Eight new species of Scissurellidae and Anatomidae (Mollusca: Gastropoda: Vetigastropoda) from around the world, with discussion of two new senior synonyms
Author
Geiger, Daniel L.
text
Zootaxa
2006
1128
1
33
journal article
50738
10.5281/zenodo.273358
ba17466e-c23e-4583-ae92-0bf956c83ca3
11755326
273358
Sinezona globosa
new species
:
Figure 11
Type
material
.
Holotype
(
MNHN
).
Paratype
(
MNHN
, 1).
415–420 m
,
Wallis
Island,
13.350°S
,
176.133°W
.
Type
locality
.
310–315 m
, Loyality Basin,
New Caledonia
,
21.533°S
,
166.483°E
.
Etymology
.
Globosa
, Latin adjective, noting the overall globular shape of the shell.
Description
. Shell large (to
3.1 mm
), trochiform globular. Protoconch of 0.875 whorls, embryonic cap with flocculant sculpture, remainder smooth with 3–4 fine spiral threads, apertural varix connected to embryonic cap, apertural margin unknown. Teleoconch I of 1.66 whorls, approximately 46–50 distinct axial cords, run over equaly spaced spiral lines, first spiral after 0.33 whorls, 14 at beginning of selenizone, interstices with broad growth marks. Teleoconch II of 1.125 whorls. Shoulder quite convex, suture modrately impressed, axials of same density as on teleoconch I, forming small points at intersection with spiral lines. Base slightly constricted below selenizone, with same density and strength of axials, approximately 20 spiral lines, becoming stronger and more closely spaced towards umbilicus. Umbilicus narrow in small specimens (
paratype
), moderately wide in large specimens (
holotype
), bordered by last spiral line of base, walls straight, smooth. Selenizone above periphery, keels elevated but often eroded due to their fragility, growth marks distinct, slit closed to elongated foramen. Aperture suborbicular, lip inflated, roof overhanging. Animal unknown.
Differential diagnosis
.
Sinezona macleani
new species
from the
Philippines
is more depressed, less globular, has a protoconch with flocculant sculpture, lacks an apertural varix, has a sharp elevated keel bordering the umbilicus, and usually a projecting shelf in the basal adumbilical corner of the aperture.
Sinezona plicata
(Hedley, 1899)
with broad tropical Pacific distribution is overall more depressed, has a smooth protoconch occasionally with fine spiral lines, and has strong, elevated lamellae on the teleconch.
Distribution
. Only known from
type
material.
Remarks
. The
paratype
is slightly immature evidenced by the hardly descending aperture on the last quarter whorl, while the
holotype
is a fully grown specimen. It appears that the closure of the foramen occurs early on.