Microphysa pumila Hutton, 1882

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 : 45-46

Microphysa pumila Hutton, 1882

Pl. 5, fig. H

Hutton, 1882. The New Zealand Journal of Science, 1: 281.

Type material. Lectotype (designated here), CMNZ M1393.2 , and paralectotypes (2), CMNZ M1393 (dry shells). Shell fragments mounted on a glass slide with the label details ‘ Microphysa pumila, Christchurch, XV p. 134, XVI p. 166’, in Hutton’s handwriting (i.e., CMNZ 2017.17.106–2017.17.107), are probably also primary type material. Type material from Eyreton , North Canterbury (see below), was not found during a search of the CMNZ molluscan collection in 2017 and is apparently lost.

Label details. CMNZ M1393—‘Christchurch, J.F. Armstrong’. Hutton coll. pillbox no. 113’.

CMNZ molluscan catalogue details. M1393—‘ Phrixgnathus pumila Hutton, Christchurch (3 specimens) (old No. 113) ’.

Type locality. ‘North Canterbury (C. Chilton)’ ( Hutton 1882p: 281); ‘Eyreton, North Canterbury (Mr. C. Chilton), Christchurch (Mr. J. F. Armstrong)’ ( Hutton 1883d: 135).

Previous illustrations of type material. Radula teeth illustrated by Hutton (1884b: pl. 9, fig. Q) probably from type material; shell(s) illustrated by Pilsbry (1892 [in 1892–1893]: pl. 23, figs. 97–99, ‘H. Suter, del.’) and Suter (1915: pl. 9, figs. 24, a, b) may be from the type series.

Remarks. Hutton submitted a description of Microphysa (?) pumila to the Transactions and Proceedings of the New Zealand Institute issue for 1882, but publication was delayed until May 1883 ( Hutton 1883d: 134), and was pre-empted by his brief description of Microphysa pumila in an account of a meeting of the Philosophical Institute of Canterbury ( Hutton 1882p: 281). There has been confusion over the nomenclature of this taxon in New Zealand, and it has appeared under several different species names. Examination of type material indicates that M. pumila is conspecific with Helix caputspinulae Reeve,1852 and H. epsilon Pfeiffer, 1853 , both based on the same type material from New Zealand in the Cuming collection (NHMUK 1962724: Brook & Ablett 2019: 69), and with Paralaoma ambigua Iredale, 1913 (CMNZ M4974) and P. raoulensis Iredale, 1913 (CMNZ M5000), from Raoul Island, Kermadec Islands. Reeve’s species name caputspinulae was misapplied by some (e.g., Suter 1913: 715, Climo 1970: 330, Powell 1979: 309) to material of Helix eta Pfeiffer, 1853 , and H. caputspinulae was also designated as the type of subgenus Subfectola, Powell, 1939 , based on material of H. eta Pfeiffer, 1853 (see Climo 1981: 9, Goulstone 1995: 63). Climo (1981: 9, 10) re-examined the type material of H. caputspinulae Reeve, 1852 , and noted that it was conspecific with Paralaoma raoulensis Iredale, 1913 , the type of genus Paralaoma Iredale, 1913 (subsequent designation of Iredale 1937).

Roth (1987: 95, 96) interpreted Paralaoma caputspinulae (Reeve, 1852) as being a weedy species that had a wide global distribution and had been described under many different names. He noted that Helix pusilla Lowe, 1831 , based on specimens from the Atlantic island of Madeira, was the earliest published name of this species, but was pre-occupied by H. pusilla Fleming, 1828 . Falkner et al. (2002: 117–118) treated P. caputspinulae (Reeve, 1852) as a junior synonym of Paralaoma servilis (Shuttleworth, 1852) , which had been described from material from Canary Islands (see Neubert & Gosteli 2003: 49, pl. 15, fig. 3), but this decision requires re-evaluation (see below). As presently interpreted, the distribution of P. servilis includes New Zealand (Kermadec, Three Kings, North, South, Rakiura/Stewart and Chatham islands), Australia, parts of Europe, Middle East, Africa, Asia, North and South America, Jamaica, Macaronesia, Réunion, Indonesia, Hawai’i, and Easter Island (e.g., Gittenberger et al. 1980 and Roth 1986 —as Punctum pusillum ; Smith, 1992 and Griffiths & Florens 2006 —as Paralaoma caputspinulae ; Neubert 1998 —as Toltecia pusilla ; Hausdorf 2002, Christensen et al. 2012, Welter-Schultes 2012, Gittenberger et al. 2020 —as Paralaoma servilis ). Paralaoma caputspinulae (= P. servilis ?) is definitely native to the New Zealand region, having been found in Holocene fossil assemblages in North Island, Rēkohu/Chatham Island and Rakiura that predate human occupation ( Brook 1999b,c; F. Brook unpub. data). Preliminary results of a phylogenetic study of New Zealand Punctidae indicate that Paralaoma of authors is polyphyletic, and that there appears to be one species only of this genus in the Recent New Zealand fauna; the various other New Zealand species assigned to Paralaoma (e.g., by Powell 1979; Spencer & Willan 1996; Spencer et al. 2009) are not congeneric (M. Kennedy unpub. data). A species closely resembling P. caputspinulae is evidently also native to Norfolk Island, having been recorded from Holocene fossil assemblages that predate human settlement of this island ( Neuweger et al. 2001 —as Paralaoma duncombei Iredale, 1945 ). Several punctid taxa described from Tasmania and eastern mainland Australia also resemble P. caputspinulae , and have been treated as synonyms of it (e.g., by Smith and Kershaw 1979: 264, 265; Smith 1992: 282, 283; Stanisic et al. 2010: 566). However, Stanisic et al. (2018: 126, 127) reinstated some of these as separate, probably endemic, species of Paralaoma , noting their “occurrence in often remote habitats of native forest where it is difficult to envisage anthropogenic introduction”. If correct, this would indicate that the genus Paralaoma is native to Australasia, with multiple species in mainland Australia and a single species in the New Zealand region. Interestingly, a North American punctid species that Roth (1987) identified as P. caputspinulae has been recorded from a wide range of environments in western USA and Canada, including remote, undisturbed, montane forest habitats where an anthropogenic origin is improbable. It has been considered by some authors to be indigenous to this continent (e.g., Roth 1986 —as Punctum pusillum ; Metcalf & Smartt 1997: 39 —as Paralaoma caputspinulae ), whereas others have suggested that it had been introduced there (e.g., Christensen et al. 2012: 5 —as P. servilis ). Bequaert & Miller (1973: 153 —as Punctum conspectum ) and Roth (1986: 23) stated that this species was not known fossil in North America, but Metcalf (1997: table 5—as Paralaoma caputspinulae ) recorded it from Quaternary alluvial/colluvial deposits in Sacramento Mountains, New Mexico, which suggests that it is indeed native. However, whether it is conspecific with P. servilis (or P. caputspinulae ) remains to be determined. To date, species identifications and biogeographic interpretations of Paralaoma servilis and its many putative synonyms have been based mainly on comparison of shell morphological characters, but molecular studies will be required to reliably determine the global systematics and phylogeography of this species and its congeners.

Taxonomy. Presently interpreted as a subjective junior synonym of Paralaoma servilis (Shuttleworth, 1852) (e.g., Brook & Ablett 2019: 69, Gittenberger et al. 2020: 78), but this requires re-evaluation.