C. VlLVENS 
Novapex 13(1): 1-23, 10 mars 2012 
Comments. Regarding the huge gap between the type 
locality (Philippines) and French Polynesia, one can 
wonder to find this species in Australes Archipelago 
stations. But no clear conchological distinctions can 
be made between santples from the two areas, except 
that some Polynesian shells are less elevated, the 
subsutural spiral cord can be divided into two cords on 
the last whorls and the colour of the whorls is orange 
based rather then red wine. 
Genus Thalotia Gray, 1847 
Type species: Monodonta conica Gray, 1827 
[=Trochus pictus Wood, 1828] (by o.d.) - Recent, 
Southern Australia. 
Thalotia tiaraeides n. sp. 
Colour Figs F1-F2, Figs 33-34, Table 3 
Type material. Holotype (6.4 x 6.4 mm) MNHN 
(24969). Paratypes: 3 MNHN (24970, 24971). 
Type locality. French Polynesia, Australes 
Archipelago, Président Thiers Bank, BENTHAUS, stn 
DW 1932, 24°41’S, I46°02'W, 500 800 m. 
Material examined. French Polynesia, Australes 
Archipelago. BENTHAUS: stn DW1923, 27°01’S, 
146°05'W, 360-840 m, 1 dd. - Stn DW1932, 24°41'S, 
146°02'W, 500-800 m, 1 dd (holotype). — Stn 
DW 1955, 23°19'S, I49°26'W. 750-850 m, 1 dd sub. - 
Stn DW1958, 23°20'S, 149°30'W, 80-150 m, 1 dd sub. 
- Stn DW 1999, 22°25’S, 151°22’W, 270-500 m, 1 dd. 
- Stn DW2003, 22°28'S, 151°19’W, 250-330 m, 1 dd 
(paratype). - Stn DW2018, 22°37'S, 152°49’W, 
770-771 m, 1 dd. - Stn DW2020, 22°37’S, 151 0 49'W,’ 
920-930 m, 2 dd (paratypes). 
Distribution. French Polynesia, Australes 
Archipelago, 150-920 m (dead). 
Diagnosis. A small white Cantharidinae species with a 
moderately elevated spire, a subsutural angulate keel 
making shoulder and a thick peripheral keel; 6 main 
granular spiral cords on last whorl with a thick 
peripheral keel; slightly convex base with up to 10 
Iow, nearly smooth spiral cords; narrow and deep 
umbilicus, partly covered by a columellar expansion. 
Description. Shell of small size for the genus (height 
up to 6.6 mm, width up to 6.4 mm), as high as wide or 
slightly higher than wide, rather thick, conical with a 
subsutural angulate keel making shoulder with gentle 
slope; spire moderately elevated, height 0.9x to 1,2x 
width, 3.3x to 3.6x aperture height; umbilicus narrow 
and deep, partly covered by a columellar expansion. 
Protoconch approximately about 200 pm (eroded or 
damaged on ail samples), without visible varix. 
Teleoconch up to 6.1 convex whorls, bearing 6 main, 
similar in size spiral granular cords and peripheral 
keel produced by three close thin spiral cords. Suture 
visible, not canaliculated. 
First whorl convex, sculptured by 4 smooth primary 
spiral cords and weak, low, wide axial folds; PI, P2 
and P3 similar in size and evenly pinkish coloured, 
abapical cord P4 thinner with regular orange dashes; 
distance between P3 and P4 greater than distance 
between other cords. On second whorl, axial folds 
thinner and making PI, P2 and P3 subgranular. On 
third whorl, axial sculpture weakening; shoulder 
appearing with a round keel made by PI at fîrst 
adapical quarter; PI stronger than other cords; S2 
appearing rather quickly as strong as P2 and P3; 
strong suprasutural angulation above P4. On fourth 
whorl, keel much more angulate; S3 appearing above 
suprasutural angulation, quickly as strong as P3; Tl 
appearing at end of whorl on shoulder between suture 
and PI, quickly as strong as P2 but weaker than PI; 
T2 appearing between suprasutural angulation and P4, 
both cords thinner than other cords; ail spiral cords 
granular. On fifth whorl, S3 stronger than P3, S2 and 
P2; T3 appearing between angulation and T2, similar 
in size to T2 and P4; beads of cords prosoclinely 
elongated. On last whorl, additional Ti appearing by 
intercalation; P4, T2 and T3 very close, hard to 
distinguish and forming a thick peripheral keel. 
Aperture subquadrangular, slightly transversally 
elongated; outer lip thickened inside, meeting inner lip 
with obtuse angle. 
Columella straight, almost vertical, with a strong tooth 
at abapical third. 
Base weakly convex to almost fiat, with 8-10 smooth 
to subgranular, similar in size spiral cords; distance 
between cords smaller than cords. 
Umbilicus fairly narrow (diameter about 9% of shell 
width) and deep, funnel shaped with thin axial ridges 
inside, partly covered by columellar expansion. 
Colour of protoconch and teleoconch first whorl deep 
pink, next whorls orange brown with wide, irregular 
axial white patches; spiral cords of three last whorls 
alternating pinkish white and orange dashes; umbilical 
area and inner part of base light pink, spiral cords of 
outer part alternating orange and pink. 
TW 
H 
w 
HA 
H/W 
H/HA 
holotype 
6.1 
6.4 
6.4 
1.8 
1.00 
3.56 
paratype 1 
5.8 
5.9 
6.4 
1.8 
0.92 
3.28 
paratype 2 
6.1 
6.2 
5.8 
1.8 
1.07 
3.44 
paratype 3 
5.7 
—- 
6.6 
5.5 
1.9 
1.20 
3.47 
Table 3. - Thalotia tiaraeides n. sp.: Shells measurements in mm for types. 
