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NUMBER 557 31
M547411, reported as F. montereyensis by Durham (1947);
Alb-4551,4, USNM M547407, M547410, reported as paratype
and nontypes by Durham (1947); Alb-4543, 1, USNM 92614
(ex. USNM M547409) reported as P. montereyensis by
Durham (1947). Reference Specimen: Holotype of J. duncani
Wells, 1977 (USNM 1208332). Type Locality of J. californica:
Alb-4550: 36°45'N, 121°55'W (off Point Pinos,
Monterey Bay, California), 91-104 m.
DISTRIBUTION.—Known only from Monterey Bay and
Cordell Bank; 62-170 m.
Polymyces Cairns, 1979
DIAGNOSIS.—Corallum solitary, ceratoid to trochoid, fixed.
Wall epithecal, reinforced basally by symmetrically or asymmetrically
arranged, contiguous hollow rootlets. Calicular edge
lacerate to serrate. Pali absent; columella rudimentary.
TYPE SPECIES.—Rhizotrochus fragilis Pourtales, 1871, by
original designation.
Polymyces montereyensis (Durham, 1947)
PLATE lla-/
Flabellum (?) montereyense Durham, 1947:37, pi. 1: figs. 5, 9 [in part: not
paratype from Alb-4551; only 1 of 2 specimens from Alb-4543; only 1 of 3
nontypes from Alb-4551; not Alb-4550: all Javania californica].—Durham
and Barnard, 1952:97, pi. 14: fig. 59a-c—Austin, 1985:81.
Flabellum tannerense Durham and Barnard, 1952:97-98, pi. 14: fig. 60a-c
[new synonym].—Bythell, 1986:19.
Polymyces montereyensis.—Cairns, 1979:158; 1991a:22.—Cairns et al.,
1991:48.
Polymyces montereyense.—Bythell, 1986:19-20.
Polymyces tannerensis.—Cairns, 1991a:22.—Cairns etal., 1991:48.
DESCRIPTION.—Corallum trochoid, the thecal walls increasing
in diameter at a constant angle. Largest known specimen
(SEPBOP 18B-764, Plate 11/) 39.1 x 30.7 mm in calicular
diameter and 34.4 mm in height, with a pedicel diameter of
10.8 mm. Calice elliptical and only slightly serrate, each S1-4
forming a small triangular apex. Corallum pedicel enlarged by
a ring of contiguous rootlets, characteristic of the genus (see
Discussion for more detail). Corallum white.
Septa hexamerally arranged in five incomplete cycles
according to the formula: S1_2>S3>S4»S5. At a GCD of 11
mm 36-48 septa are present; the largest two coralla examined
have only 90 or 92 septa, each lacking several pairs of S5. All
septa have slightly sinuous inner edges and sparsely granular
septal faces. S^_2 slightly exsert: the upper, inner edges of
opposing lateral septa almost meeting in center of fossa, their
lower inner edges fusing into a rudimentary columella deep in
fossa. S3 about 80% width of Su2, nonexsert, and do not fuse
with columella. S4 50%-80% width of S3; S5 rudimentary,
about one-quarter width of S4 and extending only 4-5 mm
down inner theca. Fossa deep and elongate, defined by inner
edges of S^_2.
DISCUSSION.—Polymyces montereyensis is easily distin-
guished from the two other species in the genus (Cairns, 1991a)
by having five cycles of septa, the other species having only
four cycles. It is more difficult to distinguish it from the genus
Javania, especially J. borealis, the basic difference between the
two species being that J. borealis has a solid, stereomereinforced
pedicel, whereas that of P. montereyensis is
reinforced by hollow rootlets and secondarily by stereome,
which gives it a less dense corallum. Because rootlets are hard
to detect in adult coralla, a cross section of the pedicel
sometimes must be made to verify the generic placement.
Polymyces montereyensis also differs from J. borealis in
having less wide S3 that do not fuse with the S^_2. The broad
pedicel of P. montereyensis led Durham (1947) to correctly
doubt its placement in Flabellum; the inclusion of specimens of
Javania californica in the type series of F. montereyense added
to that uncertainty.
Polymyces tannerensis is herein synonymized with P.
montereyensis. It was previously thought that it could be
distinguished from P. montereyensis by its lack of a fifth cycle
and its highly exsert S^; however, small specimens of P.
montereyensis of the same size as the types of P. tannerensis
(holotype: 11.2 x 8.9 mm in calicular diameter; paratype: 9.9 x
8.6 mm in calicular diameter) have only four septal cycles. The
highly exsert S^ of P. tannerense may be explained by the
poor preservation of the two types, their epitheca entirely worn
away at the calicular edge between major septa. In all other
characters, P. tannerensis resembles P. montereyensis of an
equivalent size. Furthermore, both "species" were collected at
the same station (Velero-1348-41) and no additional specimens
of the P. tannerensis growth form have been collected
subsequently.
The rootlets appear to form in the following manner. Each
corallum forms a prototheca about 5-6 mm in height and
diameter. A secondary epitheca develops from the basal plate
and encircles the prototheca at a distance of 1.0-1.5 mm, the
secondary epitheca eventually growing upward to form the
adult wall. In the basalmost 1-2 mm of the pedicel, the ring
formed by the encirclement of the prototheca by the epitheca is
divided into 12 compartments (rootlets) by outward extentions
of the S3 (Figure 3A; Plate 1 lc). Slightly higher in the pedicel
(4-6 mm above basal plate) outward extensions of the S^
further subdivide the ring into 24 compartments (rootlets).
These 24 chambers communicate with the polyp through a
series of 12 pairs of pores, each pair flanking an S3 about 6-8
mm above calicular base, essentially at the top of the
protothecal ring (Figure 3B). Rudimentary S4 are also found
within the prototheca, these septa being continuous with the S4
of the adult corallum, only higher in the corallum. S5 are not
found within the prototheca, these septa formed later and thus
higher in the corallum. The space between each S4 and adjacent
S1 and S2 within the prototheca does not result in an additional
pore, but is sealed with a dissepiment-like structure. Sometimes
rootlet development is irregular, several pairs missing from one
side of a corallum. Rootlets can usually be distinguished