Limax molestus Hutton, 1879

Brook, Fred J., Kennedy, Martyn, King, Tania M., Ridden, Johnathon, Shaw, Matthew D. & Spencer, Hamish G., 2020, Catalogue of New Zealand land, freshwater and estuarine molluscan taxa named by Frederick Wollaston Hutton between 1879 and 1904, Zootaxa 4865 (1), pp. 1-73 : 53-54

Limax molestus Hutton, 1879

Hutton, 1879. Transactions of the New Zealand Institute, 11 (1878): 331.

Type material. Syntypes (11), OMNZ IV5714 (in alcohol), syntype (1), NHMUK 1886.11.18.26 (in alcohol). The molluscan collection at CMNZ has a radula mounted on a glass slide with the label details ‘ Limax agrestis, Dunedin, XVI p. 167’, in Hutton’s handwriting (i.e., CMNZ 2017.17.86), which is probably primary type material of Limax molestus Hutton, 1879 (see radula description by Hutton 1882h: 154 ).

Label details. OMNZ IV5714—‘ L. molestus Hutton , = Limax agrestis Hutton, Dunedin (in Hutton’s handwriting)’.

NHMUK molluscan register details. 1886.11.18.26—‘ Limax molestus Hutton, Dunedin, Purchased of the Commission for the New Zealand, Indian and Colonial Exhibition 1886’.

Type locality. ‘ Dunedin, Wellington, etc. Abundant everywhere’ ( Hutton 1879: 331 ) .

Previous illustrations of type material. Hutton (1882h: 154, pl. 3, figs. H, P—as Limax agrestis ; radula and jaw ‘from one of my type specimens from Dunedin’,).

Remarks. The original label of the type material of Limax molestus at OMNZ has been lost or destroyed, but transcribed details indicate that this material was collected and identified by Hutton himself. A specimen of L. molestus that was mentioned by Cockerell & Collinge (1893: 201) as being “in the British Museum … from Dunedin (Otago Univ. Mus.)” is possibly a syntype (NHMUK 1886.11.18.26). It was evidently sent to London as an exhibit in the Colonial and Indian Exhibition of 1886 and was subsequently purchased by the British Museum. There has been confusion over the identity L. molestus . Hutton (1879: 331) noted that it was “closely allied to L. agrestis of Europe’, but differed in some anatomical characters. Its distribution was initially listed as New Zealand only ( Hutton 1879: 331 , 1880: 25), but it was subsequently treated as a junior synonym of Limax agrestis Linnaeus, 1758 ( Hutton 1882h: 154 ; Hutton 1884c: 212 ; Musson 1891: 891; Suter 1892b: 279; Cockerell & Collinge 1893: 175, 201; Hedley & Suter, 1893: 665; Suter 1913: 1071) and Limax laevis Müller, 1774 ( Grimpe & Hoffmann 1925: 408). Barker (1979: 427) inferred that early records of L. agrestis from New Zealand were misidentifications of Deroceras reticulatum (Müller, 1774) . He listed L. molestus as a junior synonym of the latter taxon, noting that ‘Hutton’s brief description appears to fall within the general description of this species’, albeit without examination of type material. Deroceras reticulatum is native to Europe, and has a wide adventive distribution including in central Asia, North and South America, South Africa, islands of the Atlantic and Indian oceans, Australia, New Zealand and some Pacific islands ( Barker 1999: 39; Wiktor 2000: 509; Herbert 2010; Welter-Schultes, 2012: 469). In New Zealand this species is present mostly in modified habitats, throughout the North and South Islands, and on Rakiura/Stewart, Chatham, Auckland and Campbell islands ( Barker 1999: 39, 40, map 3).

Current taxonomy. A subjective junior synonym of Deroceras reticulatum (Müller, 1774) — Barker (1979: 427, 1982: 179, 1999: 38).

Family ARIONIDAE Gray, 1840