Helix conella Pfeiffer, 1861

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 : 69-70

Helix conella Pfeiffer, 1861

Pl. 8, fig. B

Pfeiffer, 1861. Malakozoologische Blätter, 8: 147.

Type material: Listed by Suter (1913b: 744) as being in the ‘ K.K. Hofmuseum, Vienna’, but not found during a search of the collections in the Naturhistorisches Museum Wien in 2014 (Anita Eschner pers. comm.). As noted in the Introduction (above), the type material may have gone to the Pommersches Museum, Stettin [= Szczecin], after Pfeiffer’s death in 1877, in which case it has probably been lost or destroyed .

Type locality: ‘Kakepuku’ ( Pfeiffer 1861: 147).

Remarks: There are no published illustrations of the type material. The original description was based on one or more specimens collected by Ferdinand von Hochstetter at Mount Kakepuku, in the Waikato region, in 1859 (see Hochstetter 1867: 318). Pfeiffer’s description referred to a species with a carinate periphery, a colour pattern of fine reddish tessellations, and a maximum shell diameter of 4.7 mm and height of 2.75 mm. The identity of this species has subsequently been misinterpreted, as indicated by the descriptions and illustrations of Pilsbry (1892 [in 1892–1893]: 58, pl. 23, fig. 16), Suter (1913b: 743, pl. 29, fig. 9) and Powell (1979: 327, pl. 59, fig. 9). These authors referred to a smaller species with a proportionately taller spire (shell diameter up to 3.5 mm, height to 2.8 mm), and with a bluntly angled rather than carinate periphery, and a colour pattern of close, irregular, tawny brown stripes rather than fine reddish tessellations. Examination of collections at NMNZ indicates that Pfeiffer’s description of Helix conella closely matches juvenile specimens of Laoma mariae (Gray, 1843) from Mount Kakepuku (e.g., NMNZ M.191632), and the two species are here interpreted as conspecific. Given that the type material of Helix conella Pfeiffer, 1861 has most probably been destroyed, and in order to prevent ongoing confusion over the identity of this species and stabilise the nomenclature, we designate a specimen from Kakepuku illustrated in pl. 8, fig. B (NMNZ M.321351) as the neotype of Helix conella Pfeiffer, 1861 , to ensure that synonymy is absolute and unequivocal. A replacement name is required for Laoma conella of Pilsbry, 1892 [in Pilsbry, 1892–1893] (non Pfeiffer, 1861), and subsequent authors.

Taxonomy: Treated here as a subjective junior synonym of Helix mariae Gray, 1843 N. syn.