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
Lissodrillia schroederi
(Bartsch & Rehder, 1939)
(
Plate 127
)
Cerodrillia (Lissodrillia) schroederi
Bartsch & Rehder, 1939: 130
; pl. 17, fig. 8: Powell (1966: 74 [list]); Williams (2005: 1532).
Cerodrillia schroederi
Bartsch & Rehder, 1939
: Perry (1940: 165; pl. 38, fig. 262); Perry & Schwengel (1955: 182; pl. 38, fig. 262); Abbott (1974: 272, sp. 3024 [list]); Turgeon
et al.
(1988: 96 [list]).
Lissodrillia schroederi
(Bartsch & Rehder, 1939)
: Turgeon
et al.
(1998: 256 [list]).
Not this species, or unconfirmed extralimital reports.
|
Cerodrillia
schroederi
Bartsch & Rehder, 1939
: García
|
(2007: 8 |
[prob. |
=
Lissodrillia
|
robusta
,
|
new |
species]); |
Tunnell |
et
|
al.
|
(2010: 242 [=
Syntomodrillia
sp.]).
|
Type
material.
Holotype
5.0 x 2.0 mm (USNM 530585).
Type
locality.
R/V
Albatross
Sta. 2410, off Charlotte Harbor, W Florida, in 28 fms [
51 m
].
Other material examined.
An additional
25 specimens
were examined: 1 spec., 4.7 x
1.9 mm
, in
55 m
, SW of
Panama
City, Bay Co., W Florida, J. Moore! (EFG 11826); 4 spec., 5.2 x 2.0, 5.0 x 1.9, 4.9 x 1.9 & 5.2 x
1.9 mm
, in
73–91 m
, SW of Egmont Key, Hillsborough Co., W Florida, D. Steger! 1975 (DMNH 107133); 5 spec., 4.7, 4.6, 5.5, 6.7 &
6.3 mm
, SW of Johns Pass, Pinellas Co., W Florida, D. Steger! 1975 (DMNH 107816); 5 spec., 3.3 x 1.6, 4.9 x 1.9, 5.1 x 1.9, 5.3 x 1.9 & 5.0 x
1.9 mm
, in
183–229 m
, W of Cape San Blas, Gulf Co., W Florida, R. & D. Black! (USNM 900145); 2 spec., 5.3 x 1.9 & 5.3 x
1.9 mm
, in
73 m
,
153 km
W of Egmont Key, Hillsborough Co., W Florida, J. Moore! aboard
Cavalier
,
Aug 1968
(UF 470335); 2 spec., 1 measured: 5.0 x
1.9 mm
, in
30 m
, W of Egmont Key, Hillsborough Co., W Florida, J. Moore! (ANSP 336130); 2 spec., 5.6 x 2.0 & 5.7 x 2.0 mm, in
73– 91 mm
, SW of Egmont Key, Hillsborough Co., W Florida, D. Steger! 1966 (ANSP 306359); 4 spec., the best 3: 5.4 x 2.2, 5.3 x 1.9 & 4.9 x
1.9 mm
, in
165 m
,
16 mi
SE of Dry
Tortugas
, Florida Keys, USBF Sta. 20030 (USNM 411179).
Range and habitat.
W Florida (Gulf Co.; Bay Co.; Pinellas Co.; Hillsborough Co.); Florida Keys (off Dry
Tortugas
in Gulf of
Mexico
). Reported from
30–229 m
; most depths are>
50 m
.
Description.
Shell
very small (to
6.7 mm
in total length), smooth and glossy, fusiform, anterior truncated, with up to about 7 slightly convex whorls, the last about 55% of total shell length; sculpted with ribs whose peripheries are near the anterior suture such that whorls appear to be cinched, or to sag. Aperture short, oval, with a short and wide but distinctly formed anterior canal.
Protoconch
of 1¾–2 smooth, glossy, relatively large (for shell size) whorls, the first partially imbedded in the second such that the shell apex appears blunt.
Axial sculpture
of smooth, round-crested ribs that run from suture-to-suture on spire whorls, evanesce at the columella on shell base; 10–11 on penultimate and 6–8 on last whorl to varix. Ribs are about as wide as intercostal space, sigmoidal and only slightly reduced on whorl shoulder. Growth striae microscopic, oblique to ribs and recurved on shoulder.
Varix
an enlarged rib, up to twice the width of preceding rib and positioned ⅓–½ turn from edge of outer lip.
Spiral sculpture
absent.
Sulcus
absent; recurved ribs and striae on whorl shoulder mark past positions of the sulcus.
Outer lip
thin and smooth, translucent except for axial folds, usually one near the edge of the outer lip, the effect is a smooth dorsum of the last whorl smooth, without axial folds. Edge of lip, together with anal sinus, trace a reversed “S” from sinus to anterior canal; stromboid notch weak.
Anal sinus
a deep wide notch with a round apex near suture, outer side divergent from inner.
Inner lip
narrow, margined, free on anterior canal, recumbent on parietal wall, formed into an elongate callus at the posterior end of the aperture.
Anterior canal
short, open, unnotched; fasciole not swollen.
Color
white or pink; a wide central white band is most evident on pink specimens.
Remarks.
Taxonomy.
Lissodrillia schroederi
is the
type
species of the genus, consequently, characteristics considered important at the level of genus are the model of the genus: a small glossy shell with ribs suture-to-suture on spire whorls, anal sulcus lacking; anal sinus a deep, wide notch, its outer side and edge of outer lip tracing a reversed “S” from the sinus to the anterior canal; and spiral sculpture lacking.
Variability.
The average total length of
24 specimens
is
5.16 mm
(
3.3–6.7 mm
), their average W/
L ratio
0.303. In addition to all-white forms, all-pink, or pink with white ribs or a white band occur.
Identification.
Lissodrillia schroederi
is similar to
L. simpsoni
(Dall, 1887)
,
L. robusta
,
new species
,
L. lactea
,
new species
, and
L. levis
,
new species
.
Lissodrillia simpsoni
has ribs that end before the anterior fasciole, whereas they continue to the fasciole in
L. schroederi
.
Lissodrillia schroederi
is white to pink in color, whereas
L. simpsoni
is a golden brown. There are also habitat differences—
L. schroederi
is found in deeper water. From
L. robusta
it differs in being slimmer in form, lacking the bulging ribs that characterize
L. robusta
. This latter species is also uniformly colored, lacking the broad central band and sometimes pink color of
L. schroederi
. From
L. lactea
it differs in possessing less convex whorls, usually more ribs that are narrower and more distinct (10–11 versus 6–10 on the penultimate whorl). From
L. levis
it differs in being somewhat smaller (5.16 versus
6.74 mm
in average total length), in having more distinct, but narrower ribs, and colored differently, white or pink, not the pale amber of
L. levis
.