A Generic Revision and Phylogenetic Analysis of the Primnoidae

34 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY
polyp not being large enough to accommodate eight adjacent
marginal scales; distal margins of marginals spinose,
folding over lower portion of operculars, forming a circumoperculum.
Inner face of operculars and marginals
bear ornate keels, each longitudinal keel bearing several
smaller ridges oriented at right angles, altogether forming
a foliate process (Figure 6i–j); distal edges of same scales
fi nely serrate. Polyps protected by six longitudinal rows
of body wall scales, the adaxial face being covered by enlarged
inner-lateral scales, resulting in complete coverage
of polyp. Outer and inner faces of body wall scales radially
ridged distally. Coenenchymal scales in two layers: outer
layer composed of irregularly shaped scales with granular
outer surface; inner layer composed of small spheroids.
Discussion. Much of the taxonomic history
of this subgenus was summarized in Cairns (2006).
An additional specimen of the type species T. antarctica
is reported herein: Hero 715-873, 54°34′S, 65°50′W
(Tierra del Fuego), 118 m, USNM 97966.
Distribution. Subantarctic, South Africa, off
Chile, western Atlantic from Burdwood Bank to northern
Florida, Japan, Aleutian Islands, 60–1,005 m.
Type Species. Thouarella: Primnoa antarctica
Valenciennes, 1846, by monotypy. Type deposited at the
MNHNP.
Primnodendron: P. superbum Nutting, 1912, by monotypy.
The holotype is deposited at the USNM (30691).
Rhopalonella: R. pendulina Roule, 1908, by monotypy.
Type presumably deposited at the MNHNP.
Parathouarella: Primnoa antarctica Valenciennes,
1846, by virtue of including the type species of the genus
in this subgenus. Being the nominate subgenus, it was unnecessary
for Kükenthal (1915) to give it another name.
12. Thouarella (Euthouarella) Kükenthal, 1915
?Hookerella Gray, 1870:45.
FIGURE 6M–S
Plumarella.—Studer, 1878:648 [in part: P. hilgendorfi ].
Thouarella.—Wright and Studer, 1889:59 [in part].—Versluys, 1906:24 [in
part: hilgendorfi -Gruppe].—Kükenthal, 1912:297–299 [in part: hilgendorfi -
Gruppe].
Thouarella (Euthouarella) Kükenthal, 1915:149–150 [in part: not T. coronata,
key to subgenus and species]; 1919:414–415 [key to subgenus and
species]; 1924:292 [key to species].—Bayer, 1956:F220.—Bayer and Stefani,
1989:455 [key to subgenus].—Cairns, 2006:176, 187–188.
Discussion. Differs from the nominate subgenus
only in having calyces arranged in pairs or whorls
(i.e., not isolated) (Figure 6m) and in having primarily alternately
pinnately branched colonies (e.g., type species),
although some species are bottlebrush in shape.
Distribution. Western Pacifi c, East Africa,
North Atlantic, Indian Ocean, 256–1,644 m.
Type Species. Euthouarella: Plumarella hilgendorfi
Studer, 1878, by subsequent designation (Bayer,
1956:F220). The type is presumably deposited at the
ZMB; a fragment of the type is deposited at the ZMA
(Coel. 3085) (van Soest, 1979:119).
Hookerella: H. pulchella Gray, 1870, by monotypy.
Type not traced.
13. Thouarella (Diplocalyptra) Kinoshita, 1908
FIGURE 7A–H
Thouarella (Diplocalyptra) Kinoshita, 1908c [15 Nov]:454, 457 [key to subgenus],
pl. 17, fi g. 2 [in Japanese, English translation at Smithsonian]; 1908d
[15 Dec]:517–519 [in Japanese, English translation at Smithsonian]; 1908e
[25 Dec]:52 [key to subgenus, in German].
Thouarella (Euthouarella).—Kükenthal, 1915:151 [in part]; 1924:296
[in part].
Diagnosis. Colony uniplanar and dichotomously
branched. Calyces arranged in pairs and whorls
of three (Figure 7b), the calyces oriented perpendicular to
branch. Operculum small; inner face of operculars keeled.
Marginals arranged in two circles of four that alternate
with one another, the circumference of distal polyp not
being large enough to accommodate the eight marginal
scales; distal tips of marginals acutely pointed (almost spinose)
and fold over operculars, forming a circumoperculum
(Figure 7a, c–d); distal inner face of each marginal
and all other body wall scales bear multiple, prominent
longitudinal ridges. Polyps protected by six longitudinal
rows of almost smooth body wall scales, the adaxial face
being covered by enlarged lateral scales, resulting in complete
coverage of the polyp; however, the orderly linear
arrangement sometimes disrupted on lower half of calyx.
Coenenchymal scales in two layers, the inner layer composed
of tuberculate spheroids and rods.
Discussion. In the early twentieth century
(see synonymy) Diplocalyptra was considered to be a subgenus
of Thouarella, distinguished from other subgenera
by its dichotomous mode of branching. It was later essentially
synonymized with Thouarella, and forgotten, but is