Dicharax (?) biexcisus (Pilsbry, 1902)

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 (?) biexcisus (Pilsbry, 1902) Fig. 13C

Alycaeus biexcisus Pilsbry, 1902d: 26.

Awalycaeus biexcisus - Kuroda and Abe 1980: 20, pl. 2, figs 1-4.

Cipangocharax biexcisus - Minato 1981: 135-137, fig. 4; Minato and Abe 1982: 200-202, figs 10-12; Azuma 1982: 12, pl. 4, fig. 41; Minato 1988: 16, pl. 2, fig. 5; Minato 1993: 1, figs 2, 4.

Chamalycaeus (Cipangocharax) biexcisus - Egorov 2013: 36, fig. 64.

Type locality.

"Suimura, Awa".

Material examined.

ANSP 82660a (lectotype, designated by Baker 1964, photographs examined), Nagai-mura, Awa, Tokushima Pref., Japan, coll. Hirase (#263), NSMT-Mo 2050 (3 shells).

Remarks.

Protoconch low, finely granulated, rather matte; R2 with ca. 26 low, blunt, irregular ribs, which are connected to each other near the tube, gradually becoming free towards the edge of the body whorl (here the distance between neighbouring ribs is very small, much less than the width of a rib); no spiral lines visible on R1.

Figures

Figure 13. Type species of alycaeid genus-group taxa A Dicharax hebes (Benson, 1857) (SMF 109244; type species of Dicharax) B D. (?) abei (Kuroda, 1951) (NSMT 50125; type species of Awalycaeus) C D. (?) biexcisus (Pilsbry, 1902) (NSMT 263; type species of Cipangocharax) D D. (?) itonis (Kuroda, 1943) (NSMT 78866; type species of Sigmacharax). Close-up images of the aperture are not to scale. All photographs: Barna Pall-Gergely.