Letepsammia franki Owens, 1994

Fig. 14C, D

Stephanophyllia formosissima . - van der Horst 1927: 7. - Gardiner and Waugh 1939: 234. - Boshoff 1981: 24.

Letepsammia formosissima . - Cairns and Keller 1993: 218.

Letepsammia franki Owens 1994: 586-589, figs 1, 2. - Cairns 1999a: 59. -Seilitz et al. 2020: 2, fig. 2. - Kitahara and Cairns 2021: 57- 58, 60, figs 14, 15A-C.

Type locality.

Off Durban area, South Africa (RV 'Anton Bruun’ stn. 390S: 29°35'00"S, 31°42'00"E); 138 m (Owens 1994).

Type material.

The holotype is deposited at the NMNH (Owens 1994).

Material examined.

ORI_BIVa1 (2 specimens): Eastern margin, Locality data unknown. SAMC_A073050 (14 specimens): Eastern margin, 26 km from Cape Vidal / 25 km off St Lucia Estuary, 27°54'18.00"S, 32°37'59.87"E; 105 m. SAMC_A073151 (7 specimens): Eastern margin, 29 km from Durban / 14 km off Mbokodweni Estuary, 30°06'24.12"S, 31°00'47.88"E; 160- 170 m. SAMC_A073152 (7 specimens): Southern margin, 12 km from Gonubie / 12 km off Gqunube Estuary, 33°01'48.00"S, 28°04'23.87"E; 85 m. SAMC_A073164 (1 specimen): Eastern margin, 28 km from Durban / 14 km off Mbokodweni Estuary, 30°06'00.00"S, 31°01'36.00"E; 245- 250 m. SAMC_A073175 (1 specimen): Eastern margin, 28 km from Coffee Bay / 16 km off Hluleka Estuary, 31°55'58.79"S, 29°25'12.00"E; 300 m. SAMC_A073177 (1 specimen): Eastern margin, 19 km from Coffee Bay / 18 km off Mdumbi Estuary, 32°02'53.87"S, 29°19'41.87"E; 250- 280 m. SAMC_A073178 (4 specimens): Eastern margin, 28 km from Durban / 14 km off Mbokodweni Estuary, 30°06'00.00"S, 31°01'36.00"E; 245- 250 m. SAMC_A073185 (1 specimen): Eastern margin, 19 km from Durban / 14 km off Mbokodweni Estuary, 30°00'36.00"S, 31°03'47.99"E; 140 m. SAMC_A087428 (1 specimen): Locality data unknown, SAMC_A090070 (1 specimen): Eastern margin, 20 km from Durban / 16 km off Beachwood Mangrove, 29°50'12.12"S, 31°12'17.99"E; 95 m. SAMC_A090148 (1 specimen): Eastern margin, 30 km from Durban / 31 km off Tongati Estuary, 29°43'11.99"S, 31°25'47.99"E; 185 m. SAM_H1364 (1 damaged specimen): Eastern margin, 2 km from Durban / 8 km off Umgeni Estuary, 29°51'59.99"S, 31°00'00.00"E; 99 m. SAM_H1429 (1 specimen): Southern margin, 6 km from Kidds Beach / 5 km off Ncera Estuary, 33°11'59.99"S, 27°40'59.99"E; 79 m. SAM_H1453 (1 specimen): Southern margin, 6 km from Kidds Beach / 5 km off Ncera Estuary, 33°11'59.99"S, 27°40'59.99"E; 79 m. SAM_H3126 (2 specimens): Southern margin, 15 km from Port Alfred / 11 km off Riet Estuary, 33°39'18.00"S, 27°01'05.99"E; 90 m. SAM_H3127 (3 specimens): Southern margin, 31 km from Port Alfred / 20 km off Kleinemond (Oos) Estuary, 33°39'24.00"S, 27°11'42.00"E; 86 m. USNM 75640 (7 specimens): Eastern margin, 26 km from Port St. Johns /off Bulolo Estuary, 29°34'47.99"S, 31°41'59.99"E; 138 m.

Imagery data.

BMNH 1939.07.20.401 (1 specimen): Locality data unknown. UCTES_NAD10B (6 specimens): Eastern margin, 29 km from Durban/22 km off Mdloti Estuary, 29°46'00.00"S, 31°16'59.99"E; 110-130 m. Mortensen-Java (4 specimens): Locality data unknown.

Description.

Corallum discoidal (GCD:H = 3.2-4.1), with a flat to convex and porous base. Closely packed septa, with coarse dentition giving the corallum a beaded appearance. Largest specimen examined (SAMC_A073164) 33.5 mm in CD and 8.0 mm in H. Calice circular, with serrated calicular margin. Costae ridged and thin, with closely packed low profile granules resulting in serrated costae. Costal bifurcations correspond to septal pattern. Intercostal spaces porous, thin at calicular margin and broaden towards epicentre of base. Synapticular bars connect each costa to neighbouring septa near calicular margin, and near epicentre of base synapticular bars connect adjacent costae. Marginal shelf low and narrow, reaching a maximum of 3 mm. Corallum white.

Septa arranged in a typical micrabaciid fashion reaching ≤ 120 septa. S1-2 non-bifurcate and straight, with subsequent S3 leading to multiple bifurcations. S1 imperforate and extend from columella to calicular margin. S1 with vertical and slightly dentated axial margin. S2 also straight and extending to columella, but joined by S3 near columella. S2-3 fusions form porous delta bearing numerous spines. S3 bifurcates repeatedly. First bifurcation produces two S3i on either side of S2. Resultant edges of S3i adjacent to S2 bifurcates three more times in which the first bifurcation gives S3ii, second one S3iii, and the last gives two S3iv. S3i adjacent to S1 bifurcates four times, in which the first gives three S3iii and two S3iv. Axial edge of S1-2 and sometimes S3, join the spongy columella.

Distribution.

Regional: Southern to eastern margin of South Africa, from off Port Alfred extending towards Cape Vidal; 79-300 m. Elsewhere: Off Pemba, Tanzania (Gardiner and Waugh 1939); 50-650 m (Owens 1994).

Remarks.

Letepsammia franki was first reported in the region as Stephanophyllia formosissima . This misidentification, together with Boshoff’s (1981) (ORI_BIVa1), was noted by Cairns (1989a) and Cairns and Keller (1993). However, the undescribed species was named a year later by Owens (1994), who emphasiszed the difference between L. franki and L. formosissima to be the closely packed and dentate septa, which gave L. franki a more compact and beaded appearance. Another notable difference between the two species is that S1 are imperforate in L. franki and perforate in L. formosissima .