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
Leptadrillia splendida
Bartsch, 1934
(
Plate 116
)
Leptodrillia
[sic]
splendida
Bartsch, 1934: 24
, pl. 7, figs. 2, 5, 7.
Cerodrillia simpsoni
(auct. non Dall, 1887) is a misidentification by Nowell-Usticke (1959: 81–82, pl. 4, fig. 10).
Leptadrillia splendida
Bartsch, 1934
: Powell (1966: pl. 14, fig. 14); Kaicher (1984c: card 3904); Turgeon
et al.
(1988); Williams (2005, 2006, 2009: species “+1575” [not synonymy with
L. cookei
]).
Cymatosyrinx (Leptadrillia) splendida
(Bartsch, 1934)
: Abbott (1974: 276, specimen no. 3119).
Leptadrillia cookei
auct. non (E.A. Smith, 1888): Jong & Coomans (1988: 113 [incorrectly synonymize
L. splendida
with
L. cookei
]). Williams (2005: species 1575 [left photo of
holotype
only]); Williams (2006: species 1575 [left photo of
holotype
only; right photo =undescribed Brazilian species]).
Not this species or unconfirmed extralimital reports.
Leptadrillia splendida
Bartsch, 1934
: Warmke & Abbott (1961: 136, pl. 25, fig. j [
Puerto Rico
]); Rice & Kornicker (1965: 126, pl. 7, fig 1 [Campeche Bank]); Houbrick (1968: 17 [
Costa Rica
]); Rios (1970 [
Brazil
]); Ekdale (1974: 650 [Quintana Roo,
Mexico
]); Rios (1975: 134, pl. 40, fig. 607 [fig. not clear]); Rios (1985: 140, pl. 48, fig. 649 [
Brazil
]); Rios (1994: 161, pl. 53, fig. 722 [
Brazil
]); Díaz (1994 [
Colombia
]); Diaz & Puyana (1994: 224, pl. 67, fig. 886 [fig. of Colombian specimen not clear]); Absalão
et al.
(2005: 24, fig. 18 [fig. of Brazilian specimen not clear]); Daccarett & Bossio (2011: 130, fig. 796 [
Colombia
]).
Cymatosyrinx splendida
(Bartsch, 1934)
: Sander & Lalli (1982: 317 [
Barbados
=
Leptadrillia violacea
,
new species
]).
Type
material.
Holotype
9.2 x
3.1 mm
(USNM 429368).
Type
locality.
R/V
Caroline
Sta. 56, Samaná Bay, [
Dominican Republic
], between
19°10'15"N
,
69°27'20"W
and
19°10'15"N
,
69°28'05"W
, in 17 fms [
31 m
].
Other material examined.
Three additional specimens were examined: 9.0 x 3.0, 8.1 x 2.8 & 7.5 x
2.5 mm
, Altona Bay, St. Croix,
U.S.
Virgin Is.,
May 1958
, ex coll. G. Nowell-Usticke (AMNH 192601, in part).
Range and habitat.
Dominican Republic
;
U.S.
Virgin Is. (St. Croix). The
holotype
was taken from a depth of
31 m
.
Description.
Shell
very small (to
9.2 mm
in total length), glossy and translucent, narrowly fusiform; whorls moderately convex with peripheries below mid-whorl, up to 8¾ whorls, last approximately 57% of total length including canal; axial ribs are sculptural element; aperture moderately wide, long.
Protoconch
of 1½–2 evenly expanding, smooth, glossy whorls, the first only a little smaller in diameter than the second.
Axial sculpture
of sigmoid ribs that run from suture-to-suture, highest, widest, and inflected near whorl midpoint; low, narrow, and curved in sulcus such that the leading face is concave; evanesce at anterior fasciole on last whorl, except mostly obsolete on parietal wall. Ribs on first three teleoconch whorls knob-like then lengthen on subsequent whorls; ribs number 8–10 on penultimate and 6–8 to the varix on last whorl. Very fine, microscopic growth striae present throughout.
Varix
runs from suture to anterior fasciole, gradually diminishing anteriorly; larger than and 2–3 times the width of the preceding ribs; positioned about ¼–⅓-turn from the edge of the outer lip.
Spiral sculpture
absent, except for approximately 9 spiral threads on the anterior fasciole.
Sulcus
obscure, marked by lower, narrower ribs curved to reflect the outline of the anal sinus.
Outer lip
mostly missing on
type
specimen.
Anal sinus
missing on
type
specimen.
Inner lip
thin, recumbent, margined, thicker anteriorly along anterior canal, posteriorly forms a weak parietal lobe.
Anterior canal
long, straight, open, anterior end turned very slightly to the right when viewed ventrally; end unnotched.
Color
white, outer lip, and rib interspaces translucent.
PLATE 116.
Leptadrillia
splendida
, Bartsch, 1934
. Figs. 1–3: holotype, Samaná Bay, Dominican Republic (USNM 429368). Fig. 1: ventral, lateral & dorsal views; Fig. 2: enlarged view of protoconch (not to scale); Fig. 3: apical view, V = varix, L = edge of outer lip. Figs. 4–6: Altona Bay, St. Croix, U.S. Virgin Is., ventral views (AMNH 192601).
Remarks.
Taxonomy.
Leptadrillia splendida
has all the important characteristics of the genus: a narrow, spindly shell with a long anterior canal, narrow ribs that extend from suture-to-suture, and the absence of spiral sculpture, except for threads or ridges on the anterior fasciole.
Variability.
The four examined specimens have an average total length of
8.45 mm
(
7.5–9.2 mm
) and an average W/
L ratio
of 0.337.
Identification.
Leptadrillia splendida
is may be confused with some of its congeners:
L. campechensis
,
new species
,
L. lizae
,
new species
,
L. loria
Bartsch, 1934
,
L. profunda
, and
L. histriata
,
new species
.
Leptadrillia campechensis
is very similar but has slightly more convex whorls, taller spire, and more oblique ribs. It also has a more convex last whorl. From
L. lizae
it differs in having more oblique ribs, and a longer anterior canal. From
L. loria
it differs in being larger (total length is
9.2 mm
versus
6.8 mm
) and having a proportionately longer anterior canal and larger protoconch. From
L. profunda
it differs in possessing more angular whorls with peripheries more anterior to whorl midpoints, and a longer anterior canal. From
L. histriata
it differs in possessing fewer ribs (up to 10 versus 13–15 on the penultimate whorl), and round-crested ribs, not ridged ones.