378 
S.D. Cairns 
and a tendency to have a curved corallum, instead 
of being straight. 
Distribution 
Western Australia: continental slope of 
northwestern coast from Kimberley to Rowley 
Shoals; 224-260 m. Elsewhere: Indonesia (Banda 
Sea, Arafura Sea); 176-263 m (Cairns and 
Zibrowius 1997). 
Etymology 
The species name decamera (Latin decern, ten + 
camera, chamber) alludes to the decameral 
symmetry of the species resulting in ten equal 
chambers, or systems, of septa. 
Genus Crispatotrochus Tenison Woods, 1878b 
Crispatotrochus mgosus Cairns, 1995 
Crispatotrochus rugosus Cairns, 1995: 57, pi. 13, figs, 
a-b.—Cairns and Zibrowius, 1997: 104. 
New Record 
Soela: stn 01/84/55, 6, WAM 560-84 and 453-96. 
Distribution 
Western Australia: continental slope off Cape 
Leveque, Dampier Land; 296-298 m. Elsewhere: 
Philippines; Malaysia; Kermadec Islands; Lord 
Howe Seamount Chain; 142-508 m (Cairns and 
Zibrowius 1997). 
Crispatotrochus inomatus Tenison Woods, 1878b 
Figure 2 g-h 
Crispatotrochus inomatus Tenison Woods, 1878b: 
309-310, pi. 6, figs. 2a-c.—Cairns and Parker, 
1992: 20-21, pi. 5, figs, a, d, g-h (synonymy and 
description). 
New Records 
Soela: stn 01/84/74, 1, WAM 534-84. 
Lady: stn RW96-29, 1, NTM C8087. 
Distribution 
Western Australia: continental slope south of 
Cartier Island and west of Browse Island; 302-400 
m. Elsewhere: southeastern Australia off Victoria 
and New South Wales; 146-220 m (Cairns and 
Parker 1992). 
Genus Oxysmilia Duchassaing, 1870 
Oxysmilia circularis sp. nov. 
Figure 2 i-k 
Records 
Soela: stn 02/82/16, holotype, WAM 102-83; stn 
02/82/17, cluster of 9 paratypes, WAM 105-83; stn 
02/83/13A, 4 paratypes: 1 (WAM 85-84), 3 (USNM 
96990). 
Type Locality 
18°41'S, 117°54'E (off Port Hedland, WA); 200- 
204 m. 
Description 
Corallum elongate-conical, straight to 
slightly bent, and attached by a slender 
(PD:GCD = 0.26-0.28), nonreinforced pedicel. 
Holotype 19.1 mm in calicular diameter, 31 
mm in height, and 5.5 mm in pedicel 
diameter. Calice circular. Theca heavily 
encrusted with calcareous epifauna, obscuring 
costae. Septa hexamerally arranged in 5 
cycles, the fifth not complete: 
S1>S2>S3>S4>S5. Holotype contains 66 septa: 
5 half-systems with no S5, 5 having 1 pair of 
S5, and 2 having 2 pairs of S5. SI slightly 
exsert (about 1.2 mm), with straight, 
thickened inner edges reaching to columella. 
S2 about 4/5 width of the SI, also having 
straight inner edges. S3 4/5 width of the S2, 
with straight inner edges. S4 half width of the 
S3, unless flanked by a pair of S5, in which 
case they are almost as large as the S3, the S5 
being half the width of the S4. Septal faces 
bear numerous very small, low granules, 
resulting in almost smooth, planar faces. 
Fossa deep, containing a papillose columella 
composed of 1-10 slender, irregularly-shaped 
pillars. 
Remarks 
Only one other Recent species is known in this 
genus, O. rotimdifolia (Milne Edwards and Haime 
1848a), endemic to the western Atlantic at depths 
of 46-640 m (Cairns 1979). O. circularis differs in 
having a circular calice (that of O. rotimdifolia is 
elliptical); SI that are wider than the S2 (SI and 
S2 are equal in width in O. rotimdifolia); a 
nonreinforced base (the base of O. rotimdifolia is 
often reinforced with rings of exothecal rootlets); 
and in having fewer septa (66 vs 96+), although 
larger coralla of O, circularis may prove to have a 
complete fifth cycle. 
Distribution 
Western Australia: continental slope of 
northwestern coast off Port Hedland and south of 
Rowley Shoals; 201-404 m; 9.6°-16.2°C. 
Etymology 
This species name circularis (Latin circularis, 
round) refers to the round calice of this 
species. 
