Endothyrella oakesi (Gude, 1915)

Pall-Gergely, Barna, Budha, Prem B., Naggs, Fred, Backeljau, Thierry & Asami, Takahiro, 2015, Review of the genus Endothyrella Zilch, 1960 with description of five new species (Gastropoda, Pulmonata, Plectopylidae), ZooKeys 529, pp. 1-70 : 34-36

Taxon classification Animalia Pulmonata Plectopylidae

Endothyrella oakesi (Gude, 1915) Figure 16A

Endothyrella oakesi 1915 Plectopylis (Endothyra) oakesi Gude: Records of the Indian Museum, 8: 505-506, Plate 41, Figs 1 a–d. ["Yamne Valley, Abor Hills and Sibbum", "between Riu and Singging, on the Dihang River"].

Types.

Yamne Valley, Abor Hills, leg. C.F.G. Oakes, R.E., NHMUK 1903.7.1.3125 (5 syntypes, Figure 16A).

Additional material examined.

Sibbum, Abor, NHMUK, coll. Godwin-Austen, NHMUK 20150157/1; Abor Hills, "exact position not known", below alt. 3000' between lat. 28°15'+29°15', long. 94°50'+95°10', leg. Oakes, coll. Godwin-Austen, NHMUK 1903.7.1.3125/1.

Diagnosis.

Shell small, sinistral, with wide umbilicus, and slightly domed dorsal surface; callus strong, palatal plicae complicated, their anterior part is horizontal, but the posterior part vertical; there are several short horizontal plicae between posterior parts of the palatal plicae; lamella almost straight with posteriorly elongated upper end, and sometimes with a long lower plica which reaches the aperture.

Measurements

(in mm): D: 11.7-12.5, H: 4.7-5.5 (n = 3, type series).

Differential diagnosis.

Endothyrella nepalica sp. n. also has simpler palatal plicae than those of Endothyrella oakesi . Moreover, Endothyrella nepalica sp. n. has a flatter shell and a less descending aperture. See also under Endothyrella pinacis and Table 5.

Distribution.

This species was reported only from the localities mentioned in the original description (Yamne Valley, Abor Hills and Sibbum", "between Riu and Singging, on the Dihang River") (Figure 10).

Remarks.

Three specimens (two adults and a juvenile) of the type lot of Endothyrella oakesi were opened (probably by Gude). The long lower parietal plica, described as characteristic feature of this species, is present only in one specimen. In face of this, Endothyrella oakesi seems to be a distinct species on the basis of the palatal plicae and shell shape.