Chamalycaeus humilis (W.T. Blanford, 1862 )

Chamalycaeus humilis (W.T. Blanford, 1862)

Fig. 5E–I

Alycaeus humilis W.T. Blanford, 1862: 136–137 View in CoL .

Alycaeus humilis View in CoL – Sowerby 1877: pl. 5, species 40. — Godwin-Austen 1914: 408–409, pl. 151 fig. 8. Alycaeus ( Dicharax) humilis View in CoL – Kobelt 1902: 372. — Gude 1921: 255–256.

Dicharax humilis View in CoL – Páll-Gergely et al. 2020: 64 View Cited Treatment .

Type material examined

MYANMAR • holotype (single shell mentioned in the original description: Fig. 5E–I); River Bank, Myanoung , Pegu; NHMUK 1906.4 About NHMUK .4.69 .

Type locality

“ad Akouktoung, ad ripas fluminis Irawaddi, in provincia Burmana Pegu ”.

Differential diagnosis

This species has a comparatively smaller aperture than C. armillatus . Chamalycaeus irmatallus has denser and finer R1 ribs, more expanded outer peristome and a less inflated R3 swelling.

Remarks

Only a single, corroded shell is known, therefore the important traits (presence or absence of spiral striation on the teleoconch) could not be examined without doubt. We classified this species in the genus Dicharax in our previous catalogue, but during the revision of Himalayan Dicharax , we had to reconsider our decision. Since the shell shape of A. humilis is most similar to the geographically closely occurring Chamalycaeus armillatus and C. irmatallus , we move this species to Chamalycaeus .