Gulella (Huttonella) bicolor ( Hutton, 1834 )

Páll-Gergely, Barna, Hunyadi, András, Grego, Jozef, Sajan, Sheikh, Tripathy, Basudev & Chen, Zhe-Yu, 2020, A review of the Diapheridae (Gastropoda: Eupulmonata: Streptaxoidea), with special emphasis on India and Myanmar, Raffles Bulletin of Zoology 68, pp. 682-718 : 712-713

Gulella (Huttonella) bicolor ( Hutton, 1834)

( Figs. 21 , 22A )

Pupa bicolor Hutton, 1834: 86 , 93.

Ennea (Huttonella) bicolor — Nevill, 1878: 6.

Ennea (Huttonella) bicolor — Kobelt, 1904b: 128, pl. 19, figs. 1–3.

Ennea (Huttonella) bicolor — W.T. Blanford & Godwin-Austen, 1908: 19.

Gulella bicolor — Richardson, 1988: 56.

Gulella (Huttonella) bicolor — Ramakrishna et al., 2010: 192.

Type locality. “Mirzapoor beneath garden pots and at the base of the walls of my bungallow”.

Material examined. 9 shells ( NHMUK), Rajmahal, India, coll. Dr. T.V. Oldham.

Remarks. Peristome discontinuous, the parietal callus is only very slightly indicated by transparent calcareous layer. Parietal lamella relatively low and short, no inner and outer parts distinguishable. Palatal wall with a single, pointed, inward-pointing hook-like denticle, which is probably homologous with the lower palatal tooth of Sinoennea species. In some G. bicolor shells there is an additional tooth closer to the peristome edge, which may be homologous with the upper palatal tooth. Basal tooth pointed. Columellar lamella slightly oblique to shell axis, rather sharp. Basal swelling prominent, situated close to peristome.

The overall aperture shape and the arrangement of the barriers is similar to that of Sinoennea . The differences are the following: the parietal lamella of Sinoennea is long and consists of an inner and outer portion, which usually differ in orientation; peristome is continuous in most Sinoennea , and the parietal callus is clearly developed; the basal tooth, if present, only weakly developed in Sinoennea ; Sinoennea shells are almost always ribbed; juveniles are edentate, whereas in many (all?) Sinoennea species juveniles are dentate.

Figures

Fig. 21. Gulella (Huttonella) bicolor (Hutton, 1834), NHMUK. Both scales represent 1 mm; scale “a” refers to fig. A, scale “b” refers to figs. B–G.

Fig. 22. Apertures of Streptaxidae (A) and Diapheridae (B–P). A, Gulella (Huttonella) bicolor (Hutton, 1834); B, Rowsonia beddomei (W.T. Blanford, 1881); C, Platylennea subcostulata (W.T. Blanford, 1881); D, Pupennea planguncula (Benson, 1863); E, Diaphera polita, Páll-Gergely new species; F, Diaphera cylindrelloidea (Stoliczka, 1871); G, Bruggennea cf. bongi (Dance, 1970), H, Parasinoennea ovulum (Bavay & Dautzenberg, 1912); I, Sinoennea otostoma Páll-Gergely, A. Reischütz & Maassen in Páll-Gergely, Reischütz, Maassen, Grego & Hunyadi, 2020; J, Sinoennea infantilis Páll-Gergely & Grego in Páll-Gergely et al., 2020; K, Sinoennea variabilis Páll-Gergely & Grego in Páll-Gergely et al., 2020; L, Sinoennea sutchariti Páll-Gergely & Hunyadi in Páll-Gergely et al., 2020; M, Sinoennea montawana Páll-Gergely & Hunyadi, new species; N, Sinoennea angustistoma Páll-Gergely, A. Reischütz & Maassen in Páll-Gergely et al., 2020, O, Sinoennea woodthorpei (Peile, 1929); P, Sinoennea fartoidea (Theobald, 1870). Not to scale.