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TYPE SPECIES.—Phyllangia americana Milne Edwards and
Haime, 1849, by subsequent designation (Milne Edwards and
Haime, 185Oa:xliv).
Phyllangia hayamaensis (Eguchi, 1968)
Astrangia hayamaensis Eguchi, 1968:C26, pi. C27: figs. 8-10; pi. C28: fig.
7.—Wells, 1983:233.
Phyllangia hayamaensis.—Cairns, 1991 a: 18.
DIAGNOSIS.—This species is known only from the holotype
colony, which is about 7.4 cm wide and consists of an
encrusting corallum of about 40 corallites. Unfortunately this
specimen is not available for study and thus the following
diagnosis is taken from the original description. Corallites
cylindrical, up to 7 x 6 mm in diameter and 7 mm in height, and
bud from a thick, common basal coenosteum. Theca thin and
covered with small granules. Septal symmetry octameral, each
coral lite having 8 primary, 8 secondary, and 2-5 pairs of
tertiary septa, for a total of 20-26 septa. Primary septa thick,
exsert, and have entire (smooth) vertical inner edges. Secondary
septa only slightly less wide but have dentate inner edges.
S3 rudimentary and also have dentate inner edges. A crown of
8 paliform lobes (P2) occur before the secondary septa.
Columella spongy.
DISCUSSION.—Wells (1983) implied that A. hayamaensis
belonged in the genus Phyllangia by stating that it was a
"related species" to Phyllangia consagensis. I concur that the
species belongs to Phyllangia, but suggest that it is probably
more closely related to the eastern Pacific P. dispersa Verrill,
1864. These two species have approximately the same calicular
diameter, and both have highly exsert primary septa, rudimentary
P2, and a similar growth form. Phyllangia hayamaensis
appears to differ in having only about 20-26 octamerally
arranged septa, whereas P. dispersa usually has 48 hexamerally
arranged septa. Examination of additional specimens from off
Japan is required to understand this species and to properly
compare it with its eastern Pacific congener.
MATERIAL EXAMINED.—New Records: None. Reference
Specimens: P. dispersa, Paitilla Point, Canal Zone, Gulf of
Panama, 1 colony, USNM 83526.
TYPES.—The holotype of P. hayamaensis is deposited in the
Biological Laboratory of the Imperial Household, Tokyo
(#640). Type Locality: Kamegisho One, Sagami Bay, 5.5 m.
DISTRIBUTION.—Known only from the type locality.
RhizosmiUa Cairns, 1978
DIAGNOSIS.—Phaceloid coral la formed by extratentacular
budding from a thin common basal coenosteum. Corallite bases
increase in diameter by adding exothecal dissepiments over
raised costae producing concentric rings of partitioned chambers
resembling polycyclic development in cross section.
Vesicular endothecal dissepiments present. Paliform lobes
present before penultimate cycle (usually P3). Columella
variable, including papillose, lamellar, and fascicular.
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY
TYPE SPECIES.—RhizosmiUa gerdae Cairns, 1978, by original
designation.
RhizosmiUa sagamiensis (Eguchi, 1968), comb. nov.
PLATE 27C -e
Coenocyalhus sagamiensis Eguchi, 1968:C34, pi. C10: figs. 6, 7.
DESCRIPTION OF SPECIMENS FROM Alb-4944.—One corallum
consists of a phaceloid clump of 13 interconnected
corallites (Plate 27c), the other corallum is a large solitary
specimen (Plate 21d,e). Corallites of colony connected basally
by a thin encrusting coenosteum. Corallites ceratoid, the largest
measuring 13.3 x 10.3 mm in calicular diameter, 20.1 mm in
height, and 5.2 mm in pedicel diameter. Pedicel reinforced by
thin raised costae overlain with exothecal dissepiments, this
process usually visible on any large specimen. Costae equal in
width (0.5-0.6 mm) and finely granular, the C^_3 being
slightly ridged near calice. Lower half of theca of largest
(solitary) specimen also bears fine transverse rugae. Corallum
white, except for brown crescent-shaped bands that parallel the
septal edges of S^.
Septa generally hexamerally arranged in 4 complete cycles
according to the formula: S1>S2>S3>S4, but larger corallites
have additional septa and paliform lobes, the largest calice
having 68 septa and 16 paliform lobes. S1 highly exsert (up to
3.4 mm), relatively thick, and have straight, vertical inner edges
that almost attain the columella. S2 up to 2.5 mm exsert,
three-quarters width of S,, and also have straight inner edges.
S3 least exsert septa (about 1.1 mm), about three-quarters width
of S2, and have slightly sinuous inner edges. A wide (1.1-1.3
mm), lamellar paliform lobe occurs before each S3, separated
from its adjacent septum by a deep, narrow notch. S4 less wide
but more exsert (1.6-2.0 mm) than S3. Each pair of S4 flanking
an S1 or S2 is fused with that septum at the calicular edge to
form a 3-septum calicular extension resulting in a highly serrate
calicular edge. Fossa of moderate depth, containing the P3
crown of 12-16 lobes and a central fascicular columella
consisting of several slender, loosely twisted elements.
DISCUSSION.—The holotype, which was the only known
specimen of this species, is unavailable for study. Eguchi's
illustration of the holotype shows a worn or rejuvenescent
corallum of three corallites. The specimens described above are
consistent with Eguchi's description and depth range and thus
believed to be conspecific.
Three other species of RhizosmiUa are known: R. maculata
(Pourtales, 1874); R. gerdae Cairns, 1978; and R. robusta
Cairns in Caims and Keller, 1993. R. sagamiensis is most
similar to the type species, R. gerdae, known only from the
western Atlantic at 123-287 m, both species having four cycles
of septa and approximately the same calicular diameter.
RhizosmiUa sagamiensis differs in having ceratoid corallites, a
fascicular columella, and highly exsert, pigmented S.^.
MATERIAL EXAMINED.—New Records: Alb-4944, 1 col-