Paryphanta lignaria Hutton, 1888

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 : 49-51

Paryphanta lignaria Hutton, 1888

Hutton, 1888. Transactions of the New Zealand Institute, 20 (1888): 43.

Type material. The original description was based on a single broken shell (i.e., holotype, by monotypy) that was loaned to Hutton by ‘Dr Gaze, of Westport’ ( Hutton 1888a: 44 ; Suter 1913: xiv; Powell 1946: 106). The whereabouts of the type specimen is not known, and it is presumed to have been lost or destroyed (see below).

Type locality. ‘… on the saddle between the Mokihinui and Lyell Rivers’ ( Hutton 1888: 44 ).

Remarks. Described in genus Paryphanta Albers, 1850 , assigned to subgenus Powelliphanta by O’Connor (1945), and the latter treated as a full genus by Climo (1977: 60) and subsequent authors. Hutton’s (1888: 43–44) original description of the holotype of Paryphanta lignaria stated that it had a maximum diameter of about two inches (= c. 50 mm), a slightly-elevated spire “forming an angle of about 135 o”, and that the base had been mostly broken off, leaving the “shape of the umbilicus and the aperture uncertain”. The remaining part of the base was “smooth and polished”, in contrast to the apical surface, which was “finely irregularly granulated by deeply undulating impressed lines”, and had a colour pattern of irregular “dark reddish brown and pale brownish-yellow” radial streaks. There are no published illustrations of the holotype. Pilsbry (1894: 31, pl. 1, figs. 1–3) illustrated a putative type specimen of lignaria , “drawn by Mr. H. Suter”. It is the larger one of two specimens in CMNZ M690 that had been presented to Canterbury Museum by Dr Gaze in 1893 (i.e., entry for 14 August 1893 in CMNZ Accession Register for 1891– 1933), and which was incorrectly listed as a ‘cotype’ of lignaria by Hutton (1898 – 1900: 7), and as the ‘type’ by Suter (1913: 784). The entry in the Accession Register does not state where the specimens in M690 were collected, and the original label has been lost or destroyed. A handwritten note associated with M690 states: “Note by A.W.B. Powell pasted to previous mount: Paryphanta unicolorata Powell 1930 . Mt Frederick locality probably correct but omit reference to saddle between Mokihinui and Lyell Rivers. Certainly not the type of lignaria which measures 2 ins. in greatest diameter ( Hutton 1888 ), 21.7.1930 ”. Although not stated explicitly, Powell’s note suggests that the specimens in M690 were originally labelled as being from two separate localities. The two specimens differ from Hutton’s description of lignaria , and from Paryphanta unicolorata Powell, 1930 (see comments on the latter taxon below), in being smaller, and having weakly calcified shells with a smooth, shiny apical surface. From shell characters they appear to belong to the group of Powelliphanta patrickensis ( Powell, 1949) and related species (see Walker 2003, Walker et al. 2008), which was referred to as the Powelliphanta Kawatiri complex by Daly et al. (2019).

Hutton (1900: 22, pl. 2) and Suter (1915, pl. 32, fig. 12, a, b) illustrated a shell from ‘Mount Rochfort, near Westport’, which they identified as Paryphanta lignaria . This specimen (i.e., CMNZ M694) was of a similar size to the holotype of lignaria , but differed in having a more elevated spire and being “of a yellowish-brown or luteous colour, the brown bands being obsolete” ( Hutton, 1900: 22 ). In the first of a series of papers on the taxonomy of New Zealand Paryphantidae (now Rhytididae ), Powell (1930: 42–43) interpreted the distribution of typical lignaria as extending from the north side of the Mokihinui River to Karamea. He included the Mt Rochfort taxon in a new species, Paryphanta unicolorata Powell, 1930 , with a type locality at Seddonville, and a distribution south of the Mokihinui River (see also Powell 1936: pl. 10). The latter taxon was differentiated from lignaria on shell colour, being uniformly olive-brown rather than radially striped as per Hutton’s original description of lignaria . Powell (1941: 239, 253) inferred that the type material of lignaria was probably lost, but later ( Powell 1946: 106; 1949: 348) suggested that “an unlabeled specimen from the collection of the late Mr. Boswell of Westport” (i.e., AIM MA71492) may be the missing holotype of lignaria , albeit without providing any convincing evidence in support of this. Powell (1949: 350) designated a shell that he had illustrated previously ( Powell, 1930: pl. 4, fig. 1) as a neotype. It is part of a lot of 20 specimens (AIM MA64520) from near St. Helens, Mokihinui, c. 25 km NW of the type locality of lignaria cited by Hutton (1888) . Powell (1949: 347–357) gave a detailed account of the taxonomic history of Paryphata (Powelliphanta) lignaria sensu lato. He inferred that the type locality of lignaria given by Hutton (1888) was incorrect, and that “Hutton’s locality for his 1900 record of ‘ lignaria ’ [i.e., from Mt Rochfort] is evidently erroneous, the specimen being a unicolorata , probably from the Seddonville area”. In the same paper he reinterpreted the distribution of lignaria sensu stricto as being restricted to coastal hill country extending north from the Mokihinui River mouth to Kongahu Point and Corbyvale, and recognised several subspecies from adjoining areas (including lignaria unicolorata ), and one from the Leslie and upper Karamea rivers, based mainly on differences in shell colouring ( Powell 1949: 350, pl. 67). Most subsequent workers have followed Powell’s interpretations of the lignaria group of subspecies (e.g., Parkinson 1979, Powell 1979, Meads et al. 1984, Walker 2003), but Climo (1978b) proposed an alternative classification in which lignaria sensu lato of Powell was treated as a subspecies of Powelliphanta hochstetteri (Pfeiffer, 1862) . Genetic studies by Walker (2003: 200), Trewick et al. (2008), and Buckley et al. (2014) indicated that Powell’s lignaria group is monophyletic and not closely related to hochstetteri . The last-mentioned study also found that there was a lack of monophyly in mitochondrial COI sequences among Powell’s subspecies of lignaria , and that only one subspecies, Powelliphanta lignaria rotella Powell, 1938 , had a distinct nuclear genotype as determined from microsatellite data.

