Helix decora, Ferussac, 1821

Cowie, Robert H., Héros, Virginie, Yeung, Norine W. & Hayes, Kenneth A., 2016, Annotated catalogue of types of Hawaiian land and freshwater snails (Mollusca: Gastropoda) in the Muséum national d’Histoire naturelle, Paris, with lectotype designations, Zoosystema 38 (2), pp. 245-266 : 250

decora Férussac, 1821 , Helix

( Fig. 1C )

Helix (Cochlogena) decora Férussac, 1821a: 60 ; 1821b: 56.

Turbo lugubris sinistrorsus Chemnitz, 1795 : pl. 213, figs 3014, 3015 [unavailable name].

CURRENT TAXONOMIC STATUS. — Achatinellinae, Achatinella Swainson, 1828 (Achatinella) . Valid species.

TYPE MATERIAL. — Possible syntypes MNHN IM-2000-30806 (4 spms, Fig. 1C ).

TYPE LOCALITY. — “Les îles Sandwich” (Oahu, Hawaiian Islands, as the genus is endemic to Oahu).

REMARKS

The name decora is available by indication ( ICZN 1999, art. 12.2.7) as Férussac provided bibliographic reference to illustrations (apertural and abapertural views of a sinistral shell) of Turbo lugubris sinistrorsus (unavailable name) by Chemnitz (1795: pl. 213, figs 3014, 3015), whose work was rejected for nomenclatural purposes as it did not consistently apply binominal nomenclature (Opinion 184; Direction 1; ICZN 1999, art. 11.4, 11.5). No other specimens were mentioned. The specimen was from Spengler (“Ex Museo Spengleriano”), bought by Spengler in London ( Chemnitz 1795: 307). Pilsbry & Cooke (1914 [in 1912-1914]: 333) stated that “The type of A. decora in the Spengler collection was probably brought to London by the expedition of Captain Dixon”; and based on extensive material they considered the species to be sinistral. Férussac in Quoy & Gaimard (1825: 478) stated that his material, which derived from the Freycinet expedition, differed from Spengler’s specimen in its colour and banding. Whether Férussac had the present four MNHN specimens (one of them is dextral) at hand when he listed the species in 1821 is not known (there are no Férussac collection labels with the specimens); nor is it known for sure whether the MNHN specimens are those from the Freycinet expedition. They are indeed very different in shell colour and banding from Spengler’s specimen ( Fig. 1C ). However, the collection labels do indicate that the specimens were in the Deshayes (and therefore possibly Férussac) collection. The species was treated and illustrated by Deshayes (1851: 191, 192, pl. 155, figs 5-7), but the specimens do not closely match his illustrations. They are here considered only to be possible syntypes.

Figures

FIG. 1. — Achatinellidae Gulick, 1873: A, Tornatellina cincta Ancey, 1904, syntype MNHN IM-2000-20012, 3.8 mm, fig. 5 of Ancey (1904a); B, Helicter compta Pease, 1869, lectotype MNHN IM-2000-30805, 24.7 mm; C, Helix decora Férussac, 1821, possible syntype MNHN IM-2000-30806,18.0 mm, fig. 3015 of Chemnitz (1795); D, Auriculella expansa Pease,1868, lectotype MNHN IM-2000-30807, 6.4 mm, fig. 8 of Pease (1868); E, Helix lorata Férussac, 1825, lectotype MNHN IM-2000-30808, 14.2 mm, fig. 8 of Férussac in Quoy & Gaimard (1825); F, Helix lugubris Férussac, 1821, possible syntype MNHN IM-2000-30810, 17.2 mm, fig. 2062 of Chemnitz (1795). Scale bars: A, D, 1 mm; B, C, E, F, 10 mm. Dimensions given are shell height; reproductions of original illustrations not to scale.