almost clavate avicularium, budded from a laterobasal position on the abaxial side of the autozooid, is presently unique to C. bryonyae, and distinguishes it from all other described species of the genus.
Cornucopina pectogemma (Goldstein, 1882) is the common Cornucopina species at Marion Island, which is the type locality for the species. Colonies are flexuose, forming large, dense, feathery tufts up to 10 cm long. Autozooids are rather small, distal portion 0.35-0.4 mm60.15-0.2 mm, proximal (axial) portion 0.5-0.65 mm long. The five to nine curved spines arise directly from the disto-basal wall of the autozooid. Very long and slender coach horn-like avicularia are characteristic, and together with the lack of a distolateral process bearing the spines, distinguish this species from C. elongata sp. nov. and C. bryonyae sp. nov. The characteristic avicularia, differently proportioned autozooids and fewer, shorter spines distinguish C. antlera sp. nov. from C. pectogemma.

Description
Colony delicate, translucent, branching dichotomously at frequent and regular intervals, each new ramus separated from the preceding internode by a fracture joint and secured by chitinous rhizoids; up to about 30 mm, internodes usually less than 5 mm long and 0.5 mm wide. Autozooids disposed in alternating whorls of three; elongate hexagonal, separated by thin raised ridges; 0.55-0.7060.40-0.45 mm. Opesia situated close to the distal border of the autozooid, comprising ca one-tenth of total autozooid length; semicircular, slightly wider than long, 0.160.09 mm, with raised, thickened rim; a short, thick denticle visible in each proximo-lateral corner. Cryptocyst concave, smooth medially, grading to finely granular; a pair of curving cryptocystal ridges, with distinctly crenulated edges, extend for ca two-thirds of autozooid length, from adjacent to the opesia, where they are raised and prominent. Avicularia interzooidal, smaller than autozooids, triangular to diamond shaped, with narrow triangular rostrum, 0.1 mm long, directed disto-lateral to the axis of the internode.

Etymology
Named for the first author's mother-in-law, Elizabeth Branch.

Remarks
Paracellaria elizabethae sp. nov. is especially characterized by its short, wide opesia, and the disto-lateral orientation of the avicularium, features particularly important in distinguishing species of this genus. Paracellaria is presently constituted by the endemic Antarctic type species, P. wandeli (Calvet, 1909), by the subantarctic P. calveti (d 'Hondt, 1984) and P. elephantina (Hayward and Thorpe, 1989), and by P. cellarioides (Hayward and Thorpe, 1989), which is known from the southern Patagonian shelf. Raised cryptocystal ridges are seen in all of the latter three species. Paracellaria cellarioides differs from P. elizabethae sp. nov. in its distally directed avicularia and elongate opesia, and in the arrangement of autozooids, in spiral whorls of eight. In P. calveti autozooids are arranged in whorls of four, the opesia is proportionately shorter and broader than that of P. elizabethae sp. nov., and the projecting distal portions of the crytocystal ridges meet and fuse medially. Paracellaria elephantina, finally, has proximo-laterally orientated avicularia, and an opesia that is much longer than wide.

Description
Colonies forming small irregular patches on rock, thickly calcified. Autozooids oval, convex, separated by deep grooves; 0.8-1.160.55-0.6 mm. Gymnocyst reduced forming a smooth, imperforate rim around autozooid. Frontal shield consisting of 14-21 (most commonly 18-20) broad costae, not touching around the edges of the shield but fused medially, and at two to three points along their length, leaving large round lacunae between them. One small uncalcified spot (pelmatidium) present on the surface of most costae, usually at the second point of fusion between adjacent costae. The distalmost pair of costae with broad bases, and especially thickened, forming a stout, nodular apertural bar. Aperture bordered by four to six (usually five) short, stout, flattened and basally jointed oral spines; proximal pair persist in ovicelled zooids. Large avicularia absent. Ovicell elongate oval, about 0.3 mm long60.4 mm wide; hyperstomial, with a longitudinal median ridge and, on each side, an elongate, drop-shaped, transverse frontal fenestra; closed by autozooidal operculum. Small, irregularly shaped kenozooids sporadically distributed throughout the colony, lacking an aperture and with a complete, though reduced, frontal shield.

