Clatrosansonia Sabelli & Taviani, 2003

Renard, Jacques Le & Bouchet, Philippe, 2003, New species and genera of the family Pickworthiidae (Mollusca, Caenogastropoda), Zoosystema 25 (4), pp. 569-591 : 571-574

Genus Clatrosansonia Sabelli & Taviani n. gen.

TYPE SPECIES. — Mecoliotia philippina Bandel & Kowalke, 1997 ( Fig. 2 ).

ETYMOLOGY. — From the Latin clatri (= bars, lattice), and from Sansonia . The spelling clathr-, although widely used (as in clathrate), is not Greek and seems uncommon in Latin.

SPECIES INCLUDED. — Mecoliotia jousseaumei Bavay, 1921 ; Manzonia (Taramellia) minuta Hornung & Mermod, 1928 [= Merelina hians Laseron, 1957 ]; Alvania (Taramellia) corayi Ladd, 1966 ; Mareleptopoma cubensis Espinosa, Fernández-Garcés & Rolán, 1990 , M. chefyae Rolán, Espinosa & Fernández-Garcés, 1991 [similar to M. cubensis ], M. scalaris Rolán & Fernández- Garcés, 1993, Microliotia circumserrata Raines, 2002 , and Clatrosansonia trondlei n. sp. Clatrosansonia philippina n. comb. has been designated as type species because it is the most common of all included species.

DESCRIPTION

Shells very small (height from 1 to 2 mm); H/D ratio ranging from 1 to 2. Sculpture very regularly clathrate, with numerous evenly-spaced spiral cords (eight to 13 on body whorl), similar in appearance on base and spire; spiral cords intersected by numerous axial lamellae (25 to 45 on body whorl). Intersection of axial and spiral sculpture forming slightly or very slightly prominent nodes. In addition to this primary sculpture, microsculpture of spiral lamellae distinctly visible between ribs and cords. Stronger spiral cord or keel may mark periphery of body whorl. The more developed this peripheral keel, the flatter the spire whorls. Suture narrow but rather deep. Narrow but deep umbilicus always present, lined by strong prominent rib merging abruptly with base of peristome. Aperture rather broad; peristome consisting of numerous concentric rings stacked in flat disk projecting strongly outwardly. In lateral view, disc lying obliquely, parallel to one side of spire, so that the stouter the shell, the more oblique the apertural rim. Spiral sculpture extending onto body whorl to back and side of outer lip. Protoconch of all species except one planktotrophic, with 2.5 whorls; seven spiral cords, often in pairs, plus additional small pustules forming more or less regular spiral alignments. Sculpture of teleoconch initially with a single spiral cord, continuous with main spiral cord of larval shell.

REMARKS

The species included by us in Clatrosansonia n. gen. are very homogeneous in the following characters: fine and regular reticulated sculpture, identical on the base and spire; umbilicus deep and lined with a rib; peristome with numerous concentric lamellae onto which the spiral sculpture extends.

Figures

FIG. 2. — Clatrosansonia philippina (Bandel & Kowalke, 1997) n. comb., Jeddah, Red Sea (MZB 003794), H = 1.27 mm; A, B, apertural and side views; C, protoconch. Scale bar: C, 50 µm.