Parashiela liddelliana ( Hedley, 1907 )

Amati, Bruno, Giulio, Andrea Di & Oliverio, Marco, 2023, Shallow-water Rissoidae of the genera Alvania Risso 1826 Haurakia Iredale 1915 Parashiela Laseron 1956 Simulamerelina Ponder 1985 and Subestea Cotton 1944 Gastropoda Caenogastropoda Rissooidea from French Polynesia with the description of a new deep-water genus, Zoosystema 45 (25), pp. 803-892 : 837

Parashiela liddelliana ( Hedley, 1907)

( Figs 23 ; 50 )

Rissoa liddelliana Hedley, 1907: 494 , pl. xvii, fig. 24.

TYPE MATERIAL. — Holotype. Australia • dd; Queensland, Capricorn Group, Mast Head Reef ; AMS-C.19544 .

Paratypes. Australia • 14 dd; Queensland, Capricorn Group, Mast Head Reef ; AMS-C.170431 .

TYPE LOCALITY. — Australia: Queensland, Capricorn Group, Mast Head Reef.

DISTRIBUTION. — Pacific from the northern part of Australia to Japan and Hawaii (van Gemert 2016: 8) ( Fig. 50 ).

DIAGNOSIS. — Parashiela small for the genus, height 1.20 mm. Whorls convex with weak double anglulation on the last whorl. Protoconch multispiral.Teleoconch devoid of spiral macro-sculpture; 20 narrow and slightly flexuose axial ribs on the last whorl, reaching the base and entering the narrow umbilical fissure. Peristome duplicated, with thick and wide varix crossed by evident growth striae. Colouration whitish.

REMARKS

The holotype (AMS-C.19544) ( Fig. 23A, B ) is rather damaged, especially on the aperture (it has also suffered partial corrosion from the Byne’s disease). This species has rarely been reported in the literature (e.g. Middelfart et al. 2020: 171, fig. 8C) and more often under other names (e.g. Kay 1979: 78, pl. 27, fig. D, as Parashiela beetsi , fide Hasegawa 2006b:109; Fukuda 1993: 40, pl. 13, fig. 188, as Parashiela ambulata ; Ekawa, 1993, as Parashiela sp. , fide Hasegawa 2006b: 109).

See under P. expansilabrum n. sp., P. rimatara n. sp. and P. soniae n. sp. for detailed comparisons.

Figures

FIG. 23. — Parashiela liddelliana (Hedley, 1907): A, B, holotype, height 1.2 mm, width 0.76 mm, Queensland, Capricorn Group, Mast Head Reef, depth unknown, AMS-C.19544 (Images: A. C. Miller, Copyright: Australian Museum); C, original drawing.

FIG. 50. — Type localities of Parashiela invisibilis (Hedley,1899) (Funafuti Atoll: ○), Parashiela liddelliana (Hedley,1907) (Mast Head Reef:●), Parashiela ambulata Laseron, 1956 (Michaelmas Cay: ✩), and Parashiela beetsi Ladd, 1966 (Eniwetok Atoll: *).