Helix biconcava Pfeiffer, 1853

Pl. 2, fig. D

Pfeiffer, 1853a. Monographia heliceorum viventium, 3: 109.

Type material: Syntypes (3), NHMUK 20040907 (dry shell material); ex. Mus. Cuming (Acc. no. 1829) .

Label details: ‘biconcava P.’ in Pfeiffer’s handwriting, ‘New Zealand’.

Type locality ‘Nova Seelandia’ (Pfeiffer 1853a: 109).

Previous illustrations of type material: Reeve (1852 [in 1851–1854]: pl. 132, fig. 810); Pfeiffer (1853 [in 1852–1860]: pl. 155, figs. 43–47); Tryon (1885 [from Reeve 1852]: pl. 24, fig. 75).

Remarks: Helix biconcava Reeve, 1852 and H. biconcava 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 810; Pfeiffer 1853a: 109, 1854 [in 1852–1860]: 458), but publication was delayed until 1854 (Pfeiffer 1854b: 149), and was pre-empted by Reeve (1852 [in 1851–1854]). Authorship of this species has generally been attributed to Pfeiffer (e.g., Hector 1873: 13; Hutton 1880: 11; Suter 1913b: 729; Climo 1969a: 214; Powell 1979: 307; Spencer et al. 2009: 215), but Reeve (1852) has priority. Incorrectly listed as a junior synonym of Helix infecta Reeve, 1852, by Climo (1969a: 214) and Powell (1979: 307).

Taxonomy: Helix biconcava Pfeiffer, 1853 is a junior primary homonym and an objective junior synonym of Cavellia biconcava (Reeve, 1852) N. syn.