Smithsonian National Museum of Natural History

Original Description
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"Bostrychopora gen. nov.

Diagnosis

Colony rising from an encrusting base, developing erect, broad, folded, unila­minar sheets. Autozooid frontal wall with inferred cryptocystidean development, bordered by deep areolae, incorporating distinct frontal septula. Vertical walls with small, recessed, multiporous septula. Primary orifice with short condyles, and a well developed proximal lyrula. Paired adventitious avicularia typically present lateral to orifice, enclosed within a peristomial rim, one frequently enlarged ; additional avi­cularia developed along margins of autozooids, budded from marginal septula. Ovicell hyperstomial, coarsely calcified, imperforate ; developing a thickened, su­tured ooecial cover.

Type species : Smittia dentata Waters, 1904.

Discussion

The frontal wall ontogeny, and the form of the orifice of S. dentata Waters (Fig. 3C, D) militate against its retention in Umbonula Hincks, to which it was re­ferred by Rogick (1956). It clearly belongs in the Smittinidae, but does not con­form to the diagnosis of any genus presently recognized within that family.

Consequently, it is practical to introduce a new genus, Bostrychopora, for this endemic Antarctic species. Bostrychopora dentata forms substantial, thickly calcified plates, which may be flat, folded or enrolled. The largest fragments present in the "Discovery" collections had surface areas in excess of 10 cm' , but no complete, undamaged colonies had survived.

Geographical distribution

B. dentata was described by Waters (1904) from the Bellingshausen Sea (70° S, 80° 48' W), and was subsequently reported by Rogick (1956) from Marguerite Bay, Graham Land, on the eastern side of the Bellingshausen Sea, and by Hayward and Taylor (1984) from the Ross Sea. Of the nine large samples in the present collec­tion, one originates from the Palmer Archipelago, close to the type locality ("Discovery" stn. 190), a second from off Oates Land ("Terra Nova" stn. 194), and the rest from the Ross Sea (National Antarctic Expedition, Coulman Isd. ; "Terra Nova" stns. 294, 316, 339, 355 ; "Discovery" stns. 1652, 1660)." (Hayward and Thorpe, 1988: 288)