Dicharax asaluensis (Godwin-Austen, 1914)

Pall-Gergely, Barna, Sajan, Sheikh, Tripathy, Basudev, Meng, Kaibaryer, Asami, Takahiro & Ablett, Jonathan D., 2020, Genus-level revision of the Alycaeidae (Gastropoda, Cyclophoroidea), with an annotated species catalogue, ZooKeys 981, pp. 1-220 : 1

Dicharax asaluensis (Godwin-Austen, 1914)

Alycaeus crispatus var. - Godwin-Austen 1874: 93, pl. 4, fig. 2.

Alycaeus asaluensis Godwin-Austen, 1914: 385-386, pl. 145, figs 2, 2a, 2b.

Alycaeus (Dicharax) asaluensis - Gude 1921: 237.

Chamalycaeus (Dicharax) asaluensis - Ramakrishna et al. 2010: 56.

Type locality.

“Neuglo,” “Phulong” and "Dihung River, N. Cachar, north of Asalu".

Material examined.

Dihung, N. Cachar, coll. Godwin-Austen, NHMUK 1903.7.1.2636. (2 syntypes); Asalu, North Cachar, NHMUK 1903.7.1.2761 (probably figured sample, with images on the sides of the box). See under D. crispatus .

Remarks.

Syntypes: protoconch low, spiral lines not visible; R1 irregularly ribbed, without spiral lines; R2 moderately long, with lamella-like, straight ribs.

Other sample.

The specimens are conspicuously variable in term of shell size (smallest: D = 2.7 mm, H = 2.1 mm; largest shell: D = 4.0 mm, H = 2.9 mm), the sculpture of R1 (nearly smooth to strongly, regularly ribbed) and the sculpture of R2. Despite the large variability, we consider all shells to belong to the same species since the variation is continuous between the extreme morphological forms. Protoconch low without spiral striation. R2 of some specimens typical Dicharax -like (ribs are curved towards the aperture), whereas those of other specimens are more lamella-like and less curved. Note that the shells with straight, lamella-like ribs on R2 are not weathered, which demonstrates that the two types of ribbing are a part of the intraspecific variation.