Cigclisula buski n. sp.

(Figs 13–14, Table 3)

Escharoides occlusa Busk, 1884: 150 (in part), pl. 21, fig. 8 (?in part). [Cape York, Australia]

Lepralia occlusa: Kirkpatrick 1890: 604, 612 (?in part). [Torres Straits]

Lepralia occlusa: Waters 1909: 152 (in part), pl. 13, fig. 15; pl. 14, figs 1–9, 13 (?in part). [Cape York, Australia]

Cigclisula occlusa: Hastings 1932: p. 43 (in part), text-fig. 13 (?in part). [Australia]

? Myriozoum occlusum: Marcus 1921: 20, pl. 1, fig. 8; pl. 2, figs 1–2. [Australia]

Material examined. Holotype: NHMUK 1887.12.9.593, ‘ Escharoides occlusa’, G. Busk coll., Challenger Expedition, Stn 186, coral mud, off Cape York, Australia, 10°30’ S, 142°18’ W, ex. Dundee coll. Paratypes: NHMUK 1963.2.12.197; NHMUK 1899.7.1.2139; NHMUK 1899.7.1.4487; NHMUK 1887.12.9.591; NHMUK 1994.1.8.282; NHMUK 1994.1.8.283; USNM 9231 [exchange from NHMUK], same data as holotype .

Type locality. Cape York, Australia .

Diagnosis. Erect, frontal shield with small protuberances; usually 1–2 frontal avicularia; interzooidal avicularia of 2 sizes, with oval foramen; ooecium rugose with 38–50 irregular pseudopores.

Etymology. Honorific for George Busk (1807–1886), the notable bryozoologist who studied the original material.

Description. Colony erect, bilaminar, branching. Zooids hexagonal, longer than wide, delimited by slightly raised lateral walls. Frontal shield thickly calcified, with small protuberances, uniformly punctured by 10–46 pseudopores. Primary orifice small relative to frontal shield, somewhat hoof-shaped, as long as wide, sunken, with high-arched anter; condyles in proximolateral corners delimit a very weakly defined poster with shallow median sinus. Secondary orifice raised, non-tubercular, subcircular. Suboral avicularium elliptical, laterally placed and distally directed, of 2 sizes, 1 small (0.046 –0.071 mm long), the other double-sized, commonly associated with ovicelled zooids and zooids in center of branches. Frontal avicularia small, common, elliptical, 1–2 per zooid, placed at zooidal margins. Interzooidal avicularia of 2 sizes, 1 small the other double-sized; both longer than wide, with broadly spatulate mandible; rostrum with rounded proximal edge, median constriction distinct and distal edge concave; calcified palate occupying more than half rostral length, with oval foramen. Ooecium subglobose, slightly prominent; with small protuberances; ectooecium with longitudinal band of 38–50 irregular pseudopores.

Remarks. Along with C. australis n. sp., this species comprised part of the material described as Escharoides occlusa by Busk (1884). Re-examination of the type material led us to reassign them to three different species (see Remarks under C. occlusa and C. australis n. sp.).

Cigclisula buski n. sp. is characterized by the frontal shield and ooecium with small protuberances, two sizes of interzooidal spatulate avicularia, both with an oval foramen, and an ectooecium with a longitudinal band of 28–50 irregular pseudopores.

Cigclisula buski n. sp. resembles C. cautium, C. fruticosa and C. fissurata in having erect bilaminar colonies, but differs in possessing suboral avicularia of two sizes, a frontal shield with 23–46 pseudopores and ectooecium with 38–50 pseudopores. The species also differs from C. fissurata in the distribution of frontal pseudopores (uniform in C. buski n. sp., marginal in C. fissurata) and frontal and interzooidal avicularia (absent in C. fissurata). Cigclisula fruticosa differs in the distribution of frontal pseudopores (uniform in C. buski n. sp., irregular in C. fruticosa), shape of primary orifice (subelliptical in C. buski n. sp., an elongate D shape with a short U-shaped median sinus in C. fruticosa) and secondary orifice (non-tubercular in C. buski n. sp. and with blunt processes in C. fruticosa).

Distribution. Pacific: Australia (Queensland and Torres Straits).