Etymology
Greek, lithos, stone; Latin, crusta, shell or rind, with reference to the growth habit of the species.

Remarks
Filaguria lithocrustata sp. nov. is very similar to the Antarctic species Filaguria spatulata (Calvet, 1909), which also has about 20 costae, fused medially and at one or two points along their length, and four to five oral spines. However, in F. spatulata the uncalcified spots on the surfaces of the costae are situated close to the median line of fusion of the costae (Moyano 1991, Plates 8, 9), while in F. lithocrustata sp. nov. they are not median in position, but usually close to the second point of lateral fusion between adjacent costae. Filaguria lithocrustata differs from F. spatulata in its larger autozooids, and in the prominent, thickened apertural bar, which does not occur in the latter species. The ovicell of F. lithocrustata sp. nov. has a distinctive shape, with narrow drop-shaped fenestrae, and large avicularia are absent. D' Hondt (1979) listed F. spatulata from Heard Island and McDonald Island, in the southern Indian Ocean, although it is otherwise known no further north than the South Shetland Isles. The source of d'Hondt's records is not apparent.

Description
Colony erect, branching, jointed, up to 10 mm high, attached by chitinous rhizoids. Singlezooid internodes 0.77-0.84 mm60.32 mm, lightly calcified; orifice D-shaped, as long as wide, 0.1 mm; costate frontal shield slightly larger than the orifice, comprising five fused costae with five conspicuous infra-costal pores, the distalmost pair, bordering the aperture, about three times as wide as the rest. Proximo-lateral pore chambers (vittae) extending along the proximal half of the zooid, elongate oval and shallow with a few small median pores. Two smaller chambers lateral to the orifice and shield, and a further pair of small chambers distal to the orifice. A pair of small avicularia at disto-lateral corners of autozooid, single at dichotomy; rostrum 0.04 mm long. No brooding zooids present. In older parts of the colony rhizoids partly cover and obscure the zooids.

Remarks
This is only the third record of T. frigida, and represents a considerable extension of its geographical range. It was described from a single station in the Bellingshausen Sea, at 580 m (Waters 1904), and recorded, and figured, by Ló pez Gappa and Lichtschein (1990) from a single locality on the southern Patagonian shelf, at 145 m. Talivittaticella was introduced (Gordon and d 'Hondt 1985) for three species with deep-sea distributions. Talivittaticella frigida is unique in the genus, but similar to other Catenicellidae, in evidently ranging into far shallower water.

Description
Colony erect, branching, jointed, up to 10 mm or more high. Sterile internodes consist of a single, slender autozooid, 0.8560.28 mm; dichotomous branching occurs at bizooidal internodes, the disto-lateral autozooid slightly narrower than the other autozooids; fertile internodes subterminal, bizooidal, the proximal zooid short and broad, the ovicell as long as the zooid, occupying most of the frontal surface of the distal zooid. Frontal shield smoothly calcified, imperforate; each zooid with a pair of narrow and elongate, curving, lateral pore chambers (vittae), extending from just distal to the node, to level with the orifice, each with a single line of pores. Primary orifice D-shaped, as wide as long, 0.12 mm; proximal border formed by an inconspicuous pair of residual costae, with a single minute pore medioproximally; condyles not apparent. Distolateral corners of single autozooids each with a small avicularium, with obtuse-triangular rostrum, 0.03 mm long, distally directed. A small (suprascapular?) chamber apparent distal to the avicularium in single autozooids; presence or absence of a (subscapular) chamber proximal to it not established. Originating autozooids at a dichotomy with a single avicularium; ovicell-bearing zooids with a pair of short, cylindrical disto-lateral processes (damaged in all specimens). Ovicell as long as wide, smoothly calcified, imperforate but with indistinct, longitudinal frontal striations.

