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NUMBER 557 81
hollow rootlets anchor corallum base, the rootlets tending to be
concentrically arranged in cycles. Three to six cycles of
nonexsert septa, the lower cycle septa being highly concave
near calicular edge. Pali absent; columella rudimentary.
TYPE SPECIES.—Rhizotrochus typus Milne Edwards and
Haime, 1848a, by monotypy.
Rhizotrochus typus Milne Edwards and Haime, 1848
PLATES 35a-c, 40/!./
Rhizotrochus typus Milne Edwards and Haime, 1848a:282, pi. 8: fig.
16.—Cairns, 1989a:79-81, pi. 41: figs, f-j [synonymy].
Rhizotrochus niinoi Yabe and Eguchi, 1942b: 136-137, 154-155, pi. 12: fig.
4a,b [new synonym].
Monomyces niinoi.—Eguchi, 1965:292, 2 figs; 1968:C48-49.—Kikuchi,
1968:8, pi. 5: fig. 9.
Monomyces typica.—Eguchi, 1968:C49.
Flabellwn transversale.—Nishimura and Suzuki, 1971:11, pi. 4: fig. 1.
Monomyces uchiuraensis Eguchi, 1972:160, pi. 1: figs. 1-7; 1973:83-84, pi.
1: figs. 1,2.
DISCUSSION.—Based on the 10 small specimens reported
herein, nothing can be added to the characterization (Caims,
1989a) of this species. R. typus is distinguished from the other
Pacific species, R. levidensis Gardiner, 1899 (Loyalty Islands),
by having a rather squat (trochoid) corallum; up to six cycles of
septa; and one to two or more cycles of rootlets (6, 18, >20).
Rhizotrochus levidensis has a much smaller, ceratoid corallum;
an incomplete fourth cycle of septa; and 7 or less rootlets.
At a GCD of 10-12 mm a full four cycles of septa are
usually present; between 12-27 mm the fifth cycle is formed;
and above 27 to 57 mm GCD the sixth cycle is formed, but
never fully completed (Cairns, 1989a). The holotype of R.
niinoi has a GCD of 9.75 mm and has 48 septa (the S4 being
rudimentary), which is consistent with the ontogeny of R.
typus. Furthermore, at this small size it is not unusual for the S1
to be larger and thicker than the S2. It can also be seen from this
small specimen that the pores that lead to the first ring of six
rootlets flank the six Sv whereas the pores that correspond to
the second, higher ring of 6-12 rootlets flank both the S1 and
S2.
MATERIAL EXAMINED.—New Records: Off Misaki, Sagami
Bay, depth unknown, 9, USNM 92750, 1, ORI; Okinose,
Sagami Bay, 110 m, 1, ZMC. Previous Records: Holotype of
R. niinoi, TIUS; Philippine specimens (Caims, 1989a). Reference
Specimens: 3 syntype of R. levidensis, BM 1970.1.26.9-
10.
TYPES.—Two syntypes of R. typus are deposited at the
MNHNP. Type Locality: Singapore, depth unknown.
The holotype (Plate 40h,i) of R. niinoi is deposited at the
TIUS (60820). Type Locality: Hukui Maru-16: Wakasa Bay,
Sea of Japan, Honshu, 76-104 m.
The deposition of the 3 syntypes of Monomyces uchiuraensis
is unknown. Eguchi (1973b) designated a lectotype from the
syntype series (specimen #45), a specimen that was originally
illustrated by Eguchi (1972d, pi. 1: figs. 3, 4). Type Locality:
Near Awashima, Uchiura Bay, Suruga Bay, Honshu, 20 m.
DISTRIBUTION.—Japan: Sagami, Suruga, and Wakasa Bays;
off Amakusa Island, Kyushu; 20-104 m. Elsewhere: Philippines,
Singapore, Pelau, Indonesia, Andaman Islands, Persian
Gulf, Red Sea (see Caims, 1989a); 20-1048 m.
Suborder DENDROPHYLLIINA
Family DENDROPHYLLIIDAE
Balanophyllia Wood, 1844
DIAGNOSIS.—See Part 1.
DISCUSSION.—The taxonomy of the genus Balanophyllia is
quite confused, there being about 53 described Recent species,
at least 31 of which occur in the Indo-West Pacific region. This
number will certainly be refined and perhaps reduced as larger
collections and more types are examined. Not all of the
specimens available for study have been reported herein. In this
regard I agree with Yabe and Eguchi (1942b: 142), who stated:
"Besides the above mentioned species, we have examined
many different forms of the genus Balanophyllia, some of them
may probably constitute new species, but mostly represented
by [a] single, worn specimen; their description are left for
another occasion."
Balanophyllia cumingii Milne Edwards
and Haime, 1848b
PLATE 35d.e
Balanophyllia cumingii Milne Edwards and Haime, 1848b:87-88, pi. 1: fig.
8.—Eguchi. 1968:C51, pi. C21: figs. 7, 8.
Balanophyllia cumingi.—Eguchi, 1934:368.
?Balanophyllia qffinis.—Yafoe and Eguchi, 1942b: 140-141, pi. 12: figs. 11.
12.—Eguchi, 1968:C50-51. pi. C12: figs. 1-3, 7-9, 13, 14.
Balanophyllia cf. cumingii.—Yabe and Eguchi, 1942b: 141 [in part: pi. 12: fig.
13a,b. and specimen from Soyo Maru-429 cataloged as TIUS 58990, not
58236].
Balanophyllia diomedae [sic].—Yabe and Eguchi, 1942b: 142.
?Balanophyllia cf. imperialis— Eguchi, 1968:C52-53, pi. C21: figs. 9, 10.
DESCRIPTION.—Corallum ceratoid and small, the largest
specimen examined (TM (KT9015, CB1-2)) only 10.3 x 7.8
mm in calicular diameter and 18.9 mm in height, with a pedicel
diameter of 4.0 mm. Corallum firmly attached: PD:GCD =
0.40-0.50. Costae porous and coarsely granular. Often a thin
epitheca encircles the lower synapticulotheca, providing a
better substratum for encrusting organisms. Corallum white.
Septa hexamerally arranged in 4-5 cycles, the fourth cycle
complete at a GCD of about 7.5 mm, and the fifth cycle
remaining incomplete (up to total complement of 90 septa)
even in the largest specimens examined. S1-2 equal in size,
about 1.3 mm exsert, and thickened at upper, outer (thecal)
edges such that they fuse with their adjacent lower cycle septa.
Inner edges of S^ straight, vertical, and smooth for upper
half, but becoming dentate to laciniate adjacent to columella.
83.4 equally exsert (about 0.8 mm), the S3 only about half the
width of an S1 _2. In small coralla, each pair of S4 fuse before its
adjacent S3 and extends to the columella as a single septum, its