Page 24 - 3(3)_201-228
P. 24
224 F. LIberto, S. GIGLIo, M.S. CoLoMba & I. SparaCIo
spire more or less flat, with 5 regularly growing C. metabola is an endemic species from Lam-
whorls, slightly convex; marked sutures; last whorl pedusa island; it is distinguished from C. tineana
very convex below and keeled at its periphery; um- by the shell with the globose shell with disconti-
bilicus deep and wide, about 1/3 of maximum shell nuous, thick ribs and narrow umbilicus. A prelimi-
diameter; aperture oval and slightly angled, peri- nary study on the genitalia of this species seems to
stome simple, interrupted, with internal rib. highlight significant differences from the other Cer-
nuella species (unpublished data).
Body. Animal whitish; dorsal region provided,
more or less extensively, of dark spots. C. cisalpina is a polymorphic species, with a
Mediterranean distribution, for which several taxa
Genitalia. Short free oviduct, duct of bursa co- of still difficult taxonomic interpretation were
pulatrix of medium length, with large base, ending established. Shell of small-medium size, “small
in a sac-like bursa copulatrix; vagina short (1-1.6 sized Cernuella” sensu Manganelli & Giusti
mm), 2 tufts of digitiform glands with 4-5 slender (1987), subglobose, with thin ribs, sometimes well
lobes and 8-12 apexes, disposed on opposite sides raised, last whorl usually rounded or angled at its
of proximal vagina. Dart-sac complex consisting periphery (keel-like) (Figs. 82-84). Some popula-
of a pair of stylophores located on one side of va- tions of C. cisalpina present a shell similar to that
gina; large outer stylophore containing dart. Penial of C. tineana, but in addition to the morphological
complex composed of flagellum, epiphallus and characteristics of C. tineana pointed out above,
penis; flagellum long (2-2.4 mm), ending where they are always distinguishable by their genitalia
vas deferens enters penial complex; epiphallus with epiphallus 2-3 times longer than penis, fla-
long 3-5 times the length of the penis (4.5-5.5 gellum and penis proportionally shorter and digi-
mm), ending where penial retractor muscle con- tiform glands lower, i.e. between the vagina and
tacts penial complex wall; penis short (1.5-2.2 the inner dart sac (Fig. 86).
mm); penial papilla cylindrical, elongate, with api-
cal opening, and base connected to penial walls by C. virgata is a polymorphic species showing a
three small muscles (frenula). European-wide distribution. In Sicily it is common
at low and medium altitudes where specimens can
BIOLOGY AND DISTRIBUTION. C. tineana is found be found on grass and shrubs. C. virgata is distin-
on the ground, usually on grass often under stones. guished from C. tineana for the shell which is smo-
It is endemic to Sicily, distributed with point popu- oth or with faint wrinkles, without keel and larger,
lations in coastal and low-hill territories ranging from "large sized Cernuella" sensu Manganelli & Giusti
Custonaci (Monte Cofano) in the province of Trapani (1987); genitalia resembling those of C. cisalpina
to Ribera in the province of Agrigento (Fig. 90). but with epiphallus longer and more numerous di-
gitiform glands.
COMPARATIVE NOTES. Anatomical character of
"Helix" tineana suggest to ascribe this species to C. rugosa, endemic of Western Sicily known
the genus Cernuella Schluter, 1838 sensu stricto: only for two locations (Figs. 79-81, 90), is an ex-
penial papilla with three basal frenula, two groups tremely vulnerable species deserving of protection.
of digitiform glands on opposite sides of the vagina, From the morphological point of view C. rugosa is
proximal vagina short or absent, proximal portion distinguished from C. tineana for the shell with rai-
of the duct of bursa copulatrix wide (Manganelli & sed, irregularly spaced ribs and a cordlike, crenula-
Giusti, 1987; Manganelli et al., 1996a, b, 2001). ted keel at its periphery, and for the penial complex
Currently, five species of Cernuella s. str. are reco- (Figure 87; Manganelli at al., 1996b, Fig. 16) with
gnized in Sicily (Bank, 2012): C. aradasi (Pirajno, penis longer, epiphallus and flagellum shorter.
1842), C. metabola (Westerlund, 1889), C. cisal-
pina (Rossmässler, 1837), C. virgata (Da Costa, C. tineana is morphologically well distinguisha-
1778), C. rugosa (Lamark, 1822). ble from other Cernuella species sensu stricto. Dif-
ferential diagnosis problems may arise with the shell
C. aradasi is a dune-species with limited distri- of Cernuella (Xeroamanda) amanda Rossmässler,
bution to the dunes near the lighthouse in Messina 1838 (see also Benoit, 1862-1857) (Figs. 76-78).
(North-east Sicily) and neighbouring sandy soils.
It’s distinguished from C. tineana for shell smaller, In the latter species the shell is as convex infe-
smooth, globose and without keel; genitalia cha- riorly as in the upper part, the keel is less obtuse
racterised by relatively large penis and by epiphal- than C. tineana, opening more angled and the um-
lus twice as long as penis.
