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
Fenimorea elongata
,
new species
(
Plate 75
)
Type
material.
Holotype
25.0 x
7.4 mm
, D. Steger! (UF 155626); one
paratype
: 18.4 x 6.0 mm, SW of Cape San Blas, Gulf Co., W Florida, in 125 fms [
229 m
] depth (UF 158188).
Type
locality.
130 mi
[
209 km
] SW of Egmont Key, Hillsborough Co., W Florida, in 70 fms [
128 m
].
Range and habitat.
Eastern Gulf of
Mexico
, (off Gulf Co.; off Hillsborough Co.) in
128–
229 m
.
Description.
Shell
medium sized (to 25.0 mm), fusiform, truncated anteriorly, spire quite tall for genus, up to 11¼ slightly convex whorls overall, suture undulates over ribs of preceding whorl, last whorl approximately 47% of total length. Aperture narrow, about as wide as the short open anterior canal anteriorly; with a deep notch posteriorly.
Protoconch
of approximately 1½ smooth, glossy, round whorls.
Axial sculpture
of strong straight ribs that extend from suture-to-suture that tend to align whorl-to-whorl, 7–9 on the penultimate, 5–6 to the varix on last whorl where they evanesce on the ventral surface before the anterior fasciole but extend to the fasciole on the dorsal surface.
Varix
an expanded rib about ¼- to ⅓-turn from the edge of the outer lip.
Spiral sculpture
lacking; shell surface microsculpture of fine, wavy, incised lines, sometimes obsolete near the suture, that are intersected by growth striae, producing rows of pits between.
Sulcus
absent, ribs are very slightly recurved, but not diminished below the suture.
Outer lip
thin, flattened from varix to its edge, with a strong fold (on the
holotype
) just posterior of the anal sinus. Lip edge forms a low arc from anal sinus to anterior canal; is folded inward from anal sinus, then anteriorly for about ½ the length of the lip. Stromboid notch close to anterior end of anterior siphon, very weak.
Anal sinus
deeply notched, U-shaped and offset laterally a little from the shell axis by the parietal lobe.
Inner lip
thin, unemarginate in parietal area, slightly erect on anterior canal, formed into a parietal lobe posteriorly.
Anterior canal
short, open, and a shallow notch. Anterior fasciole with the same microsculpture as shell.
Color
uniformly beige-white with a narrow pale-pink diffuse band between ribs, and a yellow hue on varix and columella.
PLATE 75.
Fenimorea elongata
,
new species
. Figs. 1–2: holotype, SW of Egmont Key, Hillsborough Co., W Florida (UF 155626). Fig. 1: ventral, lateral & dorsal views; Fig. 2: enlarged views of protoconch (not to scale). Figs. 3–4: paratype, SW of Cape San Blas, Gulf Co., W Florida (UF 158188). Fig. 3: ventral view; Fig. 4: apical view, V = varix, L = edge of outer lip.
Remarks.
Taxonomy.
Fenimorea elongata
possess the shell surface microsculpture typical of
Fenimorea
, ribs that extend from suture-to-suture, and a deep U-shaped anal sinus. Its lack of a distinct sulcus seems to typify offshore, deeper-water species, which it is, as well as the erect, expanded rib, not hump-like varix (see under key characteristics in the introduction to
Fenimorea
).
Identification.
Fenimorea elongata
is similar to
F. pagodula
(Dall, 1889)
, and
F. petiti
Tippett, 1995
. It differs from
F. pagodula
in possessing whorls that are slightly more convex and more evenly so. The whorls of
F. pagodula
have peripheries below mid-whorl. The last whorl of
F. elongata
is straighter in profile, not angled to the right when viewed ventrally as in
F. pagodula
. The base color of
F. elongata
is a similar beige-white but has a diffuse pinkish band confined to intercostal space, not the better defined pale yellow to brownish yellow band that tends to override the ribs exhibited by
F. pagodula
.
Fenimorea elongata
also differs from
F. pagodula
in possessing a narrower shell (W/
L ratio
= 0.311 versus 0.326), and may prove to be a slightly larger species (to 25.0 versus
22.3 mm
maximum length).
Fenimorea petiti
differs from
F. elongata
in possessing more convex ribs, a shorter spire and broader shell, and a more distinct mid-whorl color band. The characteristics that separate
F. elongata
from
F. petiti
and
F. pagodula
, as described above, are sufficiently distinct to merit description of the specimen as new. None of the examined specimens from over what is believed to be most of the range of
F. petiti
have the elongate form or coloration of
F. elongata
.
Fenimorea elongata
differs from
F. pagodula
in more subtle but important ways (whorl profile, shape, color, and size), which are nonetheless believed to add up to a true species, not a variant of
F. pagodula
.
Etymology.
The Elongated
Fenimorea
, referring to the unusually high spire of the species. Derived from the Latin verb
elongo
(
elongata
= perfect passive participle, nominative single feminine).