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484 N. MAIO, A. PETRACCIOLI, P. CROVATO, N. AMOR & G. ODIERNA

Capri (Alzona, 1971; Cossignani & Cossignani, and perhaps the Balearic Islands (Gargominy,
1995; Manganelli et al., 1995). The aim of the 2011). In Italy it is present in Liguria, Tuscany,
present paper is to provide new data on the presence Umbria (Misuri, 1907), Latium and doubtful in
of T. caroni in certain regions of Italy and to collect Sicily. It is a xerophilous species with wide ecolog-
all data in the literature and available from museum ical valence colonising coastal, ruderal and culti-
collections on its present and past distribution. vated calcareous environments. The biometric
T. caroni has close anatomical affinity (“elegans character hitherto used therefore does not discrimi-
group”) with T. (T.) elegans (Gmelin, 1791), T. (T.) nate the three species with absolute certainty and
spratti (Pfeiffer, 1846), a species endemic to the is- various anatomical similarities also exist. Since
land of Malta, and T. (T.) cumiae (Calcara, 1847), there are currently no other diagnostic criteria, it
endemic to the island of Lampedusa (Giusti et al., was decided to list the data available in the literature
1995). In particular, the systematic and biogeographi- and from museum collections, exactly as reported
cal positions of T. caroni, T. elegans and T. trochlea by the original authors or collectors, also for T.
(Pfeiffer, 1846), the latter a little-known North- trochlea and T. elegans.
African species, are still unclear.
T. trochlea was described as a new species by
Pfeiffer (1846) but the original types are not known. MATERIALS AND METHODS
According to the original description (Pfeiffer,
1846), this species is morphologically characterised In order to obtain an exhaustive picture of the
by a conical shell with eight keeled, crenulated distribution of T. caroni in Italy, field surveys were
whorls, having diameter about the same as height, conducted and their results were compared with his-
or slightly greater (h/d = 1.04 in Pfeiffer (1846), torical data obtained from other sources. This re-
1.05 in Bourguignat (1864) with a variety B minor search was carried out in addition to the
reaching 1.14). In the continuation of Rossmässler’s data-gathering in the literature and by studying
“Iconographie”, Kobelt (1877) also reports similar malacological collections in different Italian and
measurements for Helix trochlea Pfeiffer [“Diam. foreign museums and private collections. The field
et alt. 7-8 Mm”, h/d= 1.14]. Bourguignat (1864) studies were conducted between September 2002
adds other distinctive characters with respect to T. and September 2006 on Capri and in Sicily and in
elegans, such as more accentuated striations, small the period 2006-2009 in Latium. The species iden-
umbilicus, crenulated keel and more imbricated tification was based on Giusti et al. (1995); the tax-
whorls that overlap each other. Its distribution is onomical and nomenclatural arrangement follows
thought to include Algeria and Northern Tunisia Manganelli et al. (1995) and Bank (2011).
(Pfeiffer, 1853; Morelet, 1853; Bourguignat, 1864,
1868; Kobelt, 1877; De Saint-Simon, 1882; Le-
tourneux & Bourguignat, 1887; Monterosato, 1893; RESULTS
Sacchi, 1955a).
Morphologically, T. elegans is characterised by Trochoidea (Trochoidea) caroni (Deshayes, 1832)
a conical shell with 6-7 whorls of variable height
and diameter greater than height. It is distinguished ORIGINAL DESCRIPTION. Deshayes, 1832, species
from T. caroni by a different height-to-diameter n. 142, pag. 262, locus typicus “Sicile”: “Hélice de
ratio (h/d) of the spire, in the range 0.82–0.62 Caron. Helix Caroni. Nob. H. testa conica, elon-
(Sacchi, 1954) or less (“scitula” form); external sur- gato-pyramidata, trochiformi, longitudinaliter
face with fine regular growth ridges; umbilicus striata, striis confertis, sublamellosis; anfractibus
small. Its distribution is European-Western Mediter- numerosis, basi carinatis; carina squamosa; aper-
ranean (Southern France, Spain, Greece, Tunisia, tura depressa, quadrangulari, simplici; labro tenui.
Algeria and perhaps Morocco; (Pallary, 1904)) with Diamètre de la base 9 millim., longueur 11 millim”.
isolated populations in Belgium, Northern France, [h/d = 1.22]”.
Sardinia and Corsica; introduced into Great Britain Férussac (1821) reports the species for the first
from the early 1800s (Férussac, 1821), into South time as: “Helix elata Faure Biguet [J. P. Faure-Biguet]
Carolina (USA) from before 1875 (Mazyck, 1876) espèce n. 304, p. 46, “Hab. L’île de Caprée”, without