Helix (Theba) ziczac Gould, 1846

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 : 65

Helix (Theba) ziczac Gould, 1846

Pl. 14, fig. K

Gould, 1846. Proceedings of the Boston Society of Natural History, 2: 166.

Type material: One or more specimens, consisting of, or including, a syntype at the United Sates National Museum, Washington, DC (see Suter 1894e: 124). Type material details not listed by Johnson (1964: 170 —as H. (T.) zizac sic), and present whereabouts not known. A specimen from ‘Hunua Range, Auckland’, which Henry Suter sent to William Dall to compare with the type material of H. ziczac (see Suter 1894e: 124), has been incorrectly listed in the USNM catalogue as the holotype (i.e., USNM 106958).

Type locality: ‘New Zealand’ (Gould 1846: 166); ‘found by Dr. Pickering, in a crater near Taiaimi, New Zealand’ ( Gould 1852: 42).

Previous illustrations of type material: Gould (1856: pl. 3, fig. 44, a–c [reproduced here in pl. 14, fig. K]); Tryon (1886 [from Gould 1856]: pl. 62, figs. 35–37).

Remarks: The place name Taiaimi does not appear on current maps, but comments by Wilkes (1845, vol. 2: 394) indicate that it was located west of the Bay of Islands and had a hot spring that was “situated in a small basin, and forms a lake of three or four acres in extent; near the edge of this lake, gas is constantly bubbling up”. This corresponds to the geothermal area at Ngawha Springs. Wilkes (1845, vol 2: 394) also described the nearby scoria cone of ‘Poerua’ (= Pouerua), and this may be where the type material was collected. Helix portia Gray, 1850 is a subjective junior synonym of H. ziczac Gould (e.g., Hedley & Suter 1893: 635; Suter 1894d: 256, 1894e: 124, 1913b: 632; Powell 1979: 318). Previously Helix collyrula Reeve, 1852 and H. kappa Pfeiffer, 1853 were also treated as junior synonyms of H. ziczac Gould (e.g., Hutton 1884b: 203; Tryon 1886: 213; Hedley & Suter, 1893: 635; Suter 1913b: 632; Powell 1979: 318) but, as noted above, collyrula and kappa , based on the same type material as one another, are a different species. The species name ziczac has been misspelt ‘ ziczag ’ by some authors (e.g., Suter 1913b: 632; Powell 1979: 318; Goulstone 2001: 77; Spencer et al. 2009: 216). Included in Thalassohelix by Pilsbry (1892 [in 1892–1893]: 72; 1893 [in 1893–1895]: 13), Hedley & Suter (1893: 635), Suter (1894e: 123; 1913b: 632), Powell (1979: 318), and transferred to Phenacohelix Suter, 1892 by Goulstone (2001: 77). Protoconch morphology and preliminary results of a phylogenetic study (M. Kennedy, T. King & F. Brook unpub. data) indicate that ziczac is not congeneric with Phenacohelix pilula (Reeve, 1852) , the type species of that genus ( Pilsbry 1892a: 56), and it is here provisionally assigned to Neophenacohelix Cumber, 1961 , pending further study.

Taxonomy: Treated here as? Neophenacohelix ziczac (Gould, 1846) n. comb.

Distribution: New Zealand; northern North IsIand ( Goulstone 2001). Records from New South Wales, Australia (e.g., by Gould (1862: 18) and Cox (1868a: 19, 1868b: 71) were in error (see Suter 1894e: 124).