Taxonomical study on the mollusks collected in Marion-Dufresne (MD 55) and other expeditions to SE Brazil: the Fissurellidae (Mollusca, Vetigastropoda)
Author
Simone, Luiz Ricardo L.
Author
Cunha, Carlo M.
text
Zootaxa
2014
3835
4
437
468
journal article
10.11646/zootaxa.3835.4.2
01da15e5-14ca-4506-89fd-2055b906f4ff
1175-5326
249622
F492B5ED-0CA7-436B-94AF-EE4C99D630AF
Cornisepta uirapa
new species
(
Figures 1–5
)
Types
.
Holotype
MNHN 25281.
Type
locality.
Brazil
. Espírito Santo; off Regência, continental slope of Abrolhos,
19°40’S
37°48’W
,
790–940 m
depth (MD55, sta. CB77; Bouchet, Leal & Métivier col,
27/v/1987
).
Diagnosis.
Slightly curved posteriorly. Height ca. 87% of length. Sculptured by uniformly distributed small pustules arranged in alternate rows, ca. 80 per row (close to aperture).
Description.
Shell height ca.
5 mm
; highly conical, slightly arched posteriorly (
Figs 1, 2
); height 87% of length. White, translucent. Apex about equidistant from anterior and posterior margins. Protoconch no longer present. Foramen terminal, elliptical, width ca. 60% of length; turned dorsal; occupying ca. 2% of aperture area in dorsal view; edges rather irregular (
Fig. 4
). Shell increasing in width towards aperture uniformly, gradual; main axis almost vertical; apical angle ca. 35°, total shell angle ca. 40°. Outer sculpture uniform rows of small pustules (
Figs 1–3
), ca. 80 per row close to aperture, slightly intercalated in adjacent rows; this mosaic somewhat regular towards apex, pustules increasing in number from dorsal to ventral; each pustule surrounded by smooth area equivalent to 3 times its width. Aperture in same plane (straight), elliptical, width approximately 72% of length; edges slightly irregular. Inner surface smooth, glossy (
Fig. 5
). Septum ca. 1/2 shell height; ca. 3 times higher than wide, ventral edge shallowly concave, almost straight, ca. 1/2 of aperture width; gradually narrowing up to posterior edge of fissure.
Measurements.
Holotype
: 4.7 by 5.3 mm.
FIGURES 19–27:
Cornisepta aninga
n. sp.
types. Fig. 19: holotype MNHN 25287, right view (L 3.2 mm). Fig. 20: same, left view. Fig. 21: same, dorsal view. Fig. 22: same, ventral view. Fig. 23: paratype MNHN 25288#1, young specimen left view (L 2.7 mm). Fig. 24: same station, #2, young specimen (L 2.4 mm). Fig. 25: same station, #3, very young specimen, right view (L 1.5 mm). Fig. 26: paratype MZSP 102942, SEM, dorsal-slightly left view (L 2.1 mm). Fig. 27: same, right view.
FIGURES 28–30:
Cranopsis hycavis
n. sp.
holotype MNHN 25292 (L 1.9 mm). Fig. 28: dorsal view. Fig. 29: right view. Fig. 30: ventral view.
FIGURES 31–36:
Cranopsis nymphalis
n. sp.
holotype MNHH 25293 (L 7.2 mm). Fig. 31: detail of anterior region, dorsal view (lateral side= 4 mm). Fig. 32: whole dorsal view. Fig. 33: right view. Fig. 34: ventral view. Fig. 35: detail of apex, right view (right side= 3 mm). Fig. 36: same left view (left side= 1 mm).
Distribution.
Only known from
type
locality.
Habitat.
Sandy mud bottoms,
790–940 m
depth (dead specimen).
Material examined.
Holotype
.
Etymology.
The specific epithet is derived from the Tupy native language
uirapa
, meaning arc, arched, in allusion to the arched shape of the shell.