Helix nematophora Reeve, 1854

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 : 52

Helix nematophora Reeve, 1854

Pl. 16, fig. A

Reeve, (1851–1854) 1854. Conchologia iconica, 7: species 1333, pl. 190, figs. 1333a, b.

Type material: Syntype (1), NHMUK 1962713 (dry shell material); ex Museum Cuming (Acc. no. 1829) .

Label details: ‘ nematophora Pfr., Solomons Islands’ in Pfeiffer’s handwriting.

Type locality: ‘Solomon’s Island’ (Reeve 1854 [in 1852–1854]).

Previous illustrations of type material: Reeve (1854 [in 1851–1854]): pl. 190, figs. 1333a, b; Tryon (1886 [from Reeve 1854]: pl. 38, fig. 46); Delsaerdt (2006 [from Reeve 1854]: 117, text fig.).

Remarks: The original description was based on one or more specimens in the Cuming collection. Helix nematophora Reeve, 1854 and H. nematophora Pfeiffer, 1855 are based on the same type material. Pfeiffer’s original description in the Proceedings of the Zoological Society of London issue for 1854 was not published until January 1855 ( Pfeiffer 1855a: 49 —see Sclater & Waterhouse 1893 for date of publication), and was pre-empted by Reeve’s description published in August 1854. Authorship previously attributed to Pfeiffer (e.g., Pfeiffer 1859: 15, 1868a: 55, 1876: 68; Cox 1868b: 42; Pfeiffer & Clessin 1881: 36; Tryon 1886: 114, 245; Clapp 1923: 355; Delsaerdt 2006: 117), but Reeve (1854) has priority. The type material of H. nematophora Reeve, 1854 [= H. nematophora Pfeiffer, 1855 ] is mislocalised, and records from Solomon Islands by Reeve (1854), Pfeiffer (1855a, 1859, 1868a, 1876), Cox (1868b), Pfeiffer & Clessin (1881), Tryon (1886) and Clapp (1923) were in error. Delsaerdt (2006: 118) noted that this species may not be from Solomon Islands. Helix nematophora is in fact a New Zealand species in genus Allodiscus Pilsbry, 1892 . Notes associated with the type material and in the NHMUK accessions register indicate that Alan Solem recognized this c. 1962, but neither he nor anyone else published this finding. Examination of the type material indicates that H. nematophora Reeve is conspecific with Allodiscus conopeus Marshall & Barker, 2008 . The specimen in NHMUK 1962713 is identical to a paralectotype of Helix dimorpha Reeve, 1852 from H. Cuming’s collection (NHMUK1962729) that Marshall & Barker (2008: 71) identified as Allodiscus conopeus , and may be from the same collection event.

Taxonomy: Allodiscus nematophora (Reeve, 1854) n. comb. is accepted here as an available valid name. Helix nematophora Pfeiffer, 1855 is a junior primary homonym and an objective junior synonym. Allodiscus conopeus Marshall & Barker, 2008 is a subjective junior synonym.

Distribution: New Zealand; southern North Island ( Marshall & Barker 2008 —as Allodiscus conopeus ).