"Fungiacyathus fragilis G. O. Sars, 1872
Fungiacyathus fragilis M. Sars, 1869, pp. 250, 265, 274 (nomen nudum).—G. 0. Sars, 1872; p. 58, pi. 5, figs. 24-32. Cairns, 1979, p. 206. —Zibrowius, 1980, pp. 23, 24, pi. 5, figs. A-J.
Bathyactis symmetrica; Verrill, 1882, p. 313; 1883, p. 65.—Gravier, 1920, p. 97 (part).—Thomson, 1931, p. 9.
Bathyactis hawaiiensis Vaughan, 1907, pp. 145, 146, pi. 27, figs. 1, la.
Fungiocyathus fragilis; Jungersen, 1916, p. 35 (part).—Broch, 1927, p. 8.—Nordgaard, 1929, p. 103.
Description. Base of corallum flat, very thin, sometimes irregularly perforate. Evidence of regeneration from fragments of corallum. Largest specimen reported 45 mm in basal diameter; largest specimen from Subantarctic 25 mm in diameter. Slightly ridged C1-31 radiate from center of base. Septa hexamerally arranged in five complete cy cles, fifth cycle appearing at CD of 9-10 mm. Septal arrangement similar to previously described species: S1 independent; inner edges of septa of remaining cycles fused to one another by thin, perforate triangular lamellae (canopies). Each larger septum forming large nonserrate lobe for most of its length, with few, if any, projecting spines near columella. Height of septal lobes up to one fifth to one fourth of CD. These lobes, as well as all septa, with highly sinuous outer and upper edges, corresponding to septal corrugations. Corrugations vertical near upper edge, becoming more horizontal as they curve toward columella near base. About 12 corrugations per septum, or 1/mm, giving septa 'wrinkled’ aspect. Crests of
corrugations regularly spaced, usually rounded and smooth, but may bear row of low, pointed granules or may even be slightly carinate. Small, pointed granules usually on all septa near columella. Septa extraordinarily fragile. All septa joined to adjacent septa by synapticular plates, these plates increasing in size toward calicular edge. About 7-10 plates occurring per centimeter, continuing to add on as corallum increases in diameter. Columella round and small, sometimes a solid, horizontal lamella but usually a loose fusion of inner edges of larger septa.
Discussion. There are four other nominal Recent species of Fungiacyathus with five cycles of septa. F. fragilis differs from western Atlantic F. pusillus (Pourtales, 1868) in being larger and having sinuous septa, from Indian Ocean F. stephanus (Alcock, 1893) in having a flat base and lower septa, and from Indian Ocean and eastern Pacific F. paliferus (Alcock, 1902) in lacking paliform lobes. It is indistinguishable from F. hawaiiensis (Vaughan, 1907); however, comparisons involving only one specimen (the holotype) cannot be conclusive. F. kikaiensis (Yabe and Eguchi, 1942), also with five cycles, is from the Pliocene-Pleistocene of Japan.
Material. Eltanin sta. 1412 (5+), USNM 47536; sta. 1846 (3), USNM 47537. Specimens of Verrill
[1882], (Yale Peabody Museum, New Haven) YPM 8322 and USNM 47538-47539; specimens of Zibrowius [1980], SME. Holotype of B. hawaiiensis.
Types. One syntype of F. fragilis is deposited at the Oslo Museum (B626). Type-locality: 'Skraaven in Lofoten’; 549 m. The holotype of B. hawaiiensis is deposited at the United States National Museum (20834). Type-locality: between Oahu and Kauai islands, Hawaii; 1761-2056 m.
Distribution. Eastern Atlantic in area bordered by Norway, Cape Verde Islands, and the Azores; off
Massachusetts; off Hawaii; west of South Island, New Zealand; Macquarie Ridge (Map 1). Worldwide
depth range: 285-2200 m; New Zealand-Macquarie records: 1647-1693 m."
Cairns 1982, p. 7, 4Plate 1, figs. 3-7
