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Morphological data
Detailed conchological and anatomical descriptions of the individual taxa of the mazzullii complex are given in the
systematic part. Their shells are illustrated in Figs. 9–20, their genital systems in Figs. 21–23.
The morphological data showed that within the mazzullii group the three taxa are different in many features
including (i) shell size (decreasing from insolida to mazzullii to cephalaeditana) and, to some extent, shape and
sculpture (insolida is more globose and smooth, mazzullii is regularly wrinkled, whereas cephalaeditana is, expe-
cially on the last whorls, strongly wrinkled and irregularly reticulated); (ii) diverticulum of bursa copulatrix (BCD)
and duct of bursa copulatrix (DBC) length ratio, which is 1:1 for insolida, nearly 2:1 for mazzullii and 1.5–1.2:1 for
cephalaeditana; (iii) number of digit-like appendices of the digitiform glands (decreasing from insolida to maz-
zullii to cephalaeditana); and (iv) number of vaginal longitudinal pleats which varies from 7–8 (insolida) to 5–6
(mazzullii) to 4–5 (cephalaeditana).
Genitalia of Cornu aspersum, Cantareus apertus and Eobania vermiculata (O.F. Müller, 1774), used as exter-
nal comparisons, are shown in figures 24–26; shells of the three species are illustrated in figures 27–29 (for
detailed descriptions, see Giusti et al. 1995).
When compared to Cornu aspersum, Cantareus apertus and Eobania vermiculata, genitalia of the three taxa of
the mazzullii complex notably differ in many morphological characters, although the general architecture of the
genitalia is similar (see Giusti et al. 1995).
Geographic distribution
The current confirmed distribution of the H. mazzullii complex is shown in Fig. 1. Records from museum and pri-
vate collections are listed in Appendix 1.
The taxon mazzullii inhabits the calcareous mountains around Palermo including Monte Pellegrino, Monte
Gallo and the entire mountain chain which proceeds from Monte Cuccio north-west towards Sferracavallo, Capaci,
Monte Columbrina, Monte Pecoraro (Carini) up to Monte Palmeto (Terrasini). There is no evidence of these ani-
mals at Monte Catalfano and Capo Zafferano which represent the eastern limit of the mountains of Palermo (Lo
Brano & Sparacio 2006).
The taxon cephalaeditana is endemic of Cefalù, La Rocca, with several small populations occurring either at
its base or peak, whereas the record of Rocca di San Nicola (previously known as Feudo Costa) reported by Pirajno
(1840) was not confirmed during our field explorations. Finally, records from Barcellona Pozzo di Gotto (Messina
province, northeastern Sicily) (Benoit 1857, 1875, 1882) which haven’t been verified yet, most likely refer to a
taxon related to cephalaeditana (see Benoit 1882).
The taxon insolida is distributed from the calcareous mountains around Trapani, Monte San Giuliano and
Monte Cofano to San Vito lo Capo and the surroundings of Scopello.
In our opinion, the former distribution area of H. mazzullii s. l. (= mazzullii group) was much wider than the
present one, currently limited to northwestern Sicily. This is documented by a high number of collection sites, fos-
sils or peculiar tunnels (holes in mesozoic limestone made by these saxicavous helicids) reported for numerous
places of the island, including a few northeastern ones where at present there is no evidence of extant populations
of the mazzullii complex (Table 5).
Biology
The taxa within the H. mazzullii complex are rupicolous and strictly bound to calcareous cliffs from which they
descend only on moist and rainy days to reach the soil. Generally, they move forward vertically on the cliff and stay
within peculiar groupings of tunnels (Fig. 30) dug into the limestone (Gaudin 1860; Brehm 1869; Platania 1890;
Meunier 1890; De Gregorio 1890, 1916a; Lamy 1930; Kuehnelt 1932; Di Salvo 1932; Rensch 1932a, 1932b, 1937;
Manganelli et al. 2000).
Bibliographic references, integrated with personal observations, allow us to provide a detailed description of
the tunnels. They are mostly cylindrical with a diameter of 3–4 cm and a variable depth ranging from about 8–40
cm. Tunnels are horizontal (perpendicular to the vertical wall) at first, but after a few centimetres the direction turns
12 · Zootaxa 3134 © 2011 Magnolia Press COLOMBA ET AL.
