Helix collyrula Reeve, 1852

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 : 34

Helix collyrula Reeve, 1852

Pl. 3, fig. G

Reeve, (1851–1854) 1852. Conchologia iconica, 7: species 811, pl. 132 fig. 811.

Type material: Syntypes (2), NHMUK 20140670 (dry shell material); ex Museum Cuming (Acc. no. 1829) .

Label details: ‘N. Zealand’.

Type locality: ‘New Zealand’ (Reeve 1852 [in 1851–1854]: species 811).

Previous illustrations of type material: Reeve (1852 [in 1851–1854]: pl. 132, fig. 811); Pfeiffer (1853 [in 1852–1860]: pl. 154, figs. 25–28—as Helix kappa ); Tryon (1886 [from Reeve, 1852]: pl. 62, fig. 56); Tryon (1886 [from Pfeiffer, 1853]: pl. 63, fig. 60–62—also as Charopa kappa ).

Remarks: Helix collyrula Reeve, 1852 and H. kappa Pfeiffer, 1853 are based on the same type material, which H. Cuming had obtained from the Australian-based naturalist Frederick Strange. Pfeiffer evidently intended to publish the original description of this species in the Proceedings of the Zoological Society of London issue for 1851 (see Reeve 1852 [in 1851–1854]: species 811; Pfeiffer 1853a: 154; Pfeiffer 1854 [in 1852–1860]: 455), but publication was delayed until 1854 ( Pfeiffer 1854a: 58), and was pre-empted by Reeve (1852 [in 1851–1854]). This taxon was previously regarded as a junior synonym of Helix portia Gray, 1850 (e.g., Hutton 1884b: 203; Tryon 1886: 213), and of the earlier Helix ziczac Gould, 1846 (e.g., Hedley & Suter 1893: 635; Suter 1913b: 632; Powell 1979: 318). However, re-examination of the type material indicates that it differs from H. ziczac and H. portia , and instead is conspecific with Phenacohelix (Neophenacohelix) giveni Cumber, 1961 . To preserve nomenclatural stability and avoid confusion, giveni Cumber, 1961 is preserved here as the valid name (i.e., nomen protectum) for this taxon, and collyrula Reeve, 1852 is deemed invalid (i.e., nomen oblatum), in accordance with ICZN Article 23.9.2. Although collyrula is the earliest available name for this species, it has not been used as a valid name after 1899 (ICZN Article 23.9.1.1), whereas giveni has been used consistently as the valid name since 1961. The latter name has been mentioned ‘in at least 25 works, published by at least 10 authors in the immediately preceding 50 years [i.e., since 1969] and encompassing a span of not less than 10 years’ (see synonymy in Appendix 1), as required under ICZN Article 23.9.1.2 for reversal of precedence of the names. Phenacohelix (Neophenacohelix) giveni Cumber, 1961 has a wide distribution in the North Island, New Zealand, and is the type species of Neophenacohelix Cumber, 1961 , by original designation. Powell (1979: 322) and Goulstone (2001: 40) listed Neophenacohelix as a junior synonym of Phenacohelix Suter, 1892 , but Marshall & Worthy (2017) reinstated the former as a separate genus, based on morphological differences.

Taxonomy: Helix collyrula Reeve, 1852 is treated here as a junior synonym of Phenacohelix (Neophenacohelix) giveni Cumber, 1961 nomen protectum.