Etymology
Latin, glaber, smooth, with reference to the calcification of the zooids.

Remarks
The generic assignment of this species is only provisional. Its slender autozooids, with narrow, elongate vittae and short disto-lateral processes, are similar to those of many species of Catenicella. However, the ovicell of C. glabrosa differs from those of other described species of the genus in its smooth, imperforate ectooecial calcification. The apparent lack of condyles is also unusual for a species of Catenicella. Talivittaticella Gordon and d 'Hondt, 1985 is characterized by a very reduced costate frontal shield, visible as three to five minute costae, closely fused just proximal to the primary orifice, and by subterminal, bizooidal fertile internodes. SEM reveals a single pair of much reduced costae constituting the proximal edge of the primary orifice in C. glabrosa sp. nov., and the bizooidal fertile internodes are also similar to those seen in Talivittaticella. However, the ovicell of Talivittaticella, in those species in which it is known, typically has an uncalcified portion of ectooecium frontally, and the vittae are broad and shallow, with very few pores. Unfortunately, much of the material available for study is damaged; details of the morphology of the distolateral chambers and avicularia are unclear, and confident generic assigment must await the collection of better, more extensive material.

Description
Colony forming thick, fan-shaped sheets, encrusting pebbles, coherent but with small spaces between the tubular communication structures linking adjacent zooids. Autozooids, ovicelled female zooids and presumed male zooids present. Autozooids elongate oval, convex; commonly 0.4-0.456,0.2 mm; primary orifice as long as wide, 0.09 mm; with a deep U-shaped sinus comprising approximately one-fifth total length and occupying half the total proximal width; condyles distinct, bifid; frontal shield with coarse, transverse corrugations and three to four prominent umbones in a longitudinal series down the midline. Female zooid slightly shorter than autozooid; primary orifice wider than long, more or less D-shaped, proximal edge almost straight, with a short, narrow, U-shaped sinus; frontal shield with three to four prominent umbones in a median longitudinal series, the distalmost umbo not completely obscuring the orifice; ovicell globular with about six large pores around its periphery, and up to nine blunt umbones on its frontal surface. Male zooids smaller than autozoids, up to 0.3 mm long, with smaller orifice, 0.04 mm wide. Ancestrula not present.

Etymology
Named with reference to the type locality.

Remarks
This species is most similar to C. bougainvillei (d'Orbigny, 1842), which is common in shallow coastal waters of magellanic South America and ranges southwards to South Georgia and the tip of the Antarctic Peninsula. It differs in the proportionately larger sinus of the autozooid orifice, and in the morphology of the female zooid, in which the sinus is proportionately much smaller than in the latter species, and distinctly parallel-sided rather than rounded. The ovicell of C. marionensis is similar to that seen in some populations of C. bougainvillei in having peripheral perforations (Moyano 1986), but differs in bearing a conspicuous group of frontal umbones. Significantly, all specimens of C. marionensis sp. nov. encrusted pebbles from depths of 35-84 m, while C. bougainvillei seems to be invariably associated with algae. Celleporella bougainvillei is also recorded here from Marion Island, considerably extending its known geographical range. However, in view of the facts that the type locality of C. bougainvillei is the Falkland Isles; that d'Orbigny's original materials do not seem to have been described or figured again since the introduction of the taxon, and that Moyano (1986) has drawn attention to morphological differences between geographically remote populations of the species, it may prove to be that this extensive range encompasses several similar but distinct species.
Celleporella alia Hayward, 1993, previously known only from the South Orkney Islands, South Georgia and the southern Patagonian Shelf, is also here recorded from Marion Island. It forms thin, translucent sheets on bryozoans and on hydrozoans such as Lafoea dumosa and Symplectoscyphus subdichotomous The autozooids of C. alia are closely conjoined and rather flat; the frontal shield bears fine longitudinal ridges and transverse wrinkles but umbones are small and sparsely developed. The female zooid has an ovicell with about 20 tubaeform pores, and its orifice has a V-shaped sinus.

