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38-41 mm; seventh cycle gradually added up to a GCD of
about 65 mm at which size all 384 septa are usually present.
S1_4 equal in size only in large coralla, the S4 being slightly
less wide than S1-3 in smaller coralla; regardless of size, inner
edges of all S^ attain the columella. Upper, inner edges of
S1-4 moderately sinuous, becoming thicker and more sinuous
deeper in fossa. S5 half to three-quarters width of S1_4, have
moderately sinuous inner edges, and do not attain the
columella. S6 about one-third width of S5, and S7, if present,
rudimentary: only about 0.5 mm wide and 2-3 mm long. Fossa
deep and narrow, formed by vertical inner edges of S1_4.
Columella elongate, composed of a trabecular to solid fusion of
the lower, inner edges of the S1_4, as much as 30 mm long and
about 2 mm wide.
DISCUSSION.—Several of the Indo-West Pacific species of
Flabellum (Flabellum) were compared by Cairns (1989a, table
5) and further distinguished by discriminant analysis (Cairns,
1989b). Flabellum patens was found to be most similar to F.
pavoninum, differing primarily in corallum shape. To quantify
the difference in shape, F. patens has a lower face angle
(20°-32° vs 32°-42° for F. pavoninum), a higher GCD:LCD
(2.05-2.50 vs 1.98-2.41), a lower GCD:H (1.04 vs 1.34),
higher edge crests (4.8-6.1 vs 2.5-3.8 mm), and a tendency to
have S7.
Yabe and Eguchi's (1942a) report of F. pavoninum
lamellulosum from off Seto was not illustrated and their two
specimens cannot be located, but based on their description,
these specimens would appear to be F. patens.
MATERIAL EXAMINED.—New Records: Alb-5313, 8,
USNM 40757,2, ORI; Alb-5314,1, USNM 92813; YO70-770,
1, USNM 92314; off Pengue, Taiwan, 3, CAS 74993. Previous
Records: 4 syntypes of F. patens, BM; F. pavoninum
paripavoninum of Yabe and Eguchi (1942a,e): Soyo Maru-4\9,
1, TIUS 43441; 5oyo Maru-343, 1, TIUS 43445.
TYPES.—The lectotype and 5 paralectotypes of F. patens are
deposited at the BM, the lectotype designated by Cairns
(1989a:52). Type Locality: Challenger-192: 5°49'S,
132°14'E (Kei Islands, Banda Sea), 256 m.
DISTRIBUTION.—Japan: Kii Strait, Honshu; off northeastern
Shikoku; off southwestern Kyushu; Formosa Strait; South
China Sea north of Pratas Island; 223-402 m. Elsewhere:
Philippines, Banda Sea; 256-439 m.
Flabellum (F.) magnificum Marenzeller, 1904
PLATE 31./-/
Flabellum magnificum Marenzeller. 19O4a:276-277.pl. 17: fig. 13.—Utinomi,
1965:255.—Cairns, 1989a:5O-51, pi. 25: figs, a-j [synonymy].
Flabellum pavoninum.—Yabe and Eguchi. I942a:90-91. pi. 5: fig. 2a-c [in
part Soyo Marn-437]; 1942b: 129. pi. 11: fig. 7a-c.
Flabellum pavoninum magnificum.—Yabe and Eguchi, 1942a:89-90, pi. 5:
fig. la-c; 1942b:129, pi. 11: fig. 8a-c.
DIAGNOSIS.—Angle of thecal edges 140°-172°; inclination
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY
of planar thecal faces quite open, 44°-58°. Discontinuous edge
crests usually not present. Thecal faces bear reddish brown
stripes associated with each costa. Pedicel narrow, only
1.5-2.3 mm in diameter. Ratio of GCD:LCD = 1.65-1.96.
Septa hexamerally arranged in 7 cycles, the last cycle never
complete, the largest known specimen having 376 septa. Septal
formula: S1_4>S5>S6>S7. Columella well developed.
DISCUSSION.—No additional specimens of this large and
elegant species are reported herein. It is known in Japanese
waters from only four specimens reported by Yabe and Eguchi
(1942a,b) and Utinomi (1965). A full description and illustrations
are given by Cairns (1989a). It is distinguished (Cairns,
1989a,b) from other Indo-West Pacific Flabellum by attaining
a very large corallum size with up to 7 cycles of septa, having
the largest face angle (44°-58°), and having very long lateral
edges.
MATERIAL EXAMINED.—New Records: None. Previous
Records: Soyo Maru-437, 1, TIUS 43448 (F. pavoninum of
Yabe and Eguchi, 1942a) (Plate 31»; Soyo Marw-416, 1, TIUS
50094 (F. p. magnificum of Yabe and Eguchi, 1942a).
TYPES.—The holotype appears to be lost from the ZMB (see
Cairns, 1989a). Type Locality: Valdivia-199: 0° 15.57*,
98°04'E (off western Sumatra), 470 m.
DISTRIBUTION.—Japan: Off Seto, Kii Strait, Honshu; off
southeastern Shikoku; East China Sea off southwestern Kyushu
(induing off Danjo Gunto); 307-700 m. Elsewhere: Philippines,
Indonesia, west of Sumatra; 291-616 m.
Flabellum (F.) angustum Yabe and Eguchi, 1942
PLATE 31/
Flabellum disticlum angustum Yabe and Eguchi, 1942a:95, pi. 6: figs. 5-7;
1942b: 131.—Eguchi, 1968:C4.
DISCUSSION.—A new subspecies of F. distinctum was
described by Yabe and Eguchi (1942a,b) based on 60 Pliocene
coralla from Kochi-ken, Shikoku. Although a Recent specimen
from Sagami Bay was also attributed to this taxon, Yabe and
Eguchi (1942a) clearly indicated that the type locality
corresponded to the fossil locality and illustrated only fossil
specimens. Their rationale for the new subspecies was that the
specimens had edge angles less than 70°. In fact, the edge angle
of the fossil specimens is bimodal, ranging from 102°-123°
near the pedicel to 52°-54° in upper corallum. The fossil
specimens from Shikoku do appear to be a separate species, but
the Recent specimen(s) from Sagami Bay were not illustrated
and were not examined by the author.
MATERIAL EXAMINED.—New Records: None. Previous
Records: Syntypes of F. p. angustum, TIUS.
TYPES AND TYPE LOCALITIES.—Sixty syntypes (Plate 31/)
from the Pliocene of Tonohama, Kochi-ken, Shikoku are
deposited at the TIUS (43436). Additional Recent syntypes
from Sagami Bay are also deposited at the TIUS (59333).
DISTRIBUTION.—Known only from the type localities.