396 
S.D. Caims 
3.0-3.2. Basal scar small and elliptical: 2.8M.3 x 
2.5-3.3 mm in diameter. One pair of short, 
downward projecting thecal edge spines occurs 
within 2-3 mm of basal scar. Edge spines usually 
only apparent on small specimens, those of larger 
coralla often breaking off and their stubs covered 
by encrusting organisms. Thecal faces usually 
highly encrusted with calcareous epifauna, 
including: bivalves, serpulids, barnacles, bryozoa, 
foraminifera, and acrothoracican cirripede borings. 
Theca otherwise white. Septa hexamerally 
arranged in 6 and often a partial 7th cycle in larger 
coralla according to the formula: S1-4»S5>S6>S7. 
S7 begin to appear at a GCD of 30-33 mm; the 
holotype (GCD = 45.2) has a complement of 
50:50:100:68 (268 septa); and larger coralla increase 
the number of equally large primary septa to 66. 
The shape of the primary septa (Sl-4) is complex. 
Within 0.3-0.4 mm of the calicular edge these septa 
are notched, below which they broaden into a wide 
lobe that often rises slightly above the calicular 
edge. Midway to columella the axial edge of an Sl- 
4 is slightly concave, but nearer the columella the 
septum widens. Inner edges of SI—4 straight and 
thin except near the columella, where they thicken. 
55 only about 1/3 width of Sl-4 near the calicular 
edge, but about 4/5 width of Sl-4 lower in fossa. 
56 about half width of S5. S7 same width as S6 but 
do not extend as far downward from calicular 
edge. Fossa deep and elongate, containing a 
trabecular columella about 1.5 mm wide. 
Remarks 
Because of my previous confusion in identifying 
this species, a complete description is provided 
above, based on the holotype and additional 
specimens from the same region. Comparisons to 
T. spheniscus are made in the account of that species 
and in Table 4. 
Although not apparent from the original 
description, the base of the holotype bears a natural 
scar resulting from transverse division, and the 
remnants of two thecal edge spines, which clearly 
places this species in T rimcatoflabellum. 
Distribution 
Western Australia: continental shelf of 
northwestern coast from Joseph Bonaparte Gulf to 
Nickol Bay; 22-136 m; 23.9° to 28.8°C; sandy, shelly 
substrates. Elsewhere: Northern Territory (Beagle 
Gulf and Anson Bay); 15-115 m; sand and gravel 
substrates. 
Trtincatoflabellum formosum Cairns, 1989 
Truncatoflabellum formosum Cairns, 1989: 69-70; 
1994: 77, pi. 33, figs. g-h.—Cairns and 
Zibrowius, 1997: 169-170. 
New Records 
Lady Basten: stn LB5(s), 8, exWAM 24-96- stn 
LB6(s), 1, WAM 44-96. 
Remarks 
Among the Western Australian 
Truncatoflabellum, T. formosum is most similar to 
T. australiensis, but can be distinguished (Table 4) 
by having a slightly smaller basal scar, and 
decamerally arranged septa, which results in 80, 
instead of 96 septa. 
Most (7 of 9) of the specimens reported above 
bear up to seven thecal burrows of acrothoracican 
cirripedes. 
Distribution 
Western Australia: continental shelf of 
northwestern coast southwest of Rowley Shoals; 
160-173 m. Elsewhere: TIndian Ocean; western 
Pacific from Japan through Indonesia; 42-933 m 
(Caims and Zibrowius 1997). 
Truncatoflabellum australiensis sp. nov. 
Figures 7 d-f, 8 b 
Records 
Other records: "between Shark Bay and Onslow", 
depth unknown, coll. W. and VV. Poole, 1966, 
holotype, WAM 169-83, and 5 paratypes, WAM 
171- and 172-83 and 442-96. 
Soela: stn 05/82/37, 2 paratypes, WAM 59-83; 
stn 05/82/42, 1 paratype, WAM 61-83; stn 05/82/ 
47, 2, WAM 63- and 66-83. 
Umataka Marti: stn 6927, 2 paratypes, WAM 102- 
84. 
Sprightly: stn 34M, 1 paratype, WAM 134-83. 
Diamantina: stn 208, 2 paratypes, WAM 224- and 
225-93. 
Lady Basten stn: LB5(s), 19 paratypes, WAM 24- 
96. 
V\1.A. Haivaiian Expedition: 16-32 km NNW 
Anchor Island, 119 m, 17 VI 1960, 9 paratypes: 6 
(WAM 144-83, 231- and 259-93), 3 (USNM 96652). 
Lady: stn RW96-17, 1 paratype, NTM C8070. 
Type Locality 
"Between Shark Bay and Onslow, WA"; depth 
unknown. 
Description 
Anthocyathus: Angle of thecal edges 44°-73°; 
angle of thecal faces 18°-28°. Holotype 21.9 x 10.8 
mm in calicular diameter and 17.9 mm in height, 
with a basal scar 7.1 x 3.5 mm in diameter; largest 
specimen 25 mm in GCD. Upper calicular edge 
only slightly arched: GCD:LCD = 1.95-2.35. Basal 
scar elliptical and of moderate size, its greater 
diameter ranging from 5.5 to 8.6 mm. Two or 3 