Description
Colony, erect, branching at irregular intervals, attached basally by chitinous rhizoids; at least 40 mm high, with cylindrical branches up to 1 mm diameter. Autozooids in four alternating longitudinal series (two series at branch tips), their apertures occupying about three-quarters of the branch circumference, defining a clear abfrontal surface; approximately 0.860.4 mm but individual autozooid boundaries indistinct. Aperture circular, wider than long; 0.260.16 mm, with a low, medio-proximal umbo, more pronounced in early ontogeny; a short lip present within the proximal rim, and a laterally orientated, adventitious avicularium, with short, triangular mandible, situated below it, deep within the peristome. A small laterally orientated frontal avicularium present proximal to the aperture in a minority of autozooids. Frontal shield of autozooids with marginal perforations; developing a reticulate secondary calcification which thickens progressively, and appearing regularly porous with elongate perforations in sinuous lines around the apertures. Ovicell not apparent in present material.

Remarks
Reteporella myriozoides was founded by Busk (1884) on material from a single station, at 210-500 fm depth, off Crozet Island, and does not seem to have been collected subsequently. Gordon (1988) re-examined, and redescribed, Busk's specimens, demonstrating that R. myriozoides should be assigned to Sclerodomus. SEM illustrations of a syntype specimen (Gordon 1988, Figures 12-15) are closely similar to those of the Marion Island material ( Figure 6C, D). Gordon stated that autozooids of the Crozet syntype colony were ordered in six longitudinal series, whereas those of the Marion Island specimens are in series of four. However, this difference may be an astogenetic or ecophenotypic effect, in other respects the Marion Island species seems identical to S. myriozoides, and considering the proximity of the two localities a single taxon seems most probable.

Description
Colony unilaminar, forming partly attached curled sheets. Autozooids in regular, spreading rows, broad, rectangular to irregularly polygonal; 0.5-0.760.35-0.45 mm; frontal shield flat to slightly convex, coarsely granular, with a corrugated, reticulate surface; large circular marginal pores only, occasionally two rows distally. Primary orifice about as wide as long, 0.13 mm, with a broad, shallow sinus occupying about two-thirds of its proximal width; condyles small, blunt. Four distal, oral spines present, usually lost in later ontogeny, and obscured in ovicelled autozooids. Each autozooid with one small adventitious avicularium medio-proximal to the orifice, on a low prominence, the rostrum elongate oval, slightly acute to distal plane, directed proximally; crossbar slender, palate with an extensive foramen; dimorphic avicularia, as long as the orifice and with a lingulate rostrum, replacing the small type in some autozooids; both types of avicularia present in a single colony. Ovicell globose, slightly wider than long; 0.2560.20 mm; smoothly calcified, perforated by about 24 small, thick-rimmed pores. Basal pore chambers and mural septula present.

Etymology
Latin, corrugatus, wrinkled, with reference to the frontal shield calcification of the zooids.

Remarks
Parkermavella was introduced by Gordon and d 'Hondt (1997) for two new species from New Caledonia, and for a suite of species from the Australian region variously attributed to Hippomenella, Schizoporella, and Schizomavella. The morphology of Parkermavella corrugata sp. nov. recalls those south-west Pacific species formerly attributed to the northern hemisphere genus Schizomavella (which has an evenly perforated frontal shield, and is most similar to P. punctigera (MacGillivray) (see Gordon 1984)). It differs from that species in its larger, flatter autozooids, and broader, shallower sinus, and in possessing four rather than six, distal oral spines. The holotype colony was encrusting the bryozoan ''Myriozoum'' marionense Busk, 1884, while other specimens grew on shell (SAM A27500) or formed thick, white patches on rock (SAM A27558, A27570).

