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 maryae
,
new species
(
Plate 113
)
Type
material.
Holotype
7.9 x
2.8 mm
, T. McCleery!
Nov 2005
, ex. coll. P. Stahlschmidt (SMF 336444). No
paratypes
.
Type
locality.
Rosario I., Cartagena Dept.,
Colombia
, in
73–
165 m
.
Range and habitat.
Known only from the
holotype
.
PLATE 113.
Leptadrillia maryae
,
new species
. Figs. 1–3: holotype, Rosario I., Cartagena Dept., Colombia (SMF 336444). Fig. 1: ventral, lateral & dorsal views; Fig. 2: enlarged views of protoconch (not to scale); Fig. 3: apical view, V = varix, L = edge of outer lip.
Description.
Shell
very small (
7.9 mm
in total length), narrowly fusiform (W/L = 0.354), glossy and translucent; whorls moderately convex with peripheries just below mid-whorl, 9¼ in number, the last approximately 56% of total length; aperture narrow, anal sinus and anterior canal only slightly narrower; sculpture of axial ribs.
Protoconch
of approximately 3 smooth round translucent whorls.
Axial sculpture
of strong, broad, slightly opisthocline ribs that run suture-to-suture and evanesce before the anterior fasciole on shell base, widest mid-whorl; lower, narrower, and slightly curved on shoulder; 10 on penultimate, 7 on body whorl to varix with intercostal space about as wide as ribs.
Vari x
strong, larger and less oblique than preceding ribs; positioned about ⅓-turn from the edge of the outer lip.
Spiral sculpture
absent except for threads on the anterior fasciole.
Sulcus
absent. Former positions of the anal sinus on the whorl shoulder indicated by lower, narrower and slightly recurved ribs.
Outer lip
thin, with 2 slender strengthening axial folds; lip edge flexed only slightly outward near the anal sinus, otherwise projecting out in a nearly circular arc from the anal sinus to stromboid notch; stromboid notch shallow and wide.
Anal sinus
deep, U-shaped, offset from the axis of the shell by the parietal wall and lobe and slight outward flex of the outer lip near the sinus such that it appears spout-like.
Inner lip
narrow, recumbent, margined; thicker on the anterior portion of the columella, developed into a weak parietal lobe posteriorly.
Anterior canal
long, open, turned right at its end when viewed ventrally, unnotched; fasciole not swollen, spiral threads present.
Color
of shell pale golden brown, ribs, anterior canal and outer lip lighter.
Remarks.
Taxonomy.
Leptadrillia maryae
has all of the distinguishing characteristics of the genus: a narrow fusiform shell with a long anterior canal, ribs that extend from suture-to-suture, without a sulcus, and the absence of spiral sculpture except for spiral grooves near or on the anterior fasciole.
Identification.
Leptadrillia maryae
is most similar in shape to
L. incarnata
,
new species
, but is smaller and differently colored. It resembles
L. loria
Bartsch, 1934
but has a 3-whorl versus 1¾-whorl protoconch, and straighter ribs. It may also be mistaken for
Syntomodrillia hesperia
,
new species
or
Syntomodrillia stahlschmidti
,
new species
from the same region, but may be most readily differentiated by the absence of spiral grooves between ribs.
This single specimen is believed to merit description as new on account of morphological differences of protoconch whorl count of its two closest congeners,
L. incarnata
and
L loria
(3 versus 2 and 1¾, respectively), size, and color. The size range of the
L. incarnata
is
8.8–14.1 mm
, which is larger that the
7.9 mm
length of
L. maryae
.
L loria
is only
6.8 mm
.
Etymology.
Mary’s
Leptadrillia
, named after my wife, my life companion, and best friend.