Patula lucetta Hutton, 1884

Pl. 3, fig. E

Hutton, 1884. Transactions of the New Zealand Institute, 16 (1883): 162.

Type material. Lectotype (designated here), CMNZ M217.2, and paralectotypes (6), CMNZ M217 (dry shells).

Label details. CMNZ M217: ‘88. Patula lucetta Hutton, Hawkes Bay’, pillbox label in Hutton’s handwriting.

Type locality. ‘ Hawke’s Bay (W. Colenso)’ (Hutton 1884b: 163).

Previous illustrations of type material. Hutton (1884b; pl. 11, fig. A—radula).

Remarks. Patula lucetta Hutton, 1884 is a subjective synonym of Helix (Patula) stokesi Smith, 1884, which was described from material collected in Wairarapa, North Island (e.g., Hedley & Suter 1893: 654; Suter, 1894b: 268, 1913: 668; Cumber, 1961: 186; Powell, 1979: 323; Brook &Ablett 2019: 58). Hutton’s and Smith’s descriptions were published in May 1884 (see title page of the Transactions and Proceedings of the New Zealand Institute issue for 1883), and October 1884 (see Duncan 1937: 74), respectively, so Patula lucetta Hutton,1884 has priority, as noted by Powell (1979: 323). The type material of this species was listed as being in Canterbury Museum, Christchurch, by Hutton (1898 – 1900: 9), and reported as missing by Freeman et al. (1997: 36) but has since been found. It comprises a mixed assemblage, containing five specimens of P. lucetta one of which (lectotype) is illustrated for the first time in pl. 3, fig. E, and two of Charopa coma (Gray, 1843). This is consistent with the observation by Murdoch (1899: 323), that Hutton’s original account of P. lucetta described the shell and animal coloration of his new species, and a radula of C. coma. Patula lucetta has been listed in genus Phenacohelix Suter, 1892 (e.g., Suter 1913: 668; Powell 1979: 323; Goulstone 2001: 57; Spencer et al. 2009: 216), in Phenacohelix (Neophenacohelix) Cumber, 1961 by Cumber (1961: 186), and in genus Neophenacohelix Cumber, 1961 by Marshall & Worthy (2017: 305), but preliminary results of a phylogenetic study (M. Kennedy & T. King unpub. data) indicate that it belongs in genus Phacussa Hutton, 1883. Patula lucetta has been recorded from both the North and South islands (e.g., Hedley & Suter 1893: 654; Suter 1894b: 269, 1913: 669; Powell 1979: 323; Goulstone 2001: 59, fig. 12). However, Cumber (1961: 186) noted that there are morphological differences between populations on either side of Cook Strait and referred to the taxon as a species complex. The phylogenetic study referred to above found that COI sequences in populations from the North and South islands differed substantially (M. Kennedy & T. King unpub. data), indicating that they should be treated as separate species.Accordingly, Hutton’s name is used here for North Island populations only (below), and northern South Island populations that were previously referred to as lucetta are treated here as an unnamed sister species of lucetta, with a distribution from Marlborough Sounds to Nelson Lakes (AIM and NMNZ collection records). Records of lucetta from ‘Greymouth (R. Helms)’ by Hedley & Suter (1893: 654), Suter (1894b: 269, 1913: 669) and Cumber (1961: 188) were based on mislocalised material (i.e., NMNZ M.275314).

Taxonomy. Treated here as Phacussa lucetta (Hutton, 1884) n. comb.

Distribution. New Zealand; southern North Island, from Wellington and Wairarapa north to Mt. Taranaki, Lake Taupo and Urewera (Suter 1913: 669 —as Phenacohelix stokesi in part; Cumber 1961: 188 —as P. stokesi in part; Powell 1979: 323 in part; Goulstone 2001: 59, fig. 12 in part; AIM and NMNZ collection records).