Etymology
Greek, hyalinos, glassy, with reference to the calcification of the zooid frontal shield.

Remarks
Ipsibuffonella was introduced by Gordon and d 'Hondt (1997) for I. repens, recorded from 675 m on the northern Norfolk Ridge, New Caledonia. This new species resembles I. repens in its imperforate cryptocystal frontal shield, the shape of the primary orifice, and lack of spines, and in the ovicell, which in I. hyalina is almost completely composed of endooecial calcification. While the lateral walls of I. hyalina are low, they do not form the smooth slope continuous with the frontal shield, seen in I. repens, and the colony consists of a coherent sheet, without the tendency to uniserial growth seen in the latter. Avicularia have not been found in this new species, but they are present medio-proximal to the orifice in I. repens.

Description
Colony forming small rounded patches, encrusting on rock. Autozooids oval to hexagonal, convex, separated by distinct sutures; 0.55-0.6560.35-0.4 mm. Primary orifice slightly wider than long, 0.160.09 mm, sinus narrowly U-shaped 0.02 mm, parallel-sided, condyles short and broad, occupying entire proximal border of orifice on either side of the sinus. Six to eight oral spines spaced around lateral and distal margins of orifice, three pairs persisting in ovicelled autozooids. Frontal wall thinly calcified, glossy, hyaline, smooth; imperforate except for a single series of large, widely spaced marginal pores, with two to three adjacent to the sinus, on each side. Ovicell 0.3 mm long, slightly longer than wide; basal ring of ectooecium thickly calcified, with basal pores, entooecium smooth.

Remarks
Phonicosia jousseaumei, the type species of the genus, was originally described from the Magellan Strait (Jullien 1888). Hayward (1991) re-examined Jullien's holotype specimen, and considered that it represented the same species collected by Discovery Investigations from the southern Patagonian shelf, Gough Island, the South Sandwich Islands, and Marion Island. However, following Powell (1967) and Gordon (1984Gordon ( , 1984, these records were attributed to the Indo-West Pacific species, P. circinata (MacGillivray). Powell (1967) noted two ''forms'' of P. circinata in material from New Zealand, and Gordon (1984) recorded further morphological variation in specimens from the Kermadec Ridge. It is possible that the broad geographical range attributed to P. circinata is founded upon several different species; D. P. Gordon (in litt.) considers that, at least, P. jousseaumei is distinct from P. circinata and, on the basis of Hayward's (1991) examination of Jullien's holotype, the Marion Island species is here referred to the former.

Description
Colony a flat unilaminar sheet, encrusting rock. Autozooids oval to hexagonal, convex, separated by distinct grooves; 0.7-0.860.4-0.6 mm; frontal shield with distinctive surface of smooth nodules, and sparse small pores. Primary orifice slightly wider than long, ca 0.1060.09 mm; the rim with fine denticulation revealed by SEM, proximal border straight, the proximo-lateral corners slightly convex; a raised peristomial rim surrounds the entire orifice. Six short, cylindrical spines spaced around lateral and distal borders of orifice. Ascopore prominent, separated from proximal border of orifice by a distance equivalent to ca two-thirds orifice length; crescentic, its rim with fine denticulations that do not fuse. The ascopore is enclosed within a cupped depression, raised proximally as a projecting umbo. A single large adventitious avicularium on each autozooid, adjacent or slightly proximal to ascopore, disto-laterally orientated; rostrum acute to frontal plane, short, bluntly triangular and supporting a slender, setiform mandible, 0.2 mm long. Ovicells not present in sample. Large basal pore chambers present. The specimen was smothered with diatoms.

