Helix corniculum 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 : 38-39

Helix corniculum Reeve, 1852

Pl. 5, fig. A

Reeve, (1851–1854) 1852. Conchologia iconica, 7: species 826, pl. 133 fig. 826 (not Reeve, 1852 [in 1851–1854]: species 502, pl. 133, figs. 502a, b = Helix corniculum Hombron & Jacquinot, 1847 ).

Type material: Syntype (1), NHMUK 1962725 (dry shell material); ex Museum Cuming (Acc. no. 1829). Possible syntypes (2), ZMH 45987 (dry shell material); from Altonaer Museum, coll. O. Semper ex Cuming.

Label details of NHMUK 1962725: ‘n.sp. H. eta Pfr. N. Zealand’.

Type locality: ‘New Zealand’ (Reeve 1852 [in 1851–1854]: species 826).

Previous illustrations of type material: Climo (1981: figs. 1A–C—as Helix eta ). A shell purported to be Helix corniculum was illustrated by Reeve (1852 [in 1851–1854]: pl. 133, fig. 826 [reproduced by Tryon (1887: pl. 3, fig. 12]), but does not match Reeve’s accompanying description, or the type material of corniculum , and evidently represents another species.

Remarks: Helix corniculum Reeve, 1852 and H. eta 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 826) and Pfeiffer (1853a: 107), but publication was delayed until 1854 ( Pfeiffer 1854a: 57), and was pre-empted by Reeve (1852 [in 1851–1854]) [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)]. Reeve’s name was pre-occupied by Helix corniculum Hombron & Jacquinot, 1847 , applied to material from New Guinea ( Martens 1873: 10). Iredale (1941) proposed the new name Mocella cogitata for Reeve’s corniculum , but Climo (1970a: 312) pointed out that the earlier name Helix eta Pfeiffer, 1853 was available. Helix corniculum Reeve, 1852 [= H. eta Pfeiffer, 1853 ] is the type species of Mocella Iredale, 1915 , by original designation. Historically there was considerable confusion over the identity of Helix corniculum Reeve and H. eta Pfeiffer , as noted by Climo (1981) and Goulstone (1995). Some authors (including Suter 1913b: 725; Iredale 1915: 482; Climo 1970a: 314; Powell 1979: 310) used Reeve’s or Pfeiffer’s names for one or more species having a radially ribbed teleoconch and spirally-ribbed protoconch. However, Climo (1981) noted that the type specimen of Helix corniculum Reeve and Helix eta Pfeiffer had a radially-ribbed protoconch, and matched shells that some authors (including Suter 1913b: 715; Iredale 1915: 482; Powell 1939: 238; Climo 1970a: 330; Powell 1979: 309) had incorrectly identified as Helix caput-spinulae Reeve, 1852 (see entry for caput-spinulae below).

Current Taxonomy: Junior homonym of Helix corniculum Hombron & Jacquinot, 1847 ; objective junior synonym of Helix eta Pfeiffer, 1853 , the first available name ( Climo 1970a: 312, 1981: 9).