Helix regularis Reeve, 1854

Brook, Fred J. & Ablett, Jonathan D., 2019, Type material of land snails (Mollusca: Gastropoda) described from New Zealand by taxonomists in Europe and North America between 1830 and 1934, and the history of research on the New Zealand land snail fauna from 1824 to 1917, Zootaxa 4697 (1), pp. 1-117 : 93-94

Helix regularis Reeve, 1854

Pl. 11, fig. D

Reeve, (1851–1854) 1854. Conchologia iconica, 7: species 1259, pl. 182, fig. 1259.

Type material: Syntype (1), NHMUK 20141112 (dry shell material); ex Museum Cuming (Acc. no. 1829) .

Label details: ‘N. Zealand’

Type locality: Not known. Incorrectly stated as ‘New Zealand’ by Reeve (1854 [in 1851–1854]: species 1259).

Previous illustrations of type material: Reeve (1854 [in 1851–1854]: pl. 182, fig. 1259), Tryon (1887 [from Reeve 1854]: pl. 21, fig. 12), Climo (1979: fig. 1K–L).

Remarks: Helix regularis Reeve, 1854 and H. regularis Pfeiffer, 1855 were both described from one or more specimens in H. Cuming’s collection, and were based on the same type material.The specimen in NHMUK 20141112 ex Museum Cuming does not have an original Pfeiffer taxon label, but is treated here as a syntype of H. regularis Reeve, 1852 because the locality listed on the label matches that in Reeve’s description. Pfeiffer evidently intended to publish the original description of this species in the Proceedings of the Zoological Society of London issue for 1854 (see Reeve 1854 [in 1851–1854]: species 1259), but publication was delayed until 1855 ( Pfeiffer 1855a: 50) [publication date of January 1855, according to Sclater & Waterhouse (1893)], and was pre-empted by Reeve (1854 [in 1851–1854]: species 1259). Authorship previously attributed to Pfeiffer (1855) (e.g., Hector 1873: 7; Hutton 1880: 17; Suter 1913b: 756; Climo 1979: 407; Powell 1979: 329), but Reeve (1854) has priority. There has been confusion over the identity of H. regularis , as noted by Climo (1979: 407). The name was mis-applied to species of Punctidae from New Zealand (e.g., Hedley & Suter 1993: 648; Suter 1894d: 277, 1913b: 756; Powell 1979: 329), which have since been assigned to the genus Kokopapa Climo & Mahlfeld, 2011 . The type material of H. regularis Reeve, 1854 was mis-localised, and there have been no subsequent valid records of this species from New Zealand ( Climo 1979: 407). We have not been able to determine where the type material was collected, but it may have come from Vanuatu [ New Hebrides], like the type lots of Helix guttula Pfeiffer , Helix rapida Pfeiffer and Hydrocena vestita Pfeiffer in the Cuming collection, which were also mis-labelled as being from New Zealand. Climo (1979: 407) noted that H. regularis is closely related to, or a senior synonym of, Nanina microconus Mousson, 1865 . He compared the type material of H. regularis with specimens of N. microconus from ‘Vutuna’ (= Futuna, Wallis et Futuna), one of which he unnecessarily designated as a neotype, noting differences in teleoconch microsculpture and colour. Examination of a syntype of N. microconus from ‘Loma-Loma, Viti’ [= Lomaloma, Vanua Balavu, Fiji], ZMZ 501061, and non-type material of putative microconus from Fiji, Samoa and Tonga, indicates that this taxon is indistinguishable from H. regularis in teleoconch characters. The early whorls of the only known extant type material of H. regularis are missing, and details of the protoconch sculpture of this species are not known, so it is not possible to confidently state on the basis of shell morphology alone that regularis and microconus are synonyms. Genetic analyses may resolve this conundrum, but in the meantime for taxonomic stability we prefer to treat H. regularis and N. microconus as separate taxa. The latter is recorded as having a distribution extending from Peninsular Malaysia to northern Australia and Samoa ( Baker 1941: 236; Solem 1959:95; Benthem Jutting 1964: 21; Solem 1989: 545–546; Vermeulen & Whitten 1998: 99; Stanisic et al. 2010: 338, 2018: 212), and has several junior synonyms, including Helix sansitas Cox, 1870 , Helix barkasi Liardet, 1876 and Sitala bandongensis Boettger, 1890 (see Baker 1941: 236; Solem 1959: 94, 1989: 545; Benthem Jutting 1964: 21–22).

Taxonomy: Coneuplecta regularis (Reeve, 1854) n. comb. is accepted here as an available valid name. Helix regularis Pfeiffer, 1855 is a junior primary homonym and an objective junior synonym.

Distribution: Not determined.