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A. matricidus by its broader and shorter corallum, its thinner
S^, and its 1:1 correspondence of septa and costae. It is quite
similar to A. atlanticus Zibrowius, 1980 (known only from the
northeast Atlantic at 450-1716 m), the Pacific species differing
primarily in having notched septa near the thecal edge. It might
also be confused with Conotrochus funicolumna, but is usually
easily distinguished by its residual parent fragment that
remains attached to the base.
MATERIAL EXAMINED.—New Record: Alb-4958, 1,
USNM 92704.
TYPES.—The "numerous" syntypes of A. recidivus reported
by Dennant (1906) cannot be located (see Zibrowius, 1980).
Type Localities: Off Cape Jaffa and Neptune Island, South
Australia, 165-190 m.
DISTRIBUTION.—Japan: Bungo Strait (Okino I.) off Shikoku
(new record for North Pacific); 741 m. Elsewhere: South
Australia, Tasmania, Macquarie Ridge, off Madagascar, 128—
1000 m.
Aulocyathus matricidus (Kent, 1871)
PLATES 26C -g, MJb-d
Flabellum matricidum Kent, 1871:276, pi. 23: fig. 2a-c.
Fragilocyathus conotrochoides Yabc and Eguchi, 1932a:388, 389, fig. 1;
1941b:101; 1942b:116, 145. pi. 9: fig. 15.—Eguchi, 1965:288. 4 figs —
Eguchi and Miyawaki, 1975:57.—Zibrowius, 1980:105, 107.
Aulocyathus cf. matricidum.—Yabe and Eguchi, 1941b: 101.
Aulocyathus cf. matricidus.—Yabe and Eguchi, 1942b: 112, 116.
DESCRIPTION.—Corallum elongate-conical, up to 31.0 mm
in length but with a maximum calicular diameter of 8.5 mm
(Yabe and Eguchi, 1942b). Illustrated specimen (TM (KT7802,
Z4)) only 16.4 mm in length and 6.2 mm in diameter, tapering
gradually to a broad pedicel 2.1 mm in diameter. Coralla appear
to reproduce predominantly by budding from corallum fragments
following the longitudinal fission of a parent corallum.
Theca rough and striate, possessing twice the number of
longitudinal ridges as septa. The true costae, those ridges
corresponding in position to the septa, are 0.18-0.20 mm wide;
whereas, between each costa occurs another narrower ridge
0.10-0.11 mm in width. Both ridges bear hollow, conical,
apically inclined granules, many of which are abraded apically
revealing a hollow interior. Corallum light brown.
Septa hexamerally arranged in 4 cycles, the fourth cycle
rarely complete. Each system of a typical corallum contains 1
S2,2 S3, and only 2 S4, resulting in a corallum total of 36 septa.
As the corallum increases in size, additional pairs of S4 are
added, completing various systems. Yabe and Eguchi (1942b)
reported specimens of GCD = 6-8.5 mm to have 36-49 septa;
the holotype of F. conotrochoides (GCD = 6.6 mm) has 44
septa; specimens reported herein (GCD = 5.2-7.5 mm) range
from 38-40 septa; and a syntype of F. matricidum (GCD = 7.4
mm) has 40 septa. S1 only very slightly exsert (0.5 mm) and
have vertical, straight to slightly sinuous inner edges, which
become quite thick (up to 0.7 mm) and coarsely granular to
tuberculate at their lower edges. S2 about three-quarters width
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY
of an S1 and also have thickened, tuberculate inner edges,
sometimes bearing a narrow paliform lobe or columellar
process that extends upward into the fossa. S3 that are flanked
by a pair of S4 are about three-quarters width of an S2 and have
thick inner edges; S3 that stand alone are only half width of an
S2 and have coarsely dentate, narrow inner edges. S4 similar in
shape to those S3 unflanked by S4. Upper outer edges of septa
not notched near thecal edge. Fossa deep. Columella rudimentary,
composed of the tuberculate, widened lower inner edges
of the SU2 and often a single rudimentary tubercle.
DISCUSSION.—The holotype of F. conotrochoides is a
well-preserved specimen 30.9 mm in height and 6.6 mm in
calicular diameter, having 44 septa. It is the only specimen
known to me that does not evidence asexual development from
a parent fragment, instead having a slender pedicel 0.9 mm in
diameter including the six original protoseta. It is also
distinctive in bearing 14 brown longitudinal stripes of various
thickness on its theca, these stripes not associated with any
particular septal cycle. Despite these peculiarities, F. conotrochoides
is considered to be a junior synonym of Aulocyathus
matricidus.
Three other species occur in the genus: A. juvenescens
Marenzeller, 1904a (known only from off Tanzania, 302-463
m); A. recidivus (Dennant, 1906) (S. Australia, New Zealand,
Madagascar, off Japan, 128-1000 m); and A. atlanticus
Zibrowius, 1980 (northeast Atlantic, 450-1716 m). Aulocyathus
matricidus is unique in having pseudocostae in
addition to costae and tuberculate inner edges of S1-2. It is
more slender and has a less well-developed columella than A.
recidivus and A. atlanticus, but has a broader corallum than A.
juvenescens (Plate 26h,i). Among the four species, it has the
shallowest depth range (84-207 m).
MATERIAL EXAMINED.—New Records: TM (KT7802,
Z4), 1, USNM 92703; TM (KT7414, B2), 1, ORI. Previous
Records: Syntypes of F. matricidum, BM. Reference Specimens:
4 syntypes of A. juvenescens, ZMB 5064 and 7032;
holotype of F. conotrochoides, TIUS; Toyama Bay, 2, TIUS
58223 (Yabe and Eguchi, 1942b) (Plate 42c,d).
TYPES.—Two syntypes (Plate 26c,e,f) of Flabellum matricidum
are deposited at the BM (1862.7.16.72). Type Locality:
"Off Japan," depth not reported, but Zibrowius (1980)
gives 84 m, this information obtained from the label with the
syntypes.
The holotype (Plate 42b) and paratype of Fragilocyathus
conotrochoides are deposited at the TIUS (50084 and 50083,
respectively). Type Locality: Soyo Maru-352: 33 o 39'50"N,
135°O6'3O"E (Kii Strait, Honshu), 154 m (elucidated by Yabe
and Eguchi, 1942b: 145, footnote).
DISTRIBUTION.—Tsugara Strait; Pacific coast of Honshu
from Suruga Bay to Kii Strait; Sea of Japan from Toyama Bay
to Wakasa Bay; 84-207 m.
Desmophyllum Ehrenberg, 1834
DIAGNOSIS.—See Part 1.