Sansonia alisonae, Renard & Bouchet, 2003

Renard, Jacques Le & Bouchet, Philippe, 2003, New species and genera of the family Pickworthiidae (Mollusca, Caenogastropoda), Zoosystema 25 (4), pp. 569-591 : 586-587

Sansonia alisonae n. sp.

( Fig. 11 )

TYPE MATERIAL. — Holotype (dd) AMS 135348 .

TYPE LOCALITY. — North Queensland, Australia, Carter Reef, 14°32’S, 145°35’E, 27- 30 m.

ETYMOLOGY. — The species is named after Dr Alison Kay, who contributed a great amount of unpublished information about Pickworthiidae in central Pacific.

MATERIAL EXAMINED. — A total of 6 specimens (6 lots).

La Réunion. Marion-Dufresne, cruise MD 32, stn DC85, 21°00’S, 55°15’E, 58-70 m, 1982, leg. Bouchet, Métivier & Warén, 1 dd ( MNHN).

New Caledonia. LAGON, stn 830, off Poindimié, 20°49’S, 165°19’E, depth 105-110 m, 1987, leg. B. Richer de Forges-ORSTOM, 1 dd ( MNHN).

Hawaii. Waimea Bay, Oahu, 30 m, leg. Kay, 1 dd ( UHM).

Australia. Carter Reef, 14°32’S, 145°35’E, North Queensland, 27-30 m, 1980, leg. Ponder, 1 dd (holotype, AMS 135348). — Davis Reef, 30 m, 1987, leg. K. Severin, 1 dd ( LACM 144377).

Red Sea. Marion-Dufresne, core MD 1022, off Sanganab, Sudan, 19°44.34’N, 37°28.23’E, 720 m, core length 10-20 m (?Holocene calciturbidite), 1992, leg. Taviani, 1 dd ( MZB).

DISTRIBUTION. — Red Sea; Indian Ocean: La Réunion; Pacific Ocean: Queensland, New Caledonia, Hawaii.

DESCRIPTION

Holotype ( Fig. 11 ). Shell small, trochiform, consisting of eight whorls. Protoconch consisting of two whorls, but corroded in material examined and cannot be studied in detail. Teleoconch whorls very angular due to spiral keel at upper adapical third. Second keel of same strength situated above adapical suture, becoming dominant on body whorl. Additional subsutural cord rather faint. Body whorl occupying 62% of total height. Base flat, with four concentric cords and very narrow umbilicus lined by another cord. Periphery marked by very strong keel, forming crenulated margin around base. Axial sculpture consisting of ribs (10 on earlier teleoconch whorls, 16 on last whorl), forming prominent, slightly spiny tubercles when intersecting spiral keel, and rather round tubercles when intersecting subsutural keel. Axial sculpture not extending over base on body whorl. Axial ribs and spiral keels forming regular, coarse reticulated pattern, with pointed nodes at intersections, giving spire an angular and shouldered appearance. Axial ribs becoming more crowded on last fourth of body whorl as they approach peristome and become weaker. Round, double aperture appearing rather small because of strong development of outer lip, the latter forming rather thin, broad, oblique rim reaching columellar area. Two spiral keels of body whorl reaching outer lip. Microscopic granular sculpture, most probably original.

Dimensions

H = 4.2 mm, D = 3.4 mm.

REMARKS

This is one of the largest species of Sansonia . The general morphology is very characteristic, especially because of the prominent periphery of the body whorl, the shouldered whorls and the coarse reticulation formed by intersection of axial and spiral sculpture.

Figures

FIG. 11. — Sansonia alisonae n. sp., holotype, Carter Reef, North Queensland (AMS 135348), H = 4.2 mm.