Bryozoa collected by the United States Antarctic Research Program: new taxa and new records
Author
Hayward, Peter J.
Author
Winston, Judith E.
text
Journal of Natural History
2011
2011-10-31
45
37 - 38
2259
2338
http://dx.doi.org/10.1080/00222933.2011.574922
journal article
10.1080/00222933.2011.574922
1464-5262
5204333
Smittoidea cancellata
sp. nov.
(
Figure 23
)
Material
Holotype
.
NMNH 1154053
:
Eltanin
cruise 9, station 740, 56
◦
06’ to
56
◦
07’ S
, 66
◦
19’ to
66
◦
30’ W
, 494–
384 m
,
18 September 1963
; one fragment.
Paratypes
.
VMNH 01367.200
: same data as holotype; seven fragments
.
Description
Colony architecture unknown;
type
material consists of flat or curled, unilaminar flakes, with no evidence of substratum, basal walls of autozooids clean. Autozooids hexagonal, flat; frontal shield flat, or just convex medially, with thin, dimpled calcification, bordered by projecting vertical walls, and large, closely spaced marginal pores. Primary orifice wider than long, proximal edge with broad, straight-edged lyrula, occupying two-thirds of total width; condyles conspicuous, sharply pointed, down-curved. No oral spines. Peristome thin, low, with medio-proximal notch, above a small, oval suboral avicularium, with semi-elliptical mandible, parallel to frontal plane, directed proximally, crossbar slender with thin median columella. Sporadically, the avicularium is dimorphic, with scaphoid rostrum, ca
0.4 mm
long, proximally directed. Ovicell recumbent on frontal shield of distally succeeding autozooid, hemispherical, ectooecium with large, uncalcified frontal area, the exposed entooecium pierced by numerous, irregularly shaped pores.
Figure 23.
Smittoidea cancellata
sp. nov.
, Paratype. (A) Group of autozooids, two with enlarged dimorphic avicularia; (B) detail of primary orifice; (C) ovicelled zooids. Scale bars: 0.25 mm (A, C), 0.1 mm (B).
Measurements
For all measurements
n
= 20, mean ± SD: autozooid length 1.24 ±
0.11 mm
; autozooid width 0.18 ±
0.01 mm
; orifice width 0.25 ± 0.01.
Etymology
Latin,
cancellatus
: latticed, with reference to the dimpled calcification.
Remarks
Species of
Smittoidea
have been described from shelf-sea environments worldwide, including
Antarctica
and the subantarctic southwest Atlantic. In its distinctive frontal calcification and small, oval, suboral avicularium
S
.
cancellata
sp. nov.
is most similar to
S
.
malleata
Hayward and Thorpe, 1989
, reported from the South Shetland Islands, Graham Land and the Ross Sea, and
S
.
albula
Hayward and Taylor, 1984
, known only from the Ross Sea. However, both of these species have elongate oval ovicells, much larger than that of
S
.
cancellata
and more densely perforated.
Smittoidea malleata
is further distinguished in lacking a peristome, and in its lyrula, which is simply a short projection from the distal edge of the avicularium. The lyrula of
S
.
albula
is a conspicuous square structure, and a thin, raised peristome extends along the lateral borders of the orifice, and proximally incorporates the avicularium. In both of the described species the condyles are thick and angular, quite unlike the slender, pointed condyles of
S
.
cancellata
.