Conescharellina biarmata ( Maplestone, 1909 )

Bock, Philip E. & Cook, Patricia L., 2004, A review of Australian Conescharellinidae (Bryozoa: Cheilostomata), Memoirs of Museum Victoria 61 (2), pp. 135-182 : 148

Conescharellina biarmata ( Maplestone, 1909) .

Figures 2A, B

Bipora biarmata Maplestone, 1909: 268 , pl. 75 figs 1a, b. Conescharellina biarmata .— Harmer, 1957: 729.

Specimens examined. BMNH 2000.2 .23.2, (4 colonies, part of material sent by Maplestone to BMNH, labelled “cotypes”) ; NMV F98980 , no locality (89 colonies, labelled by Maplestone, probably part of type material) ; NMV F101880 , South Australia, (9 colonies, from Maplestone, with “S.A.” on box) ; NMV F101881 , stn SLOPE-19 (2 colonies) ; NMV F101882 , stn BSS-170 (1 colony) ; NMV F101883 , no locality, slide labelled E3195, suspected material from “Endeavour” (New South Wales) but no other information (2 colonies) .

Description. Colonies very small, conical, distinctly higher than wide. Calcification smooth. Orifices in radial series, patent, with little raised peristome, elongated oval, with a very small sinus formed by paired condyles. Frontal septular pores slit-like. Adapical pore placed just outside the edge of the peristome. Avicularia regularly paired, proximolateral to the orificial sinus, small, elongated, narrow, triangular, with a ligulate bar, orientated laterally and slightly antapically. Lunate root pores adapical, uncommon. Antapical surface with small avicularia in mature specimens, adapical surface solid with kenozooidal calcification and scattered avicularia.

Specimens 2.0– 2.3 mm high, 1.4–1.6 mm wide, and comprise approximately 10–13 astogenetic generations arranged in radial rows. The number of zooids in each whorl, 6–8.

Remarks. Livingstone (1924) placed C. biarmata in the synonymy of C. angulopora . Maplestone’s material differs from Livingstone’s concept of this species in the consistently small colonies, and the characters of orifices and avicularian orientation. Harmer (1957) did not describe C. biarmata but treated it as a distinct species. Maplestone’s specimens are numerous and very consistent in characters that are shared by the specimens from stn SLOPE-19 and the slide E3195. Other specimens with elongated, triangular, paired avicularia from the SLOPE stations differ in several respects and are here described as Conescharellina ecstasis (see below).

Figures

Figure 2. A–B, Conescharellina biarmata (Maplestone, 1909). NMV F98980. A, lateral view of colony, growth direction arrowed, scale=1 mm. B, detail of orifices with adapical pore, avicularia and slit-like frontal septular pores, scale= 100 µm. C–D, Conescharellina multiarmata Maplestone, NMV F98981. C, Lateral view of colony, growth direction arrowed, scale=500 µm, D, detail of orifices from slightly antapical view, showing tubular adapical pores, avicularia and minute frontal septular pores, scale = 200 µm. E–F, Conescharellina multiarmata (Maplestone, 1909). E, NMV F98983, orifices and avicularia; note pattern of septular pores, scale= 200 µm. F, NMV F98982, Antapical view of colony showing small solitary coral. Note paired, marginal peristomial avicularia, scale= 500 µm.