Helix (Helix) thessalica Boettger, 1886

Figs 22, 23

References.

Korábek et al. 2016 a, 2016 b, 2020, 2023 b; Korábek and Hausdorf 2024.

Description.

Shell (Fig. 22) large, globular; body whorl large; very spacious aperture; umbilicus narrow, completely covered or slit-like; shell surface with irregular fine ribs; strongly developed fine spiral grooves (well visible above the aperture); shell covered with a thick periostracum, yellowish brown; bands largely missing in Greek populations; aperture margins white in Greek populations; mantle pale. Animal (Fig. 23) pale brown or yellowish.

Distribution and habitat.

In Greece it lives in higher altitudes. It is relatively broadly distributed in the Rhodopes (Fig. 24), there are isolated occurrences in Thessaly (Ossa / Kissavos, Pelion), and we report it here from the Paiko Mts. (SW of Gevgelija). Its typical habitat in Greece is beech forests, where it can be found in places enriched in nutrients (e. g. along streams, in nettles). Geophilous, but juveniles climb on herbs and can be often found on their leaves.

Remarks.

The most similar species in Greece is H. schlaeflii . In Helix thessalica, the shell is in most cases much more darkly coloured with a distinctly developed periostracum. Greek populations lack any brown colour on the columella, which in turn is characteristic for H. schlaeflii . Helix thessalica has a dark grey penis, epiphallus and vagina. The description as provided fits the Greek populations, but in other parts of the range the species may be distinctively banded, with brown apertural margins and darker foot.