C. VlLVENS 
NOVAPEX 13(1): 1-23, 10 mars 2012 
Teleoconch up to 6.7 convex whorls, with 6 main, 
granular, similar in size spiral cords and an additional 
peripheral cord on last whorl; beads of ail cords 
rounded conical, bluntly pointed. Suture not 
canaliculated, poorly visible. 
First whorl convex, sculptured by thick axial folds and 
3 primary spiral cords PI, P2 and P3 more or less 
similar in size, rather low, granular by intersection 
with folds; distance between folds 1.5x size of folds; 
distance between cords similar in size to cords. On 
second whorl, spiral cords stronger and wider, with 
well rounded beads; P3 slightly stronger than other 
cords, with rounded conical beads; axial folds more 
prosocline. On third whorl, beads of ail cords bluntly 
pointed; P4 emerging from suture at end of whorl, 
beaded, weaker than other cords. On fourth whorl, P4 
stronger, similar in size and shape to other cords; 
distance between P4 and P3 smaller than cords, 
distance between other cords similar in size to cords; 
S2 appearing at end whorl, thinner than other cords; 
axial folds weakening into axial threads. On fifth 
whorl, SI appearing at mid whorl; S3 absent. On last 
whorls, ail cords similar in size except P4 slightly 
stronger; ail cords with conical, blunt pointed beads; 
axial threads weak but still visible; Tl appearing 
between P2 and S2; S4 visible on last whorl, 
peripheral, thinner than other cords; distance between 
ail Pi and Si similar in size to cords, except S4 doser 
to P4; T2 appearing between SI and P2. 
Aperture subelliptic, slightly prosoclinely elongated; 
outer lip with nacreous thickened inside, with fine 
ridges at rim, without angle at meeting with thick 
inner. 
Columella weakly arcuated, slightly oblique, thick and 
nacreous, flaring at lower part, without tooth. 
Base moderately convex, with 12 granular spiral 
cords; subquadrate beads of cords made by thin axial 
threads across base; distance between cords smaller 
than cords; size of cords increasing in width from 
outer part of base to inner part. 
No umbilicus (closed by columellar expansion). 
Colour of protoconch and teleoconch yellowish light 
brown; base shiny white; aperture and columella 
nacreous. 
Discussion. The new species is rather close to 
Calliostoma (Fauîor) necopinatum Marshall, 1995 
(Figs 57-58) from New Caledonia, but this similar in 
size species has a different, narrowly conical, weakly 
cyrtoconoidal shape, more convex last whorls, a spiral 
cord S3, a wider protoconch (400-420 pm) and a 
subquadrangular thin aperture without ridges inside. 
Etymology. Flazelnut (Greek : Z£7rcov), used in 
apposition as a noun - with reference to light hazelnut 
colour of the shell, reminding of a eut hazelnut. 
Genus Thysanodonta Marshall, 1988 
Type species : Thysanodonta aucktandica Marshall, 
1988 (by o.d.) - Recent, New Zealand. 
Thysanodonta cf aucklandica Marshall, 1988 
Figs 59-60 
Thysanodonta aucklandica Marshall, 1988: 217-219, 
figs 3A-C. Type locality: off Auckland Islands, New 
Zealand, 549 m. 
Material examined. Tuamotu Archipelago. 
TARASOC: stn DW3389, 14°55'S, 148°15'W, 889 m, 
1 dd. 
Comments. This single specimen (6.8 x 5.5 mm) has 
the spiral cords ontogeny of T. aucklandica (P1-P2- 
S2-P3-S4 with P4 peripheral on last whorl), but has 
only 7 spiral cords on the base (instead of 10 fide 
original description Marshall, 1988). This specimen, 
with First whorls rather eroded and an indistinct 
suture, could be subadult because its teleoconch has 
only 5.3 whorls. Additional material is clearly needed 
to décidé if this is a different species or not. 
Family TllRBINIDAE Rafinesque, 1815 
Subfamily MARGARIT1NAE Thiele, 1924 
Genus Gaza Watson, 1879 
Type species: Gaza daedala Watson, 1879 (by o. d.) - 
Recent, Fiji Islands. 
Gaza p oly ch oronos n. sp. 
Colour Figs B1-B2, Figs 61-67, Table 5 
Type material. Holotype (14.5 x 18.4 mm) MNHN 
(24977). Paratype (12.9 x 16.5 mm) MNHN (24978). 
Type locality. French Polynesia, Société Islands, Bora 
Bora, TARASOC, stn DW3418, 16°33’S, 151°48'W, 
580-618 m. 
Material examined. French Polynesia, Société 
Islands. TARASOC: stn DW3418, 16°33'S, 
151°48'W, 580-618 m, 1 lv (holotype). - Stn 
DW3497, 17°43'S, 149°14'W, 365-850 m, 1 lv 
(paratype). 
Distribution. French Polynesia, Société Islands, 
living at 580-618 m. 
Diagnosis. A rather small white Gaza species with a 
moderately elevated, more or less conical spire, a 
rounded periphery; First whorls smooth, last whorls 
with numerous spiral cords, granular on adapical half 
and almost smooth on abapical half; granular callus 
covering a fairly wide umbilicus. 
Description. Shell of rather small size for the genus 
(height up to 14.5 mm, width up to 18.4 mm), wider 
than high, thin, conical, with a rounded periphery; 
spire moderately elevated, height 0.7x to 0.8x width, 
1.8x to 2.2x aperture height; fairly broad umbilicus. 
Protoconch of about 200-250 jum, of 1.25 whorl, low, 
smooth, glossy, without terminal varix. 
19 
