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NUMBER 557 71
edge as low, discontinuous crests. Angle of thecal edges quite
variable, ranging from 74° (coalitum form) to 139° (typical
form); inclination of lateral faces, 27°-42°.Edge angle of lower
5-8 mm of corallum considerably lower (e.g., 48°) than
remainder of corallum. GCD:LCD also variable, ranging from
1.9-2.1 {coalitum form) to 2.4 (typical form). Largest
specimen known (lectotype of F. distinction) 60.6 x 25.1 mm in
calicular diameter and 42.8 mm in height. Holotype of F.
coalitum 32.3 x 14.3 mm in calicular diameter and 30.0 mm in
height. Pedicel circular, 1.0-1.5 mm in diameter, and usually
worn, revealing 6 protosepta. Thecal faces of most specimens
examined discolored and worn; however, in well-preserved
specimens there are narrow brown stripes associated with the
theca overlaying every septum. Calicular edge a smooth arc.
Septa hexamerally arranged in 6 cycles (S1-3>S4>S5>S6),
the last cycle progressively appearing throughout a GCD range
of 30-45 mm, and a full sixth cycle (192 septa) usually attained
at a GCD of 45-47 mm. S1-3 quite wide, their inner edges
extremely sinuous and thick, almost touching their counterparts
from the opposite face. S4 of larger coralla as wide as S^_3, but
have less thick and less sinuous inner edges. S4 of smaller
coralla about 80% width of an S^_3 and thus more easily
distinguished. S5 about half width of an S1-4 and also have
moderately sinuous inner edges. S6 rudimentary, only onequarter
to one-third width of an S5. Fossa very deep and
elongate. Columella an elongate fusion of inner edges of S1_4,
but often obscured from view by the narrow fossa.
DISCUSSION.—Yabe and Eguchi (1942a) synonymized F.
coalitum Marenzeller, 1888a (type locality: Japan) with F.
distinctum Milne Edwards and Haime, 1848a (type locality:
Japan); however, based on an examination of the type series of
both species, I (Cairns, 1989a) maintained their distinction
based on the considerably lower edge angle (74°) and lower
number of septa (130°) of the holotype of F. coalitum. Despite
its long synonymy, F. pavoninum (= F. distinctum) is known
from remarkable few specimens, but the Japanese material
reported herein includes one group (TM (KT8412, 14)) of 44
specimens that displays a range of edge angles of 78°-117° and
a range of septal number from 130°-192°, the septal number
being directly correlated to GCD. Since all other characters of
F. pavoninum and F. coalitum are the same, these Japanese
specimens would appear to link the two extremes of the
species: form coalitum having a relatively low edge angle and
5'/2 septal cycles; the typical form having a greater edge angle
(up to 139°) and 6 full cycles. Although only several of Yabe
and Eguchi's (1942a,b) Japanese specimens were examined
(see "Material Examined"), they all appear to be the coalitum
form of the species.
MATERIAL EXAMINED.—New Records: Alb-5310, 1,
USNM 86552; Alb-5312, 3, USNM 40752; TM (KT78O2, Z2),
1, USNM 92818; TM (KT8412, 14), 38, USNM 92819,6, ORI;
TM (KT9015, CB2-2), 1, USNM 92820; TM (KT9202, KB3),
1, USNM 92815; Tsuchida-45, 1, USNM 92821; Formosa
Strait, 90 m, 2, CAS 74995; East China Sea, southeast of Cheju
Do, 80 m, 1, CAS 74997. Previous Records: Types of F.
pavoninum, F. distinctum, and F. coalitum; F. distinctum of
Yabe and Eguchi (1942b): Soyo Maru-431, 1, TIUS 43448;
Soyo Maru-429, 1, TIUS 39732 (Plate 30/); Sagami Bay, 1,
TIUS 43409; near Seto, 2, TIUS 39236 (Plate 30g,h); F.
distinctum of Marenzeller (1888a), off Japan, NMW 8197
(Plate 31 b,c); F. pavoninum of Marenzeller (1888a), off China,
NMW 8201 (Plate 31a).
TYPES.—The lectotype and 4 paralectotypes of F. pavoninum
are deposited at the MNHNP (#372) (Cairns, 1989a).
Type Locality: "Sandwich Islands" (?Hawaiian Islands),
depth unknown.
The lectotype and 3 paralectotypes of F. distinctum are
deposited at the BM and MNHNP (Cairns, 1989a). Type
Locality: "Japan" (see Gray, 1849), depth unknown.
The holotype (Plate 3ld,e) off. coalitum is deposited at the
NMW (#8196). Type Locality: "Japan," depth unknown.
DISTRIBUTION.—Japan: common off Honshu, Shikoku, and
Kyushu, its northern limits at 39°36'N (Soyo Maru-624) in the
Sea of Japan and 35° 18'N (Hasu Maru-45) on the Pacific coast
of Japan. Also known from Korea Strait and off Cheju Do,
Korea; Formosa Strait; South China Sea north of Pratas Island;
73-658 m. Elsewhere: Hawaiian Islands, southwest Indian
Ocean; 98-665 m.
F lube Hum (F.) patens Moseley, 1881
PLATE 3\g-i
Flabellum patens Moseley, 1881:172 [in part: pi. 6: fig. 5].—Cairns.
1989a:5l-52. pi. 26: figs, a-i [synonymy].
Flabellum pavoninum paripavoninum.—Yabe and Eguchi, 1942a:91-93 [in
part: Soyo Maru-343. 419. pi. 5: fig. 7a-c]; 1942b:129 [in part: Soyo
Maru-M3, 419. not pi. 11, fig. 9).—Eguchi, 1965:291, 2 figs.—Utinomi,
1965:255.
?Flabellum pavoninum lamellulosum.—Yabe and Eguchi, 1942b: 131.
DESCRIPTION.—Corallum highly compressed, having virtually
planar thecal faces that meet at a sharp angle and project as
much as 6 mm as prominent edge crests. Angle of thecal edges
(exclusive of edge crests) 117°-155°, but including the aliform
crests, the thecal edges may approach 180°. Inclination of
lateral faces 20°-32°, the faces of large specimens slightly
concave. GCD:LCD = 2.05-2.50; GCD:H about 1.04, the
corallum being about equally tall as broad. Largest specimen
known (Alb-5313) 67.5 x 28.9 mm in calicular diameter and
54.7 mm in height. Pedicel small and circular, only 1.5-2.0
mm in diameter, and often exposing the 6 protosepta. Theca
white to grey, relatively smooth, and regularly partitioned by
thin intercostal striae. Theca near calice often discolored by an
arched band about 5 mm wide than parallels the calicular edge,
which is the indication of a former association with a
commensal Lumbrineris polychaete (Zibrowius, Southward,
and Day, 1975). Upper calicular edge smooth.
Septa hexamerally arranged in 7 cycles according to the
formula: S,-4>S5>S6»S7. Sixth cycle complete at a GCD of