Powell (1949: 348) noted that following the original description there had been no further valid records of lignaria from the vicinity of the Lyell-Mokihinui Saddle. That is apparently still the case, and a brief search carried out during the present study failed to find any snails or empty shells of this species in beech and Dracophyllum forest on and around the saddle. However, surveys over the last few decades have shown that the distribution of Powelliphanta lignaria unicolorata ( Powell, 1930) extends up the Mokihinui River South Branch to within a few kilometers of the Lyell-Mokihinui Saddle ( Walker 2003: 121, pl. 39). Although shells of unicolorata are generally a plain olive-brown in colour, some have irregular, reddish-brown radial streaks matching Hutton’s original description of lignaria (e.g., NMNZ M.77190, M.125507, M.308311, and this, along with the geographic proximity of unicolorata to the type locality of lignaria , indicates that Parphanta unicolorata Powell, 1930 is probably a synonym of Paryphanta lignaria Hutton, 1888 . If this interpretation is correct a new subspecific name will be required for the population on the coastal range north of Mokihinui River, which was treated as lignaria sensu stricto by Powell (1949: 350, 1979: 336), Meads et al. (1984: 295), Walker (2003: 111, pl. 35) and others. This eventuality was anticipated by Powell (1946: 106), who noted that the identity of lignaria “cannot be finalized until topotypes of Hutton’s species are obtained, but the indications are that …. the Mokihinui-Karamea coastal form will require to be named, my nomination of a St. Helens specimen as neotype becoming void”.

During the present study a previously unreported population of Powelliphanta in the Kawatiri complex of Daly (2019) was found in alpine shrub-tussockland on the Lyell Range, above the Lyell-Mokihinui Saddle, confirming a prediction by Powell (1949: 348). The shells differ from Hutton’s description of lignaria in their smaller adult size (maximum shell diameter of c. 44 mm), and smooth, shiny surface on both the spire and base, and may be conspecific with the larger specimen in CMNZ M690. A record of Powelliphanta lignaria unicolorata further north on Lyell Range by Walker (2003: pl. 39) was an error based on misidentification of a species of the Kawatiri complex (K. Walker pers. comm. 2019).

With regard to Hutton’s (1900: 22, pl. 2) record of putative Paryphanta lignaria from Mt Rochfort, it is possible that the illustrated specimen in CMNZ M694 was in fact from this locality as originally stated (i.e., not from the Seddonville area, as suggested by Powell 1949: 352), and represents a separate taxon that has not been recollected there, and may now be extinct. The shell differs from typical unicolorata in having a more elevated spire, and a more rapidly descending final whorl, and in these regards it shows similarities with illustrations of Powelliphanta “Buller River” by Walker (2003: 130, pl. 42).

Current taxonomy. Powelliphanta lignaria (Hutton, 1888) —after Powell (1949: 350; 1979: 336; Meads et al. 1984: 295; Walker 2003: 111).

Distribution. New Zealand; South Island, northern West Coast: local populations of Powelliphanta lignaria sensu lato are present in the Mokihinui River catchment, in hill country between Ngakawau River and Seddonville Flats, on the coastal range between Mokihinui and Little Wanganui rivers, and in the lower and middle reaches of Karamea River catchment ( Powell 1949, Meads et al. 1984, Walker 2003).