Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species
Author
Fallon, Phillip J.
text
Zootaxa
2016
4090
1
1
363
journal article
10.11646/zootaxa.4090.1.1
e6b35f5a-435e-4473-b29e-1e4d842f84b0
1175-5326
263299
203BAC25-B542-48FE-B5AD-EBA8C0285833
Splendrillia bartschi
(Haas, 1941)
,
new combination
(
Plate 146
)
Cymatosyrinx bartschi
Haas, 1941: 172
, pl. 2, figs. h, i. Powell (1966: 90); Abbott (1974: 276); Jensen & Pearce (2009: 173).
Drillia interpunctata
auct. non (E.A. Smith, 1882): Peile (1926: 84).
Splendrillia coccinata
auct. non (Reeve, 1845): is likely a misidentification by Jensen & Pearce (2009: 173).
Type
material.
Holotype
10.5 x 4.0 mm (FMNH 13672). T.H. Bean!,
13 Oct 1905
. Only a photograph was examined, which is courtesy of Mr. Jochen Gerber of the FMNH.
Type
locality.
Argus Bank,
Bermuda
Is., in 30 fms [
55 m
] depth.
Material examined.
A total of
4 specimens
were examined: 3 spec., 12.2 x 4.8, ex H.G. Lee coll. (USNM 1291357), 10.9 x 4.1, & 9.6 x
3.9 mm
(H.G. Lee coll.), in
11–12 m
, North Rock,
Bermuda
, A.T. Guest & J.R.M. Lightbourn! 1976; 1 spec. 2.9 x
1.6 mm
, in
100 m
,
6 mi
[
9.7 km
] N of boat yards, Somerset Pt.,
Bermuda
, R. Jensen & J.R.M. Lightbourn!
May 1994
(H.G. Lee coll.).
Range and habitat.
Known only from
Bermuda
. Dredged from
11–
100 m
. This species (as
Cymatosyrinx bartschi
Haas, 1941
) is listed as endemic to
Bermuda
by Jensen & Pearce (2009).
Description.
Shell
small (to
12.2 mm
in total length), glossy-smooth, fusiform, truncated anteriorly, with 8 or perhaps a few more convex whorls, the last approximately 61% of the total length. Predominant sculptural element of axial ribs; aperture wide, anterior canal very short.
Protoconch
of approximately 1¾–2 smooth round whorls; tip immersed such that the first whorl is at an angle above the horizontal.
Axial sculpture
of narrow opisthocline ribs that run from the sulcus to suture on spire whorls, and evanesce just below whorl periphery on last whorl. Ribs number 12–15 on penultimate, 7–11 on last whorl to varix, and are wider than their intercostal spaces. Growth striae very fine, strongest near end of last whorl, on outer lip.
Varix
hump-like, approximately ¼-turn from the edge of the outer lip.
Spiral sculpture
absent except for faint threads on shell base near anterior fasciole; stronger on anterior fasciole.
Sulcus
concave, without ornamentation except for an occasional rib trace to the suture; about ⅓- height of spire whorls.
Outer lip
flattened from varix to lip edge, which forms a low arc from anal sinus to slightly beyond and out from the tip of anterior canal (ear-like); only a slight indentation in place of a stromboid notch; thickened along its edge.
Anal sinus
a deep notch, its apex adjoining suture behind parietal lobe.
Inner lip
narrow, thin, unemarginate; formed into a weak parietal lobe posteriorly.
Anterior canal
open, very short but distinctly demarcated from aperture, end of canal notched; fasciole not swollen.
Color
white to light pink with a broad, light pink to deep-rose band from the whorl periphery to the shell’s anterior; band reduced to spots or lines between ribs.
Remarks.
Nomenclature.
The
type
specimen was tentatively placed in
Cymatosyrinx
Dall, 1889
by Haas who remarked that the material (presumably the single
type
specimen) was too poor to be certain of its [generic] placement. Dall did not formally describe
Cymatosyrinx
but did designate a
type
(
Pleurotoma lunata
Lea, 1843
) from which subsequent workers developed a description (Fargo, 1954 and Powell, 1966). Powell (1966: 90) described
Cymatosyrinx
as having, among other characteristics, a polished surface, protoconch with a carinate second whorl, subsutural fold made nodulose at axial rib intersections, axial ribs extending to the anterior fasciole, ridge-margined inner lip, and deeply notched anterior canal.
Taxonomy.
Haas’ description and illustration of
S. bartschi
is more consistent with those of
Splendrillia
, including a smooth protoconch without a carinate second whorl, no subsutural fold, an anal sulcus without sculptural elements, axial ribs that fade on the shell base, and no ridge on the inner lip. Furthermore, although not described by Haas, the anal sinus of
S. bartschi
is typical of
Splendrillia—
its apex adjoins the suture behind the parietal lobe (its entrance offset from the suture by the parietal lobe).
Variability.
The three mature specimens examined have an average length of
10.90 mm
(
9.6–12.2 mm
) and average W/
L ratio
of 0.390. Their color varies from white to a light pink with a broad, deep-rose band from the whorl periphery to the shell base. It may also be a “vinaceous cinnamon” color, the color description employed by Haas for the
holotype
.
Identification.
Splendrillia bartschi
is unique among
Splendrillia
in having a well-rounded somewhat globose body whorl. It is close in size to
S. bahamasensis
,
new species
but the latter has broader, straighter, and more angular, and fewer axial ribs.
Splendrillia bartschi
differs from
S. interpunctata
(E.A. Smith, 1822)
principally in having much less angular shoulders and a more globose last whorl. From
S. cruzensis
,
new species
, it differs in being stouter, in having a more globose last whorl, and less angular shoulders.