Euphaedusa sheridani (Pfeiffer, 1866)

Hwang, Chung-Chi, 2014, Annotated type catalogue of land snails collected from Taiwan (Formosa) in the Natural History Museum, London, ZooKeys 428, pp. 1-28 : 8

Taxon classification Animalia Stylommatophora Clausiliidae

Euphaedusa sheridani (Pfeiffer, 1866) Figure 1I

Clausilia sheridani Pfeiffer, 1866: 830-831. [1865] (Apr. 1866).

Euphaedusa sheridani , Yen 1939: 107, pl. 10, fig. 54.

Type locality.

Formosa [Taiwan] (Swinhoe).

Material examined.

Lectotype. Formosa, coll. Swinhoe, from collection of H. Cuming NHMUK 20040589/1), new designation, 16.0 × 3.5 mm, whorls 10.

Paralectotypes. Formosa, coll. Swinhoe, from collection of H. Cuming (NHMUK 20040589/2-4, 3 shells; NHMUK 20040589/5, 1 shell, non sheridani).

Remarks.

Pfeiffer (1866) described a variety with a projecting peristome inside, a narrowed aperture and an inconspicuous inferior lamella. Among the five specimens found, two shells are typical sheridani and two shells are of variety. The variations observed in the variety are caused by the thickened callus in the aperture of the fully matured shells. The original description gives a range of shell dimensions.

The largest specimen corresponds well in size with the measurements of Pfeiffer (1866). It is here selected as the lectotype for the stabilization of the name ( ICZN 1999: Art. 74). The specimen NHMUK 20040589/5 has similar shell dimensions, but it differs from the other four in having a thin and brownish corneous exterior, a shinier surface, finer striation, a less expanded peristome, a non-protruding aperture and a superior lamella not connected to the spiral lamella. This specimen is closely resembles Euphaedusa aculus (Benson, 1842) allies but is not a true Euphaedusa sheridani . Because this specimen was examined by Pfeiffer, it should be included in the type series ( ICZN 1999: Art. 72.4, 73.2). This specimen is still designated as a paralectotype.