Iberellus balearicus (Rossmassler, 1838)

Altaba, Cristian R., 2022, Nomenclature of Helicidae (Gastropoda: Pulmonata) endemic to the Balearics, Nemus 12, pp. 168-186 : 171-173

Iberellus balearicus , not “ I. hispanicus ”

Starting in 1835, Valery-Louis-Victor Potiez and André-Louis-Gaspard Michaud serialized their valuable “Galerie des Mollusques” ( Potiez & Michaud, 1835 -1838). Over time, the installments underwent obvious changes in paper, typographic composition and the format of plates (where publication date is printed); eventually, they were (also) offered bound together as the first volume at the end of 1838 ( Paulucci, 1879; Falkner et al., 2002). By the third installment, at the end of 1835 (p. 89), they published the novel Hispanicâ variety of Helix lactea Müller, 1774 . The latter is now unanimously placed in the genus Otala Schumacher, 1817 . For taxonomy, Otala lactea var. hispanica ( Potiez & Michaud, 1835) is irrelevant, as it designates simply those specimens whose aperture is very dark; in terms of nomenclature, it preoccupies the name hispanica /us/um for taxa of specific rank within the (once large) genus Helix Linnaeus, 1758 . The availability of the work by Potiez and Michaud prior to 1838 has been questioned ( Kadolsky, 2012). As a matter of fact, it appears in a book catalogue for that year ( Anonymous, 1839). However, it is also clear that the work was printed in installments. For example, this is obvious from the footnote on page 120 ( Falkner et al, 2002: 103). This points unambiguously at various dates of publication for the different parts of the book; the relevant part here was issued in 1835. Serializing books was commonplace throughout the 19 th century across Europe and the United States ( Brake & Demoor, 2009), and many malacological works were issued in this way (including Tryon & Pilsbry, 1894 -1895). There is no reason whatsoever to assume the authors would have been careful to print the date on the installments only to keep the expensive (and uneven) serial at home for three years.

Thus, when Emil Adolf Rossmässler presented in his monumental work on the European land and freshwater snails (likewise printed and undoubtedly distributed by installments) his Helix hispanica Rossmässler, 1838 , this name (extracted from a manuscript catalogue by Partsch) was already preoccupied. Such description, corresponding to figure number 460 (in plate 33), has repeatedly been interpreted as belonging to a species endemic to the Serra de Tramuntana in Mallorca, whose common name is “caragol de serp” (snake’s snail). Two issues therein have remained eclipsed but deserve mention.

In the first place, Rossmässler (1838: 15) states that his H.hispanica shows a noteworthy variation.In reality, it encompassed several species from the Balearics and southernmost Spain. The specimen figured does not belong to any Iberellus: the columellar callus covering the umbilicus almost completely, the markedly descending aperture and the color pattern consisting of five narrow, well defined bands (two continuous below and three broken above) make a combination of traits absent from any native Balearic helicid. However, they support the identification of the figured shell as an Andalusian endemic the same author described a few years later: H. guiraoanus var. angustatus Guirao in Rossmässler, 1854. Graells (1846) erroneously identified the “caragol de serp” as H. hispanica , but in exchange was right in thus identifying some specimens he had received from Jaén. Likewise, Hidalgo (1875) mentioned from the Balearics Helix marmorata (Férussac in Férussac & Deshayes, 1831), also endemic to Andalusia; he soon corrected the mistake, identifying them as H. balearica (Hidalgo, 1978, 1890).

Rossmässler’s angustatus is now included in the genus Iberus Montfort, 1810 , endemic to the south and east of the Iberian Peninsula and including several taxa of unclear rank ( Boettger, 1938; García San Nicolás, 1957; Elejalde et al., 2008; Bank & Luijten, 2014). Assuming two Iberus specimens in the Senckenberg Museum would be the type series, and that the type locality given by Rosmässler (1854) would be wrong, Martínez-Ortí & Robles (2012) designated a lectotype, along with other alterations to the nomenclature of the genus. Whether such changes are warranted is dubious ( Bank & Luijten, 2014); at any rate, they don’t affect the current understanding of I. angustatus .

