Nomenclature of Helicidae (Gastropoda: Pulmonata) endemic to the Balearics
Author
Altaba, Cristian R.
Department of the Environment and Territory, Government of the Balearic Islands, 07009 Palma, Balearic Islands, Spain. & Research Group on Human Evolution and Cogniton (EVOCOG), University of the Balearic Islands, 07072 Palma, Balearic Islands, Spain. cristianr. altaba @ uib. cat
cristianr.altaba@uib.cat
text
Nemus
2022
2022-12-31
12
168
186
journal article
10.5281/zenodo.12170426
2386-3803
12170426
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
).