Helix glabriuscula 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 : 72

Helix glabriuscula Reeve, 1852

Pl. 8, fig. E; Pl. 14, fig. I

Reeve, (1851–1854) 1852. Conchologia iconica, 7: species 822, pl. 133, fig. 822.

Type material: Lectotype (here designated), NHMUK 20141113 /1; paralectoptypes, NHMUK 20141113 /2–4 (3), NHMUK 20040908 (4) (dry shell material); ex Museum Cuming (Acc. no. 1829).

Label details: ‘N. Zealand’; ‘n.sp. glabriuscula Pfr. ’—in Pfeiffer’s handwriting.

Type locality: ‘New Zealand’ (Reeve (1852 [in 1851–1854]: species 822).

Previous illustrations of type material: Reeve (1852 [in 1851–1854]: pl. 133, fig. 822), Pfeiffer (1853 [in 1852–1860]: pl. 156, figs. 14–16), Tryon (1887 [from Reeve 1852]: pl. 21, fig. 14).

Remarks: Helix glabriuscula Reeve, 1852 and H. glabriuscula 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 822; Pfeiffer 1853a: 51, 1854 [in 1852–1860]: 470), but publication was delayed until 1853 ( Pfeiffer 1853d: 262), and was pre-empted by Reeve (1852 [in 1851–1854]: species 822) [note that the publication date of ‘ October 1851 ’ listed for plate 133 of Reeve (1851 –1854) is presumed to be an error, as the immediately preceding and following plates were dated ‘ October 1852 ’ (see Petit 2007: table 3)]. Authorship of this species has generally been attributed to Pfeiffer (e.g., Hector 1873: 6; Hutton 1880: 23; Suter 1913b: 729; Powell 1979: 328; Spencer et al. 2009: 217), but Reeve (1852) has priority. The two lots in the NHMUK collection that were identified as glabriuscula by Pfeiffer, and which are regarded here as type material, contain three species. We interpret three of the specimens in NHMUK 20141113, and two in NHMUK 20040908, as being closest to Reeve’s original description and illustration (see pl. 14, fig. I) of H. glabriuscula , and designate NHMUK 20141113/1 (pl. 8, fig. E) as the lectotype of this species. One paralectotype in 20040908 and one in 20141113 have more weakly convex spire whorls than glabriuscula Reeve , and appear to be conspecific with Laoma lucida Suter, 1896 , and with Laoma sublucida Suter, 1896 , which we interpret as a subjective junior synonym of lucida . Another species, represented by a single paralectotype in 20040908, differs in having a well-developed peripheral carina, and appears to be Phrixgnathus ariel Hutton, 1883 . There has been confusion among New Zealand authors over the identity of Helix glabriuscula . For example, specimens in Suter’s collection (now at NMNZ) that were identified as glabriuscula are not conspecific with the the type material in NHMUK, and records attributed to glabriuscula by Suter (1913b: 752) and Powell (1979: 328) are instead mostly referrable to Laoma moellendorffi Suter, 1896 , and Punctidae sp. 56 (M.62133) of Spencer et al. (2009). Punctidae sp. 140 (M.29067) and Punctidae sp. 223 (M.151458) of Spencer et al. (2009) are conspecific with Helix glabriuscula Reeve as interpreted here. The range of morphological variation of the five specimens of glabriuscula Reeve in NHMUK 20141113 and NHMUK 20040908 matches that in some populations from the Auckland region (e.g., NMNZ M.107800, M.182388, M.104482), and it is probable that this is where the type material was collected.

Taxonomy: Phrixgnathus glabriusculus (Reeve, 1852) n. comb. is accepted here as an available valid name. Helix glabriuscula Pfeiffer, 1853 is a junior primary homonym and an objective junior synonym.

Distribution: New Zealand; northern and north-eastern North Island, mostly restricted to coastal and nearcoastal sites (AIM and NMNZ collection records).