A second aspect of the description of Helix hispanica is critical. Rossmässler (1838) mentions in synonymy the manuscript names H.speciosa and H.balearica , attributed to Ziegler. Some authors have considered that such names were introduced merely as synonyms ( Beckmann, 2007; Welter-Schultes, 2012, Chueca et al., 2013). However, such reading is incorrect: under the heading dedicated to the varieties of his new species, Rossmässler explicitly mentions one of them with scientific name: “ Ziegler besitzt eine anders gefärbte und etwas kugeligere Form, welche er H. balearica nennt” [Ziegler has a differently colored and somewhat more spherical form, which he calls H. balearica ]. This sentence, albeit bearing limited information, contains diagnostic traits, thus constituting the formal description of a taxon of subspecific rank: H. hispanica var. balearica Rossmässler, 1838 .

Rossmässler considered both balearica and hispanica as belonging to the same (wide) species, selecting the latter name for the set. In fact, there are several species whose names are universally used even if they were described in the same work as synonymous: Pupa frumentum var. illyrica Rossmässler, 1835 (currently Granaria illyrica (Rossmässler, 1835)) , Helix foetens var. achates Rossmässler, 1835 (currently Chilostoma achates (Rossmässler, 1835)) , Helix candidula var. muehlfeldtiana Rossmässler, 1837 (currently Xerocrassa muehlfeldtiana (Rossmässler, 1837)) , Helix setosa var. setigera Rossmässler, 1836 (currently Helicigona setigera (Rossmässler, 1836)) , Helix villosa var. villosula Rossmässler, 1838 (currently Trochulus villosulus ( Rossmässler, 1838)) and Helix arbustorum forma stenzii Rossmässler, 1835 (currently Arianta stenzii (Rossmässler, 1835)) .

A further quirk of Helix hispanica is the suggestion by Graells (1846, footnote), that this name could be in conflict with H. hispana Linnaeus, 1758 (p. 772: Vermes Testacea number 599; also in Linné, 1767). Unfortunately, nobody seems to have clarified what this Linnean species might be. At any rate, the words hispana and hispanica are not strictly equivalent (although undesirably similar: Recommendation 58 A of the Code), so the problem does not exist. However, Rossmässler (1854) accepted Graells’ suggestion, not without bitterly complaining, and thus recovered the name he had already given to a variety: he proposed H. balearica as the valid species name. In terms of nomenclature, this just meant raising balearica to species rank in order to avoid a supposed homonymy; for taxonomy, a chimaera was made even more bizarre, with the type series of H. hispanica now representing a different taxon. Although nobody dismissed this change, it was unjustified and clearly is in conflict with the original description of H. balearica .

For over 150 years almost everybody followed Rossmässler (1854) in calling the “caragol de serp” as balearica . Until the erroneous interpretation of original sources by Beckmann (2007), leading to the novel proposal by Welter-Schultes (2012), Chueca et al. (2013, 2015) and Neiber et al. (2021) to use the combination Iberellus hispanicus ( Rossmässler, 1838) . Such a name is inadmissible.

Having a keen eye for detecting differences in shell shapes, Bourguignat (in Pechaud, 1883) was right — albeit at odds with his contemporaries— in claiming that the specimen figured initially as Helix hispanica and later called H. balearica by Rossmässler did not agree with any of the specimens he had received from the mountains of Mallorca. He thus described three new species: H. ramisi Bourguignat in Pechaud, 1883, H. valdemusana Bourguignat in Pechaud, 1883 and H. eustapa Bourguignat in Pechaud, 1883. I have examined the types in the Bourguignat collection at MHNG and it is clear they all come from the southern part of the Serra de Tramuntana range. They represent individual variations of the same species, which grows slightly larger at higher elevation, although there is considerable variability in size even within microhabitats. It is likely they were all collected at the same locality, in the vicinity of the mountain village called Valldemossa (hence the fictitiously Latinized demonym valdemusana ). The three are subjective junior synonyms of H. balearica in its original sense. Nobody appears to have ever used these three of Bourguignat’s names, his correct assessment being lost amidst a pleiad of confusing or superfluous nominal species.

Attending to its description (as well as its origin indicated as adjective), balearica fits perfectly to the “caragol de serp” living in the southern part of the Serra de Tramuntana. The taxon living in the northern part of this mountain range is anatomically distinct, clearly more discoidal and often strongly depressed; it has recently been described as Tramuntanicola culminalis Altaba, 2022 . In order to prevent further arbitrary changes, a neotype has also been designated for Iberellus balearicus from near Valldemossa ( Altaba, 2022).