Sinoarinia Chen & Wu, 2020

Chen, Zhe-Yu & Wu, Min, 2020, Two new cyclophoroid species from Hubei, China, with proposal of a new genus (Gastropoda, Caenogastropoda, Diplommatinidae and Alycaeidae), ZooKeys 935, pp. 37-46 : 37

Sinoarinia Chen & Wu gen. nov.

Type species.

Sinoarinia feii Chen, sp. nov.

Diagnosis.

Shell minute, dextral, thin, translucent, cylindrical. Penultimate whorl strongly constricted. Last whorl strongly ascending, covering part of penultimate whorl. Protoconch oblique. Apical whorls depressed, with strong or weak ribs. Aperture rounded; peristome double, expanded but not reflected. Columellar lamella not visible from aperture but internally present; one parietal lamella and one palatal plica extending inwards from last whorl to penultimate whorl (in type species). Palatal plica visible through semitransparent parietal wall. Constriction absent or very weak where lamellae and plica terminate. Umbilicus closed, forming a chink.

Etymology.

Combination of the Latin prefix sino- (= China) with Arinia .

Distribution.

Southern China (Hubei, Guizhou), northern Vietnam.

Remarks.

The new genus can be distinguished from the sympatric diplommatinid genera ( Arinia , Diplommatina Benson, 1849 and Gastroptychia Kobelt & Möllendorff, 1900) by its constricted penultimate whorl and the ascending last whorl ( Kobelt 1902; Zilch 1953; Vermeulen 1996; Vermeulen et al. 2007; Páll-Gergely and Hunyadi 2018). In general, Sinoarinia gen. nov. has a cylindrical shell, depressed apex, and deeply incised lamellae and plica, which differs from the conical shell with an exposed columellar lamella in Diplommatina and Gastroptychia . Arinia usually lacks internal apertural barriers ( Kobelt 1902; Vermeulen 1996; Vermeulen et al. 2007), which are well developed in Sinoarinia gen. nov. The constricted structure of the new genus is similar to that found in the non-sympatric diplommatinid genus Diancta E. von Martens, 1864, which differs from the new genus by its mostly sinistral coiling and conical whorls as showed in Diancta (s. str.) ( Neubert and Bouchet 2015), or by the constricted penultimate whorl which is not partially covered by the last whorl, as showed in Diancta (Paradiancta) Möllendorff, 1895 ( Egorov 2013).

Three species, Arinia mirifica Li, Zhuo & Luo, 2005, A. maolanensis Zhang, Chen & Zhuo, 2013, and Diplommatina aesopus Bavay & Dautzenberg, 1904, which some authors currently assign to Arinia ( Li et al. 2005; Zhang et al. 2013) and Diplommatina (Bavay & Dautzenberg, 1904), are here transferred to Sinoarinia gen. nov.

Included species.

Sinoarinia aesopus (Bavay & Dautzenberg, 1904) comb. nov., Sinoarinia feii Chen sp. nov., Sinoarinia maolanensis ( Zhang et al., 2013) comb. nov., and Sinoarinia mirifica ( Li et al., 2005) comb. nov.

Vernacular name.

华阿勇螺属