Helix arbustorum var. icterica Roffiaen 1868

Helix arbustorum var. icterica Roffiaen, 1868 Fig. 4 A Helix arbustorum var. icterica Roffiaen, 1868: 70. Type material. RBINS I.G.7065 / MT.3421: 1 syntype from Weesen, ex Colbeau coll. (nr. 7065). Type locality. Switzerland: Tamina, Weesen, Iseltwald, Meiringen, Sarnen. “ Gorge de la Tamina, Wesen, Iseltwald, Meyringen, Sarnen ” (Roffiaen 1868: 70). Taxonomic status. Junior synonym of Arianta arbustorum (Linnaeus, 1758). Discussion. The present specimen stems from the collection of Jules Colbeau, is from one of the localities that constitute the taxon’s type locality as mentioned by Roffiaen (1868) and the label bears the writing “ type ”. Thus, it can be considered a syntype. This variety was described to denote specimens lacking the typical colour pattern of nominate A. arbustorum, consisting instead of entirely pale-yellow shells. Roffiaen also mentioned that such specimens were “ not common but not rare either ” (Roffiaen 1868: 70). This type of colouration is often seen in some members of this species across its range, consistent with natural interspecific phenotypic variation and sometimes is more common at some localities than others (e. g., Grime and Blythe 1969; Parkin 1971; Arter 1990; Cameron and Riley 2008; von Proschwitz et al. 2023). Thus, A. A. icterica is here considered synonymous with A. arbustorum. The variability in shell shape, size and colour of A. arbustorum has led to many forms, varieties, and subspecies to be described in the past centuries, which have almost always been considered junior synonyms (e. g., Taylor 1914).