A Generic Revision and Phylogenetic Analysis of the Primnoidae

26 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY
having compressed polyps, nonfused basally fused polyps,
a smooth inner opercular surface, and a circumoperculum
that folds over the operculars (Table 3). The 10 species
currently attributed to Primnoella are listed in Table 4.
Characters used to distinguish species include number of
polyps per whorl, number of abaxial body wall scales,
number of adaxial body wall scales, size and shape of
marginal scales, and size of polyps (Cairns, 2006).
The generic placement of P. antarctica Kükenthal, 1907
is problematic. Kükenthal (1919) placed it in the Convexae
section of the genus Primnoella (later called Convexella by
Bayer, 1996b) because of its round-in-cross-section calyces,
but Bayer removed it from that genus in 1996 because
it had a bare adaxial body wall. He suggested an affi nity
with Ophidiogorgia but did not elaborate. Because it appears
to have a distinct, if small, operculum, and its body
scales are arranged in longitudinal rows, it does not seem
to belong in Ophidiogorgia. Short of describing a separate
genus for this species, we suggest a tentative placement in
Primnoella, but differing from that genus in having a calyx
round in cross section and thus having four body wall scale
rows visible in abaxial view.
Distribution. Lesser Antilles, entire eastern
and southwestern coasts of South America, southeastern
Australia, New Zealand, Tasmania, 8–1,249 m (Cairns,
2006).
Type Species. Primnoella: Primnoa australasiae
Gray, 1850, by monotypy. Dry syntypes deposited at
the BM (1850.1.21.1, 6, and 10; 1983.3.2.13–14) (Bayer,
1996b).
Callirrhabdos: C. chilensis Philippi, 1894, by monotypy.
Type not located.
7. Convexella Bayer, 1996
FIGURE 5A–I
Primnoella.—Studer, 1887:51 [in part].—Wright and Studer, 1889:83–84
[in part: Convexae].—Versluys, 1906:51 [in part: Convexae].—Kükenthal,
1908:12–13 [in part: Convexae]; 1915:148 [in part: Convexae, in part, key
to genus and species]; 1919:384–386 [in part: Convexae, in part, key to species];
1924:279–280 [in part].—Madsen, 1944:39.—Bayer, 1956:F220 [in
part]; 1981b:936, not 938 [= Primnoella] [key to genus].—Bayer and Stefani,
1989:455 [in part: key to genus].
Convexella Bayer, 1996b:171–180.
Diagnosis. Colonies usually unbranched (fl agelliform)
or sparsely dichotomously branched. Calyces
arranged in whorls of up to 15 (Figure 5b), each calyx
round in cross section and inclined upward or perpendicular
to axis. An inconspicuous operculum consisting
of 6–10 opercular scales is present (Figure 5a, f–g), often
hidden from view by the eight infolded marginal (= circumopercular)
scales; operculars smooth on inner surface.
Marginals arranged in two circles of four that alternate
with one another, the circumference of the distal polyp
not being large enough to accommodate eight marginal
scales. Polyps protected by eight complete longitudinal
rows of body wall scales, four of which can be seen in abaxial
view. Body wall scales not paired but alternate with
those of adjacent rows, appearing to spiral around calyx.
Coenenchymal scales in two layers: outer layer composed
of smooth, rounded scales; inner layer composed of small,
irregularly shaped tuberculate rods.
Discussion. As mentioned in the discussion
of the genus Primnoella as well as in the publications of
Bayer (1996b) and Cairns (2006), species now placed
in the genus Convexella had been placed in the species
group “Convexae” of Primnoella. Bayer (1996b) fi nally
separated fi ve species (Table 4) from Primnoella to form
the basis of Convexella, the latter differing in having calyces
round in cross section, eight rows of equal-sized body
wall scales and thus no naked adaxial region, four rows
of body wall visible in abaxial view, and calyces inclined
(not appressed) upward. The species are briefl y reviewed
by Bayer (1996b).
Distribution. Antarctic, subantarctic South
America, Kermadec Trench, North Atlantic, 12–5,850 m,
C. krampi being the deepest known primnoid.
Type Species. Primnoella magelhaenica
Studer, 1879, by original designation. Type assumed to be
deposited at the ZMB. The type species is well described
and copiously illustrated by Bayer (1996b).
8. Dicholaphis Kinoshita, 1907
FIGURE 5J–N
Dicholaphis Kinoshita, 1907:230–231; 1908a [27 Jul]:24–27 [best description
of genus and species]; 1908c [15 Nov]:57 [key to genus, in Japanese];
1908d [15 Dec]:524 [in Japanese]; 1908e:50 [key to genus].
Primnoella.—Kükenthal, 1919:404 [in part: P. delicata]; 1924:279, 287.
Diagnosis. Colonies branch in a regular, planar,
dichotomous manner. Calyces occur without order
on branches (not in pairs, whorls, or rows) and are inclined
upward. A tall, well-developed operculum present,
the operculars smooth on their distal inner face (not