394 
S.D. Cairns 
notched near calicular edge (SCI only about 4.3). 
55 about 2/3 width of Sl-4 and thus easily 
distinguishable from them; only slightly sinuous. 
56 about half width of S5, and when present, S7 
rudimentary, composed of a series on low spines 
occurring only near calicular edge of larger 
specimens. Fossa deep and narrow (1.5-2.0 mm in 
width), containing a low, crispate columella. 
Remarks 
Flabellum folkesoni is similar to F. lamellulosum, 
particularly regarding thecal edge angle, edge 
ornamentation, and septal formula, but can be 
distinguished by having highly sinuous axial edges 
of the Sl-4, a smaller pedicel, a narrower face 
angle, a denser coral] um, and smaller S5 in relation 
to the Sl-4. F. folkesoni is also found in shallower, 
warmer waters than F. lamellulosum. 
Flabellum folkesoni might also be confused with 
Truncatoflabellum angiostomum, which occurs in the 
same region at similar depths, both species being 
similarly shaped and about the same size. 
However, T. angiostomum can be distinguished by 
having straight inner edges of the SI—1; a small 
truncated base flanked by two thecal edge spines; 
rounded thecal edges; differently shaped septa; 
and an edge angle that is usually less than 180°. 
Characteristically-shaped (Figs 6h-i) acro- 
thoracican cirripede burrows were found in the 
coralla from four of the stations listed above, some 
coralla having as many as 14 burrows on one thecal 
face. Crescent grooves of commensal lumbrinerid 
polychaetes were also found on coralla from half of 
the stations listed above (see Zibrowius, 
Southward and Day 1975). 
Distribution 
Western Australia: continental shelf of 
northwestern coast from Rowley Shoals to Onslow 
Bay and perhaps as far south as Shark Bay; 124- 
173 m; 19°-22.8°C. 
Etymology 
This species is named in honour of Folke 
Folkeson, who described several new 
azooxanthellate species from Western Australia 
(Folkeson 1919). 
Flabellum (F.) politum Cairns, 1989 
Flabellum politum Cairns, 1989: 53-54, pi. 28, figs, 
a-f (synonymy and description); 1994: 73, pi. 
32, figs. a-c.—Cairns and Zibrowius, 1997: 153- 
154. 
New Records 
Soela: stn 02/82/10A, 1, WAM 48-84; stn 02/82/ 
13A, 15: 11 (WAM 55-84), 4 (USNM 96588); stn 
01/84/85, 1, WAM 682-84; stn 05/82/36, 1, 
WAM 58-83. 
Umataka Marti: stn 6920, 3, WAM 130-84. 
Lady hasten: stn LBlb(s), 2, WAM 9-96; stn LB5(s), 
59, WAM 25-96; stn LB5(t), 16, WAM 21-96; stn 
LB6(s), 2, WAM 43-96. 
Remarks 
Acrothoracican cirripede burrows were present 
on the theca of specimens from half of the stations 
reported above, usually with an infestation rate of 
2 or 3 per corallum. 
Distribution 
Western Australia: continental shelf of 
northwestern coast from south of Scott Reef to Port 
Hedland; 45-220 m; 23.1° C; soft (muddy) 
substrates. Elsewhere: Ryukyu Islands through 
Indonesia; 40—402 m (Cairns and Zibrowius 1997). 
Subgenus Ulocyathus Sars, 1851 
Flabellum (U.) hoffmeisteri Cairns and Parker, 
1992 
Flabellum hoffmeisteri Cairns and Parker, 1992: 47- 
48, pi. 16, figs. d-f.—Cairns, 1995: 103-104, pi. 
33, figs, g-h (synonymy and description).— 
Cairns and Zibrowius, 1997: 157-158. 
New Records 
Soela: stn 01/84/24, 1, NMV F78391; stn 01/84/ 
51, 1, WAM 539-84; stn 01/84/52, 2, WAM 545-84; 
stn 01/84/53, 2, WAM 568- and 569-84; stn 01/ 
84/59, 2, WAM 570- and 571-84; stn 01/84/63, 1, 
WAM 740-84; stn 01/84/64, 13: 9 (WAM 582-84), 
4 (USNM 96595); stn 01/84/65, 3, WAM 664-84; 
stn 01/84/66, 3, WAM 666-84; stn 01/84/67, 11: 7 
(WAM 745-84), 4 (USNM 96638); stn 01/84/71, 1, 
WAM 538-84; stn 01/84/77, 2, WAM 523-84; stn 
01/84/81, 1, WAM 675-84; stn 01/84/91, 1, WAM 
687-84; stn 01/84/116, 3, WAM 698-84; stn 01/84/ 
119, 2, WAM 782- and 783-84; stn 01/84/120, 7, 
WAM 805-84; stn 01/84/121, 3, WAM 781-84; stn 
02/82/17A, 2, WAM 106-83; stn 02/82/35, 1, 
WAM 110-83; stn 04A/82/8B, 1, WAM 85-83. 
Courageous: stn 002, 8, WAM 26-84; stn 003, 8: 6 
(WAM 24-84), 2 (USNM 96591); stn 004, 1, WAM 
37-84; stn 015, 6, WAM 36-84; stn 022, 1, WAM 
32- 84; stn 023, 2, WAM 30-84; stn 090, 1, WAM 
33- 84. 
Remarks 
Flabellum hoffmeisteri is most similar to F. tuthilli, 
but can be distinguished by having lower calicular 
apices; a more elongate corallum with ridged 
primary costae that reach almost to the calicular 
edge; striped costae; and less septa at an equivalent 
