Zonites helmsii Hutton, 1882

Brook, Fred J., Kennedy, Martyn, King, Tania M., Ridden, Johnathon, Shaw, Matthew D. & Spencer, Hamish G., 2020, Catalogue of New Zealand land, freshwater and estuarine molluscan taxa named by Frederick Wollaston Hutton between 1879 and 1904, Zootaxa 4865 (1), pp. 1-73 : 26-27

Zonites helmsii Hutton, 1882

Pl. 2, fig. H

Hutton, 1882. New Zealand Journal of Science, 1: 281.

Type material. Lectotype (designated here), CMNZ M12783 [ex M254], and paralectotypes, CMNZ M254 (6), CMNZ M1068 [ex ZS 653] (3), NMNZ M.275691 [ex H. Suter colln.] (4) (dry shells). The molluscan collection

at CMNZ has radulae and jaws mounted on glass slides with the label details ‘ Phacussa helmsi, Greymouth, XVI p. 172’, in Hutton’s handwriting (i.e., CMNZ 2017.17.117–119), which are probably primary type material (see descriptions of radula and jaw by Hutton 1883d: 138, 1884b: 172–173).

Label details. CMNZ M254—‘42. Phacussa helmsi Hutton , Greymouth’, pillboxlabel—in Hutton’s handwriting; NMNZ M.275691—’18. Flammulina Phacussa helmsi, Hutt., Hel. , Greymouth’, in H. Suter’s handwriting.

CMNZ molluscan catalogue details. M1068—‘ Phacussa helmsi Hutton, Greymouth (old number ZS 653)’.

Type locality. ‘Greymouth (R. Helms)’ ( Hutton 1882p: 281, 1883d: 138).

Previous illustrations of type material. Jaw and radula teeth illustrated by Hutton (1884b: pl. 10, fig. I, pl. 11, fig. W) probably from type material.

Remarks. Hutton submitted a description of this species to the Transactions and Proceedings of the New Zealand Institute issue for 1882, but publication was delayed until May 1883 ( Hutton 1883d: 137), and was preempted by a brief description in an account of a meeting of the Philosophical Institute of Canterbury ( Hutton 1882p: 281). A shell from the type series (lectotype) is illustrated here for the first time in pl. 2, fig. H. The species name has been consistently listed as helmsi by New Zealand authors from Hutton (1884b: 172, 1884c: 205) onwards (e.g., Suter 1913: 624, Powell 1979: 315, Spencer et al. 2009: 215), and because this subsequent spelling has been in prevailing use since 1884 it is deemed to be correct under ICZN Articles 33.4 and 33.3.1. Descriptions by Hutton (1884b: 172–173, pl. 10, fig. I, pl. 11, fig. W) of the jaw and radula of helmsi were probably based on the putative type material in CMNZ 2017.17.117–2017.17.119 mentioned above. Zonites helmsi is the type species of Phacussa Hutton, 1883 , by subsequent designation of Pilsbry (1893 [in 1893–1895]: 12). Phelussa Iredale, 1915 is an unnecessary replacement name for Phacussa Hutton, 1883 . Phacussa helmsi has been interpreted as having a wide distribution in the southern South Island (e.g., Suter 1913: 625; Powell 1979: 315), but this refers to a species complex (M. Kennedy unpub. data), and the identity and distribution of Hutton’s species needs to be re-evaluated. At present it is known definitely from the West Coast only (below).

Current taxonomy. Phacussa helmsi (Hutton, 1882) — Hutton (1884b: 172, 1884c: 205), Suter (1913: 624), Powell (1979: 315), Spencer et al. (2009: 215).

Distribution. New Zealand; South Island, West Coast, between Greymouth and Westport (AIM and NMNZ collection records).