Allognathus graellsianus (Pfeiffer, 1848)

Altaba, Cristian R., 2022, Nomenclature of Helicidae (Gastropoda: Pulmonata) endemic to the Balearics, Nemus 12, pp. 168-186 : 171

Allognathus graellsianus is the correct name

In his pioneering “Catálogo de los moluscos terrestres y de agua dulce de España ”, Mariano de la Paz Graells (1846) ably described and figured a species endemic to the northern Serra de Tramuntana mountain range in Mallorca, which he called Helix grateloupi Graells, 1846 . However, this species name had already been used: Helix grateloupii Pfeiffer, 1842 was validly proposed as a synonym (through bibliographic indication; Pfeiffer, 1842: 99) of a species from Madagascar (now included in the family Ariophantidae ) that had been described as H. rufescens Grateloup, 1840 . The latter was preoccupied earliest by H. rufescens Pennant, 1777 ; this is obviously a juvenile of Arianta arbustorum ( Linnaeus, 1758) . Helix grateloupii was subsequently validated (article 11.6.1 of the Code) by Pfeiffer (1846: 13), and later on described in detail ( Pfeiffer, 1848: 69). Thus, the combination Kalidos rufescens ( Grateloup, 1840) to designate the Malagasy species ( Fischer-Piette et al., 1966: 26, 1994: 254) is incorrect, as it must be K. grateloupii ( Pfeiffer, 1842) .

When discovering the conflict of H.grateloupi, Ludwig Pfeiffer (1848: 437) proposed H. graellsiana Pfeiffer, 1848 for the species discovered by Graells. During the second half of the 19th century some authors used the name initially proposed by Graells ( Bourguignat, 1864; Kobelt, 1871; Paetel, 1889), while others chose to use graellsiana (for example, Reeve & Sowerby, 1851 –1854; Hidalgo, 1875). Among the latter is Henry Augustus Pilsbry ( Tryon & Pilsbry, 1888), who designated H. grateloupi Graells, 1846 as the type of his new genus Allognathus Pilsbry in Tryon & Pilsbry, 1888. However, he soon corrected this, stating H. graellsiana is the type (Tryon & Pilsbry, 1894). Throughout the 20th century ( Hesse, 1915; Gasull, 1964, 1967; Breure & Gittenberger, 1982; Altaba, 1991), the species was correctly known (and legally protected since 2008) as A. graellsianus ( Pfeiffer, 1848) .

At the onset of the 21st century, and attending only to the priority principle (but ignoring the species from Madagascar), Schileyko (2006) proposed to return to the name coined by Graells; this was followed by several authors ( Welter-Schultes, 2012; Chueca et al., 2013, Altaba & Ríos Jiménez, 2021). However, Welter-Schultes (2012), justifies his choice considering that H. grateloupii Pfeiffer, 1842 might not have been intentionally proposed as a new name (this contradicts the original text), or alternatively that it could have been proposed in synonymy (which is not the case, nor would it affect the availability and date of a name once used first in 1848); it is clear that both Graells and Pfeiffer were never confusing the Malagasy and Mallorcan species. After such oscillating history, the coin eventually falls heads up for Pfeiffer.

Another problematic conclusion is that of Beckmann (2007), who in his posthumous book on the land and freshwater mollusks of the Balearics maintains the remarkable stand that the name erected by Graells (1846) would be a nomen nudum. Beckmann (2007) cited Fig. 7-8 in the booklet by Graells; with that alone, he should have reached the conclusion that such a name accompanied by a figure has an indication (in the sense of Article 12.2.7 of the Code).

Another mistake is the spelling “ H. graellsi ” proposed by Bourguignat (1864: 356). Nobody seems to have followed him. This constitutes an incorrect subsequent spelling (Art. 33.3 of the Code).

There is another synonym for this species: Helix tessellata Férussac in Férussac & Deshayes, 1851. Based on an explicit reference to the Mallorcan species (Férussac in Deshayes, 1819–1851: 232), it is a junior subjective synonym. Besides, this name is preoccupied by H. tessellata Pfeiffer, 1842 . The latter has been attributed to the mention by Anton (1839: 36, nº 1359), but this author only wrote the name without giving any description; Pfeiffer (1842: 40) describes it adequately, mentioning a letter from Anton and attributing the name to Mühlfeld. This species is now included in the (sub)genus Stephanoda Albers in Albers & Martens, 1860 ( Endodontidae ); it is endemic to the island of Juan Fernández in the southeastern Pacific (Anton, 1839: 36; Pfeiffer, 1848; Albers & Martens, 1860; Solem, 1978; Stuardo & Vega, 1985; Valdovinos, 1999). The invalidity of the name H. tessellata Férussac was already detected by Pfeiffer (1848: 117), so it has never been used.