Flabellum (Ulocyathus) lowekeyesi Squires & Ralph, 1965

Fig. 11M, N

Flabellum lowekeyesi Squires & Ralph, 1965: 259-261, figs 1, 2. - Squires and Keyes 1967: 27, pl. 6, figs 1, 2.

Flabellum (Ulocyathus) lowekeyesi . - Cairns 1989a: 54. - Cairns and Keller 1993: 262, fig. 10 D, E. - Cairns 1995: 100-101, pl. 32, figs G-I. -Cairns 2004a: 304. - Kitahara and Cairns 2021: 200-202, figs 100I-L, 101.

Type locality.

Off Cape Brett, New Zealand (stn. 29: 26 miles off Cape Brett); 732 m (Squires and Ralph 1965).

Type material.

The holotype is deposited at the MoNZ and one paratype at the NMNH (Cairns 1995).

Material examined.

SAM_H1695 (1 specimen): Eastern margin, 49 km south of Ponta Do Ouro / 37 km off Kosi Bay Estuary, 27°17'30.00"S, 32°54'59.99"E; 720-780 m. SAM_H1696 (1 specimen): Eastern margin, 44 km south of Ponta Do Ouro / 32 km off Kosi Bay Estuary, 27°14'47.99"S, 32°54'35.99"E; 700 m. SAM_H2814 (2 specimens): Eastern margin, 36 km from St. Lucia / 34 km off Mfolozi Estuary, 28°37'47.99"S, 32°38'29.99"E; 1200- 1000 m. SAM_H3095 (1 specimen): Eastern margin, 17 km from St. Lucia Estuary / 16 km off Mfolozi Estuary, 28°21'53.99"S, 32°34'36.00"E; 775-825 m.

Description.

Corallum unattached and bearing a narrow and circular pedicel. Calice compressed (GCD:LCD = 1.3), with highly lacerated calicular margin. Largest specimen examined (SAM_H2814) 27.6 × 20.9 mm in CD, 30.1 mm in H, and 2.8 mm in PD. Thecal faces straight and diverging in an angle between 55-73°. Thecal edge short and continuously crested. Angle of thecal edges (excluding crest) between 160-190°. C1-3 well developed and extending from calicular margin towards base. Theca bear chevron-shaped growth lines, and fine granulation. Corallum predominantly white, but pedicel, intercostal striae, and axial septal faces reddish brown.

Septa hexamerally arranged in a variable number of cycles. Examined specimens have five or six cycles, last being incomplete, according to the formula: S1-3> S4> S5> S6 (88-110 septa). S1-3 equidistant and joining columella deep in fossa with straight and thickened axial margins. S4 ~ 1/3 the size of S1-3, and also have straight axial margin. S5 rudimentary in specimens with fifth cycle incomplete, but ½ the width of S4 in specimens having sixth cycle incomplete. S6 rudimentary. Septal faces finely granular. Fossa deep, narrow, with a trabecular columella following the shape of the curved corallum.

Distribution.

Regional: Eastern margin of South Africa, off St. Lucia extending towards Kosi Bay Estuary (49 km south of Ponta Do Ouro: Mozambique); 700-1200 m. Elsewhere: Off Mozambique; Mascarene Plateau; Madagascar (Cairns and Keller 1993); New Caledonia (Kitahara and Cairns 2021); Tasmania; New Zealand (Squires and Ralph 1965; Cairns 1995, 2004a); 278-1100 m.

Remarks.

Specimens represent at range extension, from Mozambique to South African territory. Flabellum (U.) lowekeyesi closely resembles F. messum Alcock, 1902a but differs in its greater thecal edge angle, tendency of S4 axial margin to fuse to adjacent septa, larger white coralla, and smaller pedicel (Cairns 1989a, 1995).