Gerontia cordelia Hutton, 1883

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 : 48-49

Gerontia cordelia Hutton, 1883

Pl. 6, fig. B

Hutton, 1883 . The New Zealand Journal of Science, 1: 476.

Type material. Lectotype (designated here), CMNZ M274 (dry shell).

Label details. ‘40. Gerontia cordelia Hutton, Titirangi , Auckland’, pillbox label in Hutton’s handwriting.

Type locality. Listed as ‘Titirangi, Auckland (Cheeseman)’ by Hutton (1883g: 476, 1884b: 179), but this is probably incorrect (see below).

Previous illustrations of type material. Pilsbry (1892 [in 1892–1893]: 66, pl. 22, figs. 34–36—‘drawn by Mr. Suter from Prof. Hutton’s type’); Suter (1913: pl. 25, figs. 8, a, b—possibly the same specimen as illustrated by Pilsbry).

Remarks. Hutton submitted a description of Gerontia cordelia to the Transactions and Proceedings of the New Zealand Institute issue for 1883, but publication was delayed until May 1884 ( Hutton 1884b: 178 ), and was pre-empted by his brief description of Gerentia [sic] cordelia in an account of a meeting of the Philosophical Institute of Canterbury ( Hutton 1883g: 476 ). These descriptions were based on one or more specimens that were putatively collected by Thomas Cheeseman in Titirangi, West Auckland. However, the locality details are probably incorrect as there have been no subsequent records of this species from the Auckland region (e.g., Powell 1952: 167, AIM and NMNZ collection records). Early workers variously assigned G. cordelia to family Charopidae (e.g., Hutton 1884c: 200 ), Helicidae (e.g., Pilsbry 1892–1893, Suter 1894b), Phenacohelicidae (e.g., Suter 1913) and Flammulinidae (e.g., Powell 1937). Powell (1952: 167) recognised that G. cordelia was a paryphantid [i.e., = family Rhytididae ], and designated it as the type species of subgenus Delouagapia Powell, 1952 , in genus Delos Hutton, 1904 . Delouagapia has generally been treated as a separate genus following Climo (1977: 61).

Current taxonomy. Delouagapia cordelia (Hutton 1883) — Climo (1977: 61), Spencer et al. (2009: 218).

Distribution. New Zealand; northern North Island, from Tangihua Range to North Cape ( Powell 1979: 348, AIM and NMNZ collection records).