The geographical distribution of Pleurodiscus erdeli (Pulmonata, Pleurodiscidae)

The Pleurodiscidae contain a single genus, Pleurodiscus Wenz, 1919. During the Upper Oligocene and the Upper Miocene its range included Central Europe: P. falciferus and P. frici are known from Bohemia (Zilch, 1969). Its recent distribution is limited to a number of regions along the Mediterranean coast which are now isolated one from another. Each of these regions is inhabited by its own species (fig. 1): P. balmei (Potiez & Michaud, 1838) in Sardinia, Sicily, Malta, and Algeria (Zilch, 1969; Kobelt, 1904; Forcart, 1965); P. klemmi Brandt, 1958, in Lybia (Brandt, 1958); P. sudensis (Pfeiffer, 1846) in Crete and Cyprus (Zilch, 1969); P. erdeli (Roth, 1839) in Turkey, Syria, the Lebanon, and Israel (Fuchs & Käufel, 1936; Boettger, 1957). Pleurodiscus lives in close contact with the soil, especially in niches sheltered from sunlight. Kobelt (1904) records the snail from rock crevices; Boettger (1957) observed it retreating into caves and under stones when the weather was dry. In Israel the animal is likewise found under stones as noted by Barash & Danin (1966) and by the present author. The snails are rather rare and generally found as single individuals.