Dicharax khasiacus (Godwin-Austen, 1871)

Fig. 68

Alycaeus Khasiacus Godwin-Austen, 1871: 90, pl. 3 fig. 4.

Alycaeus duorugosus Godwin-Austen, 1914: 391 . Syn. nov.

Alycaeus khasiacus – Sowerby 1877: pl. 1, species 8. — Godwin-Austen 1914: 356, 376–377, 393, pl. 143 figs 7, 7a–b.

Alycaeus (Dicharax) khasiacus – Kobelt 1902: 372–373. — Gude 1921: 257–258.

Alycaeus khasiacus var. – Godwin-Austen 1914: 356.

Alycaeus (Dicharax) duorugosus – Gude 1921: 249.

Chamalycaeus (Dicharax) duorugosus – Ramakrishna et al. 2010: 59.

Chamalycaeus (Dicharax) khasiacus – Ramakrishna et al. 2010: 62.

Dicharax (?) khasiacus – Páll-Gergely et al. 2020: 90.

Dicharax (?) duorugosus – Páll-Gergely et al. 2020: 86.

Diagnosis

Dicharax khasiacus is characterized by the rounded outline, the short, smooth R2, and the two, anteriorly situated R3 swellings.

Type material examined

INDIA • 29 syntypes of A. khasiacus (Fig. 68A–E); Lailangkote, Khasi Hills; NHMUK 1903.7.1.2650 • 1 syntype of A. duorugosus (Fig. 68F–J); Burrail; Godwin-Austen coll.; NHMUK 1903.7.1.2771 .

Additional material examined

INDIA • 4 shells; Jawai, Assam; Oberwimmer coll.; NHMW • 2 shells; same data as for preceding; NHMW 14711 • 4 shells; Jawai, India; Dr. Leo P. Rušnov coll., ex coll. Dr W. Blume ex coll. W.F. Webb; NHMW 15168 .

Type localities

“On the highest parts of the Khasi and Jiantia Hills” ( A. khasiacus); “Burrail Range, Naga ” “Also Angaoluo Trigonometrical Station, No. 2572; South Barak, No. 2629, and Munipur, No. 2654 B.M.” ( A. duorugosus).

Differential diagnosis

Dicharax lahupaensis has a ribbed R2 (smooth in D. khasiacus) and a thicker peristome. Dicharax akhaensis is larger, has a shorter R3 swelling, and a less fringed aperture.

Remarks

The single examined syntype of A. duorugosus fits the morphological variability of the 29 syntypes of A. khasiacus; therefore the former is a junior synonym of the latter.