Unio depauperata Hutton, 1883

Pl. 1, fig. A

Hutton, 1883. New Zealand Journal of Science, 1: 478.

Type material. Lectotype, CMNZ M670 (pair of dry valves), and paralectotypes, NMNZ M.644 (pair of dry valves), NMNZ M.125068 [ex M.644] (pair of dry valves). Lectotype fixed by inference of holotype (ICZN Art. 74.6) by Allan (1938: 182). Lectotype designation of Dell (1953: 231) preceded by that of Allan (1938: 182).

Label details. CMNZ M670—‘ D. depauperata, L. Takapuna, Type’; NMNZ M.644— ‘U. depauperatus Hutton n.s., Lake Takapuna, Auckland’.

CMNZ molluscan catalogue details. ‘ Diplodon menziesi depauperatus (Hutton), Lake Takapuna, Holotype, (2 valves), (ZS 968c—old number)’.

Type locality. ‘Lake Takapuna, Auckland’ [= Lake Pupuke] (Hutton 1883h: 478, 1884d: 216).

Previous illustrations of type material. Dell (1953: pl. 17, fig. 10— paralectotype); Marshall et al. (2014: fig. 4A, C—paralectotype).

Remarks. Hutton submitted a description of Unio depauperata to the Transactions and Proceedings of the New Zealand Institute issue for 1883, but publication was delayed until May 1884 (Hutton 1884d: 216), and was preempted by a brief description of Unis [sic] depauperata in an account of a meeting of the Philosophical Institute of Canterbury (Hutton 1883h: 478). Hutton (1884d) noted that this taxon was “perhaps an impoverished form of U. zelebori [Dunker, 1866: see Marshall & Fenwick 2006], but too distinct to be passed over”. It has been treated as a subspecies of the morphologically variable species Unio menziesii Gray (e.g., by Simpson 1900: 890; 1914: 1292; Suter 1913: 941; Dell 1953: 231) and as a junior synonym of U. menziesii by McMichael & Hiscock (1958: 460), Powell (1979: 384) and Marshall et al. (2014: 10). The last-mentioned species is endemic to New Zealand, and is widely distributed in lakes, rivers and streams in the North and South Islands, and on Great Barrier Island (Marshall et al. 2014: 12, fig. 6).

Current taxonomy. A junior synonym of Echyridella menziesii (Gray, 1843) — McMichael & Hiscock (1958: 460 —in Hyridella ( Echyridella)), Powell (1979: 384 —in Hyridella), Marshall et al. (2014: 10).