Remarks
Species of Microporella have been described from shelf and coastal waters worldwide, and many are confusingly similar. Pending a review of this apparently homogenous, and species-rich genus (Taylor and Mawatari 2003), taxa are best characterized by the shape and dimensions of the primary orifice, the number of spines, the morphology of the ascopore and its position relative to the primary orifice, and the morphology and position of the avicularium. In all of these characters M. mandibulata is distinct from those southern hemisphere species presently adequately described, and illustrated by SEM (e.g. Gordon 1984Gordon , 1989, but distinctions between it and other described species will be best made following systematic revision of the genus on a worldwide basis.

Description
Colony encrusting on rock, forming small, unilaminar patches. Autozooids oval to hexagonal, convex, separated by thin ridges marking the vertical walls; 0.55-0.660.4-0.45 mm. Frontal shield irregularly spinous, the ''spines'' representing projections of the frontal calcification; imperforate centrally, but with large, rounded areolar pores closely spaced around the margin. Primary orifice slightly wider than long, 0.160.09 mm, with straight proximal border. Six short, cylindrical oral spines present. Ascopore close to the proximal border of the orifice, separated from it by a distance equivalent to one-quarter orifice length; narrowly crescentic, with a toothed rim, set within a shallow dish, ca 0.05 mm diameter; a thick, raised peristome, with coarsely crenulated edge, extends proximally between the bases of the proximal spine pair, enclosing the ascopore. One or two large pores present within the peristome, close to the proximo-lateral corners of the orifice, and equally large pores are present around the distal end of the autozooid. Ovicell not found.

Etymology
Latin, spinosus, thorny, with reference to the spinous frontal shield calcification of the zooids.

Remarks
The rather robust frontal calcification, with deep areolar pores, and the flaring peristome enclosing the ascopore, suggest that this new species is more appropriately accommodated within Calloporina than Fenestrulina, although the distinction between the two genera is perhaps becoming less clear. Calloporina is characterized by a thickly calcified ovicell, with only a narrow area of entooecium exposed frontally. Most species bear adventitious avicularia, and have large marginal areolar pores. However, in Calloporina patagonica Hayward and Ryland, 1990 avicularia are only sparsely present and the ovicell has a broad frontal area of exposed entooecium, and rather resembles that of Fenestrulina pumicosa sp. nov. (below). The thick peristomial calcification seen in C. spinosa sp. nov. is also a feature of C. patagonica. Further material of this new species is required before its taxonomic affinity can be confidently established. It is apparent, however, that the systematics of Fenestrulina, Calloporina, and related genera in the southern hemisphere are in need of review. Calloporina was introduced for a Miocene fossil, C. decorata (Reuss, 1848), that is said to be extant, though rare, in the Mediterranean (Zabala and Maluquer 1988). With the exception of C. patagonica, the genus is otherwise known from the western Pacific, from Japan to Australasia, and from Tertiary deposits of Australia and New Zealand.

Description
Colony encrusting on rock, forming small, unilaminar patches. Autozooids large, oval to hexagonal, convex, separated by deep grooves; 0.68-0.7260.55-0.6 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; 0.1660.13 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, 0.4560.4 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.  medio-proximal sinus; a long fluted peristome develops in early ontogeny, its rim flared laterally, and produced into a number of short, blunt processes, and with a distinct medioproximal notch; no oral spines. Frontal shield granular, with few (less than five) large marginal pores proximally. Small, frontal adventitious avicularia sporadic, sometimes paired, rostrum triangular. Larger avicularia sparsely present, with enlarged cystid and elongate triangular rostrum, almost perpendicular to frontal plane and orientated obliquely proximally. Ovicell hyperstomial, initially prominent but becoming partly obscured by a granular ooecial cover; with a V-shaped frontal fissure; aperture overhung by a short labellum.

Etymology
Named for the first author's sister, Beryl Britten.

