Chiliborus pachychilus (Pfeiffer, 1842) Figs 2.5-2.8, Table 2

Bulimus pachychilus Pfeiffer, 1842: 48-49. Bulimus pachycheilus: Reeve 1848: 5, pl. 15, fig. 87. Strophocheilus pachychilus: Pilsbry 1895: 35, pl. 12, figs 63-64. Strophocheilus (Chiliborus) pachychilus: Pilsbry 1926: 6; Bequaert 1948: 184, pl. 8, figs 2, 4. Chiliborus pachychilus: Stuardo and Vega 1985: 129.

Material examined.

Chañaral de Aceituno (29°01'35"S, 71°26'20"W), Commune of Freirina, February 2008, RCG (unnumbered), 33 specimens. MZUC 39615.

Diagnosis.

This species has ovate-oblong, shells (up to 39 mm), with a thin, brownish periostracum and a slightly flattened apex. They are easily distinguished by their solid and thick whitish shell and their thickened, lamellate outer lip. On magnification the surface of the shell has a rugose appearance, especially in the subsutural area, due to very fine spiral threads crossed by thin axial lines (Fig. 2.8).

Distribution and remarks.

Questa de Arenas, Huasco (28°20'S, 71°15'W) and Coquimbo (29°57'S, 71°20'W) (Stuardo and Vega 1985). The specimens studied here constitute the northernmost record for the species.