Remarks
Reteporellina berylae sp. nov. is characterized by the distinctive fenestration, small frontal avicularia with short triangular rostrum, and enlarged avicularia with straight, triangular rostrum. The colony is more robust and irregularly fenestrate than that of Reteporella gigantea (Busk, 1884), another species of phidoloprid found at Marion Island, which has avicularia in the lip of the orifice as well as small adventitious avicularia with a semicircular rostrum on the frontal surface of the autozooid.

Description
Colony forms large, erect, reticulate lacy fans, to 30 mm high, with horizontal spread of at least 30 mm. Branches (trabeculae) 0.8-1.2 mm in diameter, fusing at regular intervals, leaving diamond-shaped to oval spaces (fenestrulae) between them, usually 3-4.5 mm long and 0.9-1.7 mm wide. Autozooids in two to three alternating, longitudinal series (four prior to trabecular division), opening on one surface, elongate, separated by clear, raised sutures, 0.5-0.960.35-0.5 mm. Primary orifice circular, obscured in early ontogeny by a low, thick-rimmed peristome, enclosing a small medio-proximal avicularium with a finely denticulate, semicircular rostrum, adjacent to a small, round pseudospiramen. No oral spines apparent. Frontal shield granular, with a few (less than six) large pores scattered on the surface. One or two small, frontal adventitious avicularia present on each autozooid, with semicircular rostrum. Irregularly shaped kenozooids sporadically present between the autozooids, particularly adjacent to trabecular fusion/anastomosis; each bearing one or two adventitious avicularia. Ovicell hyperstomial, partly obscured by a granular ooecial cover; with a narrow, straight frontal fissure.

Remarks
Reteporella gigantea was described by Busk (1884) from Possession Island (46u479S, 51u379E) and has not been reported again since. It is particularly characterized by its large, broadly open, fan-like colony form, by the small pseudospiramen set close to the proximal rim of the peristome, and by its small adventitious avicularia, occurring singly within the peristome, and elsewhere on the frontal shield. Busk (1884) noted a second type of avicularium, with a slender, acuminate mandible, sparsely present in his material, but none were noted in the Marion Island specimens.

Conclusion
The 57 stations sampled by the University of Cape Town survey in the vicinity of Marion and Prince Edward Islands yielded a total of 78 bryozoan taxa. Although 15 of these are considered to be new to science, eight others could only be attributed to genus, as the material was either too scanty, or damaged, to allow confident identification. An additional four species recorded in the sparse early literature results in a provisional list of just 82 species (M. L. Branch and P. J. Hayward, in preparation). While there is no inventory of the bryozoan fauna for any of the islands of the subantarctic Southern Ocean with which to make comparison, it is likely that the species list for MPE underestimates the actual fauna. This is hardly surprising considering the cost and effort associated with benthic survey work in remote and harsh locations, and that the University of Cape Town survey was the first in more than a century of oceanographic research to be devoted to this island group. Repeated surveys will be required before the fauna can be considered to be as well known as, even, that of the Scotia Arc and the Antarctic Peninsula.
The zoogeography of the MPE bryozoan fauna is potentially of interest, partly in establishing the extent of its similarity to the other islands of the Indian Ocean sector of the Southern Ocean, and to those of the South Atlantic sector, and partly for the contribution it might make towards a further understanding of the origins of the Antarctic bryozoan faunas. Hastings (1943) recorded 11 species of cellularine cheilostomes from MPE, five of which occurred also at Kerguelen, to the east, and five others which ranged westward to the South Atlantic islands; no species appeared to be endemic to MPE. The provisional list of MPE bryozoan species (M. L. Branch and P. J. Hayward, in preparation) includes six described species which are still known only from these islands, and the 15 new species might suggest that a significant degree of endemism could be expected. However, the provisional nature of the MPE inventory must be stressed, as must the fact that the faunas of all other subantarctic islands, and indeed of much of the Antarctic Scotia Arc region, are scarcely better known. There is a continuing need for taxonomic and systematic research on the bryozoan faunas of all shelf environments of the Southern Ocean.